A method for improving soda saline-alkali soil using citrus waste.

Abstract

The present application belongs to the technical field of saline-alkali soil improvement, and particularly relates to a method for improving soda saline-alkali soil by using citrus orange and tangerine waste, comprising the following steps: S1, crushing the collected citrus orange and tangerine waste and performing solid-liquid separation to obtain pretreated waste liquid A and pretreated waste residue B respectively; S21, obtaining an improvement liquid by treating the pretreated waste liquid A, and irrigating the improvement liquid to the saline-alkali soil; S22, obtaining an improvement fertilizer by treating the pretreated waste residue B, and laying the improvement fertilizer on the ground of the saline-alkali soil; and S3, planting crops after rotary plowing the saline-alkali soil. The present application uses citrus orange and tangerine fruit drop and other waste as improvement material, realizes secondary utilization of agricultural waste, is easy to collect, low in cost and pollution-free, utilizes the rich organic acid therein to improve the saline-alkali soil, and is a green and efficient soil improvement method.

Description

Technical Field

[0001] This invention belongs to the field of saline-alkali land improvement technology, specifically relating to a method for improving soda saline-alkali soil using citrus waste. Background Technology

[0002] Soda saline-alkali soils are mainly composed of sodium carbonate and sodium bicarbonate. The soil colloids are highly dispersed, expanding, dispersing, and becoming muddy when wet, and shrinking, compacting, and hardening when dry. Water permeability is extremely poor, making salt leaching difficult and hindering vegetation emergence and growth. The high soil alkalinity, high pH value, and high sodium content cause ion toxicity, limiting nutrient availability. These major obstacles of soda saline-alkali soils have seriously restricted the sustainable development of local agriculture.

[0003] The main measures for improving soda saline-alkali land at home and abroad include engineering, physical, chemical and biological methods. Among all the improvement methods, applying organic material amendments is a commonly used and quick method that is widely used in actual production. However, organic material amendments often contain livestock and poultry manure and antibiotics, which can lead to secondary soil pollution. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a method for improving soda saline-alkali soil using citrus waste. This invention uses fallen citrus fruits and other waste as improvement materials, realizing the secondary utilization of agricultural waste. It is easy to collect, low-cost, and pollution-free. The organic acids contained in the waste are used to improve saline-alkali land, making it a green and efficient soil improvement method.

[0005] The specific technical solution adopted in this invention is as follows:

[0006] 1. A method for improving soda-saline-alkali soil using citrus waste, comprising the following steps:

[0007] S1. The collected citrus waste is crushed and separated into solid and liquid components to obtain pretreated waste liquid A and pretreated waste residue B.

[0008] S211. Sterilize the pretreated waste liquid A, and dilute the sterilized pretreated waste liquid A with water at a weight ratio of 1:50-100 to obtain the improved solution.

[0009] S212. Irrigate the improved solution onto the saline-alkali land;

[0010] S221. Place the pretreated waste residue B and lactic acid bacteria solution into a fermentation tank, then seal the fermentation tank and ferment for 3-5 days to obtain a slurry-like fermentation liquid.

[0011] S222. Mix the fermentation liquid with the skeleton material to obtain a solid-liquid mixture improved fertilizer;

[0012] S223. Apply the improved fertilizer to the saline-alkali land surface;

[0013] S3. Crops can be planted after rotary tilling of saline-alkali land.

[0014] Furthermore, the irrigation described in step S212 is divided into two parts. The first irrigation uses 60-70% of the soil amendment solution. After the first irrigation, the saline-alkali land is left to dry for 2-3 days before the second irrigation is carried out. After the second irrigation, the surface soil of the saline-alkali land reaches 45-55% of its maximum water holding capacity.

[0015] Furthermore, the improved solution described in step S212 penetrates to a depth of 45-50 cm in the saline-alkali land.

[0016] Furthermore, the depth of rotary tillage of saline-alkali land in step S3 is 15-20 cm below the surface of the saline-alkali land.

[0017] Furthermore, the preparation method of the lactic acid bacteria acid solution in step S221 includes the following steps: take wheat bran, urea, water, and modified solution, mix and stir them in a mass ratio of (5-15):(1-5):(3-10):(0.3-0.5), then add lactic acid bacteria and stir evenly, and ferment at 20-40℃ for 2-3 days to obtain the lactic acid bacteria acid solution.

[0018] Furthermore, the skeleton material mentioned in step S222 includes shredded straw.

[0019] The beneficial effects of this invention are:

[0020] 1. This invention uses fallen citrus fruits and other waste materials as improvement materials, realizing the secondary utilization of agricultural waste. It is easy to collect, low-cost and pollution-free. It utilizes the rich organic acids in the waste to improve saline-alkali land, which is a green and efficient soil improvement method.

[0021] Citrus waste is rich in complex low-molecular-weight organic acids and orange oil. The complex low-molecular-weight organic acids can neutralize the alkalinity of soda-alkali soil, achieving acid-base balance. They can also break down sodium ions in soda-alkali soil, dissolving them in water and leaching them into the upper soil layer, thus reducing the harm of high concentrations of sodium ions to crop growth. At the same time, organic acids can also flocculate and aggregate soil colloids, improving soil structure. Orange oil not only has strong insecticidal and bactericidal functions, but it can also change the micro-aggregate structure of the soil, making the soil loose, porous, and more breathable, which is beneficial for soil desalination and inhibiting salt reversion.

[0022] In addition, the citrus waste improvement material in this invention contains a large amount of soluble sugars (fructose, glucose and sucrose), which not only play a necessary role in binding the soil, but also provide sufficient nutrition for soil microorganisms, improve the composition and activity of soil microorganisms, and play an important role in reducing soil bulk density and improving structure.

[0023] 2. The method for improving saline-alkali land in this invention adopts a step-by-step, simultaneous approach (e.g., Figure 1 As shown in the figure, traditional methods for improving saline-alkali land using citrus waste to make soil conditioners generally fall into two categories. One method involves crushing the citrus waste and fermenting it together, then using the fermented liquid as a soil conditioner. However, the fermentation process destroys complex low-molecular-weight organic acids and orange oil, resulting in resource waste. The second method involves directly using the pulp from crushed citrus waste as a soil conditioner. However, since citrus waste includes fruit pulp, it is relatively easy to rot, and direct application to the soil can easily breed bacteria.

[0024] Therefore, this invention first employs a solid-liquid separation method to divide citrus waste into two parts: pre-treated waste liquid A and pre-treated waste residue B. Pre-treated waste liquid A is rich in complex low-molecular-weight organic acids and orange oil, among other substances. The pre-treated waste liquid A is directly diluted to form an improved solution, which is then injected deep into saline-alkali soil. This not only delays the volatilization of organic acids but also benefits the stability of organic acids and orange oil due to the lower temperature at the depths of the saline-alkali soil, preventing their decomposition by high temperatures or sunlight. Simultaneously, the improved solution is prepared by fermenting the pre-treated waste residue B. Because pre-treated waste residue B contains… Because it contains a large amount of sugar, its fermentation liquid is a relatively viscous slurry. The fermentation liquid is then mixed with shredded straw to form a modified fertilizer similar to straw-mixed fertilizer. This modified fertilizer is then spread on the surface of saline-alkali land. Finally, by rotary tillage, the modified fertilizer on the surface is evenly mixed with the modified liquid in the deeper layers, that is, the pre-treated waste liquid A and the pre-treated waste residue B are combined into one. The slurry-like modified fertilizer with a skeleton, together with the soil, encapsulates the modified liquid. This can not only play a role in flocculating and agglomerating soil colloids and improving soil structure, but also allow the straw to absorb the modified liquid and fermentation liquid, thus playing a certain role in slow release.

[0025] 3. In this invention, the soil amendment solution is applied in two stages. The first stage involves applying most of the amendment solution to neutralize the acid and alkali in the saline-alkali soil. However, some salt will rise and accumulate on the soil surface, resulting in salt return. Therefore, after the first irrigation with the amendment solution, the soil is left to dry for a period of time before the second irrigation with the amendment solution is carried out. This can neutralize and leach the small amount of alkali in the upper layer of the saline-alkali soil, thereby ensuring that the acidity and alkalinity of the crop planting area are suitable, which is conducive to the survival of the crops.

[0026] 4. The rotary tillage area of ​​saline-alkali land is the physical rotary tillage planting layer (15-20cm), and the part below the rotary tillage area where the soil amendment solution has penetrated is the chemical neutralization buffer layer (20-50cm). The physical rotary tillage planting layer, through rotary tillage and the action of straw, can loosen the soil, increase porosity, and improve soil respiration. The chemical neutralization buffer layer, because it is not rotary tilled, has lower soil permeability, which can reduce soil transpiration and delay the volatilization of organic acids, which is conducive to the long-term improvement of saline-alkali land. At the same time, the rotary tillage layering of saline-alkali land can block the capillary water from transporting salt to the surface, thereby inhibiting evaporation and salt return, which is beneficial to crop growth. Attached Figure Description

[0027] Figure 1 This is a flowchart of the method framework of the present invention. Detailed Implementation

[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. I. Specific Implementation Methods

[0030] Example

[0031] S1. The collected citrus waste is crushed and separated into solid and liquid components to obtain pretreated waste liquid A and pretreated waste residue B.

[0032] S211. Sterilize the pretreated waste liquid A, and dilute the sterilized pretreated waste liquid A with water at a weight ratio of 1:80 to obtain the improved solution.

[0033] S212. Irrigate the improved solution to the saline-alkali land. First, flood each mu of saline-alkali land with 80 cubic meters of improved solution. After drying for 3 days, flood each mu of saline-alkali land with another 40 cubic meters of improved solution.

[0034] S221. Place the pretreated waste residue B and lactic acid bacteria solution into a fermentation tank, then seal the fermentation tank and ferment for 4 days to obtain a slurry-like fermentation liquid.

[0035] S222. Mix the fermentation liquid with the shredded straw to obtain a solid-liquid mixed improved fertilizer.

[0036] S223. Apply the improved fertilizer to the surface of the saline-alkali land, with 1500 kg of improved fertilizer applied per mu of saline-alkali land;

[0037] S3. Till the saline-alkali land to a depth of 20cm, and then crops can be planted.

[0038] Comparative Example

[0039] S1. Crush the collected citrus waste, then put the resulting solid-liquid mixture into a fermentation tank, seal the fermentation tank and ferment for 3-5 days to obtain a pulpy citrus waste improvement material.

[0040] S2. Use flood irrigation to irrigate saline-alkali land, with 100 cubic meters of water per mu of saline-alkali land, and let it dry for 3 days;

[0041] S3. Spread the citrus waste improvement material evenly on the surface of the soda saline-alkali land, using 1500 kg per mu;

[0042] S4. Till the saline-alkali land to a depth of 20cm, and then you can plant crops.

[0043] II. Performance Testing

[0044] An experimental plot was divided into three areas, serving as a blank example, an implementation example, and a comparative example. The blank example was not treated in any way, and its soil parameters were directly measured. The implementation example was improved using the method described in the implementation example, and then its soil parameters were measured. The comparative example was improved using the method described in the comparative example, and then its soil parameters were measured. The measurement results are shown in Tables 1 and 2.

[0045] Since the soil depth range of the sampling is relatively small, the soil parameters in the 10-40cm range of the blank sample show minimal variation. Therefore, the soil parameters in the 10-40cm range of the blank sample are considered to be the same as those in the 10cm range.

[0046] The method for measuring soil parameters in Table 1 is as follows: soil samples are taken in 10cm layers at a depth of 40cm. After the soil is air-dried, a soil solution is extracted at a soil-to-water ratio of 1:5, and the soil ion content and pH value are measured. HCO3- is determined using a dual-indicator titration method. - The content of Na in soil was determined using atomic absorption spectrophotometry. + The content and soil pH value were directly measured using a pH meter.

[0047] The method for measuring soil salinity in Table 2 is as follows: soil samples are taken at a depth of 40 cm, in 10 cm layers. After the soil is air-dried, the soil solution is extracted at a soil-to-water ratio of 1:5, and the soil ion content and pH value are measured. HCO3- is determined using a dual-indicator titration method. - Content, determination of Cl by AgNO3 titration method - Determination of SO4 content by EDTA indirect complexometric titration 2- Soil Ca was determined using atomic absorption spectrophotometry. 2 + Mg 2+ K + and Na + The content of soil salinity is the sum of all anions and cations.

[0048] Table 1

[0049]

[0050] Table 2

[0051]

[0052] As shown in Tables 1-2, the present invention can utilize the complex organic acid components in citrus waste to balance the acid-base balance of soda-alkali soil.

[0053] Meanwhile, the comparison between the examples and the comparative examples shows that in the comparative example, citrus waste was crushed and fermented together, and then the fermented liquid was used as a soil conditioner. The soil conditioner in the comparative example had a generally lower effect on improving soil salinity than the examples. This is because the fermentation process destroys complex low-molecular-weight organic acids and orange oil, thereby reducing the soil salinity improvement capacity.

Claims

1. A method for improving saline-sodic soil using citrus waste, characterized in that, The method comprises the following steps: S1, crushing and solid-liquid separation of the collected citrus orange and tangerine waste to obtain pretreated waste liquid A and pretreated waste residue B; S211, sterilizing the pretreated waste liquid A, and diluting the sterilized pretreated waste liquid A with water at a weight ratio of 1:50-100 to obtain an improved liquid; S212, irrigating the improved liquid to saline-alkali soil; S221, putting the pretreated waste residue B and lactic acid bacteria acid liquid into a fermentation tank, then sealing the fermentation tank and fermenting for 3-5 days to obtain a slurry of fermentation liquid; S222, mixing the fermentation liquid with a skeleton material to obtain an improved fertilizer of solid-liquid mixture; S223, laying the improved fertilizer on the ground of saline-alkali soil; S3, rotating the saline-alkali soil to plant crops.

2. The method for improving saline-sodic soil with citrus waste according to claim 1, characterized in that, The irrigation in step S212 is divided into two times, 60-70% of the improved liquid is irrigated the first time, the saline-alkali soil is dried for 2-3 days after the first irrigation, then the second irrigation is performed, and the surface soil of the saline-alkali soil reaches 45-55% of the maximum water holding capacity after the second irrigation is completed.

3. The method for improving saline-sodic soil with citrus waste according to claim 1, characterized in that, The improved liquid in step S212 penetrates to a depth of 45-50 cm underground of the saline-alkali soil.

4. The method for improving saline-sodic soil with citrus waste according to claim 1, characterized in that, The depth of the rotating in step S3 is 15-20 cm underground of the saline-alkali soil.

5. The method for improving saline-sodic soil with citrus waste according to claim 1, characterized in that, The preparation method of the lactic acid bacteria acid liquid in step S221 comprises the following steps: mixing and stirring bran, urea, water and improved liquid in a mass fraction ratio of (5-15):(1-5):(3-10):(0.3-0.5), then adding lactic acid bacteria and stirring uniformly, and fermenting at 20-40°C for 2-3 days to obtain the lactic acid bacteria acid liquid.

6. The method for improving saline-sodic soil with citrus waste according to claim 1, wherein, The skeleton material in step S222 comprises torn straw.

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