CN106478166B

CN106478166B - Treatment method for promoting decomposition of intermediate cutting residues

Info

Publication number: CN106478166B
Application number: CN201610844704.6A
Authority: CN
Inventors: 贾忠奎; 赵匡记; 马履一; 尹欢宇; 赵喆; 施晓灯
Original assignee: Beijing Forestry University
Current assignee: Beijing Forestry University
Priority date: 2016-09-22
Filing date: 2016-09-22
Publication date: 2020-02-14
Anticipated expiration: 2036-09-22
Also published as: CN106478166A

Abstract

The application provides a treatment method for promoting the decomposition of intermediate cutting residues, which comprises the following steps: 1) crushing the remainder; 2) mixing the residue after the crushing treatment with urea and a leavening agent; and 3) paving the mixture on the surface of the forest land soil. According to the embodiment of the invention, the inventor finds out through experiments that by adopting the method for promoting the decomposition of the thinning residue, the decomposition rate of the residue can be increased, the physicochemical property of soil can be maintained and improved, and the growth of forest trees can be promoted.

Description

Treatment method for promoting decomposition of intermediate cutting residues

Technical Field

The invention relates to the field of forestry, in particular to a processing method for promoting the decomposition of intermediate cutting residues.

Background

The reduction of the soil quality of the artificial forest can lead to the reduction of the productivity of the second generation artificial forest, and the development of the forestry in China is restricted. How to solve the problem of land fertility decline, improve the soil quality of artificial forests, improve forest growth and realize long-term maintenance of productivity of the artificial forests is an important problem which needs to be solved urgently in forestry research (Jia loyalty quini, 2012; Wei Tong, 2004). Residue treatment can affect the physicochemical properties of soil, decomposers, enzyme activity and growth of under-forest animals and forest trees, and a reasonable residue treatment mode is necessary to improve the soil quality. China mainly treats the residues through ways of burning, removing, tiling, crushing and the like (Wujunjunjun 2015; Li Xinle 2011; Hades Haiping 2005; Zhongying xi 2005; Hu Zheng hong 2013), although the treatment ways tend to be diversified, certain disadvantages and problems still exist. The removal of the tending residues can reduce the total content of organic matters in the forest land and is not beneficial to the maintenance of the long-term productivity of the forest land; simply retaining the remainder, the rate of decomposition of which is very low, will cause it to accumulate in large quantities in the woodland, aggravating the soil acidification problem, causing an increased leaching of the nutrient elements and worsening the fertility status of the soil (Chenxin et al, 1998). How to treat the remainder to rapidly degrade the remainder, increase the content of soil nutrients and improve the soil structure has become a research trend.

The larch (Larix principis-rupprechtii) in North China is a tree species with a large area in North China, and plays an extremely important role in developing forestry in China, improving the environment, restraining the problem of soil desertification and the like. Research shows that unreasonable cultivation systems and felling modes such as single tree species and continuous cultivation can cause decline of artificial forest land capability (Shengweitong et al, 2004). However, because of the national and forest conditions of China, the pure forest load mode will be difficult to change in the future for a long time, so how to improve the remainder processing mode (remainder wave, etc., 2005) will become an important proposition for current and future research of forestry subject science. The residue treatment can influence the land strength of the forest and the growth of the forest, and is one of the key factors for solving the problem of the productivity reduction of the second-generation larch artificial forest in North China. Therefore, the influence of different residue treatment modes on the soil quality of the larch manmade forest of North China is researched, a theoretical basis is provided for improving the residue treatment modes, and the method has extremely important significance for correctly formulating intermediate cutting residue treatment measures.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the related art. Therefore, the invention aims to provide a mode for processing the intermediate cutting residues, which is more favorable for improving the soil fertility quality of the forest land and the growth of the forest trees.

Based on the above, the invention provides a treatment method for promoting the decomposition of the intermediate cutting residues. According to an embodiment of the invention, the method comprises: 1) crushing the remainder; 2) mixing the residues after the crushing treatment with urea and a leavening agent; and 3) paving the mixture on the surface of the forest land soil. It should be noted that the term "thinning remains" in this application mainly refers to the side branches, tips and leaves left after cutting. According to the embodiment of the invention, the inventor finds out through experiments that by adopting the treatment method for promoting the decomposition of the thinning residue, the decomposition rate of the residue can be increased, the physicochemical property of soil can be favorably maintained or improved, and the growth of forest trees can be promoted.

According to an embodiment of the present invention, the method may further include at least one of the following additional technical features:

according to the embodiment of the present invention, the particle diameter of the residue after the pulverization treatment is 0.5mm to 2cm, and the water content is 257.8kg/m³The bulk density was 257.8kg/m³And further comprising adding water to the comminuted residue to obtain a comminuted residue having a water content of at least 65%, the urea being present in an amount of 6kg/m³The leaven contains EM bacteria and wood vinegar, and the volume ratio of the residues after the crushing treatment to the leaven is 500: 1. The inventor finds through experiments that the method disclosed by the application is more beneficial to the decomposition of the residues, more beneficial to the maintenance or improvement of the physicochemical properties of the soil and more beneficial to the growth of the forest under the limited conditions.

According to an embodiment of the present invention, after step 2) and before step 3), the method further comprises performing heap rot treatment on the mixture, wherein the heap rot treatment time is 2 months. The inventor finds that the mixture is firstly subjected to composting treatment and then is paved on the soil surface, so that the physical properties of the soil can be maintained or improved.

Detailed Description

The following describes embodiments of the present invention in detail. The following examples are illustrative only and are not to be construed as limiting the invention.

It should be noted that, in the following description of the examples, "removing the remainder" means removing all the remainder in the forest land; "tiling the remainder" means to tile the remainder directly and evenly into the plot; the term "pulverization" means that the remainder is pulverized by a pulverizer to obtain particles having a diameter of 0.5mm to 2cm, a water content of 24.08%, and a bulk weight of 257.8kg/m³Spraying clear water to make the water content of the granules reach 65%, uniformly mixing, and then uniformly scattering the granules into a sample plot (if other substances such as urea are required to be added, firstly adding the substances, then spraying water and uniformly mixing); "additional Nitrogen Source" means the addition of urea to the remaining granulate, the addition being measured at 6kg/m³(ii) a "adding EM bacteria and wood vinegar" means that the ratio of residues to EM bacteria liquid 500: volume ratio of 1Adding EM bacterial liquid (dissolving 100g brown sugar in hot water, cooling, adding 50g EM bacterial liquid, diluting to 10L, culturing for 48 hr, and adding 20ml pyroligneous liquor); the 'composting' is that after the corresponding reagent is added and water is sprayed, the remainder is poured into a pit which is dug outdoors in advance and is 2 multiplied by 2m, water is sprayed periodically every week to enable the composting to be piled up, and the composting is spread in a sample plot after two months.

The inventors collected all the intermediate cutting residues (mainly the side branches and treetops left after felling) in the standard plots and treated them in 11 different treatment regimes, each with 3 replicates per treatment set. The 11 different treatment regimes are as follows:

CK: removing residues;

m1: stacking in a belt shape;

m2: laying residues;

m3: crushing and spreading;

m4: crushing, urea and spreading;

m5: crushing, adding leaven (EM bacteria and wood vinegar liquid), and spreading;

m6: crushing, urea, a fermenting agent (EM bacteria and wood vinegar), and spreading;

m7: crushing, composting and spreading;

m8: crushing, urea, composting and flatly paving;

m9: crushing, fermenting agent (EM bacteria and wood vinegar), composting and spreading;

m10: crushing, urea, a fermenting agent (EM bacteria and wood vinegar), composting and spreading.

The following describes embodiments of the present invention in detail. The following examples are illustrative only and are not to be construed as limiting the invention. The examples, where specific techniques or conditions are not indicated, are to be construed according to the techniques or conditions described in the literature in the art or according to the product specifications. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available.

In the following embodiment, the influence of different residue processing modes on the residue decomposition rate, the soil fertility of the artificial forest of the larix huabeiensis and the growth of the forest is analyzed by adopting different processing modes before and after the residue of the larix huabeiensis artificial forest in the yin river forest of the mechanical forest farm of the Shihan dam in Hebei province and the change of the residue decomposition rate, the soil fertility of the artificial forest of the larix huabeiensis and the growth condition of the forest.

EXAMPLE 1 Effect of different treatment regimes on the decomposition rate of the residue

The residue decomposition rate is the most intuitive index for measuring the influence of each treatment on the residue decomposition. The results are shown in table 1 by differential testing (t-test) of the remaining mass for 5 months 2014 and 11 months 2015. The observed value of the F test is 43.315, the probability value is 0 < 0.01, which shows that the variance of the two groups of data is significantly different, and the P < 0.01 is obtained by the t test, which shows that the mean value of the overall samples of the two groups of data is significantly different, so that the residual mass change is significant within 1.5 years. Table 1:

the amount of substance remaining and the decomposition rate of the residue at 11 months in 2015 were analyzed, and the results are shown in table 2. The residue treated by M3-M10 in 11 months of 2015 was of lower quality and significantly different from the treated products of M1 and M2 (P < 0.05). The decomposition rate of the residues after M3-M10 treatment is 18.21-19.44%, which is 1.46-1.53 times and 1.28-1.38 times higher than that of M1 and M2 treatment respectively, and the difference is obvious (P is less than 0.05), but the difference between the annual average decomposition rates of M3-M10 treatment is not obvious. It is demonstrated that the M3-M10 process accelerates the decomposition of the residue compared to the conventional process of band stacking and tiling. The pulverization treatment was carried out in all of the treatments M3 to M10, and it is presumed that the pulverization is a factor for accelerating the decomposition of the residue, and the pulverization increases the contact area between the residue and the decomposed product, accelerates the decomposition of the residue, and increases the decomposition rate.

Table 2:

note a: the values in the table are (mean ± sd); b, note: different letters in the same column represent significant differences (P < 0.05).

The results of the orthogonal experimental analysis of the two-factor one-level orthogonal experiment in which M3-M6 were treated with nitrogen sources and fermentation agents (EM bacteria and pyroligneous liquor) were added are shown in Table 3. According to the comparison of the type III square sum, the influence on the annual decomposition rate of the remainder is as follows: nitrogen source > fermentation agent > interaction of nitrogen source with fermentation agent. The decomposition rate of each treatment is as follows from high to low: m6 is more than M4 is more than M5 is more than M3, so the added nitrogen source and the leaven are both beneficial to the decomposition of the residue, the nitrogen source has certain interaction with the leaven, and the addition of the nitrogen source and the leaven together is more beneficial to the decomposition of the residue than the single addition of the nitrogen source or the leaven.

Table 3:

note: 056 (298. regulating R)

The M7-M10 treatments were performed by composting based on the M3-M6 treatments, and the results of the differential test (t test) were shown in Table 4. The observed value of the F test is 0.296, the probability value is 0.592 & gt 0.05, which indicates that the variances of the two groups of data are not obviously different, and the probability value obtained by the t test is 0.994 & gt 0.05, which indicates that the average difference of the overall samples of the two groups of data is not obvious, so that the decomposition rate of the residues is not obviously influenced by the heap corruption treatment. The reason may be that the stack body needs to keep a certain water content in the process of stacking the wastes for the life activities of microorganisms, but the wastes are stacked in the forest land, the water is easy to lose, especially the water content in the center of the stack body is very low, and the requirement of keeping the stack body wet cannot be met by spraying water once a week, so the decomposition rate of the wastes cannot be obviously influenced by the stacking process.

Table 4:

the decomposition rate of the residue of the M6 treatment is 19.44% at the highest (see Table 2), which is 1.02-1.53 times that of other treatments. It is shown that the treatment with additional nitrogen source, EM bacteria and pyroligneous acid (M6) after pulverization is most advantageous for promoting the decomposition of the residue.

EXAMPLE 2 Effect of different treatments on the physical Properties of the soil

2.1 Effect of different treatment modalities on soil bulk weight

The volume weight of soil is the most basic index for measuring the physical properties of soil. The soil volume weights of 5 months and 11 months in 2014 and 2015 are subjected to difference test (t test), the results are shown in table 5, the probability value of the F test is 0.906 & gt 0.05, the significant difference between the variances of the two groups of data is shown, the probability value obtained through the t test is 0.112 & gt 0.05, the mean value of the overall samples of the two groups of data is not different, and the change of the soil volume weight is not obvious within 1.5 years. And the effect of different residual treatment modes on volume weight is not significant (as shown in table 6).

Table 5:

table 6:

note a: the values in the table are (mean ± sd);

b, note: different letters in the same column represent significant differences (P < 0.05).

2.2 Effect of different treatment modes on the porosity of the soil capillary

Capillary porosity is an important index for measuring the pore size of capillaries in soil. Capillary pores are the places where soil stores water, and in the case that the capillary pores are not excessive, the larger the capillary pores are, the stronger the soil's ability to store water is. The difference test (t test) is carried out on the porosity of the soil capillary in 5 months and 11 months in 2015, the result is shown in table 7, the probability value of the F test is 0.628 & gt 0.05, the variance of the two groups of data is not obviously different, the probability value obtained through the t test is 0.017 & lt 0.05, the average value of the overall samples of the two groups of data is different, and the porosity of the soil capillary changes obviously in 1.5 years.

Table 7:

the capillary porosity and the amount of change in the porosity for treatments 5 months 2014 and 11 months 2015 were analyzed and the results are shown in table 8. The porosity change of the capillary treated by M2-M10 is 0.26-10.15%, which is 0.63-10.37% higher and 7.15-17.04% higher than that of CK and M1 respectively. It is demonstrated that the M2-M10 treatments increased the capillary porosity of the soil compared to the cleanup and strip pack treatments.

Table 8:

note a: the values in the table are (mean ± sd);

The results of orthogonal experimental analysis of the M3-M6 treatments are shown in Table 9. According to the comparison of the type III square sum, the influence on the porosity change of the soil capillary is as follows: nitrogen source > interaction of nitrogen source with leaven > leaven. The porosity variation of each treatment capillary is as follows from big to big: m5 is more than M3 is more than M4 is more than M6, so the addition of the leavening agent is beneficial to the improvement of the capillary porosity, but the addition of the nitrogen source is not beneficial to the improvement of the capillary porosity, the nitrogen source has stronger interaction with the leavening agent, and the addition of the leavening agent alone is most beneficial to the improvement of the capillary porosity.

Table 9:

note: 010 (adjustment R square ═ 362)

The data from the two groups of M7-M10 and M3-M6 were tested for differences (t-test), the results are shown in Table 10. The probability value of the F test is 0.146 & gt 0.05, which indicates that the variances of the two groups of data are not obviously different, and the probability value of the T test is 0.456 & gt 0.05, which indicates that the average value of the overall samples of the two groups of data is not obviously different. However, the increase of the average capillary porosity of the M7-M10 treatments is 3.63%, while the increase of the average capillary porosity of the M3-M6 treatments is only 1.24%, and the increase of the average capillary porosity of the M7-M10 treatments is 2.93 times that of the M3-M6 treatments, which indicates that the heap-rot treatment has certain promotion effect on the increase of the capillary porosity of the soil.

Table 10:

the maximum variation of the porosity of the capillary treated by the M10 is 10.15%, which is 1.08-1.17 times of that of the capillary treated by other treatments, and the variation is obvious (P is less than 0.05) compared with other treatments. It is shown that after the residue is crushed, nitrogen source, EM bacteria and pyroligneous liquor are added and composting treatment (M10) is carried out, which is most beneficial to improving the capillary porosity of the soil.

2.3 Effect of different treatment modalities on the porosity of non-capillary soil

The non-capillary porosity is an important index for measuring the number of non-capillary pores in soil. The non-capillary pores refer to soil pores with the diameter of more than 0.1mm, wherein the soil pores are often filled with air, the main functions of the soil pores are air permeability and water permeability, and the most suitable non-capillary pores of the soil plough layer account for more than 50-60% of the total porosity. The difference test (t test) is carried out on the porosity of the soil non-capillary tube in 5 months and 11 months in 2015, the result is shown in table 11, the probability value of the F test is 0.989 & gt 0.05, which indicates that no significant difference exists between the variances of the two groups of data, and the probability value obtained by the t test is 0.008 & lt 0.05, which indicates that the mean value of the overall samples of the two groups of data is significant, and the porosity of the soil non-capillary tube changes significantly within 1.5 years.

Table 11:

the non-capillary porosity and its variation were analyzed for each treatment at 5 months 2014 and 11 months 2015, and the results are shown in table 12. The change of the porosity of the non-capillary tube treated by M3-M10 is 1.50-5.97%, which is 0.73-6.84% higher than that treated by CK, M1 and M2. It is demonstrated that the M3-M10 treatments increase the non-capillary porosity of the soil as compared to conventional treatments such as clean-up, strip stacking, and flat placement.

Table 12:

note a: the values in the table are (mean ± sd);

The results of orthogonal experimental analyses for treatments M3-M6 are shown in Table 13. According to the comparison of the III type square sum, the influence on the variation of the porosity of the soil non-capillary is as follows: the interaction of the nitrogen source and the leaven is more than the nitrogen source. The non-capillary porosity variation of each treatment is as follows from big to big: m6 is more than M3 is more than M5 is more than M4, so the addition of the leaven and the nitrogen source is beneficial to the improvement of the porosity of non-capillary, and the nitrogen source has very strong interaction with the leaven. The addition of the nitrogen source and the leavening agent together is more beneficial to the improvement of the porosity of the non-capillary soil than the single addition of the nitrogen source or the leavening agent.

Table 13:

note: r side ═ 079 (adjustment R side ═ 266)

The data from the two groups of M7-M10 and M3-M6 were tested for differences (t-test), the results are shown in Table 14. The probability value of the F test is 1.208 & gt 0.05, which indicates that the variances of the two groups of data are not obviously different, and the probability value of 0.357 & gt 0.05 is obtained through the t test, which indicates that the average value of the overall samples of the two groups of data is not obviously different. The composting treatment has no obvious influence on the change of the porosity of the soil non-capillary. However, the average change in porosity of the non-capillary tubes treated with M3-M6 was 4.23%, while that of M7-M10 was only 2.42%, and that of M3-M6 was 1.74 times that of M7-M10. The composting treatment is rather detrimental to the increase in non-capillary porosity compared to not performing the composting treatment. The reason may be that when the remains are composted, the treated woodland soil is not covered by the remains and the soil is exposed for a long time.

Table 14:

the variation of the porosity of the non-capillary tube treated by the M6 is 5.97 percent at most, and is 1.57 to 6.84 percent higher than that of the non-capillary tube treated by other treatments. It is shown that the residue is treated with additional nitrogen source, EM bacteria and pyroligneous liquor (M6) to increase the non-capillary porosity of the soil most advantageously.

2.4 Effect of different treatment modalities on the saturated Water content of soil

The saturated water content of soil is the water content of the soil when the pores are filled with water, which roughly reflects the capacity of the soil to store and retain water (Pekuai, 1998). The soil fertility quality evaluation indexes are selected according to the principle of relative stability, such as main organic matter content, saturated water content, volume weight, total nitrogen, quick-acting phosphorus and the like (Xujian, 2010). The saturated water content of the soil was differentially checked (t-test) for 5 months 2014 and 11 months 2015, and the results are shown in table 15. The probability value of the F test is more than 0.706 and more than 0.05, which indicates that the variances of the two groups of data are not obviously different, and the probability value of the T test is more than 0.03 and less than 0.05, which indicates that the average value of the overall samples of the two groups of data is obviously different, so that the saturated water content of the soil is obviously changed within 1.5 years.

Table 15:

the saturated water contents and the amounts of changes thereof were analyzed for each treatment of 5 months in 2014 and 11 months in 2015, and the results are shown in table 16. The change of the saturated water content of the M3-M10 treatment is 2.84-8.84%, which is 12.44-18.44% higher and 0.36-6.36% higher than that of the M1 and M2 treatments respectively. It is shown that the M3-M10 treatments are more advantageous for increasing the saturated water content of the soil than strip-wise stacking and tiling treatments.

Table 16:

note a: the values in the table are (mean ± sd);

The results of orthogonal experimental analyses of M3-M6 treatments are shown in Table 17. According to the comparison of the type III square sum, the influence on the saturated water content of the residue is as follows: the interaction of the nitrogen source and the leaven is more than the nitrogen source. The saturated water content of each treatment is as follows from big to big: m6 is more than M3 is more than M5 is more than M4, so the additional addition of the leaven and the nitrogen source are beneficial to the improvement of the saturated water content of the soil, and the nitrogen source has very strong interaction with the leaven. The addition of the nitrogen source and the fermentation agent together is more advantageous for increasing the saturated water content of the soil than the addition of the nitrogen source or the fermentation agent alone.

Table 17:

note: r side ═ 062 (adjustment R side ═ 290)

The data from the two groups of M7-M10 and M3-M6 were tested for differences (t-test), the results are shown in Table 18. The probability value of the F test is 0.216 & gt 0.05, which indicates that the variances of the two groups of data are not obviously different, and the probability value of the F test is 0.907 & gt 0.05, which indicates that the average value of the overall samples of the two groups of data is not obviously different. Indicating that the composting treatment has no significant effect on the increase of the saturated water content of the soil. However, the total average growth amount of the M7-M10 treatments is 5.23%, while the total average growth rate of the M3-M6 treatments is 4.78%, and the heap rot treatment is 0.45% higher than that of the heap rot treatment, which indicates that the heap rot has a certain promotion effect on the increase of the saturated water content of the soil.

Table 18:

the change in saturated moisture content for the M10 treatment was up to 8.84%, 1.50% to 18.44% higher than the change in saturated moisture content for the other treatments, and the second time for the M6 treatment was 7.34%. After the residues are crushed, the nitrogen source, EM (effective microorganisms) and wood vinegar are added and composting (M10) treatment is carried out, which is most beneficial to improving the saturated water content of the soil, and the M6 treatment is carried out for the second time.

2.5 Effect of different treatment modes on soil Water storage

The water storage capacity of the soil can be more comprehensively evaluated by using the saturated water storage capacity, namely capillary water storage capacity and non-capillary water storage capacity (Weiqiang, 2012). The soil saturation impoundments of 5 months 2014 and 11 months 2015 were subjected to differential tests (t test), and the results are shown in tables 4-19. The probability value of the F test is more than 0.855 and more than 0.05, which shows that the variances of the two groups of data are not obviously different, and the probability value of 0.02 and less than 0.05 is obtained through the t test, which shows that the average value of the overall samples of the two groups of data is obviously different, so that the saturated water storage capacity of the soil is obviously changed within 1.5 years.

Table 19:

the saturated water storage amounts and the amounts of change thereof in the treatments of 5 months 2014 and 11 months 2015 were analyzed, and the results are shown in table 20. The variation of the saturated water storage capacity of M2-M10 is 62.04-642.41 t/hm²Higher than CK and M1 respectively and 42.22-622.59%. It is shown that the M2-M10 treatments are more beneficial in increasing the saturated water storage capacity of the soil than the clearing and tiling treatments.

Table 20:

table a: the values in the table are (mean ± sd);

The results of orthogonal experimental analysis of M3-M6 treatments are shown in Table 21. According to the comparison of the III type square sum, the influence on the saturated water storage quantity is as follows: the interaction of the nitrogen source and the leaven is more than the nitrogen source. The saturated water storage capacity of each treatment is as follows from high to low: m6 is more than M5 is more than M4 is more than M3, so that the additional addition of the leavening agent and the nitrogen source are beneficial to improving the saturated water storage capacity of the soil, and the nitrogen source has very strong interaction with the leavening agent. The addition of the nitrogen source and the fermentation agent together is more favorable for improving the saturated water storage capacity of the soil than the addition of the nitrogen source or the fermentation agent alone.

Table 21:

note: 056 (298. regulating R)

The data from the two groups of M7-M10 and M3-M6 were tested for differences (t-test) and the results are shown in Table 22. The probability value of the F test is more than 0.074 and more than 0.05, which indicates that the variances of the two groups of data are not obviously different, and the probability value of the T test is more than 0.69 and more than 0.05, which indicates that the average value of the two groups of data is not obviously different. The composting treatment has no obvious influence on the increase of the saturated water storage capacity of the soil. However, the total average increase of the M7-M10 treatments was 306.02t/hm²While the total average growth rate of the M3-M6 treatments is 247.32t/hm²The composting treatment is 1.24 times of that of non-composting, which shows that the composting has certain promotion effect on the improvement of the saturated water storage of the soil.

Table 22:

the maximum change of the saturated water storage capacity processed by M10 is 642.41t/hm²The change amount of the saturated water storage amount is 221.85-1030.19 t/hm higher than that of other treated saturated water storage amounts²The next time M6 processing is 420.56t/hm². The method is characterized in that after the residues are crushed, a nitrogen source, EM (effective microorganisms) and wood vinegar are added and composting (M10) treatment is carried out, so that the method is most beneficial to improving the saturated water storage capacity of the soil, and the M6 treatmentNext, the method is described.

2.6 comprehensive evaluation of the impact of different treatment modalities on the physical Properties of the soil

The soil indexes are complex in relation and have interaction, different indexes are adopted to evaluate different treatment effects, results are different, one index is adopted alone to evaluate the fostering quality unreasonably, the influence of different treatment methods on the physical properties of the larix dahuricae artificial forest soil is analyzed well, and the influence of different residue treatment modes on the volume weight is not obvious, so that the method standardizes 4 indexes of the measured soil capillary porosity, non-capillary porosity, saturated water content and saturated water storage capacity, takes the principal component analysis characteristic contribution rate as the weight, calculates the evaluation indexes in a weighting mode to obtain the comprehensive value, and comprehensively evaluates each treatment.

Through principal component analysis, 2 principal components can be extracted, wherein the maximum contribution rate of the first principal component is 57.129%, the maximum contribution rate of the second principal component is 26.887%, the cumulative contribution rate of the two principal components is 84.016%, and the characteristic value is larger than 1 (see table 23). Therefore, the two main components can fully reflect the relation among all indexes of the soil and are key indexes for representing the physical properties of the soil.

Table 23:

the processing composite score is shown in table 24. A positive score indicates that the soil material properties of the treatment are above average and a negative score indicates below average. The overall score was 2.480 highest for the M10 treatment, followed by 1.440 for the M6 treatment. Therefore, the M10 and M6 treatments are advantageous for improving the physical properties of the soil compared to other treatments.

Table 24:

treatment of	FAC₁	FAC₂	Composite score	Rank of name
					M10	0.567	1.103	2.480	1
M6	0.723	-0.198	1.440	2
					M3	0.313	-0.069	0.641	3
M9	0.155	0.125	0.488	4
					M5	0.160	-0.119	0.238	5
M7	0.044	0.034	0.137	6
					M4	0.040	-0.106	-0.022	7
M2	-0.227	0.268	-0.230	8
					M8	-0.188	-0.055	-0.488	9
CK	-0.280	-0.055	-0.700	10
					M1	-1.306	-0.929	-3.983	11

EXAMPLE 3 Effect of different treatments on soil chemistry

3.1 Effect of different treatment modalities on soil organic matter

Soil organic matter is a key component constituting colloidal substances in a soil granular structure, is also a reservoir of soil nutrients, and is an important index for measuring soil quality (Zhao et al, 2013). The organic content was differentially checked (t-test) for 5 months 2014 and 11 months 2015, with the results shown in table 25. The probability value of the F test is more than 0.599 and more than 0.05, which shows that the variances of the two groups of data are significantly different, and the probability value of 0 and less than 0.01 is obtained through the t test, which shows that the mean values of the overall samples of the two groups of data are significantly different. Indicating that the organic matter content of the soil has very significant change within 1.5 years.

Table 25:

after 1.5 years of treatment, the organic matter content of all the treated soil is increased to different degrees (see table 26), the change amount of organic matters of M2-M10 is 4.60-12.21 g/kg, and is 1.52-3.36 times and 1.11-2.96 times respectively of the change amount of organic matters of CK and M1. It is shown that the M2-M10 treatment is more advantageous for organic matter enhancement than the removal and strip stacking treatment. The reason is probably that the residue is decomposed to generate organic matters, the residue removing treatment has no residue, and the decomposition rate of the residue after the M1 treatment is the lowest, so the organic matter increase amount of the soil treated by the M2-M10 is higher than that of the soil treated by the CK and the M1.

Table 26:

note a: the values in the table are (mean ± sd);

The results of orthogonal experimental analyses of M3-M6 treatments are shown in Table 27. According to the comparison of the III type square sum, the influence on the change of the organic matters is as follows: nitrogen source > fermentation agent > interaction of nitrogen source with fermentation agent. The change quantity of organic matters in each treatment is from large to sequential: m6 is more than M4 is more than M5 is more than M3, so the additional nitrogen source and the leaven are both beneficial to improving the organic matters of the soil, and the nitrogen source and the leaven have certain interaction. The addition of the nitrogen source together with the fermentation agent is most advantageous for improving the saturated organic matter of the soil.

Table 27:

note: 076 (110. the formula of R)

The difference test (t test) was performed on the organic matter data of the two groups of treatments, M7-M10 and M3-M6, and the results are shown in Table 28. The probability value of the F test is 0.543 to 0.05, which shows that there is no significant difference between the variances of the two groups of data, and then the probability value of the T test is 0.75 to 0.05, which shows that there is no significant difference between the overall sample mean values of the two groups of data. The change of the organic matter content of the soil is not obviously influenced by the composting.

Table 28:

the maximum change amount of the organic matters of the soil treated by the M6 is 12.21g/kg, which is 1.31-3.63 times of the change amount of the organic matters of the soil treated by other materials. The treatment with the addition of nitrogen source, EN bacteria and pyroligneous liquor (M6) after pulverization is the most favorable treatment for promoting the decomposition of the residue to generate organic matter.

3.2 Effect of different treatment modalities on the pH of the soil

The change of soil acidity of larch artificial forest is a very much concerned problem (item culture, 2005). The pH value of the soil can influence the soil fertility, the content of nutrient substances is a key index for evaluating the soil quality, and the pH value and the content comprehensively reflect the soil fertility condition of the artificial forest (Panjianping et al, 1997). The pH values at 5 months 2014 and 11 months 2015 were tested for differences (t-test) and the results are shown in table 29. The probability value of the F test is 0.008 to 0.05, which shows that the variances of the two groups of data are significantly different, and the probability value of the F test is 0.047 to 0.05, which shows that the mean values of the overall samples of the two groups of data are significantly different. Indicating that the pH value of the soil changes obviously within 1.5 years.

Table 29:

the pH values and the amounts of changes in pH values of the forest soil were analyzed for treatments 5 months 2014 and 11 months 2015, and the results are shown in table 30. The pH value of the M2-M10 treatment is increased by 0.02-0.44, the change amount of the pH value is 0.62-2.04 and 0.19-0.61 higher than that of the CK and M1 treatment respectively, and the pH change amount of the M2-M10 treatment is obvious different from that of the CK and M1 treatment (P is less than 0.05). It is shown that the M2-M10 treatment is more advantageous for increasing the pH of the soil than the removal and strip stacking treatments.

Table 30:

note a: the values in the table are (mean ± sd);

The results of orthogonal experimental analyses of M3-M6 treatments are shown in Table 31. According to the comparison of the type III square sum, the influence on the change of the pH value of the soil is as follows: nitrogen source is leavening agent > interaction of nitrogen source with leavening agent. The change of the pH value of each treatment is as follows from big to big: m6 is more than M4 is more than M5 is more than M3, so the additional addition of nitrogen source and leaven is beneficial to the improvement of the pH value of the soil, and the nitrogen source has certain interaction with the leaven. The addition of the nitrogen source together with the fermentation agent is advantageous for increasing the pH value of the soil.

Table 31:

note: r square ═ 033 (adjustment R square ═ 058)

The difference test (t test) was performed on the pH data of the two groups of M7-M10 treatment and M3-M6 treatment, and the results are shown in Table 32. The probability value of the F test is more than 0.87 and more than 0.05, which shows that the variances of the two groups of data are not obviously different, and the probability value of 0.002 and less than 0.01 is obtained through the t test, which shows that the mean values of the overall samples of the two groups of data are obviously different, and that the corrosion has obvious influence on the change of the pH value. The average value of the change amount of the pH value of the M7-M10 treatment is 0.27, while the average value of the M3-M6 treatment is only 0.08, so the composting is more beneficial to the improvement of the pH value of the soil than the condition without composting.

Table 32:

as shown in Table 30, the maximum change of the pH value of the woodland soil treated by M10 is 0.44, which is 1.13-22 times of the change of the pH value of other treatments, and the change is significant from the change of CK organic matters (P is less than 0.05). The residue is crushed, and then is added with a nitrogen source, EN bacteria and pyroligneous liquor to be subjected to composting (M10) so as to be most beneficial to the improvement of the pH value of the soil.

3.3 Effect of different treatment modalities on soil nutrient elements

3.3.1 Effect of different treatment modalities on Total Nitrogen in soil

Nitrogen is one of the most basic elements of soil, and the total nitrogen content of soil can be used as an important index for evaluating the soil fertility (McFarlane et al, 2010). The total nitrogen content of 5 months 2014 and 11 months 2015 was differentially tested (t-test), with the results shown in table 33. The probability value of the F test is more than 0.068 and more than 0.05, which shows that the variances of the two groups of data are not obviously different, and the probability value of 0 and less than 0.01 is obtained through the t test, which shows that the mean value of the overall samples of the two groups of data is obviously different, and shows that the total nitrogen of the soil is obviously changed within 1.5 years.

Table 33:

after 1.5 years of treatment, the total nitrogen content of all the treated soil is increased in different ranges (as shown in table 34), the total nitrogen increase after the treatment of M2-M10 is 1.14-1.93 g/kg, which is 31.03-121.84% higher and 48.05-150.65% higher than that of CK and M1, and the difference between the treatment of M2-M10 and the treatment of CK and M1 is significant (P is less than 0.05). The M2-M10 treatment is more beneficial to increase the total nitrogen content of the soil than the cleaning and strip stacking treatment. The reason may be that CK residues are purged and cannot be decomposed to produce nitrogen-containing species, while M1 process residues are decomposed at a slower rate (as shown in Table 2) and produce less nitrogen-containing species.

Table 34:

note a: the values in the table are (mean ± sd);

The results of orthogonal experimental analyses of M3-M6 treatments are shown in Table 35. According to the comparison of the type III square sum, the influence on the total nitrogen change of the soil is as follows from big to small: leavening agent > nitrogen source-nitrogen source interaction with leavening agent. The total nitrogen variation of each treatment is as follows from big to small: m5 is more than M6 is more than M3 is more than M4, so the addition of the leaven is beneficial to the increase of the total nitrogen content of the soil, and the interaction of the nitrogen source, the nitrogen source and the leaven has no obvious influence on the total nitrogen content of the soil. The reason may be that the nitrogen source has a small influence on the decomposition of the residue to produce nitrogen-containing substances, and masking by other factors is not shown.

Table 35:

note: r square is. 068 (adjusting R square is. 019)

The difference test (t test) of the total nitrogen variation of the two groups of soil treated by M7-M10 and treated by M3-M6 is carried out, and the results are shown in Table 36. The probability value of the F test is 0.551 & gt 0.05, which indicates that the variances of the two groups of data are not significantly different, and the probability value of the T test is 0.077 & gt 0.05, which indicates that the mean values of the overall samples of the two groups of data are not significantly different. However, 0.077 is very close to 0.05, and the change of the total nitrogen treated by the M7-M10 is 1.61g/kg, while the change of the total nitrogen treated by the M3-M6 is 1.30g/kg, so that the residue stacking and rotting can better promote the residue decomposition to generate nitrogen-containing substances and improve the total nitrogen content of the forest land soil to a certain extent.

Table 36:

as shown in Table 34, the total nitrogen increase of the woodland soil treated by M8 is 1.93g/kg at most, which is 23.72-156.49% higher than that of other treatments, and the total nitrogen increase of M8 is different from that of CK, M1, M3 and M4 (P is less than 0.05). The method indicates that after the residues are crushed, the residues which are externally added with urea and subjected to composting (M8) are decomposed to generate most nitrogen-containing substances, and is most beneficial to improving the total nitrogen content of the forest land soil.

3.3.2 Effect of different treatment modalities on soil available phosphorus

Phosphorus is a nutrient necessary for tree growth, participates in the circulation of soil materials and energy in various chemical forms, and can well measure the quality of soil (Liu Xiao Bing, et al, 2002). The effective phosphorus content was differentially examined (t-test) for 5 months 2014 and 11 months 2015, and the results are shown in table 37. The probability value of the F test is more than 0.182 and more than 0.05, which shows that the variances of the two groups of data are not obviously different, and the probability value of 0.013 and less than 0.05 are obtained through the t test, which shows that the mean values of the overall samples of the two groups of data are obviously different, which shows that the effective phosphorus of the soil is obviously changed within 1.5 years.

Table 37:

the available phosphorus content and the available phosphorus change amount of the forest land soil were analyzed for each treatment of 5 months 2014 and 11 months 2015, and the results are shown in table 38. The effective phosphorus content of M3-M10 is increased by 0.10-2.00 mg/kg, the effective phosphorus content of CK, M1 and M2 is reduced by 0.67-1.63 mg/kg, and the change amount of the effective phosphorus of M3-M10 is 0.77-3.63 mg/kg higher than that of the effective phosphorus of M1 and M2, which shows that the effective phosphorus content of soil is increased by the M3-M10 treatment compared with the strip stacking and tiling treatment. The decomposition of the residues can produce available phosphorus-containing materials, and the decomposition rate of the residues in the strip stacking and tiling process is slower (as shown in table 2), so that less available phosphorus-containing materials are produced, and therefore, the available phosphorus content of the soil treated by CK, M1 and M2 is reduced, while the available phosphorus content of the soil treated by other processes is increased.

Table 38:

The results of orthogonal experimental analyses of M3-M6 treatments are shown in Table 39. According to the comparison of the type III square sums, the influence on the change of the available phosphorus in the soil is as follows: the interaction between the nitrogen source and the leaven is more than the nitrogen source is more than the leaven. The change amount of effective phosphorus of each treatment is from large to sequential: m6 is more than M3 is more than M4 is more than M5, so the additional nitrogen source is beneficial to the increase of the content of the available phosphorus in the soil, and the independent addition of the leavening agent is not beneficial to the increase of the content of the available phosphorus in the soil, probably because the microorganism life activities can absorb the available phosphorus, thereby being not beneficial to the increase of the available phosphorus in the soil. The interaction of the nitrogen source and the leavening agent has strong influence on the change of the effective phosphorus content of the soil, and the addition of the nitrogen source and the leavening agent together is favorable for increasing the effective phosphorus content of the soil.

Table 39:

note: r square ═ 177 (adjustment R square ═ 009)

The difference test (t test) was carried out on the effective phosphorus variation data of the two groups of M7-M10 treatment and M4-M6 treatment, and the results are shown in Table 40. The probability value of the F test is 0.524 & gt 0.05, which indicates that the variances of the two groups of data are not significantly different, and the probability value of the T test is 0.211 & gt 0.05, which indicates that the mean values of the overall samples of the two groups of data are not significantly different. However, the total full-average available phosphorus change amount of the M7-M10 treatment is 1.27mg/kg, the total full-average available phosphorus change amount of the M3-M6 treatment is 0.79mg/kg, and the composting treatment is 60.75% higher than that of the non-composting treatment, so that the residue composting treatment can better promote the residue to be decomposed, generate more available phosphorus-containing substances and improve the available phosphorus content of the forest land soil to a certain extent.

Table 40:

as shown in table 38, the change in available phosphorus in the soil treated with M10 was up to 2.00mg/kg, the change in available phosphorus in the soil treated with other treatments was 11% to 181.5% lower than that of the treatment, and the change in available phosphorus in the soil treated with M10 was significantly different from the changes in the soil treated with treatments other than M6, M7, and M9. The residue is crushed, added with nitrogen source, EN bacteria and pyroligneous liquor and then subjected to composting (M10) treatment, which is the treatment most beneficial to decomposing the residue to generate the effective phosphorus-containing substance and improving the effective phosphorus content of the soil in the larch woodland of North China.

3.3.3 Effect of different treatment modalities on Total Potassium in soil

Potassium is one of the major elements required for tree growth and is a key index for evaluating soil fertility quality (luogong et al, 2002). The soil total potassium content in 5 months 2014 and 11 months 2015 was differentially tested (t test), and the results are shown in table 41. The probability value of the F test is 0 < 0.01, which shows that the variances of the two groups of data are very obvious different, and the probability value of 0 < 0.01 is obtained through the t test, which shows that the mean value of the overall samples of the two groups of data is very obvious different, which shows that the total potassium content of the soil is obviously changed within 1.5 years.

Table 41:

the total potassium content and the total potassium change amount of the forest land soil were analyzed in 5 months in 2014 and 11 months in 2015 of each treatment, and the results are shown in table 42. The total potassium content of each treatment is reduced in different ranges, the total potassium reduction amount of M1-M10 treatment is lower than 0.95-2.32 g/kg, the total potassium reduction amount of CK treatment is 3.42g/kg at most, the remaining residues (M1-M10) are 32.2-72.22% lower than the total potassium reduction amount of CK, and the variation difference of the total potassium variation of the soil treated by M1-M10 and the soil treated by CK is obvious (P is less than 0.05). The Liujie (2013) research shows that the soil total potassium content of the 22a and 38a China North larch artificial forest is reduced along with the increase of the thinning strength. It is assumed that thinning is the cause of the decrease in the total potassium content in each treatment in this test. The remainder is retained, and the remainder is decomposed to generate potassium-containing substances which can improve the total potassium content of the soil, so that the reduction of the total potassium of the soil treated by M1-M10 is lower than that of CK.

Table 42:

note a: the values in the table are (mean ± sd);

The results of orthogonal experimental analyses of M3-M6 treatments are shown in Table 43. According to the comparison of the type III square sum, the influence on the change of the soil total potassium is as follows from big to small: the interaction of the nitrogen source and the leaven is more than the nitrogen source. The change amount of the total potassium of each treatment is from large to sequential: m6 is more than M5 is more than M3 is more than M4, so the additional leaven is beneficial to increasing the content of the total potassium in the soil. The interaction of the nitrogen source and the leavening agent has strong influence on the change of the total potassium content of the soil, and the addition of the nitrogen source and the leavening agent together is favorable for increasing the total potassium content of the soil.

Table 43:

note: r square ═ 061 (adjustment R square ═ 067)

The difference test (t test) of the total potassium variation of the two groups of soil treated by M7-M10 and treated by M4-M6 is shown in Table 44. The probability value of the F test is 0.814 to 0.05, which shows that the variances of the two groups of data are not obviously different, and the probability value of the T test is 0.563 to 0.05, which shows that the mean values of the overall samples of the two groups of data are not obviously different. However, the total average total potassium change amount of the M7-M10 treatments is-1.46 g/kg, while that of the M3-M6 treatments is-1.31 g/kg, and the total potassium reduction amount of the heap corruption treatment is higher than that of the heap corruption treatment which is not carried out. The composting is not beneficial to the increase of the total potassium content of the soil, and the reason may be that the potassium exists in soluble compounds, and a part of soluble potassium is leached in the composting process.

Table 44:

as shown in Table 42, the total potassium reduction of M6 was as low as 0.95g/kg, followed by 0.96g/kg in M9, and the total potassium reduction of M6 was 19.49-72.22% lower than that of other soil treatments. The method is most favorable for improving the total potassium content of the soil by adding a nitrogen source, EM bacteria and pyroligneous liquor after crushing the residues. The reason may be that the process residue decomposed most rapidly (as shown in table 2) and produced the most potassium-containing species.

3.4 comprehensive evaluation of the impact of different treatment modalities on soil chemistry

In order to better analyze the comprehensive influence of different treatments on the soil chemical properties of the larch manmade forest in North China, 4 indexes of the measured change amounts of organic matters, pH values, total nitrogen, available phosphorus and total potassium are standardized, the principal component analysis feature contribution rate is used as the weight, the evaluation indexes are calculated in a weighted mode to obtain a comprehensive score, and comprehensive evaluation is carried out on each treatment.

The principal component analysis can extract 4 principal components, wherein the contribution rate of the first principal component is 35.144% at most, the contribution rate of the second principal component is 19.617%, the contribution rate of the third principal component is 17.447%, the contribution rate of the fourth principal component is 16.714%, the cumulative contribution rate of the 4 principal components is 88.921%, and the eigenvalues are all greater than 0.8 (as shown in table 45). Therefore, the 4 main components can fully reflect the relation among all indexes of the soil and are key indexes for representing the chemical properties of the soil.

Table 45:

the processing composite score is shown in table 46. A positive score indicates that the soil material properties of the treatment are above average and a negative score indicates below average. The M6 treatment gave a composite score of up to 2.995 followed by 1.705 for the M6 treatment. Therefore, the M6 and M10 treatments are most beneficial for improving soil chemistry compared to other treatments.

Table 46:

treatment of	FAC₁	FAC₂	FAC₃	FAC₄	Composite score	Rank of name
							M6	0.975	0.215	0.820	0.425	2.995	1
M10	0.476	-0.288	0.568	0.785	1.705	2
							M7	0.367	0.030	-0.541	0.536	0.651	3
M8	-0.511	0.867	0.443	0.339	0.623	4
							M9	0.069	0.620	-0.342	-0.198	0.266	5
M3	-0.200	1.025	-0.461	0.017	0.266	6
							M4	-0.094	0.323	-0.027	-0.012	0.119	7
M5	-0.147	0.131	-0.068	0.255	0.023	8
							M2	-0.416	-0.764	0.001	0.482	-1.077	9
M1	-0.248	-1.075	-0.224	-0.877	-2.418	10
							CK	-0.272	-1.083	-0.169	-1.751	-3.151	11

EXAMPLE 4 Effect of different treatments on forest growth

4.1 Effect of different treatment modes on growth of diameter at breast height of forest

The mean chest diameters at 5 months 2014 and 11 months 2015 were tested for variability (t-test) and the results are shown in table 47. The probability value of the F test is more than 0.542 and more than 0.05, which shows that the variances of the two groups of data are not obviously different, and the probability value of 0 and less than 0.01 is obtained through the t test, which shows that the mean values of the overall samples of the two groups of data are extremely obviously different. Indicating that the breast diameter of the artificial forest has extremely remarkable growth within 1.5 years.

Table 47:

the mean breast height and breast height growth rate of trees were analyzed for treatments 5 months 2014 and 11 months 2015, and the results are shown in table 48. The same difference between breast diameters was observed between 5 months 2014 and 11 months 2015, except that the breast diameter was significantly greater in the treatment M3 than in the other treatments, and the difference between the other treatments was not significant. The inter-treatment variability was not significant except that the chest diameter growth rates of the M2 and M6 treatments were significantly higher than those of the M1, M5, and M10 treatments.

Table 48:

note a: the values in the table are (mean ± sd);

The results of orthogonal experimental analyses of M3-M6 treatments are shown in Table 49. According to the comparison of the III type square sums, the influence on the growth of the breast height of the forest is from large to small: nitrogen source > interaction of nitrogen source with leaven > leaven. The growth rate of the breast diameter of each treatment is as follows from high to low: m6 is more than M3 is more than M4 is more than M5, so the additional nitrogen source is beneficial to the growth of the breast diameter of the forest. The interaction of the nitrogen source and the leavening agent has certain influence on the growth of the breast diameter of the forest, and the addition of the nitrogen source and the leavening agent together is favorable for promoting the growth of the breast diameter of the forest.

Table 49:

note: r square & 415 (adjustment R square & 196)

The difference between the breast diameter growth rates of the two groups of treatments M7-M10 and M3-M6 (t test) was examined, and the results are shown in Table 50. The probability value of the F test is 0.15 & gt 0.05, which indicates that the variances of the two groups of data are not significantly different, and the probability value of the T test is 0.677 & gt 0.05, which indicates that the mean values of the overall samples of the two groups of data are not significantly different. The stacking rot is proved to have no obvious difference on the growth of the breast diameter of the forest. The average chest diameter growth rate of M3-M6 is 5.29%, the chest diameter growth rate of M7-M10 is 4.55%, and the chest diameter growth of the heap rot treatment is lower than that of the forest stand without the heap rot treatment. The stacking and rotting treatment is unfavorable for the growth of the breast height of the trees, and the reason is probably that the bare time of the stacking and rotting treatment of the forest land soil is longer, so that the porosity of the non-capillary is reduced, and the air permeability of the soil is poor.

Table 50:

therefore, the influence of different treatment modes on the growth of the breast height is not obvious, and the reason probably is that the residue decomposition firstly influences the forest land soil and then indirectly influences the growth of the forest. However, there was a certain regularity, as shown in Table 48, the maximum chest diameter growth rate of M2 treatment was 7.28%, which was 1.29 to 2.25 times the chest diameter growth rate of the other treatments except M6 treatment, and the second chest diameter growth rate of M6 treatment was 7.21%, which was 1.28 to 2.23 times the other treatments. The M2 treatment is most beneficial to the growth of the breast height of the trees, probably because the residues are directly paved in the forest land, the coverage area of the residues in the forest land can be increased, the exposed soil area is reduced, the soil moisture content is increased, the growth of the breast height of the trees is promoted, and the treatment is the residue treatment mode which is most beneficial to the growth of the breast height of the trees in a short period of time. However, for a long time, the growth of forest trees in the residual treatment mode which has the best effect of improving the nutrients of the forest land soil will certainly be the best, because the fertility of the soil is an important factor influencing the growth of the forest trees. The M6 treatment is most beneficial to the improvement of various nutrients, so the treatment is only next to the M2 treatment, and becomes the most beneficial residual treatment mode for the breast diameter growth of the forest after a certain time.

4.2 Effect of different treatment modes on the high growth of forest trees

The forest tree high mean values at 5 months 2014 and 11 months 2015 were tested for variability (t-test) and the results are shown in table 51. The probability value of the F test is 0.697 & gt 0.05, which shows that the variances of the two groups of data are not obviously different, and the probability value of 0.007 & lt 0.01 is obtained through the t test, which shows that the mean values of the overall samples of the two groups of data are extremely obviously different. Indicating that the tree height of the artificial forest has extremely remarkable growth within 1.5 years.

Table 51:

the average tree height and the growth rate of the tree height of the forest were analyzed for 5 months in 2014 and 11 months in 2015 for each treatment, and the results are shown in table 52. The differences between the treatment residues in 5 months 2014 and 11 months 2015 were the same, and were significant between M3 and M7, except that the differences between other treatments were not significant. The high growth rate of the trees treated by M1-M10 is 0.27-3.51%, the high growth rate of the trees treated by removing the residues is-0.72%, and the high growth rate of the trees treated by M1-M10 is 0.99-4.23% higher than that of CK. The reason for the negative number of the tree high growth quantity is probably that the growth quantity of the trees processed by CK is low, so that errors cover the growth quantity and negative growth occurs. The decomposition of the residues can improve the forest land environment, release nutrients to improve the soil fertility and promote the growth of the tree height, so that the growth amount of the trees from M1 to M10 is higher than that of CK, and the residues are reserved to promote the growth of the tree height.

Table 52:

note a: the values in the table are (mean ± sd);

The results of orthogonal experimental analyses of M3-M6 treatments are shown in Table 53. According to the comparison of the III type square sum, the influence on the high growth of the forest trees is as follows: leavening agent > nitrogen source > interaction of nitrogen source with leavening agent. The high growth rate of each treatment tree is as follows from high to high: m6 is more than M4 is more than M5 is more than M3, so the additional nitrogen source and the leaven are beneficial to the high growth of the forest trees. The interaction of the nitrogen source and the leavening agent has certain influence on the growth of the height of the forest tree, and the addition of the nitrogen source and the leavening agent together is favorable for promoting the growth of the height of the forest tree.

Table 53:

note: 177 as the R (the R is the ═ 031)

The difference test (t test) was carried out on the growth rates of trees treated by the two groups of M7-M10 and M3-M6, and the results are shown in Table 54. The probability value of the F test is 0.948 & gt 0.05, which indicates that the variances of the two groups of data are not significantly different, and the probability value of the T test is 0.479 & gt 0.05, which indicates that the mean values of the overall samples of the two groups of data are not significantly different. Showing that the heap rot has no significant difference on the growth of the tree height. The average tree height growth rate of M3-M6 is 2.27%, the growth rate of M7-M10 is 1.76%, and the tree height growth of the heap rot treatment is lower than that of the forest stand without the heap rot treatment. The composting treatment is rather unfavorable for the growth of the height of the trees, probably because the soil of the composting treatment forest land is exposed for a longer time.

Table 54:

the highest growth rate of the forest trees treated by the M6 is 3.51 percent (shown in a table 52), which is 0.66 to 4.23 percent higher than that of other treatments, and the difference of the high growth rate of the forest trees treated by the M6 and the CK and M10 is obvious, but the difference of the high growth rate of the forest trees treated by the M6 and the CK and M10 is not obvious. The M6 treatment is most beneficial for tree height growth of forest trees, probably because the treatment residue decomposes faster, and is most beneficial for growth of various soil fertility quality indicators.

4.3 Effect of different treatment modes on volume growth of forest tree trunk

The trunk volume is the volume of bark from the root to the tip, the trunk value is highest, and the specific gravity of the whole tree is about 2/3 (Xun Ming, 2010) at the maximum. The volume growth rate is an important index for measuring the growth of forest stand. The stem volumes of the various forest stands of 5 months 2014 and 11 months 2015 were tested for differences (t test) and the results are shown in table 55. The probability value of the F test is 0.379 & gt 0.05, which shows that the variances of the two groups of data are not obviously different, and the probability value of 0 & lt 0.01 is obtained through the t test, which shows that the mean values of the overall samples of the two groups of data are obviously different. Indicating that there was very significant growth in the volume of forest tree trunk volume within 1.5 years.

Table 55:

the average tree trunk material and volume growth rate of the trees were analyzed for treatments 5 months 2014 and 11 months 2015, and the results are shown in table 56. The same difference in stem volume between treatments in 5 months 2014 and 11 months 2015 was observed between treatment M3 and other treatments, except that the difference between the treatments was not significant. The total average trunk volume growth rate of M2-M10 was 12.05%, whereas the total average trunk volume growth rate of CK and M1 treatments was only 9.00%, and the total average trunk volume growth rate of M3-M10 treatments was 1.34 times that of CK and M1. Indicating that the M2-M10 treatment was more favorable for forest volume growth than the removal and strip stacking treatments.

Table 56:

note a: the values in the table are (mean ± sd);

The results of orthogonal experimental analyses of M3-M6 treatments are shown in Table 57. According to the comparison of the III type square sums, the influence on the volume growth of the forest trees is as follows: nitrogen source > interaction of nitrogen source with leaven > leaven. The high growth rate of each treatment tree is as follows from high to high: m6 is more than M4 is more than M3 is more than M5, so the added nitrogen source and the leaven are both beneficial to the growth of the forest volume, and the added nitrogen source has obvious promotion effect on the growth of the forest volume (P is 0.056 is less than 0.6). The interaction of the nitrogen source and the leavening agent has stronger influence on the growth of the breast diameter of the forest, and the addition of the nitrogen source and the leavening agent together is more favorable for promoting the growth of the volume of the forest than the independent addition of the nitrogen source and the leavening agent.

Table 57:

note: 481 ═ R (287 adjustment)

The volumetric growth rates of the trunk were differentially examined (t-test) for treatments M7-M10 and M3-M6, and the results are shown in Table 58. The probability value of the F test is 0.428 and more than 0.05, which indicates that the variances of the two groups of data are not obviously different, and the probability value of the T test is 0.268 and more than 0.05, which indicates that the mean values of the overall samples of the two groups of data are not obviously different. Indicating that there was no significant difference in the growth of the heap rot on the wood volume. However, the average volume growth rate of M3-M6 is 12.50%, while that of M7-M10 is 10.58%, the volume growth of the stacking rot treatment is lower than that of the forest stand without stacking rot treatment, and the stacking rot treatment is unfavorable for the growth of the forest volume. The reason may be that the heap rot treatment of forest land soil is exposed for a long time and is not favorable for the growth of forest wood volume in a short period of time.

Table 58:

the volume growth rate of the tree trunk of the forest treated by the M6 is 17.36 percent (shown in a table 56) at most, is 1.07-2.24 times of that of other treatments, and has obvious difference with the volume growth rate of the tree trunk of other treatments except M2, M7 and M4.

The M6 treatment was most beneficial for the growth of forest tree trunk volume, probably because the treatment residue decomposed most rapidly (as shown in table 2), and was most beneficial for the growth of various soil fertility quality indicators.

4.4 comprehensive evaluation of influence of different treatment modes on forest growth

In order to better analyze the comprehensive influence of different treatments on the soil chemical properties of the larch manmade forest in North China, 3 indexes of the measured breast diameter, tree height and tree trunk volume growth rate are standardized, the principal component analysis feature contribution rate is used as the weight, the evaluation indexes are calculated in a weighting mode to obtain a comprehensive score, and comprehensive evaluation is carried out on each treatment.

Through principal component analysis, 2 principal components can be extracted, wherein the maximum contribution rate of the first principal component is 69.626%, the contribution rate of the second principal component is 30.374%, the cumulative contribution rate of the 2 principal components is 100%, and the eigenvalues are all larger than 0.9 (as shown in table 59). Therefore, the 2 main components can fully reflect the relation among all indexes and are key indexes for representing forest growth.

Table 59:

the processing composite score is shown in table 60. A positive score indicates that the soil material properties of the treatment are above average and a negative score indicates below average. The M6 treatment gave a composite score of up to 3.339 followed by 2.549 for M2 treatment. The M6 treatment is most beneficial in promoting forest growth compared to other treatments.

Table 60:

treatment of	FAC₁	FAC₂	Composite score	Rank of name
					M6	1.228	0.849	3.339	1
M2	1.256	-0.083	2.549	2
					M7	0.299	0.581	1.154	3
M4	0.357	0.195	0.923	4
					M8	-0.004	0.541	0.484	5
M3	0.057	-0.198	-0.060	6
					CK	0.014	-1.480	-1.319	7
M9	-0.588	-0.279	-1.483	8
					M1	-0.960	0.489	-1.560	9
M5	-0.970	0.195	-1.849	10
					M10	-0.689	-0.810	-2.177	11

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims

1. A treatment method for promoting the decomposition of intermediate cutting residues is characterized by comprising the following steps:

1) crushing the remainder;

2) mixing the residue after the crushing treatment with urea and a leavening agent; and

3) spreading the mixture on the surface of the forest land soil;

the particle diameter of the residue after the crushing treatment is 0.5 mm-2 cm, and the water content is 257.8kg/m³The bulk density was 257.8kg/m³And further comprising adding water to the comminuted residue to obtain a comminuted residue having a moisture content of at least 65%;

the dosage of the urea is 6kg/m³；

The leaven contains EM bacteria and wood vinegar, and the volume ratio of the remainder after the crushing treatment to the leaven is 500: 1.