Disclosure of Invention
Aiming at the problems, the invention aims to provide a soil conditioner for improving acid soil and a using method and application thereof, wherein boron modified biochar and silkworm excrement organic matter are combined for use, so that the acid-base balance of soil is maintained, the accumulation of the soil available nutrient content is promoted, the soil organic matter content is increased, the bioavailability of soil heavy metal is reduced, and the soil conditioner has obvious effects of promoting the growth and quality of brassica vegetables and reducing the heavy metal content of the vegetables.
The technical content of the invention is as follows:
the invention provides a soil conditioner for improving acid soil, which comprises boron modified biochar and silkworm excrement organic matter;
the preparation method of the boron modified biochar comprises the following steps:
1) preparing bamboo charcoal: taking dried mao bamboo rods and/or mao bamboo withered branches and leaves as raw materials, crushing the raw materials into small sections of 10-20 cm, putting the small sections into a vacuum box type atmosphere furnace, and introducing N 2 Heating to 550-650 ℃ at a speed of 8-12 ℃/min as protective gas, carbonizing at constant temperature for 1.5-2 h, cooling to room temperature, and grinding bamboo charcoal particles with particle sizes of 20-mesh sieve pores;
2) preparation of boron solution: dissolving borax in water to prepare 0.5% -1% boron solution;
3) preparing boron modified biochar: mixing bamboo charcoal, a boron solution and water, carrying out ultrasonic treatment, wherein the ultrasonic frequency is 40-120 KHz, the time is 1.5-2 h, evaporating the mixture obtained by ultrasonic treatment in a water bath, and crushing to obtain boron modified charcoal;
the mixing ratio of the bamboo charcoal, the boron solution and the water is (10-20): 1-2): 25-30);
the bamboo charcoal has the advantages of wide source, large specific surface area, high porosity, rich oxygen-containing functional groups and the like, and can change the existing form of heavy metals by physical and chemical modes such as surface pore adsorption, ion exchange and soil pH change, reduce the mobility and bioavailability of the heavy metals in soil and finally achieve the aims of repairing the heavy metal pollution of the soil and controlling the heavy metal accumulation of plants (such as vegetables). The biochar is usually alkaline and is a good soil conditioner carrier in acid soil, boron can regulate and control the absorption of crops on heavy metals through the influence on processes such as cell wall synthesis, polysaccharide metabolism and the like, and the biochar modified by boron can further improve the soil environment of crop production places and improve the soil quality safety, so that the absorption and accumulation of crops on the soil heavy metals are controlled.
Preparing silkworm excrement organic matters: collecting a mixture of waste silkworm leaf stems, silkworm excrement and padding, wetting the mixture by using water, controlling the humidity to be 35-45%, stacking the mixture into a strip-shaped stack or a circular stack, preferably 1.2-1.5 cm in height, and covering the stack with a straw curtain or plastic cloth; slowly raising the temperature in the stack after 3-5 days, enabling the temperature in the stack to reach 60-70 ℃ after 7-8 days, detecting the temperature and the humidity in time, turning the stack once within 20-25 days, adding water properly as required to preserve moisture, keeping the humidity at 35-45%, promoting the thorough decomposition, after turning the stack, allowing the stack to pass for 20-30 days, completely thoroughly decomposing, and properly crushing after natural air drying to obtain silkworm excrement organic matter particles;
the silkworm excrement is used as excrement discharged by the larvae in the process of silkworm breeding, residual mulberry and padding mixture in a silkworm seat, contains rich nutrient substances and rich microbial flora, is beneficial to improving the soil structure, adjusting the acid-base balance of soil, and can improve the utilization rate of nutrient elements, further effectively promote the growth of crops, improve the biomass of crops, optimize the distribution efficiency of the nutrient elements at each part of the plants and improve the quality of the crops.
The invention also provides a using method of the soil conditioner for the crop producing area, which comprises the following steps: firstly, spreading boron modified biochar particles in soil, turning and mixing uniformly, after 20-40 days, fully adsorbing and stabilizing heavy metals in the soil, then spreading silkworm excrement organic matter particles, controlling the water content of the soil to be 50-65% of the saturated water holding capacity during the use period, and sowing or transplanting the soil after 5 days;
the using amount of the boron modified biochar particles is 25-35 g/kg of soil;
the using amount of the silkworm excrement organic matter particles is 20-60 g/kg of soil.
The invention has the following beneficial effects:
according to the soil conditioner for acid soil, the waste bamboo poles and the withered branches and leaves thereof in the production of silkworm breeding waste silkworm excrement and phyllostachys pubescens forest are used as raw materials, the acid-base balance of soil is maintained through the combined use of boron modified biochar and silkworm excrement organic matters, the accumulation of the content of available nutrients in the soil is promoted, the content of organic matters in the soil is increased, the reduction of the soil nutrient loss and the bioavailability of heavy metals in acid soil in south China is facilitated, and the accumulation of heavy metals in vegetables is effectively reduced;
the application method of the soil conditioner comprises the steps of firstly spreading boron modified biomass charcoal, then spreading silkworm excrement organic matter, and carrying out substrate improvement on soil by using the boron modified bamboo charcoal. The loose and porous property of the biochar can reduce the loss of organic matter nutrients of the silkworm excrement through infiltration and leaching, and the like, and on the premise of ensuring the adsorption and fixation effects of the biochar on heavy metals in soil, the influence of the biochar on the adsorption of nutrients in the silkworm excrement and the insufficient effect exertion when all components are mixed for use at one time is avoided; in addition, the organic fertilizer is applied to acidic heavy metal contaminated soil for planting brassica vegetables, and achieves obvious effects on reducing the heavy metal content of the vegetables, promoting the growth of the brassica vegetables and improving the quality of the brassica vegetables. And the silkworm excrement is derived from silkworm breeding waste, and has important significance for promoting the resource utilization of organic waste and improving the problems of environmental pollution and resource waste caused by agricultural waste in China at present. The invention has obvious improvement effect aiming at the current situation that the acidic boron-deficient soil characteristic and the heavy metal pollution risk of vegetables are higher in south China.
Detailed Description
The present invention is described in further detail in the following description of specific embodiments and the accompanying drawings, it is to be understood that these embodiments are merely illustrative of the present invention and are not intended to limit the scope of the invention, which is defined by the appended claims, and modifications thereof by those skilled in the art after reading this disclosure that are equivalent to the above described embodiments.
All the raw materials and reagents of the invention are conventional market raw materials and reagents unless otherwise specified.
Example 1
Soil conditioner for improving acid soil and use method thereof
1. Preparing boron modified biochar:
1) preparing bamboo charcoal: crushing dried mao bamboo rods and mao bamboo withered branches and leaves into small sections of 10-20 cm, putting the small sections into a vacuum box type atmosphere furnace, and introducing N 2 Heating to 600 deg.C at a speed of 10 deg.C/min as protective gas, carbonizing at constant temperature for 1.5h, cooling to room temperature, and grinding into bamboo charcoal granules with particle size of 20 mesh;
2) preparation of boron solution: dissolving borax in water to prepare 0.8% boron solution;
3) preparing boron modified biochar: mixing the bamboo charcoal, the boron solution and water at a ratio of 10:1:25, carrying out ultrasonic treatment at an ultrasonic frequency of 80kHz for 1.5h, evaporating the mixture obtained by ultrasonic treatment in a water bath, and crushing to obtain boron modified charcoal;
2. preparing silkworm excrement organic matters: collecting a mixture of waste silkworm leaf stalks, silkworm excrement and padding, wetting the mixture by using water, controlling the humidity to be 40%, stacking the mixture into a strip-shaped stack with the height of 1.2-1.5 cm, and covering the stack with straw curtain cloth; slowly raising the temperature in the stack after 3-5 days, and reaching 60-70 ℃ after 7-8 days, detecting the temperature and the humidity in time, turning the stack once within 20 days, adding water properly as required to preserve moisture to promote maturity, turning the stack, and then thoroughly maturing after 20 days, and naturally drying and then properly crushing to obtain silkworm excrement organic matter particles;
3. the using method comprises the following steps: firstly, spreading 30 g/kg of soil boron modified charcoal particles, turning and mixing uniformly, after 30 days, fully adsorbing and stabilizing heavy metals in the soil, then spreading 20 g/kg of soil silkworm excrement organic matter particles, enabling the soil moisture to reach 60% of the saturated water holding capacity in the using process, and sowing or transplanting the soil after 5 days.
Example 2
Soil conditioner for improving acid soil and using method thereof
1. Preparing boron modified biochar:
1) preparing bamboo charcoal: crushing dried mao bamboo rods and mao bamboo withered branches and leaves into small sections of 10-20 cm, putting the small sections into a vacuum box type atmosphere furnace, and introducing N 2 Heating to 550 deg.C at a speed of 8 deg.C/min as protective gas, carbonizing at constant temperature for 1.5h, cooling to room temperature, and grinding into bamboo charcoal granules with particle size of 20 mesh;
2) preparation of boron solution: dissolving borax in water to prepare 0.5% boron solution;
3) preparing boron modified biochar: mixing the bamboo charcoal, the boron solution and water at a ratio of 15:1:25, carrying out ultrasonic treatment at an ultrasonic frequency of 40KHz for 1.5h, evaporating the mixture obtained by ultrasonic treatment in a water bath, and crushing to obtain boron modified charcoal;
2. preparing silkworm excrement organic matters: collecting a mixture of waste silkworm leaf stems, silkworm excrement and padding, wetting the mixture by using water, controlling the humidity to be 35%, stacking the mixture into a strip-shaped stack with the height of 1.2-1.5 cm, and covering the stack with a straw curtain; slowly raising the temperature in the stack after 3-5 days, and reaching 60-70 ℃ after 7-8 days, detecting the temperature and the humidity in time, turning the stack once within 22 days, adding water properly as required to preserve moisture to promote maturity, turning the stack, then thoroughly maturing after 25 days, and naturally drying and then properly crushing to obtain silkworm excrement organic matter particles;
3. the using method comprises the following steps: firstly, spreading 30 g/kg of boron modified biochar particles in soil, turning and uniformly mixing, after 20-40 days, fully adsorbing and stabilizing heavy metals in the soil, then spreading 60g/kg of silkworm excrement organic matter particles in the soil, enabling the water content of the soil to reach 60% of the saturated water holding capacity in the using process, and sowing or transplanting the soil after 5 days.
Example 3
Soil conditioner for improving acid soil and use method thereof
1. Preparing boron modified biochar:
1) bamboo charcoalThe preparation of (1): crushing dried moso bamboo rods into small sections of 10-20 cm, putting the small sections into a vacuum box type atmosphere furnace, and introducing N 2 Heating to 600 deg.C at a speed of 10 deg.C/min as protective gas, carbonizing at constant temperature for 1.8h, cooling to room temperature, and grinding into bamboo charcoal granules with particle size of 20 mesh;
2) preparation of boron solution: dissolving borax in water to prepare 0.5% boron solution;
3) preparing boron modified biochar: mixing the bamboo charcoal, the boron solution and water at a ratio of 15:2:28, carrying out ultrasonic treatment at an ultrasonic frequency of 100KHz for 2h, evaporating the mixture obtained by ultrasonic treatment in a water bath, and crushing to obtain boron modified charcoal;
2. preparing silkworm excrement organic matters: collecting a mixture of waste silkworm leaf stalks, silkworm excrement and padding, wetting the mixture by using water, controlling the humidity to be 35%, stacking the mixture into a circular pile with the height of 1.2-1.5 cm, and covering the circular pile with plastic cloth; after 3-5 days, slowly raising the temperature in the stack, after 7-8 days, enabling the temperature in the stack to reach 60-70 ℃, detecting the temperature and the humidity in time, turning the stack once within 23 days, adding water appropriately as required to preserve moisture to promote maturity, after turning the stack, allowing the stack to be thoroughly decomposed after 25 days, and after natural air drying, appropriately crushing to obtain silkworm excrement organic matter particles;
3. the using method comprises the following steps: firstly spreading 25 g/kg of boron modified biochar particles in soil, turning and uniformly mixing, after 20 days, fully adsorbing and stabilizing heavy metals in the soil, then spreading 30 g/kg of silkworm excrement organic matter particles in the soil, enabling the water content of the soil to reach 50% of the saturated water holding capacity in the using process, and sowing or transplanting the soil after 5 days.
Example 4
Soil conditioner for improving acid soil and use method thereof
1. Preparing boron modified biochar:
1) preparing bamboo charcoal: crushing withered bamboo leaves into small sections of 10-20 cm, putting the small sections into a vacuum box type atmosphere furnace, and introducing N 2 Heating to 650 deg.C at a speed of 12 deg.C/min as shielding gas, carbonizing at constant temperature for 2 hr, cooling to room temperature, and grinding into bamboo biomass with particle size of 20 meshCarbon particles;
2) preparation of boron solution: dissolving borax in water to prepare a 1% boron solution;
3) preparing boron modified biochar: mixing the bamboo charcoal, the boron solution and water at a ratio of 20:2:30, carrying out ultrasonic treatment at an ultrasonic frequency of 120KHz for 2h, evaporating the mixture obtained by ultrasonic treatment in a water bath, and crushing to obtain boron modified charcoal;
2. preparing silkworm excrement organic matters: collecting a mixture of waste silkworm leaf stalks, silkworm excrement and padding, wetting the mixture by using water, controlling the humidity to be 45%, stacking the mixture into a circular pile with the height of 1.2-1.5 cm, and covering the pile with plastic cloth, wherein the height is proper; slowly raising the temperature in the stack after 3-5 days, and reaching 60-70 ℃ after 7-8 days, detecting the temperature and the humidity in time, turning the stack once within 25 days, adding water properly as required to preserve moisture to promote maturity, turning the stack, and then thoroughly maturing after 30 days, and naturally drying and then properly crushing to obtain silkworm excrement organic matter particles;
3. the using method comprises the following steps: firstly spreading 35g/kg of soil boron modified charcoal particles, turning and mixing uniformly, after 40 days, fully adsorbing and stabilizing heavy metals in the soil, then spreading 50 g/kg of soil silkworm excrement organic matter particles, enabling the soil moisture to reach 65% of the saturated water holding capacity in the using process, and sowing or transplanting the soil after 5 days.
Comparative example 1
And (4) blank soil control, wherein boron modified biochar and silkworm excrement organic matters are not added.
Comparative example 2
Comparative example 2 is the control of example 1, with no boron-modified biochar added to the soil conditioner and its method of use, and with no other steps changed.
Comparative example 3
Comparative example 3 is the control group of example 2, the soil conditioner and the method of using the same are not added with boron modified charcoal, and the silkworm excrement is used in an amount 3 times that of comparative example 2, and other steps are not changed.
Comparative example 4
Comparative example 4 is a control of example 1, in which soil conditioner and method of use thereof no silkworm excrement organic matter was added and the other steps were not changed.
The soil treated by the application methods of the embodiment 1, the embodiment 2 and the comparative examples 1-4 is planted with brassica leaf flowering cabbage and pakchoi, after 30 days, the flowering cabbage and pakchoi are subjected to various index detection, and the results are as follows:
as shown in figure 1, compared with the comparative examples, the soil treated by the examples 1 and 2 has obvious effect of adjusting the physicochemical property conditions of the soil, and the organic matter content and the pH value in the soil are improved by the soil treated by the method.
As shown in fig. 2, for the change of the content of the effective state of the heavy metals cadmium and lead in the soil under different treatments, it can be seen that the soil treated by the examples 1 and 2 reduces the content of the effective state of the heavy metals cadmium and lead in the soil and slows down the harm to the planted crops.
As shown in fig. 3, in order to change the biomass of the brassica leaf vegetables and the brassica rapa pekinensis under different treatments, compared with the comparative examples, the soil treated by the examples 1 and 2 is improved due to the soil condition, so that the growth condition of the brassica leaf vegetables (the brassica heart and the brassica pekinensis) is obviously promoted, and the biomass of the edible part of the brassica leaf vegetables planted by the soil treated by the method is obviously increased.
As shown in fig. 4 and 5, in order to change the cadmium content and the lead content in the flowering cabbage and the pakchoi in different treatments, compared with the comparative example, the soil treated in the examples 1 and 2 can effectively control the heavy metal content of the planted brassica leafy vegetables (the flowering cabbage and the pakchoi) and improve the quality safety level of the vegetables.
As shown in fig. 6, 7, 8 and 9, the content of vitamin c (vc), the content of protein, the content of nitrate and the content of nitrite in the cabbage heart and the cabbage were varied according to the different treatments. Therefore, compared with the comparative example, the soil treated by the examples 1 and 2 can effectively control the heavy metal content of brassica leafy vegetables (flowering cabbage and Chinese cabbage) and improve multiple quality indexes of vegetables. The soil treated by the method disclosed by the invention is proved to increase the Vc content and the protein content of the brassica leafy vegetables which are planted, and reduce the nitrate content and the nitrite content.