CN112400396A

CN112400396A - Method for improving soil of reclaimed land in reclamation area

Info

Publication number: CN112400396A
Application number: CN202011237430.7A
Authority: CN
Inventors: 邓泓; 闫泳材
Original assignee: East China Normal University
Current assignee: East China Normal University
Priority date: 2020-11-09
Filing date: 2020-11-09
Publication date: 2021-02-26

Abstract

The invention discloses a method for improving the soil of a new land in a reclamation area. The method adopts the combination of planting the true halophyte and applying the kitchen waste compost to improve the new soil, improves the soil fertility by applying the kitchen waste compost product, and reduces the risk of soil salinization brought by applying the compost product by planting the true halophyte; the farmland soil improvement method disclosed by the invention is simple to operate, measures in two aspects of soil fertility improvement and soil salinization risk control are comprehensively considered, a new method is provided for improving the soil of the newly-grown land in the reclamation area, the soil fertility is obviously and comprehensively improved, the soil microbial activity is improved, the conversion and utilization of elements such as carbon, nitrogen and phosphorus are promoted, and the growth of the succeeding crops is finally facilitated.

Description

Method for improving soil of reclaimed land in reclamation area

Technical Field

The invention relates to the technical field of soil improvement, in particular to a method for improving the soil of a reclaimed land in a reclamation area by using a salt-containing municipal kitchen waste compost product.

Background

At present, researches on improving barren soil and organic fertilizer component content prepared from kitchen waste by using organic fertilizer prepared from agricultural wastes, sludge and livestock and poultry manure as raw materials have been reported, and researches on improving new soil in a reclamation area by using kitchen waste compost as a soil conditioner have been rarely reported. Although the kitchen waste is rich in nutrient elements and has high potential for soil improvement and application, due to the characteristics of high salt content and difficult desalination, the risk of salinization of the land can be increased when the kitchen waste is improperly applied.

Chinese patent No. 201711324166.9 discloses a method for composting kitchen waste to improve soil, which comprises the steps of adsorbing hydrogen peroxide by charcoal, separating solid and liquid from kitchen waste, mixing and impregnating charcoal and kitchen waste, mixing and decomposing agricultural and forestry wastes and mixed slag, composting and fermenting again, forming kitchen fertilizer, preparing mixed soil, preparing backfill soil and the like. In the patent, the method has complicated steps and does not solve the problem of soil salinization caused by high salt content of the kitchen waste.

The mechanism research of repairing the saline soil by utilizing the true halophyte is mature, and a good effect is achieved in the practical application. Taking suaeda glauca as an example, suaeda glauca is suaeda genus of the Li family, is an annual herbaceous plant, is a true halophyte with fleshy leaves, mainly grows in severe salinization areas such as seashore, lake and desert, and is a typical salinization improved plant developed and utilized relatively mature at present. The suaeda salsa can resist the irrigation of 24.0g/kg of saline water, can normally grow on saline soil with the soil salinity of 25.0g/kg, and the true halophilic limit reaches 35.0 g/kg. Zhang Linbin et al used Suaeda salsa to improve the saline soil, and found that after 3 years of planting Suaeda salsa on the saline soil, the salt content in the soil is reduced from 16.4g/kg to 12.0g/kg, and the salt rejection rate reaches 26.83%. Suaeda heteroptera can grow normally in saline soil with salt content of 12.71 g/kg. Moreover, the stem and leaf of the suaeda glauca in the seedling stage are fresh and tender and rich in nutrition, the content of leaf protein reaches 50%, the suaeda glauca bunge can be used as vegetables, the seeds of the suaeda glauca bunge are rich in unsaturated fatty acid, Conjugated Linoleic Acid (CLA) can be extracted, the CLA has the effects of preventing and treating various cancers, reducing organism fat and the like in the medical field, and the rape seed cakes after oil extraction are good in palatability as livestock feeds and are valued at home and abroad. The feed of Suaeda glauca can also obviously improve the growth performance, disease resistance, nutritional status and meat quality of the sheep. The Suaeda salsa is fed, so that the growth performance and the net meat rate of the sheep can be obviously improved, and the feed conversion ratio and the fat rate are reduced.

At present, no literature exists for improving soil by combining true halophyte with kitchen waste compost and improving soil fertility.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provides a method for improving the soil of a reclaimed land in a reclamation area by using an urban salt-containing kitchen waste compost product.

In order to achieve the aim, the invention provides a method for improving the soil of a new land in an reclamation area, which comprises the steps of applying urban salt-containing kitchen waste compost products on the soil to be improved, then planting true halophyte, and planting cash crops after the true halophyte is mature and harvested.

As a preferred embodiment of the present invention, the method specifically comprises the following steps:

step (1), collecting a salt-containing kitchen waste compost product in a city;

step (2), applying the urban salt-containing kitchen waste compost product on soil to be improved;

step (3), after 8-12 days, planting true halophytes on the soil obtained in the step (2);

and (4) planting economic crops after the true halophytes are mature and harvested.

As a preferred embodiment of the present invention, the halophyte is selected from the group consisting of halophytes, suaeda plants distributed in coastal areas such as suaeda salsa, salsola plants such as salsola collina, and salicornia plants such as salicornia europaea; at least one of Salicomia plant such as SALCIA MILTIORRHIZA, Salicomia plant such as SALCIA SALTIORRHIZA, Salacia plant such as CIYELLUM JAPONICA, and Salacia acuminata, and atriplex plant such as atriplex canescens (exotic species) distributed in inland region.

As a preferable embodiment of the invention, the mass ratio of the municipal saline kitchen waste compost product to the soil to be improved is (0.1-0.2): 1.

As a preferred embodiment of the invention, the mass ratio of the municipal saline kitchen waste compost product to the soil to be improved is 0.15: 1.

As a preferred embodiment of the present invention, the true halophytes are planted while maintaining a field moisture capacity of 75% to 85%.

As a preferred embodiment of the present invention, the true halophytes are planted while maintaining 80% of field capacity.

Compared with the prior art, the invention has the beneficial effects that:

the invention adopts the combination of true halophyte and kitchen waste compost to improve the new soil, improves the soil fertility by applying the kitchen waste compost product, and reduces the risk of soil salinization brought by applying the compost product by planting the true halophyte; the farmland soil improvement method disclosed by the invention is simple to operate, measures in two aspects of soil fertility improvement and soil salinization risk control are comprehensively considered, a new method is provided for improving the soil of the newly-grown land in the reclamation area, the soil fertility is obviously and comprehensively improved, the soil microbial activity is improved, the conversion and utilization of elements such as carbon, nitrogen and phosphorus are promoted, and the growth of the succeeding crops is finally facilitated.

Drawings

FIG. 1 is a graph of the effect of different amendment treatments on soil pH.

FIG. 2 is a graph of the effect of different remediation treatments on soil conductivity.

FIG. 3 is a graph of the effect of different improvement treatments on soil nutrient content.

FIG. 4 is a graph of the effect of different modification treatments on soil alkaline phosphatase.

FIG. 5 is a graph of the effect of different improvement treatments on soil sucrase.

FIG. 6 is a graph of the effect of different improvement treatments on soil urease.

FIG. 7 is a graph of the effect of different remediation treatments on soil microbial biomass carbon.

FIG. 8 is a graph of the effect of different remediation treatments on soil microbial biomass nitrogen.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention provides a reclamation area new land soil improvement method, which specifically comprises the following steps:

step (1), collecting a salt-containing kitchen waste compost product in a city;

step (3), after 10 days, planting true halophytes on the soil obtained in the step (2);

As a preferred embodiment of the present invention, the euhalophyte is selected from Chenopodiaceae, Suaeda plants distributed in coastal areas such as Suaeda salsa, Salsola plants such as Salsola collina, Salicornia plants such as Salicornia europaea; at least one of Salicomia plant such as SALCIA MILTIORRHIZA, Salicomia plant such as SALCIA SALTIORRHIZA, Salacia plant such as CIYELLUM JAPONICA, and Salacia acuminata, and atriplex plant such as atriplex canescens (exotic species) distributed in inland region. In the present embodiment, suaeda salsa is taken as an example of the true halophyte.

The implementation case is as follows:

1. material sources are as follows:

and collecting enough fresh soil in a newly reclaimed land of a horizontal sand island in a Chongming area, drying the fresh soil, removing impurities such as root systems and the like, and grinding the fresh soil by using a 10mm sieve to be used as test soil for a control test. The tested soil is sandy soil, mainly used for planting rice, and has the advantages of high sand content, coarse particles and high water seepage speed. The pH value of the soil before the test is 8.96, the conductivity is 497.43 mu s/cm, the total amount of water-soluble salts is 1.01g/kg total nitrogen 0.29g/kg, total phosphorus 0.54g/kg, total potassium 14.85g/kg, organic matters are 2.7g/kg, available phosphorus 3.35mg/kg, hydrolyzable nitrogen 10.5mg/kg, and quick-acting potassium 63.5 mg/kg.

The compost product to be tested was aerobic composting from municipal kitchen waste. And taking back the compost product, naturally drying, removing large-particle impurities, and grinding through a 10mm sieve for later use. The pH value of a tested compost product is 6.22, the conductivity is 12.17ms/cm, the total amount of water-soluble salts is 11.3g/kg, the total nitrogen is 11.2g/kg, the total phosphorus is 4.26g/kg, the total potassium is 2.26g/kg, the organic matter is 354g/kg, the available phosphorus is 630mg/kg, the hydrolyzable nitrogen is 1240mg/kg, and the quick-acting potassium is 1320 mg/kg. The raw materials of the compost products to be tested are wet garbage from catering industry, communities and vegetable yards, and a high-temperature aerobic composting technology is adopted.

The test plant was Suaeda salsa (L.) Pall.) and the seeds were purchased from seed companies.

2. Designing a test scheme:

the test was carried out in a total of one control group (CK) without modifier and five treatment groups (see Table 1), each corresponding to six application rates of compost product, four in each case. And (3) fully and uniformly mixing the compost product to be tested and the soil to be tested, putting the mixture into a flowerpot with the volume of 3 gallons, keeping the water holding capacity of 80 percent of the field stable, placing the mixture for 10 days, transplanting the mixture into the prepared soda-canopy seedlings, finally keeping four soda-canopy plants with uniform growth vigor in each pot, and periodically and manually weeding. Pure water was added periodically during the experiment to ensure that all treatments had the same moisture content (80% field capacity), temperature and lighting conditions.

Table 1 test scheme for improving new soil by combining kitchen waste compost with suaeda salsa

3. Collecting and detecting samples:

after five months, the Suaeda salsa is harvested, and soil samples are collected for the beginning and the end. The collected part of fresh soil is immediately stored at low temperature by using dry ice, and PCR amplification and subsequent sequencing analysis of microbial genes are carried out as soon as possible. Reserving enough fresh soil to measure soil microbial biomass carbon and microbial biomass nitrogen; and (3) air-drying and grinding the residual soil sample, respectively sieving the ground soil sample with a 20-mesh sieve and a 100-mesh sieve, and measuring the pH value, EC, organic matters, TN, TP, TK, quick-acting P, quick-acting K, alkaline hydrolysis nitrogen, microbial biomass carbon, microbial biomass nitrogen, sucrase activity, urease activity and alkaline phosphatase activity of the soil.

The soil pH was measured using a veeasy Plus pH meter (water: soil: 5:1) manufactured by METTLER TOLEDO corporation; EC was measured using a filveeasy Plus conductivity meter (water: soil ═ 5:1) manufactured by METTLER TOLEDO corporation; treating a soil sample by using dilute hydrochloric acid, and then measuring TOC by using an elementar vario TOC total organic carbon analyzer; determining total nitrogen by using a Kjeldahl method, digesting a soil sample by using concentrated sulfuric acid, alkalifying the soil sample by using sodium hydroxide, heating and distilling the obtained ammonia, absorbing the ammonia by using boric acid, and finally titrating the ammonia by using an acid standard solution; the alkaline hydrolysis nitrogen is measured by an alkaline hydrolysis diffusion method, 1.8mol/L sodium hydroxide solution is used for treating soil, hydrolysis, reduction, diffusion and absorption are carried out in a diffusion dish, the temperature is kept for 24 hours at 40 ℃, and finally, acid standard solution is used for titration; digesting a soil sample by concentrated sulfuric acid, and determining by using a molybdenum-antimony colorimetric-resisting method; leaching available phosphorus with sodium bicarbonate solution, and determining with Mo-Sb colorimetric method; the total potassium is measured by flame atomic absorption spectrophotometry; the quick-acting potassium is measured by ammonium acetate extraction-flame photometry; after the soil sample is digested by potassium dichromate-sulfuric acid, the amount of organic carbon is measured by using ferrous sulfate standard liquid drop, and then the constant 1.724 is multiplied to obtain the content of the organic matter; carrying out fumigation extraction on microbial carbon and microbial nitrogen by using chloroform, and then measuring by using an elementar vario TOC total organic carbon analyzer; the activity of the sucrase is expressed by the colorimetry of 3, 5-dinitrosalicylic acid, and the activity of the sucrase is expressed by milligrams of glucose generated by enzymatic reaction at 37 ℃ per 24 hours per gram of soil; the urease activity is measured by adopting a phenol-sodium hypochlorite colorimetric method, and the urease activity is expressed by the milligrams of ammonia nitrogen generated by enzymatic reaction at 37 ℃ in each gram of soil every 24 hours; alkaline phosphatase activity was determined by disodium phenyl phosphate colorimetry and expressed as milligrams of phenol enzymatically produced at 37 ℃ per 24 hours per gram of soil.

Collecting the complete plant of the soda-canopy after the completion of the planting, and measuring the average plant height of the soda-canopy in each pot; the average root surface area of the suaeda glauca per pot was determined using the plant root system scanning system WinRHIZO. And (5) drying the plants and measuring the dry weight of the ground and the underground.

4. And (4) analyzing results:

4.1 Effect of kitchen waste compost products in combination with Suaeda salsa on soil pH

FIG. 1 is a graph of the effect of the different amendment treatments on soil pH, where different letters at the same time indicate significant differences between groups (p < 0.05).

The magnitude of the soil pH directly determines whether it is suitable for crop growth. The graph shows the change of the pH value of the soil after the kitchen waste compost products with different proportions are applied. As can be seen from figure 1, the initial pH of the soil to be tested is 8.96, the soil is alkalescent, the pH value of the soil is obviously reduced by adding the compost product, the pH value is close to neutral from alkalinity, and the reduction amplitude is in positive correlation with the application amount of the compost product. After five months of treatment, the soil pH of each treatment group is increased compared with the soil pH of the initial treatment, but the soil pH of the treatment group still shows a remarkable descending trend along with the increase of the addition ratio. This is probably because a large amount of organic acids such as humic acid are produced in the composting process, and the organic acids are gradually transformed along with the progress of the potting experiment. The pH values of the kitchen waste compost products are respectively reduced by 0.17 unit, 0.32 unit, 0.5 unit, 0.62 unit and 1.13 unit compared with CK in the treatment of W5, W10, W15, W20 and W30, and the addition of the kitchen waste compost products is helpful for reducing the pH value of soil and shows a positive trend for the pH improvement of alkaline soil.

4.2 Effect of kitchen garbage compost products in combination with Suaeda salsa on soil conductivity

FIG. 2 is a graph of the effect of the different improvement treatments on soil conductivity, where different letters at the same time indicate significant differences between groups (p < 0.05).

For soil analysis, the salt content is an important comprehensive index, and the determination of the conductivity in the soil can indirectly reflect the salt content of the soil. As can be seen from fig. 2, the conductivity of the soil in each treatment group at the initial stage of improvement is significantly improved compared with that of the CK group, and the EC value shows an increasing trend as the addition ratio of the compost products increases, because the kitchen waste contains a large amount of inorganic salts and is directly applied to the soil, so that the salt content of the soil rapidly increases. After five months of treatment, the conductivity of the soil of each treatment group is remarkably reduced, wherein the conductivity of the soil of the treatment groups is not remarkably different from that of CK groups in W5, W10 and W15. CK. The amounts of W5, W10, W15, W20 and W30 were reduced by 23.9%, 45.2%, 53.4%, 68.5%, 69.9% and 61.1% respectively compared with the initial period of the test. It is stated that the growth of the soda-shed contributes to the reduction of the salt content of the soil, probably because as the soda-shed grows, its poly-salt character absorbs some of the inorganic salts in the soil.

4.3 Effect of kitchen garbage compost product in combination with Suaeda salsa on soil nutrient content

FIG. 3 is a graph of the effect of the different improvement treatments on soil nutrient content, where different letters at the same time indicate significant differences between groups (p < 0.05).

Table 2 is a table of values of the different improvement treatments on the soil nutrient content. In table 2, the data are mean ± sd, and different letters in the same column indicate significant differences between treatments for the same index (p < 0.05).

TABLE 2

The nitrogen, the phosphorus and the potassium are three nutrient elements which are necessary for the growth of the plants and have the largest demand, participate in forming a plurality of important compounds such as protein, nucleic acid, enzyme and the like in the plants, and the content of the important compounds determines the nutrient level of the soil and the growth state of the plants. As can be seen from fig. 3 and table 2, the total nitrogen and phosphorus contents of the soil generally increase with the increase of the application ratio of the compost products, and except that the total nitrogen content difference between W5 and CK is not significant, the total nitrogen and phosphorus contents of the other treatment groups are significantly higher than those of the CK control group, wherein the total nitrogen and phosphorus contents difference between W10 and W15 is not significant. Compared with CK, the total nitrogen of the soil of W5, W10, W15, W20 and W30 is respectively increased by 73.5%, 156.4%, 195.7%, 294.9% and 453%, and the total phosphorus is respectively increased by 19.3%, 32.6%, 38.9%, 75.2% and 107.1%. The soil total potassium content of each treatment group is not obviously different from that of the control group, because the potassium element is taken as the nutrient element with the highest content in the soil, the content of the potassium element is respectively 7 th and 4 th in all mineral elements and nutrient elements of the crust, and the total potassium content of the compost product is far lower than that of the tested soil, so that the influence on the soil total potassium content is limited.

The main component of soil organic matter is C, N organic compounds with different compositions and structures, the content of the C, N organic compounds is an important index for evaluating the fertility level of soil, and the C, N organic compounds have important influence on the nutrient supply of the soil, the soil structure and the ecological function of the soil. As can be seen from table 2, the soil organic content appeared to increase with increasing proportion of compost product application, and the organic content of each treatment group was significantly higher than that of the CK control group, with no significant difference between W10 and W15. The total nitrogen of the soil of W5, W10, W15, W20 and W30 is increased by 2.16, 4.58, 6.16, 9.37 and 12.92 times compared with CK respectively.

The alkaline hydrolysis nitrogen of the soil mainly comes from mineralization of soil organic matters and quick-acting components applied to soil fertilizers, is a main source of crop nitrogen nutrition, can be directly absorbed and utilized by plant root systems, plays an important role in the growth process of plants, and is an important index for evaluating soil nutrients. Therefore, the content and the variation trend of the alkaline hydrolysis nitrogen in the soil reflect the supply condition of the quick-acting nitrogen in the soil, and the method is one of indexes for evaluating the fertilizer supply capacity of the soil. The soil quick-acting phosphorus refers to inorganic phosphorus or micromolecular organic phosphorus which can be directly absorbed and utilized by plants, and the content of the soil quick-acting phosphorus can accurately evaluate the phosphorus supply capacity of soil phosphorus. Because 89.8% -96.8% of potassium in soil exists in mineral state, and is difficult to be absorbed and utilized by plants, the quick-acting potassium is also one of the necessary nutrients in the growth and development process of crops, and is an important index for evaluating the soil fertility. As can be seen from the figure, the contents of alkaline hydrolysis nitrogen, available phosphorus and quick-acting potassium in the soil tend to increase along with the increase of the application proportion of the compost products. Wherein, the alkaline hydrolysis nitrogen content of each treatment group is obviously higher than that of a CK control group, and the difference between the treatment groups is obvious. The effective phosphorus content of the treatment groups is obviously higher than that of the CK control group except that the difference between W5 and CK is not obvious. CK. The content difference of the quick-acting potassium of W5, W10 and W15 is not obvious, and the content of the quick-acting potassium of W20 and W30 is obviously higher than that of other treatment groups.

From the perspective of nitrogen, phosphorus and potassium nutrient elements and organic matters, with the increase of the application proportion of compost products, indexes of all nutrient elements have a relatively obvious increasing trend, and the soil fertility is obviously improved.

4.4 Effect of kitchen garbage compost products in combination with Suaeda salsa on soil biological indexes

FIGS. 4, 5, 6, 7 and 8 are graphs showing the effect of the different improvement treatments on soil biological indicators (alkaline phosphatase, sucrase, urease, soil microbial carbon, soil microbial nitrogen), respectively. In these figures, different letters at the same time indicate significant differences between groups (p < 0.05).

The activity of alkaline phosphatase characterizes the phosphorus supply capacity of soil, and the phosphatase in the soil participates in the mineralization and decomposition process of organic phosphorus and promotes the absorption of plants to phosphorus. From FIGS. 4, 5 and 6, it can be seen that the activities of alkaline phosphatase, urease and sucrase in soil show basically the same trend in change among the treatments, and all show an increase with the application ratio of the compost products. The alkaline phosphatase activity of each treatment group was significantly higher than that of CK, and the groups were also significantly different. Five months after compost product application, the treatment groups were all improved to varying degrees, except that the activity of W20 alkaline phosphatase was slightly reduced from the initial period of the test.

Urease is a kind of phthalamidase, and can effectively hydrolyze peptide bonds in organic molecules. Among all types of soil enzymes, urease is the only enzyme that has a significant impact on the conversion of urea in soil, and urea itself, as an important nitrogen fertilizer, has an irreplaceable position in soil fertilizer applications. As can be seen from the figure, the soil urease activity and alkaline phosphatase activity have basically the same trend. After five months of test, the soil urease activities of W5, W10, W15, W20 and W30 are respectively improved by 10.2%, 14%, 30.7%, 66.9% and 61.2% compared with the initial soil urease activities, wherein the improvement range of the treatment groups with high application ratio is large.

The soil sucrase participates in the conversion of carbohydrates by catalyzing sucrose hydrolysis reaction, hydrolyzes sucrose molecules in soil into glucose and fructose which can be directly absorbed and utilized by plants and soil microorganisms, and the activity reflects the strength of soil organic carbon accumulation and decomposition conversion to a certain extent, so that the soil sucrase is an important enzyme participating in soil carbon circulation. At the beginning of compost product application, the soil sucrase activity of W5, W10, W15, W20 and W30 was increased by 0.24 mg/(g.d), 0.52 mg/(g.d), 0.96 mg/(g.d), 1.6 mg/(g.d) and 4.42 mg/(g.d), respectively, compared to CK. Five months after the test, the soil sucrase activity of W30 was significantly lower than the initial level of the test, with no significant difference from W20, and with no significant difference from W10 for W5.

Soil microbial biomass refers to the total amount of living microorganisms living in soil. Although the proportion of the soil microbial biomass in soil organic matters is small, the soil microbial biomass plays a great role in the circulating process of elements such as carbon, nitrogen, phosphorus and the like. The soil microbial biomass is a driving force of soil nutrient circulation and substance conversion processes, is also a source and a library of plant nutrient elements, can sensitively reflect the intensity of biochemical reaction in soil, and can accurately reflect the soil fertility and the change of soil health condition.

The soil microbial biomass carbon is a part which is easy to change and has high activity in soil organic matters, and is an important 'source' of soil nutrients. As can be seen from fig. 7, the soil microbial biomass carbon of each treatment group is significantly higher than that of the control group, and the soil microbial biomass carbon tends to increase with the increase of the application ratio of the compost product, but the differences of W10, W15 and W20 are not significant, and the difference of W30 is significantly higher than that of the other treatment groups.

The soil microbial biomass nitrogen is an important reserve bank of soil nitrogen and an important component of organic nitrogen, and plays an extremely important regulation role in the circulation and conversion process of the soil nitrogen. As can be seen in fig. 8, the application of the compost product significantly increased soil microbial biomass nitrogen. Each treatment is roughly expressed as: w30> W20> W10> W15> W5> CK, wherein W20 and W10, W10 and W15 are not significantly different.

4.5 Effect of kitchen waste compost products on the growth of Suaeda salsa

Table 3 is a table of values of suaeda salsa growth indicators for different treatment groups.

TABLE 3

The purpose of improving the soil is to improve the productivity of the soil and further increase the tillage performance of the soil. The effect of each treatment group on the hood growth is detailed in table 3. It can be seen from table 3 that the application of the compost product produced a significant increase in the growth of the soda ash, and that the plant height and the above-ground biomass of each treatment group were significantly increased compared to the blank control group. The plant height and the overground biomass of W15 in each treatment group are maximum values, and reach 80.95cm and 33.73g respectively, and the plant height is obviously higher than that of other treatment groups. The plant height difference between W5, W10, W20 and W30 is not significant, but the biomass of the upper part of W5 is significantly lower than that of other treatment groups.

The root cap ratio of the CK group calabash is significantly higher than that of the control group, and reaches 0.11, so that more plant biomass is distributed underground. While the root-cap ratio between treatment groups did not differ significantly. The root surface area trend of each group of the soda-awning is similar to the plant height and the overground biomass, the control group is obviously lower than the treatment group, the difference of each treatment group is not obvious, and in contrast, the root surface area of W15 is slightly higher than that of the rest treatment groups. The effect of applying the kitchen waste compost products on improving the soil fertility is obvious, and for the soda tent, the kitchen waste compost products are most beneficial to the growth of the soda tent under the application proportion of 15% in the application proportions of 5%, 10%, 15%, 20% and 30%.

In view of the research data, compared with the control group, the soil fertility index of the W15 treatment group is greatly improved, and the growth of the soda canopy is facilitated; compared with other treatment groups, the soil conductivity is lowest and the risk of soil salinization is lowest after 150 days of treatment. Therefore, the W15 treatment is selected as the optimum improvement method.

Table 4 shows the change of each physical and chemical index of the soil before and after the treatment.

TABLE 4

As can be seen from table 4, the soil indices tested with the W15 improvement treatment were compared to the test soil background: the pH value of the soil is reduced by 5.52 percent compared with the background value of the soil to be tested; the soil conductivity EC is reduced by 2.93 percent compared with the background value of the soil to be tested and reduced by 68.51 percent compared with the initial treatment period; the organic matter of the soil is improved by 6.15 times; the total phosphorus of the soil is improved by 39.07 percent; the available phosphorus of the soil is improved by 14.53 times; the total nitrogen of the soil is improved by 1.98 times; the soil hydrolyzable nitrogen is improved by 6.46 times; the soil quick-acting potassium is increased by 94.49%. The data show that the indexes of main nutrient elements of the soil are obviously improved, the alkaline pH of the soil is relieved to a certain degree, and the risk of aggravating soil salinization is avoided.

W15 improvement treatment group versus test soil background: the activity of the soil alkaline phosphatase is improved by 4.53 times, and the activity of the soil urease is improved by 14.14 times; the activity of the soil sucrase is improved by 10.3 times, and the improvement of the activity of the soil sucrase is beneficial to promoting the circulation of nitrogen, phosphorus and carbon in the soil. The carbon content of soil microorganisms is increased by 17.19 times; the nitrogen content of soil microorganism is increased by 18.47 times. The data above demonstrate a significant increase in soil microbial activity.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims

1. A method for improving the soil of a new land in a reclamation area is characterized in that urban saline kitchen waste compost products are applied to the soil to be improved, then halophytes are planted, and after the halophytes are mature and harvested, cash crops are planted.

2. The reclamation area new land soil improvement method according to claim 1, wherein the method specifically comprises the following steps:

step (1), collecting a salt-containing kitchen waste compost product in a city;

3. The method for improving the soil in the reclaimed area new land according to claim 1 or 2, wherein the euhalophyte is selected from Chenopodiaceae plants, Suaeda plants distributed in coastal areas such as Suaeda salsa, Salsola plants such as Salsola collina, Salicornia plants such as Salicornia europaea; at least one of Salicomia plant such as SALCIA MILTIORRHIZA, Salicomia plant such as SALCIA SALTIORRHIZA, Salacia plant such as CIYELLUM JAPONICA, and Salacia acuminata, and atriplex plant such as atriplex canescens (exotic species) distributed in inland region.

4. The reclamation area new land soil improvement method according to claim 1 or 2, wherein the mass ratio of the municipal saline kitchen waste compost product to the soil to be improved is (0.1-0.2): 1.

5. The reclamation area new land soil improvement method according to claim 4, wherein the mass ratio of the municipal saline kitchen waste compost product to the soil to be improved is 0.15: 1.

6. The method for improving the soil of the new land in the reclamation area as claimed in claim 1 or 2, wherein the water holding capacity in the field is kept between 75% and 85% when the true halophytes are planted.

7. The method for improving the soil of the new land in the reclamation area as claimed in claim 6, wherein the water holding capacity of the field is maintained at 80% when the true halophytes are planted.