A method for improving the fertility of newly reclaimed red-yellow soil farmland

Abstract

The present application relates to the technical field of soil improvement, and discloses a method for improving the fertility of newly reclaimed red-yellow soil farmland, comprising the following steps: (1) after the newly reclaimed red-yellow soil farmland is leveled, urea-formaldehyde fertilizer and humic acid fertilizer are applied; (2) composted cow manure or sheep manure organic fertilizer is applied; (3) soil conditioner is applied, the soil conditioner comprising hydroxyl calcium phosphate and silicon sol modified enteromorpha-based biochar, diatomite and calcium-magnesium phosphate fertilizer; (4) liquid fertilizer is applied; steps (1) to (4) need to be carried out several times of turning into the soil respectively, so that the fertilizer is uniformly mixed with the plough layer soil. The present application improves the acid environment of the red-yellow soil by applying different fertilizers in cooperation, increases the organic matter and total nitrogen and other mineral nutrient content of the plough layer soil of the newly reclaimed farmland, achieves the effect of rapidly improving the soil physicochemical properties and increasing the microbial activity, and then fertilizes and improves the newly reclaimed red-yellow soil.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of soil improvement, and in particular to a method for improving the fertility of newly reclaimed red-yellow soil. BACKGROUND

[0002] Red soil is a common soil developed in subtropical and tropical regions, mainly distributed in most areas south of the Yangtze River and mountainous areas around the Sichuan Basin. The climate in these areas is usually warm and rainy, and the source of organic matter is abundant, but it decomposes quickly and is easily lost, so the soil has little humus and the soil is relatively sticky. Due to strong leaching, there is little accumulation of potassium, sodium, calcium and magnesium, but there is a lot of iron and aluminum, and the soil is uniformly red. According to the differences in its formation process, soil composition and properties, it can be further subdivided into the following subtypes: red-yellow soil, red soil, red-yellow sandy soil and red mountain soil.

[0003] Among them, red-yellow soil is a type of soil that is transitional between red soil and yellow soil, with soil color varying between red and red-yellow. The soil-forming process of red-yellow soil is still dominated by desilication and aluminization, with silicon and base leaching, clay and secondary clay minerals forming, and iron and aluminum oxides accumulating. Due to the relatively cool and humid climate conditions in the mountains, the soil and air humidity increases, showing a yellowing process, i.e. the soil gradually turns orange-yellow due to the increase in the crystallization water of oxidized iron in the soil body. However, due to the weak desilication and aluminization, it shows the characteristics of the transition from red soil to yellow soil.

[0004] The invention patent with publication number 115176552A discloses a method for improving the quality of red soil and yellow soil, comprising the following steps: (1) land leveling; (2) laying out lines at a row spacing of 40-60 cm and opening planting trenches; (3) sowing field beans and covering the soil; (4) 10-15 days after the field beans sprout, laying out lines and opening trenches between the two adjacent rows of field beans to plant peanuts; (5) before the peanuts reach the pod-bearing stage and mature, cutting off the aboveground parts of the peanuts to the ground level; (6) before the flowering period of the field beans, harvesting the aboveground parts of the field beans to the ground level and crushing them to obtain field bean crushed segments; (7) along the field bean planting row, digging and burying the field bean crushed segments in the soil. This method can improve the permeability and gas phase space proportion of the surface planting layer of red soil and yellow soil, but the effect of improving soil fertility is not significant, and it requires a long time and a large amount of labor, which cannot achieve the purpose of efficient utilization of the soil the year it is reclaimed. SUMMARY

[0005] In order to solve the above technical problems, the application provides a method for improving the fertility of newly reclaimed red-yellow soil, which comprises the following steps:

[0006] The application achieves the above purposes by the following technical scheme:

[0007] The application provides a method for improving the fertility of newly reclaimed red-yellow soil, which comprises the following steps:

[0008] (1) After the newly reclaimed red-yellow soil is leveled, urea-formaldehyde fertilizer and humic acid fertilizer are applied;

[0009] (2) Matured cow or sheep manure organic fertilizer is applied;

[0010] (3) Soil conditioner is applied, and the soil conditioner comprises hydroxyapatite and silicon sol modified Enteromorpha-based biochar, diatomite and calcium-magnesium phosphate fertilizer;

[0011] (4) Liquid fertilizer is applied;

[0012] The steps (1) to (4) need to be mixed into the soil for several times to mix the fertilizer and the plough layer soil uniformly.

[0013] The humic acid in the humic acid fertilizer is a macromolecular polymer, and the stable organic matter content is high, and the decomposition mineralization rate is slow, so that the organic matter of the low-fertility soil can be rapidly and efficiently increased. The urea-formaldehyde in the urea-formaldehyde fertilizer is a polymer connected with carbon, and has a low salt index, and can provide slow-release nitrogen nutrients. The reliability and safety of the slow-release nitrogen can be consumed by microorganisms as nutrients and energy and gradually released. After the urea-formaldehyde fertilizer is applied to the soil, it can be quickly melted into a colloid and tightly adsorbed and fused by the soil, so that the nutrients can be ensured to be not lost for a long time, and the loss to the environment is small.

[0014] The cow or sheep manure organic fertilizer is the matured livestock and poultry manure of herbivorous animals, has a relatively high carbon content, and is slowly decomposed, so that the organic matter of the red-yellow soil can be effectively improved, and the complete crop effective nutrients and soil beneficial microorganism carbon source can be provided. The combination of the humic acid, the urea-formaldehyde fertilizer and the cow or sheep manure organic fertilizer can balance and slowly mineralize the carbon and nitrogen nutrients, provide excellent carbon source and nitrogen source required for the reproduction of soil microorganisms, create an optimized soil carbon-nitrogen ratio, accelerate the growth and reproduction of beneficial microorganisms in the red-yellow soil, and promote the rapid improvement of the soil fertility.

[0015] The soil conditioner containing silicon, calcium and magnesium can improve the soil acidity and alkalinity, optimize the soil pH environment to meet the growth needs of crops, and provide mineral nutrients such as silicon, calcium and magnesium, so as to accelerate the formation and development of soil aggregate structure of newly reclaimed land.

[0016] Therefore, the present application can reasonably optimize and improve the soil carbon source and nitrogen source by adding humic acid, cow manure, urea-formaldehyde fertilizer and other organic materials with different properties and soil conditioners, adjust the carbon-nitrogen ratio of the soil, improve the acidic environment of red-yellow soil, increase the organic matter and total nitrogen content of the mineral nutrients in the plough layer of newly reclaimed land, and achieve the effects of rapidly improving the soil physical and chemical properties and increasing the microbial activity, thereby fertilizing and improving the newly reclaimed red-yellow soil, promoting the healthy growth of crops and ensuring food safety.

[0017] As a preferred embodiment, the preparation method of the soil conditioner comprises the following steps: dispersing calcium hydroxylphosphate into a water solution containing polyethylene glycol bis-stearate to obtain a mixed solution I; adding the mixed solution I into a silica sol while stirring to obtain a mixed solution II; immersing the Enteromorpha-based biochar into the mixed solution II and standing, and after taking out, first performing anaerobic reaction at 300-400 DEG C for 1-3h, and then performing anaerobic reaction at 500-600 DEG C for 30-50min; mixing and stirring the obtained reaction product with diatomite and calcium-magnesium phosphate fertilizer to obtain the soil conditioner.

[0018] The red-yellow soil has a serious desiliconization and aluminization phenomenon, and the soil conditioner in the present application can supplement calcium, magnesium and other cations, reduce the activity of soil exchangeable Al 3+ , and achieve the purpose of relieving aluminum toxicity. The Enteromorpha-based biochar has more -OH, -COOH and -NH2 functional groups on the surface than other biochars, and the Enteromorpha has high N and P content, so that the soil organic matter content and nutrients can be more effectively improved by adding the Enteromorpha-based biochar into the soil.

[0019] And the Enteromorpha-based biochar is modified by silica sol and calcium hydroxyl phosphate, the added polyethylene glycol distearate can improve the dispersibility and solubility of the calcium hydroxyl phosphate and the silica sol, and has thickening effect, which is beneficial to the loading of the mixed solution on the surface of the Enteromorpha-based biochar, so that the silica sol and the calcium hydroxyl phosphate can be uniformly distributed on the surface of the biochar, and then through high-temperature reaction, the silica sol will be gelatinized and dehydrated and particle agglomeration occurs at high temperature, so that the Si-OH bond is changed into Si-O bond combination, and densification effect is generated, and the generated amorphous silicon dioxide can be slowly released, and the soil can be better provided with silicon elements.

[0020] Therefore, the soil conditioner prepared by the application can effectively supplement the calcium, magnesium and silicon nutrient elements required for plant growth, the diatomite and the calcium-magnesium phosphate fertilizer in the soil conditioner can quickly increase the soil pH and timely improve the soil acidity, and the addition of the modified Enteromorpha-based biochar can better retain the fertilizer and water, and can greatly reduce the activity of soil exchangeable Al 3+ , promote the conversion of soil exchangeable Al 3+ into hydroxyl aluminum ions or the formation of hydroxide precipitate, so as to achieve the purpose of relieving aluminum toxicity, and the silicon element can also improve the absorption of crops to nutrient elements. The modified Enteromorpha-based biochar can keep the slow release of silicon and calcium elements, avoid the phenomenon of soil compaction and "re-acidification" caused by long-term use, reduce the loss to the environment, and maintain the soil fertility.

[0021] Preferably, the added amount of the calcium hydroxyl phosphate is 5-10% of the mass of the aqueous solution containing the polyethylene glycol distearate; and the mass concentration of the aqueous solution containing the polyethylene glycol distearate is 1-2%.

[0022] Preferably, the polyethylene glycol distearate is polyethylene glycol 6000 distearate (PEG6000DS).

[0023] Preferably, the mixing mass ratio of the mixed solution I and the silica sol is 1:4-5; and the mass concentration of the silica sol is 20-30%, calculated based on the content of silicon dioxide.

[0024] Preferably, the heating rate is 1-5℃ / min; and the mass ratio of the reaction product, diatomite and calcium-magnesium phosphate fertilizer is 3-4:1-2:1-2.

[0025] Preferably, the dosage of the soil conditioner is 50-100 kg / mu, and the main indicators are organic matter≥50%, and total nutrient≥4%.

[0026] Preferably, the humic acid fertilizer is applied at a dosage of 2000-6000 kg / mu, and the urea-formaldehyde fertilizer is applied at a dosage of 120-200 kg / mu.

[0027] The application dosages of the humic acid fertilizer and the urea-formaldehyde fertilizer are selected according to the soil fertility level of newly reclaimed farmland.

[0028] Preferably, the preparation method of the urea-formaldehyde fertilizer comprises the following steps: urea and formaldehyde are mixed at a feed molar ratio of 1.2-1.4:1, and polymerization reaction is carried out under alkaline conditions with a pH of 8.5-9.0.

[0029] The alkaline conditions are adjusted by KOH, and the product is weakly alkaline by adding KOH and alkaline environment synthesis process, which helps to improve the pH of red-yellow soil and increase the nutrient content.

[0030] Preferably, the dosage of the cow or sheep manure organic fertilizer is 1.5-3.0 tons / mu.

[0031] Preferably, the liquid fertilizer is a biological fertilizer containing microbial active bacteria, and the microbial active bacteria are inoculated from the long-term cultivated high-fertility farmland soil flora in the vicinity; the dosage of the liquid fertilizer is 10-30 kg / mu.

[0032] Preferably, the soil conditioner is applied 3-8 days after the cow or sheep manure organic fertilizer is applied and mixed with the soil.

[0033] Preferably, the liquid fertilizer is applied 3-8 days after the soil conditioner is applied and mixed with the soil.

[0034] Preferably, the plowing depth of the soil is controlled to 15-25 cm, and the plowing times of each step are 3-5 times.

[0035] Compared with the prior art, the present application has the following beneficial effects:

[0036] (1) By applying humic acid, cow manure, urea-formaldehyde fertilizer and other organic materials with different properties and soil conditioners, the soil carbon and nitrogen sources are reasonably optimized and improved, the soil carbon-nitrogen ratio is adjusted, the acidic environment of red-yellow soil is improved, the organic matter and total nitrogen and other mineral nutrient contents of the plough layer soil of newly reclaimed farmland are increased, the soil physical and chemical properties are rapidly improved, and the microbial activity is increased, thereby improving and improving the newly reclaimed red-yellow soil, promoting the healthy growth of crops, and ensuring food safety.

[0037] (2) The soil conditioner can effectively supplement the calcium, magnesium and silicon nutrient elements required for plant growth. The diatomite and calcium-magnesium phosphate fertilizer in the soil conditioner can quickly increase the pH of the soil and timely improve the soil acidity. In addition, the addition of the modified green algae-based biochar has a better effect of preserving fertilizer and water and can greatly reduce the activity of soil exchangeable Al 3+ , so as to achieve the purpose of relieving aluminum toxicity. DETAILED DESCRIPTION

[0038] The technical solutions of the present application are described below with specific examples, but the protection scope of the present application is not limited thereto.

[0039] In the hilly area of southern Jinhua in Zhejiang, a newly reclaimed low-fertility red-yellow soil farmland was selected, and a 0-20cm plough layer soil sample was collected for analysis of the basic physicochemical properties of the soil to determine the input amount of the fertilization material.

[0040] The preparation of the urea-formaldehyde fertilizer includes the following steps: urea and formaldehyde (37% formaldehyde aqueous solution) are mixed at a feed molar ratio of 1.2-1.4:1, and polymerization is carried out under alkaline conditions, KOH is added to adjust the pH to 8.5-9.0, the reaction temperature is controlled at 55-75℃, and the time is 75-100min.

[0041] The humic acid fertilizer is from Zhejiang Fengyu Ecological Technology Co., Ltd.

[0042] The composted cow or sheep manure organic fertilizer is from Longyou County Wangong Organic Fertilizer Co., Ltd.

[0043] The liquid fertilizer is from Zhejiang Fengyu Ecological Technology Co., Ltd.

[0044] The calcium-magnesium phosphate fertilizer is from Yunnan Gaoyao Fertilizer Co., Ltd.

[0045] Example 1

[0046] (1) The test implementation field is first irrigated with 2-5cm of water, and the surface soil is leveled with a machine so that the surface soil around the farmland has a height difference of not more than 5cm. After the field is leveled, the urea-formaldehyde fertilizer and the humic acid fertilizer are uniformly applied at dosages of 160kg / mu and 2800kg / mu, respectively, and the fertilizers are mechanically tilled into the soil to a depth of 20cm with 3-5 times of rolling, so that the fertilizers are fully mixed and uniformly distributed in the plough layer soil.

[0047] (2) The composted cow or sheep manure organic fertilizer is applied at a dosage of 2.0 tons / mu, and is mechanically tilled into the soil to a depth of 20cm with 3-5 times of rolling, so that the fertilizer is fully mixed and uniformly distributed in the plough layer soil.

[0048] (3) After 5 days when the soil is fully mixed, soil conditioner is applied again, the dosage is 75 kg / mu, and the soil is ploughed into the soil by machine, the ploughing depth of the soil is 20 cm, the ploughing times is 3-5 times, and the soil conditioner is fully mixed with the ploughed soil.

[0049] The preparation of the soil conditioner comprises the following steps: dispersing calcium hydroxyl phosphate into a water solution containing polyethylene glycol 6000 bis-stearate with a mass concentration of 2%, the amount of calcium hydroxyl phosphate added is 8% of the mass of the water solution containing polyethylene glycol 6000 bis-stearate, to obtain mixed solution I; drop the mixed solution I into a silicon sol with a mass concentration of 20% (calculated by the content of silicon dioxide), the mixing mass ratio of the mixed solution I and the silicon sol is 1:4, and stirring is performed at the same time, to obtain mixed solution II; immersing the Enteromorpha-based biochar in the mixed solution II and standing, after taking out, first performing anaerobic reaction at 300℃ for 2h, and then performing anaerobic reaction at 550℃ for 30min; mixing and stirring the obtained reaction product, diatomite and calcium-magnesium phosphate fertilizer with a mass ratio of 4:1:1, to obtain the soil conditioner.

[0050] (4) After 5 days when the soil is fully mixed, liquid fertilizer is applied again, the dosage is 30 kg / mu, and the soil is ploughed into the soil by machine, the ploughing depth of the soil is 20 cm, the ploughing times is 3-5 times, and the fertilizer is fully mixed with the ploughed soil.

[0051] Example 2

[0052] (1) The test implementation field is first irrigated with 2-5 cm of water, and the surface soil is leveled by machine, so that the height difference of the surface soil around the field is not more than 5 cm. After the field is leveled, urea-formaldehyde fertilizer and humic acid fertilizer are uniformly applied, the dosages are 140 kg / mu and 3400 kg / mu respectively, the soil is ploughed into the soil by machine, the ploughing depth of the soil is 20 cm, the ploughing times is 3-5 times, and the fertilizer is fully mixed with the ploughed soil.

[0053] (2) The composted cow manure or sheep manure organic fertilizer is applied, the dosage is 2.0 tons / mu, the soil is ploughed into the soil by machine, the ploughing depth of the soil is 20 cm, the ploughing times is 3-5 times, and the fertilizer is fully mixed with the ploughed soil.

[0054] (3) After 5 days when the soil is fully mixed, soil conditioner is applied again, the dosage is 85 kg / mu, and the soil is ploughed into the soil by machine, the ploughing depth of the soil is 20 cm, the ploughing times is 3-5 times, and the soil conditioner is fully mixed with the ploughed soil.

[0055] The preparation of the soil conditioner comprises the following steps: dispersing calcium hydroxyl phosphate into a polyethylene glycol 6000 bis-stearate-containing aqueous solution with a mass concentration of 2%, the amount of calcium hydroxyl phosphate added is 8% of the mass of the polyethylene glycol 6000 bis-stearate-containing aqueous solution, to obtain a mixed solution I; dropwise adding the mixed solution I into a silica sol (calculated by the content of silicon dioxide) with a mass concentration of 20%, the mixing mass ratio of the mixed solution I and the silica sol is 1:4, and stirring is carried out at the same time, to obtain a mixed solution II; immersing the Enteromorpha-based biochar in the mixed solution II and standing, after taking out, first carrying out anaerobic reaction at 300 DEG C for 2h, and then carrying out anaerobic reaction at 550 DEG C for 30min; mixing and stirring the obtained reaction product, diatomite and calcium-magnesium phosphate fertilizer at a mass ratio of 4:1:1, to obtain the soil conditioner.

[0056] (4) 5 days after the soil is fully mixed, liquid fertilizer is applied again, the amount is 20 kg / mu, and the soil is plowed into the soil by a machine, the plowing depth of the soil is 20 cm, and the plowing frequency is 3-5 times, so that the fertilizer is fully mixed and uniformly mixed with the plowing layer soil.

[0057] Example 3

[0058] (1) The test implementation field is first irrigated with 2-5 cm of water, and the surface soil is leveled by a machine, so that the height difference of the surface soil around the field is not more than 5 cm. After the field is leveled, the urea-formaldehyde fertilizer and the humic acid fertilizer are uniformly applied, the amount is 160 kg / mu and 2800 kg / mu respectively, the soil is plowed into the soil by a machine, the plowing depth of the soil is 20 cm, and the plowing frequency is 3-5 times, so that the fertilizer is fully mixed and uniformly mixed with the plowing layer soil.

[0059] (2) The matured cow manure or sheep manure organic fertilizer is applied, the amount is 2.0 tons / mu, the soil is plowed into the soil by a machine, the plowing depth of the soil is 20 cm, and the plowing frequency is 3-5 times, so that the fertilizer is fully mixed and uniformly mixed with the plowing layer soil.

[0060] (3) 5 days after the soil is fully mixed, the soil conditioner is applied again, the amount is 75 kg / mu, the soil is rotary plowed into the soil by a machine, the rotary plowing depth of the soil is 20 cm, and the plowing frequency is 3-5 times, so that the soil conditioner is fully mixed and uniformly mixed with the plowing layer soil.

[0061] The preparation of the soil conditioner comprises the following steps: dispersing calcium hydroxyl phosphate into a polyethylene glycol bis-stearate-containing aqueous solution with a mass concentration of 2%, the amount of calcium hydroxyl phosphate added is 5% of the mass of the polyethylene glycol bis-stearate-containing aqueous solution, to obtain a mixed solution I; dropwise adding the mixed solution I into a silicon sol (calculated by the content of silicon dioxide) with a mass concentration of 25%, the mixing mass ratio of the mixed solution I and the silicon sol is 1:5, and stirring is performed at the same time, to obtain a mixed solution II; immersing the Enteromorpha-based biochar in the mixed solution II and standing, after taking out, first performing anaerobic reaction at 400 DEG C for 2h, and then performing anaerobic reaction at 550 DEG C for 40min; mixing and stirring the obtained reaction product, diatomite and calcium-magnesium phosphate fertilizer at a mass ratio of 3:1.5:1.5, to obtain the soil conditioner.

[0062] (4) 5 days after the soil is fully mixed, liquid fertilizer is applied again, the amount is 30 kg / mu, and the soil is plowed into the soil, the plowing depth of the soil is 20 cm, the plowing times are 3-5 times, and the fertilizer and the plowing layer soil are fully mixed and uniformly mixed.

[0063] Example 4

[0064] (1) The test implementation field is first irrigated with 2-5 cm of water, the surface soil is leveled with a machine, so that the surface soil around the field has a height difference of not more than 5 cm. After the field is leveled, urea-formaldehyde fertilizer and humic acid fertilizer are uniformly applied, the amounts are 160 kg / mu and 2800 kg / mu respectively, the soil is plowed into the soil, the plowing depth of the soil is 20 cm, the plowing times are 3-5 times, and the fertilizer and the plowing layer soil are fully mixed and uniformly mixed.

[0065] (2) The matured cow manure or sheep manure organic fertilizer is applied, the amount is 2.0 tons / mu, the soil is plowed into the soil, the plowing depth of the soil is 20 cm, the plowing times are 3-5 times, and the fertilizer and the plowing layer soil are fully mixed and uniformly mixed.

[0066] (3) 5 days after the soil is fully mixed, the soil conditioner is applied again, the amount is 75 kg / mu, the soil is rotary plowed into the soil, the rotary plowing depth of the soil is 20 cm, the plowing times are 3-5 times, and the soil conditioner and the plowing layer soil are fully mixed and uniformly mixed.

[0067] The preparation of the soil conditioner comprises the following steps: dispersing calcium hydroxyl phosphate into a polyethylene glycol bis-stearate-containing aqueous solution with a mass concentration of 1%, and the amount of calcium hydroxyl phosphate added is 10% of the mass of the polyethylene glycol bis-stearate-containing aqueous solution, to obtain a mixed solution I; dropwise adding the mixed solution I into a silica sol (calculated by the content of silicon dioxide) with a mass concentration of 20%, and the mixing mass ratio of the mixed solution I and the silica sol is 1:5, while stirring, to obtain a mixed solution II; immersing the Enteromorpha-based biochar in the mixed solution II and standing, and after taking out, first performing anaerobic reaction at 400℃ for 2h, and then performing anaerobic reaction at 500℃ for 50min; mixing and stirring the obtained reaction product, diatomite and calcium-magnesium phosphate fertilizer at a mass ratio of 4:1:1, to obtain the soil conditioner.

[0068] (4) 5 days after the soil is fully mixed, liquid fertilizer is applied at a dosage of 30 kg / mu, and the soil is plowed into the soil, the plowing depth of the soil is 20 cm, and the plowing frequency is 3-5 times, so that the fertilizer is fully mixed and evenly distributed in the plowing layer of the soil.

[0069] Comparative Example 1

[0070] The difference from Example 1 is that no modified biomass charcoal is added in the preparation process of the soil conditioner.

[0071] (1) The test implementation field is first irrigated with 2-5 cm of water, and the surface soil is leveled with a machine, so that the height difference of the surface soil around the field is not more than 5 cm. After the field is leveled, urea-formaldehyde fertilizer and humic acid fertilizer are evenly applied at dosages of 160 kg / mu and 2800 kg / mu respectively, and the soil is plowed into the soil, the plowing depth of the soil is 20 cm, and the plowing frequency is 3-5 times, so that the fertilizer is fully mixed and evenly distributed in the plowing layer of the soil.

[0072] (2) The composted cow manure or sheep manure organic fertilizer is applied at a dosage of 2.0 tons / mu, and the soil is plowed into the soil, the plowing depth of the soil is 20 cm, and the plowing frequency is 3-5 times, so that the fertilizer is fully mixed and evenly distributed in the plowing layer of the soil.

[0073] (3) 5 days after the soil is fully mixed, the soil conditioner is applied at a dosage of 75 kg / mu, and the soil is rotary plowed into the soil, the rotary plowing depth of the soil is 20 cm, and the plowing frequency is 3-5 times, so that the soil conditioner is fully mixed and evenly distributed in the plowing layer of the soil.

[0074] The preparation of the soil conditioner comprises the following steps: mixing and stirring diatomite and calcium-magnesium phosphate fertilizer at a mass ratio of 1:1, to obtain the soil conditioner.

[0075] (4) 5 days after the soil is fully mixed, liquid fertilizer is applied at a dosage of 30 kg / mu, and the soil is plowed into the soil, the plowing depth of the soil is 20 cm, and the plowing frequency is 3-5 times, so that the fertilizer is fully mixed and evenly distributed in the plowing layer of the soil.

[0076] Comparative Example 2

[0077] The difference from Example 1 is that the biochar is not modified during preparation of the soil conditioner.

[0078] (1) The test field is first irrigated with 2-5 cm of water, and the surface soil is leveled with a machine so that the surface soil around the field has a height difference of no more than 5 cm. After the field is leveled, urea-formaldehyde fertilizer and humic acid fertilizer are evenly applied at dosages of 160 kg / mu and 2800 kg / mu, respectively, and the fertilizer is plowed into the soil to a depth of 20 cm with 3-5 times of plowing and rolling, so that the fertilizer is thoroughly mixed with the plowed soil.

[0079] (2) The composted cow or sheep manure organic fertilizer is applied at a dosage of 2.0 tons / mu, and is plowed into the soil to a depth of 20 cm with 3-5 times of plowing and rolling, so that the fertilizer is thoroughly mixed with the plowed soil.

[0080] (3) Five days after the soil is thoroughly mixed, the soil conditioner is applied at a dosage of 75 kg / mu, and is rotary plowed into the soil to a depth of 20 cm with 3-5 times of plowing and rolling, so that the soil conditioner is thoroughly mixed with the plowed soil.

[0081] The preparation of the soil conditioner includes the following steps: mixing and stirring the Enteromorpha-based biochar, diatomite, and calcium-magnesium phosphate fertilizer at a mass ratio of 4:1:1 to obtain the soil conditioner.

[0082] (4) Five days after the soil is thoroughly mixed, the liquid fertilizer is applied at a dosage of 30 kg / mu, and is plowed into the soil to a depth of 20 cm with 3-5 times of plowing and rolling, so that the fertilizer is thoroughly mixed with the plowed soil.

[0083] Comparative Example 3

[0084] The difference from Example 1 is that polyethylene glycol bis-stearate is not added during preparation of the soil conditioner.

[0085] (1) The test field is first irrigated with 2-5 cm of water, and the surface soil is leveled with a machine so that the surface soil around the field has a height difference of no more than 5 cm. After the field is leveled, urea-formaldehyde fertilizer and humic acid fertilizer are evenly applied at dosages of 160 kg / mu and 2800 kg / mu, respectively, and the fertilizer is plowed into the soil to a depth of 20 cm with 3-5 times of plowing and rolling, so that the fertilizer is thoroughly mixed with the plowed soil.

[0086] (2) The composted cow or sheep manure organic fertilizer is applied at a dosage of 2.0 tons / mu, and is plowed into the soil to a depth of 20 cm with 3-5 times of plowing and rolling, so that the fertilizer is thoroughly mixed with the plowed soil.

[0087] (3) After 5 days of the soil mixing, soil conditioner is applied again, the amount is 75 kg / mu, and the soil is ploughed by machine, the ploughing depth is 20 cm, and the soil is ploughed 3-5 times, so that the soil conditioner is mixed with the soil of the ploughed layer.

[0088] The preparation of the soil conditioner comprises the following steps: dispersing calcium hydroxyl phosphate into an aqueous solution, the amount of calcium hydroxyl phosphate is 8% of the mass of the aqueous solution, to obtain mixed solution I; dropwise adding the mixed solution I into a silicon sol with a mass concentration of 20% (calculated by the content of silicon dioxide), the mixing mass ratio of the mixed solution I and the silicon sol is 1:4, and stirring is performed at the same time, to obtain mixed solution II; immersing the Enteromorpha-based biochar in the mixed solution II and standing, after taking out, first performing anaerobic reaction at 300℃ for 2h, and then performing anaerobic reaction at 550℃ for 30min; mixing and stirring the obtained reaction product, diatomite and calcium-magnesium phosphate fertilizer at a mass ratio of 4:1:1, to obtain the soil conditioner.

[0089] (4) After 5 days of the soil mixing, liquid fertilizer is applied again, the amount is 30 kg / mu, and the soil is ploughed by machine, the ploughing depth is 20 cm, and the soil is ploughed 3-5 times, so that the fertilizer is mixed with the soil of the ploughed layer.

[0090] Comparative Example 4

[0091] The difference from Example 1 is that, in the preparation process of the soil conditioner, the mixing mass ratio of the mixed solution I and the silicon sol is 1:2.

[0092] (1) The test implementation field is first irrigated with 2-5 cm of water, and the surface soil is leveled by machine, so that the height difference of the surface soil around the field is not more than 5 cm. After the field is leveled, urea-formaldehyde fertilizer and humic acid fertilizer are uniformly applied, the amounts are 160 kg / mu and 2800 kg / mu respectively, the soil is ploughed by machine, the ploughing depth is 20 cm, and the soil is ploughed 3-5 times, so that the fertilizer is mixed with the soil of the ploughed layer.

[0093] (2) The composted cow manure or sheep manure organic fertilizer is applied, the amount is 2.0 tons / mu, the soil is ploughed by machine, the ploughing depth is 20 cm, and the soil is ploughed 3-5 times, so that the fertilizer is mixed with the soil of the ploughed layer.

[0094] (3) After 5 days of the soil mixing, soil conditioner is applied again, the amount is 75 kg / mu, and the soil is ploughed by machine, the ploughing depth is 20 cm, and the soil is ploughed 3-5 times, so that the soil conditioner is mixed with the soil of the ploughed layer.

[0095] The preparation of the soil conditioner comprises the following steps: dispersing calcium hydroxyl phosphate into a polyethylene glycol 6000 bis-stearate-containing aqueous solution with a mass concentration of 2%, the amount of calcium hydroxyl phosphate added is 8% of the mass of the polyethylene glycol 6000 bis-stearate-containing aqueous solution, to obtain a mixed solution I; dropwise adding the mixed solution I into a silica sol with a mass concentration of 20% (calculated by the content of silicon dioxide), the mixing mass ratio of the mixed solution I and the silica sol is 1:2, and stirring is performed at the same time, to obtain a mixed solution II; immersing the Enteromorpha-based biochar in the mixed solution II and standing, after taking out, first performing anaerobic reaction at 300 DEG C for 2h, and then performing anaerobic reaction at 550 DEG C for 30min; mixing and stirring the obtained reaction product, diatomite and calcium-magnesium phosphate fertilizer at a mass ratio of 4:1:1, to obtain the soil conditioner.

[0096] (4) 5 days after the soil is fully mixed, liquid fertilizer is applied, the amount is 30 kg / mu, and the soil is ploughed into the soil, the ploughing depth of the soil is 20 cm, and the ploughing times are 3-5 times, so that the fertilizer and the ploughed soil are fully mixed and uniformly distributed.

[0097] After the operation according to the methods in Examples 1-4 and Comparative Examples 1-3, a test area is demarcated, and rice is planted. The rice is planted by using a direct seeding technology, the variety is Zheyou 18, and the nutrients and water of the rice are managed according to local habits, and the disease and pest control is carried out. After the rice is harvested, the soil organic matter content, pH, soil exchangeable Al 3+ analysis and yield determination.

[0098] The blank group is the soil basic physical and chemical properties of the initial newly reclaimed low-fertility red-yellow soil farmland soil sample in the southern hilly area of Jinhua, Zhejiang, the organic matter content is 8.76 g / kg, the pH is 5.22, and the soil exchangeable Al 3+ is 2.85 cmol / kg.

[0099] Table 1

[0100]

[0101]

[0102] As shown in Table 1, the newly reclaimed red-yellow soil farmland soil fertility can be rapidly improved by using the method in the application, the soil pH is improved, the soil acidity is improved in time, and the yield of rice in the same year reaches a high level. Among them, the diatomite and calcium-magnesium phosphate fertilizer in the soil conditioner can rapidly improve the soil pH, improve the soil acidity in time, the addition of the modified Enteromorpha-based biochar can make the fertilizer and water retention effect better, and can effectively reduce the soil exchangeable Al 3+The modified Enteromorpha-based biomass charcoal can play a role in the process of the rice growth, and can achieve the purpose of relieving the aluminum toxicity. Moreover, the modified Enteromorpha-based biomass charcoal can slow down the release of calcium and silicon elements, and can keep the slow release of the silicon and calcium elements, so that the soil hardening and the re-acidification phenomenon can be avoided, the soil fertility can be kept at a high level, and the rice yield is high.

[0103] The comparative example 1 and the comparative example 2 do not add the modified Enteromorpha-based biomass charcoal, so that the exchangeable Al 3+ in the soil is still at a high level, and the soil organic matter content is also affected, and then the rice yield is reduced. The comparative example 3 and the comparative example 4 show that the parameter adjustment in the preparation process of the modified Enteromorpha-based biomass charcoal can affect the synergistic effect of the components, and then affect the soil fertility and the rice yield.

[0104] The above is only the preferred embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent structure or equivalent process transformation in the present application, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for improving the fertility of newly reclaimed red-yellow soil farmland, characterized in that, The method comprises the following steps: (1) after the new red-yellow soil is ploughed and leveled, urea-formaldehyde fertilizer and humic acid fertilizer are applied; (2) matured cow or sheep manure organic fertilizer is applied; (3) soil conditioner is applied, wherein the soil conditioner comprises hydroxyl calcium phosphate, silicon sol modified enteromorpha-based biochar, diatomite and calcium-magnesium phosphate fertilizer; (4) liquid fertilizer is applied; The steps (1) to (4) need to be carried out several times of turning into the soil to mix the fertilizer and the ploughed layer soil uniformly.

2. The method for improving the fertility of newly reclaimed red-yellow soil according to claim 1, characterized in that, The preparation method of the soil conditioner comprises the following steps: hydroxyl calcium phosphate is dispersed into a polyethylene glycol bis-stearate-containing aqueous solution to obtain a mixed solution I; the mixed solution I is added dropwise into silicon sol while stirring to obtain a mixed solution II; enteromorpha-based biochar is immersed in the mixed solution II and is left to stand, and after being taken out, the enteromorpha-based biochar is subjected to anaerobic reaction at 300-400 ℃ for 1-3 h and then is subjected to anaerobic reaction at 500-600 ℃ for 30-50 min; the obtained reaction product is mixed and stirred with diatomite and calcium-magnesium phosphate fertilizer to obtain the soil conditioner.

3. The method for improving the fertility of newly reclaimed red-yellow soil according to claim 2, characterized in that, The addition amount of the hydroxyl calcium phosphate is 5-10% of the mass of the polyethylene glycol bis-stearate-containing aqueous solution; and the mass concentration of the polyethylene glycol bis-stearate-containing aqueous solution is 1-2%.

4. The method for improving the fertility of newly reclaimed red-yellow soil according to claim 2, characterized in that, The mixing mass ratio of the mixed solution I and the silicon sol is 1:4-5; the mass concentration of the silicon sol is 20-30% in terms of the content of silicon dioxide; and the mass ratio of the reaction product, diatomite and calcium-magnesium phosphate fertilizer is 3-4:1-2:1-2.

5. The method for improving the fertility of newly reclaimed red-yellow soil according to any one of claims 1 to 4, characterized in that, The dosage of the soil conditioner is 50-100 kg / mu.

6. The method of improving the fertility of newly reclaimed red-yellow soil according to claim 1, characterized in that, The dosage of the humic acid fertilizer is 2000-6000 kg / mu; and the dosage of the urea-formaldehyde fertilizer is 120-200 kg / mu.

7. The method of improving the fertility of newly reclaimed red-yellow soil according to claim 1 or 6, characterized in that, The preparation method of the urea-formaldehyde fertilizer comprises the following steps: urea and formaldehyde are mixed at a feeding molar ratio of 1.2-1.4:1, and are subjected to polymerization reaction under alkaline conditions with a pH of 8.5-9.

0.

8. The method for improving the fertility of newly reclaimed red-yellow soil according to claim 1, characterized in that, The dosage of the cow or sheep manure organic fertilizer is 1.5-3.0 tons / mu.

9. The method of improving the fertility of newly reclaimed red-yellow soil according to claim 1 or 8, characterized in that, The liquid fertilizer is a biological fertilizer containing microbial active bacteria; and the dosage of the liquid fertilizer is 10-30 kg / mu.

10. The method for improving the fertility of newly reclaimed red-yellow soil according to claim 1, characterized in that, The ploughing depth of the soil is controlled to 15-25 cm, and the turning times of each step are 3-5 times.

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