A planting method for improving moderate saline-alkali soil

Abstract

The invention discloses a planting method for improving moderate saline-alkali land soil, belongs to the technical field of saline-alkali land soil improvement, and comprises the following steps: S1, dividing a planting area into a plurality of planting belts with a mesh layout by means of a grid, and planting corn and leguminous green manure in the planting belts in an intercropping manner; S2, applying fertilizers including an improver to the planting belts; S3, after the planting and harvesting are completed, crushing the straws of the two crops and returning them to the field; the improver is a carbonized product obtained by chemical treatment using crushed wood chips as raw materials; the planting method of the invention has a good effect on subsequent soil improvement, can effectively improve the soil planting environment, and plays a role in blocking salt and improving fertilizer efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of saline-alkali land soil improvement, and in particular to a planting method for improving moderate saline-alkali land soil. Background Art

[0002] Saline-alkali land is a general term for various salinized and alkaline soils; there are about 9.5×10 8 hm 2 The total area of ​​saline-alkali soil in my country is about 36 million hm2. 2 , accounting for 4.88% of the country's available land area, and growing at an annual rate of 1%. In recent years, its area has tended to expand, and the degree of salinization has continued to intensify. Soil salinization is a bottleneck problem restricting the sustainable development of agriculture. Therefore, taking reasonable and effective measures to control or manage the occurrence of salinized soil is a key issue that needs to be solved urgently.

[0003] The improvement and utilization of saline-alkali land is a long-term and arduous ecological project. Reducing harmful salt in the soil and improving the soil environment required for crop growth and development are the key to the improvement and utilization of saline-alkali land. The improvement of saline-alkali land has always been a global problem. The main improvement methods include hydraulic method, physical method, chemical method and biological method. The hydraulic method generally involves establishing a complete irrigation system and a modern drainage system to wash the salt with large-scale irrigation and drain the salt through drainage ditches. The physical method mainly regulates the movement of water and salt in the soil by changing the physical structure of the soil to inhibit soil evaporation and improve the effect of infiltration and salt leaching, including leveling the land, deep plowing and drying, inter-tillage and loosening the soil, raising the terrain, and improving the soil in micro-areas. The chemical method mainly uses improvers to improve the soil structure, accelerate the process of washing salt and alkali from the soil, change the soluble base components, increase the base exchange capacity, and adjust the soil pH. Biological improvement mainly involves afforestation, planting forage grass, cultivating salt-tolerant plants, and using microbial fertilizers. Planting salt-tolerant plants uses biological drainage to reduce underground Water level, improve surface coverage, reduce ground evaporation, prevent salt accumulation on the soil surface, use the effect of irrigation water and plant roots to control soil salinity in the soil below the soil layer with a large number of plant roots, and then fertilize the soil through reasonable crop rotation during the planting process; among them, water conservancy improvement requires the construction of a large-scale drainage and irrigation system, which requires large investment and long cycle; physical improvement methods require the use of large-scale machinery and equipment, frequent soil turning, and large engineering workload; chemical improvement methods are costly, and long-term application may produce toxic side effects; biological methods can improve soil quality, increase land productivity, and have less negative impact on the environment. It is a sustainable method for improving saline-alkali land, but the improvement effect is not obvious. Summary of the invention

[0004] In view of the above problems, the present invention provides a planting method for improving soil in moderate saline-alkali land.

[0005] The purpose of the present invention is achieved by the following technical solutions:

[0006] A planting method for improving moderate saline-alkali soil, comprising the following steps:

[0007] S1. Planting

[0008] The planting area is divided into a plurality of planting belts in a mesh layout by a grid, and corn and legume green manure are planted in the planting belts in an intercropping manner in the same row, and one crop is planted in each planting belt, that is, for each planting belt, another crop is planted in the planting belts on its four sides, and the above four sides refer to the two sides in the extension direction of the planting row and the two sides in the direction perpendicular to the extension direction of the planting row, that is: when corn is planted in one of the planting belts, legume green manure is planted in the planting belts on its four sides (if there is a planting belt on the corresponding side); when legume green manure is planted in one of the planting belts, corn is planted in the planting belts on its four sides (if there is a planting belt on the corresponding side);

[0009] S2. Fertilization

[0010] Fertilizer is applied to the planting belt, wherein the fertilizer includes an improver, and the preparation method of the improver includes the following steps:

[0011] (1) Soaking wood chips in a mixed solution of sodium hydroxide and sodium bisulfite, keeping warm and stirring at 70-90° C. for 1-10 hours, filtering out and washing to neutrality after the insulation is completed, and vacuum drying to constant weight to obtain a pre-treated product;

[0012] (2) placing the pre-treated product in a flowing protective gas for pre-carbonization and carbonization in sequence, washing the carbonized product with deionized water, vacuum drying to constant weight, and then thermally activating it in a carbon dioxide gas flow;

[0013] (3) mixing the activated product with carbon nitride nanosheets and zinc metal powder, annealing for 2-4 hours in a flowing protective gas, and acid washing to obtain the improver;

[0014] S3. Returning the land to the fields

[0015] After planting and harvesting, the straw of the two crops will be crushed and returned to the field. The straw can be crushed and returned to the field by a straw picking and crushing machine. The two types of crushed straw can be mixed during the picking and crushing process, which has a better mixing effect. The crushed straw can be subsequently turned over to keep the straw in the soil for degradation, thereby improving the moderately saline-alkali soil. The straw picking, crushing and turning operations can be completed by the same machine.

[0016] In some preferred embodiments, the planting belts are distributed in a single-row strip shape, each of the planting belts occupies only one planting row, and each planting belt contains multiple corresponding crops. When planting, each time a planting row is changed, the crop arrangement method is switched once, and the crop distributions of two adjacent planting rows are staggered.

[0017] In some preferred embodiments, the planting belts are distributed in multiple rows and blocks, each of the planting belts spans multiple planting rows, and the planting belts have multiple corresponding crops on each of the planting rows. Each planting belt is a multi-row planting area, that is, when planting, multiple planting rows are planted according to one crop arrangement method, and the crop arrangement method is changed once. This layout can facilitate multi-row harvesting by the harvester.

[0018] In some preferred embodiments, the length of the legume green manure planting belt is equal to the length of the corn planting belt, wherein the length of the planting belt is the extension distance of the planting belt in the direction parallel to the planting row; since corn is taller and legume crops are shorter, by making the length of the legume green manure planting belt equal to the length of the corn planting belt, it can be ensured that there are sufficient gaps in the planting area for ventilation, and the shading of corn to legume crops can be reduced, thereby ensuring the photosynthesis of legume crops.

[0019] In some preferred embodiments, a plurality of ridges arranged in parallel are distributed in the planting area, each of the ridges has a plurality of planting rows, the row spacing between the planting rows on the same ridge is 40-60 cm, and the spacing between the two closest planting rows between two adjacent ridges is 70-90 cm, which can facilitate drainage.

[0020] In some preferred embodiments, the concentration of the sodium hydroxide in the mixed solution of step (1) is 1-3 mol / L, and the concentration of the sodium sulfite is 1-2 mol / L.

[0021] In some preferred embodiments, the pre-carbonization temperature in step (2) is 200-300°C, and the pre-carbonization insulation time is 2-6 hours; the carbonization temperature is 800-1000°C, and the carbonization insulation time is 4-8 hours.

[0022] In some preferred embodiments, the thermal activation temperature in step (2) is 700-800° C., and the thermal activation time is 1-2 h.

[0023] In some preferred embodiments, the mass ratio of the activated product in step (3) to the carbon nitride nanosheets and the zinc metal powder is 10:(2-5):(0.1-1).

[0024] In some preferred embodiments, the annealing temperature in step (3) is 700-800° C., and the heating rate is 1-4° C. / min.

[0025] The beneficial effects of the present invention are:

[0026] (1) After the first crop is planted and harvested, the straw of leguminous green manure and corn is crushed, mixed and turned over to quickly fertilize the soil, play a role in salt blocking and fertilizing, effectively improve the fertilizer efficiency of saline-alkali land, and lay a good foundation for the planting of the next crop; compared with the existing interlaced planting method, the planting method of the present invention has a better effect on subsequent soil improvement, and the ventilation effect and photosynthesis effect are also significantly improved.

[0027] (2) The planting method of the present invention also has the following advantages: 1) A combination of tall and short trees to maximize photosynthetic utilization efficiency; 2) Increasing corn sowing density and dense planting to ensure corn yield; 3) Compared with the traditional interlaced compound planting model, the network-like interlaced planting method of the present invention can better achieve inter-row ventilation and light transmission; 4) Improving stress resistance: multiple corns grow together, which greatly improves the ability to resist lodging.

[0028] (3) By combining biological and chemical methods, harmful salts in the soil are effectively reduced and the soil environment required for crop growth and development is improved. The present invention uses waste wood chip biomass as raw material, first removes lignin and hemicellulose therein through chemical treatment, increases the pore structure of the wood raw material, and then uses carbon dioxide gas for surface activation after carbonization. Then, graphite phase carbon nitride is used as a nitrogen-rich precursor to generate nitride products on the carbonization product and its pore surface. The nitride products can effectively adsorb and store harmful salts in the soil, improve the soil planting environment, and promote the planting and survival of corn and leguminous crops. Combined with the efficient intercropping method of the present invention, crop straw is used for soil fertilization to play a role in salt blocking and improving fertilizer efficiency, effectively promoting the improvement of saline-alkali land. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention is further described using the accompanying drawings, but the embodiments in the accompanying drawings do not constitute any limitation to the present invention. A person skilled in the art can obtain other drawings based on the following drawings without creative work.

[0030] Figure 1 is a planting schematic diagram of the intercropping method according to Example 1 of the present invention, where circles and crosses represent different crops respectively;

[0031] Figure 2 This is a planting diagram of the intercropping method described in Example 2 of the present invention, where A1 and A2 represent different planting zones. DETAILED DESCRIPTION

[0032] The present invention is further described in conjunction with the following examples.

[0033] Example 1

[0034] A planting method for improving moderate saline-alkali soil, comprising the following steps:

[0035] S1. Planting

[0036] The planting area is divided into a plurality of planting belts in a mesh layout by a grid, and the planting belts are distributed in a single row strip, and corn and legume green manure are planted in the planting belts in an intercropping manner in the same row, and one crop is planted in each planting belt, that is, for each planting belt, another crop is planted in the planting belts on its four sides, and the above-mentioned four sides refer to the two sides in the extension direction of the planting row and the two sides in the direction perpendicular to the extension direction of the planting row, that is: when corn is planted in one of the planting belts, legume green manure is planted in the planting belts on its four sides (if there is a planting belt on the corresponding side); when legume green manure is planted in one of the planting belts, corn is planted in the planting belts on its four sides (if there is a planting belt on the corresponding side), each of the planting belts occupies only one planting row, and each planting belt contains multiple corresponding crops, and when planting, each time a planting row is changed, the crop arrangement method is switched once, and the crop distribution of two adjacent planting rows is staggered;

[0037] The leguminous green manure can be astragalus, sweet potato, cowpea, Astragalus, alfalfa, clover, tamarind, pea, mung bean, Sesbania, etc., and the present embodiment is alfalfa;

[0038] S2. Fertilization

[0039] Fertilizers were applied to the planting belts. Corn was routinely fertilized with water-soluble fertilizers for corn, and soybeans were not fertilized. At the same time, an improver was also applied to the planting belts. The amount of the improver applied was 160 kg / hm 2 , the preparation method of the improver comprises the following steps:

[0040] (1) Soaking poplar wood chips in a mixed solution of sodium hydroxide and sodium bisulfite, keeping warm and stirring at 85° C. for 6 hours, filtering out and washing to neutrality after the insulation is completed, and vacuum drying to constant weight to obtain a pre-treated product; the concentration of sodium hydroxide in the mixed solution is 1.5 mol / L, and the concentration of sodium sulfite is 2 mol / L;

[0041] (2) placing the pre-treated product in a flowing protective gas for pre-carbonization and carbonization in sequence, washing the carbonized product with deionized water, vacuum drying to constant weight, and then thermally activating it in a carbon dioxide gas flow; the pre-carbonization temperature is 260° C., and the pre-carbonization holding time is 4 hours; the carbonization temperature is 900° C., and the carbonization holding time is 6 hours; the thermal activation temperature is 760° C., and the thermal activation time is 1.5 hours;

[0042] (3) mixing the activated product with carbon nitride nanosheets and zinc metal powder, annealing in a flowing protective gas for 3 hours, and acid washing to obtain the improver; the mass ratio of the activated product to the carbon nitride nanosheets and the zinc metal powder is 10:3.4:0.4; the annealing temperature is 720°C, and the heating rate is 2°C / min;

[0043] S3. Returning the land to the fields

[0044] After the first crop is planted and harvested, the straw of leguminous green manure and corn are crushed, mixed and turned over. The two kinds of crushed straw can be mixed in the process of picking up and crushing, and the mixing effect is better. The straw picking up, crushing and turning over are completed by the same machine, so that the straw is kept in the soil for degradation, and the soil can be fertilized quickly, which has the effect of blocking salt and fertilizing, effectively improving the fertilizer efficiency of saline-alkali land, and laying a good foundation for the planting of the next crop. The above planting method has the following advantages: 1) matching high and short to maximize photosynthetic utilization efficiency; 2) increasing corn sowing density and dense planting to ensure corn yield; 3) compared with the traditional interlaced composite planting mode, the network-like interlaced planting method of the present invention can better achieve ventilation and light transmission between rows; 4) improving stress resistance: multiple corns grow together, which greatly improves the ability to resist lodging.

[0045] Compared with the existing alternate-row interlaced planting method, the above-mentioned interlaced planting method has a better effect on subsequent soil improvement, and the ventilation effect and photosynthesis effect are also significantly improved.

[0046] Example 2

[0047] A planting method for improving moderate saline-alkali soil, comprising the following steps:

[0048] S1. Planting

[0049] The planting area is divided into multiple planting belts in a mesh layout by a grid. The planting belts are distributed in multiple rows and blocks. Corn and leguminous green manure are planted in the planting belts in an intercropping manner. One crop is planted in each planting belt, that is, for each planting belt, another crop is planted in the planting belts on its four sides. Each planting belt spans multiple planting rows, and each planting belt has multiple corresponding crops on each planting row. In this embodiment, each planting belt is a multi-row planting area, that is, when planting, multiple planting rows are planted according to a crop arrangement method, and the crop arrangement method is changed once;

[0050] The leguminous green manure is the same as that in Example 1;

[0051] A plurality of ridges arranged in parallel are distributed in the planting area, each of the ridges has a plurality of planting rows, the row spacing of the planting rows on the same ridge is 50 cm, and the spacing between the two closest planting rows in two adjacent ridges is 80 cm;

[0052] S2. Fertilization

[0053] Fertilizers were applied to the planting belts. Corn was routinely fertilized with water-soluble fertilizers for corn, and soybeans were not fertilized. At the same time, an improver was also applied to the planting belts. The amount of the improver applied was 160 kg / hm 2 , the preparation method of the improver comprises the following steps:

[0054] (1) Soaking poplar wood chips in a mixed solution of sodium hydroxide and sodium bisulfite, keeping warm and stirring at 85° C. for 6 hours, filtering out and washing to neutrality after the insulation is completed, and vacuum drying to constant weight to obtain a pre-treated product; the concentration of sodium hydroxide in the mixed solution is 1.5 mol / L, and the concentration of sodium sulfite is 2 mol / L;

[0055] (2) placing the pre-treated product in a flowing protective gas for pre-carbonization and carbonization in sequence, washing the carbonized product with deionized water, vacuum drying to constant weight, and then thermally activating it in a carbon dioxide gas flow; the pre-carbonization temperature is 260° C., and the pre-carbonization holding time is 4 hours; the carbonization temperature is 900° C., and the carbonization holding time is 6 hours; the thermal activation temperature is 760° C., and the thermal activation time is 1.5 hours;

[0056] (3) mixing the activated product with carbon nitride nanosheets and zinc metal powder, annealing in a flowing protective gas for 3 hours, and acid washing to obtain the improver; the mass ratio of the activated product to the carbon nitride nanosheets and the zinc metal powder is 10:3.4:0.4; the annealing temperature is 720°C, and the heating rate is 2°C / min;

[0057] S3. Returning the land to the fields

[0058] After the first crop is planted and harvested, the straw of leguminous green manure and corn are crushed, mixed and turned over. The two kinds of crushed straw can be mixed during the picking and crushing process, and the mixing effect is better. The straw picking, crushing and turning over are completed by the same machine, so that the straw remains in the soil for degradation, which can quickly fertilize the soil, play a salt-blocking and fertilizing effect, effectively improve the fertilizer efficiency of saline-alkali land, and lay a good foundation for the planting of the next crop.

[0059] Example 3

[0060] A planting method for improving moderate saline-alkali soil, which is the same as Example 1, except that the preparation method of the improver comprises the following steps:

[0061] (1) placing poplar wood chips in a flowing protective gas for pre-carbonization and carbonization in sequence, washing the carbonized product with deionized water, vacuum drying to constant weight, and then thermally activating it in a carbon dioxide gas flow; the pre-carbonization temperature is 260° C., and the pre-carbonization holding time is 4 hours; the carbonization temperature is 900° C., and the carbonization holding time is 6 hours; the thermal activation temperature is 760° C., and the thermal activation time is 1.5 hours;

[0062] (2) mixing the activated product with carbon nitride nanosheets and zinc metal powder, annealing in a flowing protective gas for 3 hours, and acid washing to obtain the improver; the mass ratio of the activated product to the carbon nitride nanosheets and the zinc metal powder is 10:3.4:0.4; the annealing temperature is 720°C, and the heating rate is 2°C / min;

[0063] Example 4

[0064] A planting method for improving moderate saline-alkali soil, which is the same as Example 1, except that the preparation method of the improver comprises the following steps:

[0065] (1) Soaking poplar wood chips in a mixed solution of sodium hydroxide and sodium bisulfite, keeping warm and stirring at 85° C. for 6 hours, filtering out and washing to neutrality after the insulation is completed, and vacuum drying to constant weight to obtain a pre-treated product; the concentration of sodium hydroxide in the mixed solution is 1.5 mol / L, and the concentration of sodium sulfite is 2 mol / L;

[0066] (2) placing the pre-treated product in a flowing protective gas for pre-carbonization and carbonization in sequence, washing the carbonized product with deionized water, vacuum drying to constant weight, and then thermally activating it in a carbon dioxide gas flow, and obtaining the improver after cooling; the pre-carbonization temperature is 260° C., and the pre-carbonization holding time is 4 hours; the carbonization temperature is 900° C., and the carbonization holding time is 6 hours; the thermal activation temperature is 760° C., and the thermal activation time is 1.5 hours.

[0067] Example 5

[0068] A planting method for improving moderate saline-alkali soil, which is the same as Example 1, except that the preparation method of the improver comprises the following steps:

[0069] (1) Soaking poplar wood chips in a mixed solution of sodium hydroxide and sodium bisulfite, keeping warm and stirring at 85° C. for 6 hours, filtering out and washing to neutrality after the insulation is completed, and vacuum drying to constant weight to obtain a pre-treated product; the concentration of sodium hydroxide in the mixed solution is 1.5 mol / L, and the concentration of sodium sulfite is 2 mol / L;

[0070] (2) placing the pre-treated product in a flowing protective gas for pre-carbonization and carbonization in sequence, washing the carbonized product with deionized water, vacuum drying to constant weight, and then thermally activating it in a carbon dioxide gas flow; the pre-carbonization temperature is 260° C., and the pre-carbonization holding time is 4 hours; the carbonization temperature is 900° C., and the carbonization holding time is 6 hours; the thermal activation temperature is 760° C., and the thermal activation time is 1.5 hours;

[0071] (3) The activated product is mixed with carbon nitride nanosheets, annealed in a flowing protective gas for 3 hours, and the improver is obtained after pickling; the mass ratio of the activated product to the carbon nitride nanosheets is 10:3.4; the annealing temperature is 720°C, and the heating rate is 2°C / min.

[0072] Example 6

[0073] A planting method for improving moderate saline-alkali soil, which is the same as Example 1, except that the improver is not applied to the planting belt.

[0074] Experimental example

[0075] The yield and quality of corn and alfalfa crops grown using the planting methods described in Examples 1-6 were tested, and the soil salinity before planting and after the first-phase crop planting and harvesting was also tested. The test results are shown in Table 1-2.

[0076] Table 1 Yield and quality of corn and alfalfa

[0077]

[0078] Table 2 Soil salinity before and after planting

[0079] Before planting Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 pH 9.80 8.84 8.85 9.18 9.58 8.97 9.64 Water soluble salt (g / kg) 2.21 0.90 0.87 1.12 1.89 1.21 2.02 EC(us / cm) 1853.0 1044.1 988.4 1216.2 1613.0 1414.6 1742.5

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A planting method for improving moderate saline-alkali soil, characterized in that: The following steps are involved: S1. Planting Divide the planting area into a plurality of planting belts in a mesh layout, plant corn and leguminous green manure in the planting belts in an intercropping manner, plant one crop in each planting belt, and plant another crop in the planting belts on the four sides of each planting belt, wherein the four sides refer to the two sides in the extending direction of the planting row and the two sides in the direction perpendicular to the extending direction of the planting row; S2. Fertilization Fertilizer is applied to the planting belt, wherein the fertilizer includes an improver, and the preparation method of the improver includes the following steps: (1) Soaking wood chips in a mixed solution of sodium hydroxide and sodium sulfite, keeping warm and stirring at 70-90° C. for 1-10 hours, filtering out and washing to neutrality after the insulation is completed, and vacuum drying to constant weight to obtain a pre-treated product; (2) placing the pre-treated product in a flowing protective gas for pre-carbonization and carbonization in sequence, washing the carbonized product with deionized water, vacuum drying to constant weight, and then thermally activating it in a carbon dioxide gas flow; (3) mixing the activated product with carbon nitride nanosheets and zinc metal powder, annealing in a flowing protective gas for 2-4 hours, and acid washing to obtain the improver; S3. Returning the land to the fields After planting and harvesting, the straw of both crops will be crushed and returned to the fields.

2. A planting method for improving moderate saline-alkali soil according to claim 1, characterized in that: The planting belts are distributed in a single-row strip shape, each of the planting belts occupies only one planting row, and each planting belt contains a plurality of corresponding crops.

3. A planting method for improving moderate saline-alkali soil according to claim 1, characterized in that: The planting belts are distributed in blocks of multiple rows, each of the planting belts spans across multiple planting rows, and each of the planting belts has multiple corresponding crops on each of the planting rows.

4. A planting method for improving moderate saline-alkali soil according to claim 1, characterized in that: The length of the leguminous green manure planting belt is equal to the length of the corn planting belt, wherein the length of the planting belt is the extension distance of the planting belt in the direction parallel to the planting row.

5. A planting method for improving moderate saline-alkali soil according to claim 1, characterized in that: A plurality of ridges arranged in parallel are distributed in the planting area, each of the ridges has a plurality of planting rows, the row spacing between the planting rows on the same ridge is 40-60 cm, and the spacing between the two closest planting rows between two adjacent ridges is 70-90 cm.

6. A planting method for improving moderate saline-alkali soil according to claim 1, characterized in that: The concentration of the sodium hydroxide in the mixed solution of step (1) is 1-3 mol / L, and the concentration of the sodium sulfite is 1-2 mol / L.

7. A planting method for improving moderate saline-alkali soil according to claim 1, characterized in that: In step (2), the pre-carbonization temperature is 200-300° C., and the pre-carbonization insulation time is 2-6 hours; the carbonization temperature is 800-1000° C., and the carbonization insulation time is 4-8 hours.

8. A planting method for improving moderate saline-alkali soil according to claim 1, characterized in that: The thermal activation temperature in step (2) is 700-800° C., and the thermal activation time is 1-2 h.

9. A planting method for improving moderate saline-alkali soil according to claim 1, characterized in that: The mass ratio of the activated product in step (3) to the carbon nitride nanosheets and the zinc metal powder is 10:(2-5):(0.1-1).

10. A planting method for improving moderate saline-alkali soil according to claim 1, characterized in that: The annealing temperature in step (3) is 700-800°C, and the heating rate is 1-4°C / min.

Images