CN111501207B

CN111501207B - Biomass felt, preparation method thereof and application thereof in grassland restoration

Info

Publication number: CN111501207B
Application number: CN202010327162.1A
Authority: CN
Inventors: 刘桂霞; 吴儒琳; 王丰毅; 张晓宇; 魏少翀; 刘振
Original assignee: Yingfei Ecological Technology Shanghai Co ltd; Hebei University
Current assignee: Yingfei Ecological Technology Shanghai Co ltd; Hebei University
Priority date: 2020-04-23
Filing date: 2020-04-23
Publication date: 2022-08-19
Anticipated expiration: 2040-04-23
Also published as: CN111501207A

Abstract

The invention provides a biomass felt, a preparation method thereof and application thereof in grassland restoration, wherein the biomass felt is prepared from the following raw materials in parts by weight: 65-75 parts of wool fibers, 15-25 parts of flax fibers and 5-15 parts of corn stalks or polylactic acid fibers; the biomass felt is prepared by a needle-punched forming non-woven technology. The application of the biomass felt in the restoration of severely degenerated, salinized and desertified grasslands comprises the following steps: (a) ploughing the severely degraded salinized grassland to form ridges and furrows; (b) reseeding the selected gramineous forage grass or leguminous forage grass; (c) after the reseeding is finished, covering the biomass felt, and then covering the biomass felt with a layer of thin soil and tightly covering. The biomass felt can keep soil moisture, reduce the temperature difference of desertified soil, avoid the damage of high temperature to plant seedlings and has high emergence rate; the biomass felt can be naturally degraded, so that the environmental pollution is avoided, and the nutrients of soil can be increased after degradation.

Description

Biomass felt, preparation method thereof and application thereof in grassland restoration

Technical Field

The invention relates to the technical field of restoration and treatment of deteriorated grasslands, in particular to a biomass felt, a preparation method thereof and application thereof in grassland restoration.

Background

The grassland accounts for 41 percent of the territorial area of China, and plays an important role in the aspects of production and ecological function maintenance of grassland animal husbandry. However, due to natural factors and artificial overgrazing, grass deterioration is severe. Salinization and desertification of grasslands cause the degeneration of species communities, the reduction of biodiversity, the reduction of production capacity of grasslands, the reduction of ecological functions and the like. And the bare sand and saline-alkali soil can accelerate the evaporation of rainwater, reduce the storage capacity of water, move salt in the soil upwards and accelerate the deterioration of the grassland. At present, there are several engineering measures, material measures and biological measures for treating the heavy salinization grassland, such as sand covering, soil covering and other engineering measures (soil reconstruction engineering), but the engineering quantity is large, the cost is high, and large-area popularization is not easy. Furthermore, the evaporation of soil surface, the surface accumulation of salt and the improvement of soil water can be reduced to a certain extent by agricultural physical measures such as mulching film, straw surface covering and the like. Meanwhile, biological measures such as application of microbial fertilizers and the like are partially taken to promote the growth of plants and improve the salt tolerance of the plants, so that the effect of improving soil is achieved.

The plastic mulching film is used for covering, although the water retention is facilitated, the environment is polluted, and common plastic mulching films include common plastic mulching films, linear low-density mulching films, low-pressure high-density ultrathin mulching films, controllable photolysis films and the like. The common plastic mulching film is blown by high polyethylene, the linear low-density mulching film is prepared by adopting a method of blending and modifying linear low-density polyethylene and high polyethylene, and the low-pressure high-density ultrathin mulching film is prepared by extruding and blowing high-density polyethylene produced by a low-pressure method. Although the plastic mulching film brings great economic benefits to agriculture, the plastic mulching film also causes white pollution. Can not be automatically decomposed and disappeared under natural conditions, a large amount of residual mulching films can obstruct agricultural cultivation, soil can be hardened, the flow of water, air and fertilizer in the soil is obstructed, and the growth of plants is influenced.

The microbial agent can promote the growth of plants, but has limited effect on inhibiting salt, and the water retention and salt inhibition effects of direct straw covering are not ideal. At present, sand barriers are usually arranged on the flowing sand ground and in the wind and sand area, and wind and sand blocking barriers are arranged on dead body materials such as branches and firewood.

Disclosure of Invention

The invention aims to provide a biomass felt, a preparation method thereof and application thereof in grassland restoration, so as to solve the problems of environmental pollution, low survival rate of reseeding species and unsatisfactory comprehensive treatment effect of the existing method.

The technical scheme adopted by the invention is as follows: the biomass felt is prepared from the following raw materials in parts by weight: 65-75 parts of wool fibers, 15-25 parts of flax fibers and 5-15 parts of polylactic acid fibers; the biomass felt is prepared by the following method:

(a) putting the raw materials into water, opening the fiber raw materials into a single fiber state in the water, stirring to fully and uniformly mix the fiber raw materials to obtain fiber suspension pulp, and then conveying the fiber suspension pulp to a non-woven machine;

(b) adjusting the needling rate of a non-woven machine to be 800-1000 times/min, wherein the needling depth is 5-10mm, and penetrating fiber bundles into the fiber web by utilizing a needling forming non-woven technology to enable fibers in the fiber web to be intertwined with one another so as to obtain a formed biomass felt material;

(c) and (c) conveying the biomass felt material obtained in the step (b) into a roller dryer for drying to obtain a biomass felt finished product with the thickness of 1-3mm, the tensile force of not less than 8N/5cm and the light transmittance of not less than 60%.

The fiber length of the wool fiber, the flax fiber and the polylactic acid fiber is 5-8 cm.

In the step (a), reactive dye and sodium sulfate are added into fiber suspension pulp for dyeing, dip dyeing is carried out for 30 minutes at 30 ℃, then sodium carbonate is added, color fixing is carried out for 60-90 minutes at 40 ℃, and finally the fiber suspension pulp is washed by water and then is sent to a non-woven machine.

In the step (c), the drying temperature is 70-80 ℃, the drying time is 15-30min, and the pulling force is 5-8N.

A preparation method of a biomass felt comprises the following steps:

(a) putting 65-75 parts by weight of wool fibers, 15-25 parts by weight of flax fibers and 5-15 parts by weight of polylactic acid fiber raw materials into water, opening the fiber raw materials in the water to be in a single fiber state, stirring to fully and uniformly mix the fiber raw materials to obtain fiber suspension pulp, and then conveying the fiber suspension pulp to a non-woven machine;

(b) adjusting the needling speed of a non-woven machine to be 800-1000 times/minute, the needling depth to be 5-10mm, and penetrating fiber bundles into the fiber web by utilizing a needling forming non-woven technology to enable the fibers in the fiber web to be mutually entangled, thereby obtaining a formed biomass felt material;

The fiber length of the wool fibers, the flax fibers and the polylactic acid fibers is 5-8 cm.

In the step (c), the drying temperature is 70-80 ℃, the drying time is 15-30min, and the tension is 5-8N.

The application of the biomass felt in the restoration of severe salinization and desertification grasslands comprises the following steps:

(a) ploughing the high-salinity salinized grassland to form ridges and furrows; directly raking furrows on the heavy desertification grassland to form ridges and furrows;

(b) reseeding selected gramineous forage grass or leguminous forage grass;

(c) and after the reseeding is finished, covering the biomass felt, then covering a layer of thin soil on the biomass felt tightly, and inserting wood strips or covering soil around the biomass felt for fixing.

When the leguminous forage is reseeded, the biomass felt needs to be punched, the hole diameter is 5-10mm, the hole distance of each row is 5cm, holes are punched in one row or two rows at intervals of 25-30cm, and the distance between the holes in two rows is 10mm when the holes in two rows are punched.

The invention provides a degradable biomass felt which can be completely divided by microorganismsIs decomposed and finally metabolized into CO ₂ And H ₂ O, is completely absorbed by the nature, and does not produce secondary pollution to the environment. In addition, the degraded substances can be used by plants to promote the growth of the plants, and the felt is an environment-friendly new felt and is suitable for popularization and application. The invention has the advantages that:

1) the biomass felt material is mainly prepared from corn polysaccharide or wool fiber, has wide raw material source and relatively low price, and is simple to prepare;

2) the biomass felt can reduce the temperature difference of desertification soil, avoid the damage of high temperature to plant seedlings and has high emergence rate;

3) the biomass felt is non-toxic and harmless, can be naturally degraded, avoids environmental pollution, and can be converted into natural fertilizer and increase soil nutrients after being degraded;

4) the biomass felt can be covered to achieve the effects of absorbing water and retaining water, reduce the salt content of the surface layer of the soil, improve the humidity and the temperature of the soil, promote the growth of plants and further quickly recover the deteriorated grassland;

5) as optimization, the local high-quality gramineous forage grass or leguminous forage can be replanted, and the recovery process is accelerated;

6) compared with the traditional vegetation recovery method, the method can save a lot of funds, can obtain better practical effect after application, and can better control water loss, soil erosion and the like. The soil of the ground surface is controlled so as to be hard to displace and the friction of the ground surface can be enhanced.

Drawings

Fig. 1 is a photograph of the finished thick and thin felts prepared in example 1.

FIG. 2 is a photograph of the recovery of grass in example 2, wherein the control zone is on the left and the test zone is on the right.

FIG. 3 is a photograph of the first year of grassland recovery of example 3. The tillering of the gramineous forage grasses in the test area can be clearly seen in the figure.

FIG. 4 is a photograph of the green-turning of grass of the second year of example 3.

Detailed Description

The present invention is further illustrated by the following examples, which are given by way of illustration only and are not to be construed as limiting in any manner. The operations and reagents and the like not mentioned in the present invention are all common techniques in the art.

Example 1 preparation of biomass felt

(a) Putting 70 parts by weight of wool fibers, 20 parts by weight of flax fibers and 10 parts by weight of polylactic acid fibers into water, opening and stirring fiber raw materials in the water to enable the fiber raw materials to be in a single fiber state, fully and uniformly mixing the fiber raw materials to obtain fiber suspension pulp, and then conveying the fiber suspension pulp to a non-woven machine;

(b) adjusting the needling rate of a nonwoven machine to 800 times/minute and the needling depth to 5mm, and penetrating fiber bundles into a fiber web by using a needling forming nonwoven technology to entangle fibers in the fiber web so as to obtain a formed biomass felt material;

(c) and (c) conveying the biomass felt material obtained in the step (b) into a roller dryer for drying to finally obtain a biomass felt finished product with the thickness of 3mm, the tensile force of 10N/5cm, the light transmittance of 60% and the width of 1 m.

Tension force: the entanglement amount of the fiber bundles in the web forming process is controlled by changing the needling speed and needling density parameters of a nonwoven machine so as to control the tension.

Thickness: the thickness is controlled by varying the needling depth or needle type of the nonwoven machine.

Light transmittance: the entanglement amount of the fiber bundles in the web forming process is controlled by changing the needling speed and needling density parameters of the nonwoven machine, and the tension of the roller drying mechanism can also be changed, so that the light transmittance is finally controlled.

By controlling the above parameters, two sizes of biomass felts were obtained in this example for subsequent testing (as shown in fig. 1), and the characteristics of the two biomass felts are shown in table 1.

Table 1:

biomass felt	Pulling force (N)	Thickness (mm)	Light transmittance (%)	Colour(s)
					Thick felt	10	3	60	White colour
Thin felt	8	1	80	White colour

The two sizes of biomass mats were covered on the surface and subjected to temperature and humidity tests (in which the control was the case without the covering treatment) under the same environment and conditions, with the results shown in tables 2 and 3.

Table 2: moisture in 0-5cm soil layer (%)

Biomass felt	6 month	7 month	8 month
				Control	0.78±0.27c	5.31±0.41c	3.1±0.59c
Thin felt	3.77±0.15b	6.89±0.14b	5.08±0.31b
				Thick felt	5.26±0.15a	9.5±0.46a	7.34±0.26a

Table 3: temperature in 0-5cm soil layer (. degree. C.)

Biomass felt	6 month	7 month	8 month
				Control	31.94±0.64a	34.91±0.72ab	30.78±0.96a
Thin felt	31.76±0.70a	33.36±0.35b	30.68±0.57a
				Thick felt	29.58±0.49b	31.66±0.39c	30.58±0.49a

From the above, thick felts have significant advantages over thin felts.

Example 2

Test site: the severely degraded salinized grassland in the north China management area (the vegetation coverage is less than 10 percent);

selecting a biomass felt: thick felt of width 1 meter prepared in example 1;

and (3) reseeding forage grass: selecting drought-tolerant and salt-tolerant elymus rotundus and wild barley;

the test was performed in a randomized block design, with 4 replicates per treatment, no control coverage, and the same other conditions and operations as the test, with the results shown in table 4 and fig. 2.

Table 4:

treatment of	Grass emergence rate (%)	Height of vegetation (cm)	Degree of coverage (%)
				Control of	4.6±0.55b	8.6±1.06b	5.6±0.65b
Biomass felt	65.8±2.72a	25.6±1.26a	25.6±1.20ba

As can be seen from Table 4, the coverage of the biomass felt significantly improves the grass emergence rate, the height and the vegetation coverage of the test plot, the grass emergence rate is improved by more than 60% compared with the control, the vegetation height is 17cm higher than the control, and the coverage is improved by 20%. The covering biomass felt treatment promotes the seed germination and growth of seed banks and reseeded species due to better moisture retention, and further improves the vegetation coverage in the sample.

Example 3

Test site: background desertification grassland (vegetation coverage is less than 5%) in mountain project areas of Yudao, mouth and country of country surrounding areas of Yangde city in Hebei province;

and (3) after-sowing pasture: selecting proper and drought-resistant elymus and wheatgrass in the peripheral vegetation;

selecting a biomass felt: thick felt 1 meter wide prepared in example 1;

there were 60 test cells, 16 square meters per cell, covering the biomass mat and reseeding. The method is different from the prior art in that: covering a biomass felt on the desertification grass land which is cultivated by the fence and combining with the reseeding of the grass seeds. The control group was not covered and other conditions and operations were the same as those of the test group, and the results are shown in Table 5 and FIG. 3.

Table 5: the first year

Treatment of	Rate of emergence	Survival number (strain/m 2)	Tillering number of plants (plant/m 2)	Tillering number of single plant
					Control of	75.6±2.35b	12.9±0.68b	--	--
Biomass felt	70.5±3.02b	38.2±2.01a	5.6±0.65b	1.3±0.14b

As can be seen from Table 5, the number of surviving plants in the zone covered with the felt is significantly higher than that in the control group and is more than 3 times higher than that in the control group; the forage grass after reseeding in the control group does not produce tillering, and the tillering strain number covering the biomass felt is 5-6 strains/m ² The tillering number of a single plant is 1.3, and the growth promoting effect on the reseeding pasture grass in the first year is very obvious.

The test area was not treated any further in the second year and the growth of gramineous grasses in the second year was examined, the results of which are shown in table 6 and fig. 4.

Table 6: in the second year

As can be seen from Table 6, the survival rate of the plants in the second-year striking-green stage of the gramineous forage grass in the felt-covered plot is significantly higher than that of the control group, and reaches 56.8 percent, while the gramineous forage grass additionally sowed in the control group cannot live through the winter, and only a small amount of indigenous plants survive. The experiment fully shows that the overwintering green-turning rate of the reseeding pasture grass is obviously improved by covering. The coverage, plant height, density and reproductive branch density of the blanket are all obviously higher than those of the control group. The survival and growth of the gramineous forage grass are obviously improved by the felt covering treatment, the density reaches 180 plants/square meter, and the reproductive branches account for one tenth; the grass survival rate in the control was 0.

The soil moisture and temperature in the second year were further examined and the results are shown in tables 7 and 8.

Table 7: moisture content in soil layer of 0-5cm (%)

Treatment of	6 month	7 month	8 month
				Control of	0.78±0.27a	5.31±0.41a	3.10±0.60a
Biomass felt	5.26±0.15b	11.50±0.46b	9.34±0.26b

Table 8: temperature in 0-5cm soil layer (. degree. C.)

Treatment of	6 month	7 month	8 month
				Control of	31.94±0.64a	34.91±0.72a	30.78±0.96a
Biomass felt	25.58±0.49b	28.66±0.39b	24.58±0.49b

As can be seen from the table, the humidity and the temperature of the 0-5cm soil layer of the blanket-covered community are obviously higher than those of the control group. Data statistics and analysis show that the degradable biomass felt has the functions of heat preservation and water retention, can effectively utilize solar radiation heat and reduce heat energy consumption of soil water evaporation, and can reduce volatilization, leaching and loss of fertilizers.

Example 4

The test of covering the biomass felt is carried out on the desertification grassland, the biomass felt with the thickness of 3mm is selected, three test groups are designed in the test, namely a control group (CK), a covering biomass felt (A) and a covering perforated biomass felt (B), each group is repeated by six, and each cell is a 2 multiplied by 2m sand barrier grid. The additional sowing of the leguminous forage is Melissitus ruthenicus seeds. The biomass felt which is punched is covered, the diameter of the holes is 5mm, the distance between the holes is 5cm, and a row of holes are punched every 25 cm. The results are shown in Table 9.

Table 9:

treatment of	Percentage of emergence (%)	Survival rate (%)
			CK	51.25±2.98a	10.0±2.16b
A	7.0±2.16c	78.7±5.08a
			B	38.25±3.25b	73.75±5.05a

Test results show that although the emergence rate of the seedlings without coverage treatment is the highest, the survival rate is the lowest, and seed resources are wasted; the felt covering treatment hinders the emergence of seedlings of leguminous pasture, but the emergence rate is obviously increased and the survival rate is also obviously improved after the punching treatment. Experiments show that the covering biomass felt can promote the emergence of seedlings of the reseeding leguminous forage through punching treatment, and the water retention effect of the covering biomass felt can ensure the growth in the later period, so that the survival rate is improved.

Claims

1. The biomass felt is characterized by being used for recovering severe salinization and desertification grasslands and prepared from the following fiber raw materials in parts by weight: 65-75 parts of wool fiber, 15-25 parts of flax fiber and 5-15 parts of polylactic acid fiber; the fiber length of the wool fibers, the flax fibers and the polylactic acid fibers is 5-8 cm; the biomass felt is prepared by the following method:

(a) placing the fiber raw materials in water, opening the fiber raw materials into a single fiber state in the water, starting stirring to fully and uniformly mix the fiber raw materials to obtain fiber suspension pulp, and then conveying the fiber suspension pulp to a non-woven machine;

2. The biomass felt according to claim 1, wherein in the step (a), the fiber suspension pulp is dyed by adding reactive dye and sodium sulfate, the fiber suspension pulp is soaked for 30 minutes at 30 ℃, then sodium carbonate is added, the fiber suspension pulp is fixed for 60-90 minutes at 40 ℃, and finally the fiber suspension pulp is washed by water and sent to a non-woven machine.

3. The biomass felt according to claim 1, wherein in the step (c), the drying temperature is 70-80 ℃, the drying time is 15-30min, and the tension is 5-8N.

4. A preparation method of a biomass felt is characterized in that the biomass felt is used for severe salinization and desertification grassland restoration, and the preparation method comprises the following steps:

(a) putting 65-75 parts by weight of wool fibers, 15-25 parts by weight of flax fibers and 5-15 parts by weight of polylactic acid fiber raw materials into water, opening the fiber raw materials in the water to be in a single fiber state, stirring to fully and uniformly mix the fiber raw materials to obtain fiber suspension pulp, and then conveying the fiber suspension pulp to a non-woven machine; the fiber length of the wool fibers, the flax fibers and the polylactic acid fibers is 5-8 cm;

5. The method for preparing the biomass felt according to claim 4, wherein in the step (a), the fiber suspension pulp is dyed by adding reactive dye and sodium sulfate, the fiber suspension pulp is soaked and dyed for 30 minutes at 30 ℃, then sodium carbonate is added, the color is fixed for 60-90 minutes at 40 ℃, and finally the fiber suspension pulp is washed by water and sent to a non-woven machine.

6. The method for preparing the biomass felt according to claim 4, wherein in the step (c), the drying temperature is 70-80 ℃, the drying time is 15-30min, and the tension is 5-8N.

7. Use of the biomass felt according to any one of claims 1 to 3 for the restoration of heavily salinized and sandy grasses, characterized in that it comprises the following steps:

(b) reseeding the selected gramineous forage grass or leguminous forage grass;

8. Use according to claim 7, characterized in that, in the case of reseeding legume grasses, the mat is perforated with holes having a diameter of 5-10mm and a pitch of 5cm between each row of holes, one or two rows of holes being perforated every 25-30cm, the pitch between two rows of holes being 10 mm.