Engineering muck soil conversion method based on water and fertilizer organic matter-sugarcane synergy

Abstract

The invention provides an engineering residue soil conversion method based on water and fertilizer organic matter-sugarcane cooperation, and belongs to the technical field of soil improvement and ecological restoration. The method provided by the invention comprises the following steps: step 1, cultivating sugarcane seedlings; step 2, transplanting sugarcane seedlings; 3, dynamic gradient water and fertilizer management. According to the method, through a sugarcane-microorganism synergistic mechanism (organic acid secreted by a root system and mineral substances activated by flora), the organic matter content of the engineering residue soil is remarkably increased within 90 days, and the improvement period is shortened to 1 / 5 of that of a traditional method (3-5 years are needed in the traditional method). The root activity of the sugarcane promotes the formation of muck aggregates and increases the porosity of the soil.

Description

Technical Field

[0001] The present invention relates to the technical field of soil improvement and ecological restoration, and in particular to a method for converting engineering waste soil into soil based on the synergy of water, fertilizer, organic matter and sugarcane. Background Art

[0002] The disposal of construction waste is a major technical and ecological challenge facing current project construction. Traditionally, this method primarily involves open-air storage, which not only requires specialized equipment and high maintenance costs, but also occupies significant land resources. This waste, primarily composed of deep rock and soil, is poor in organic matter, low in nutrients, and possesses a poor physical structure. This results in slow vegetation recovery in the storage areas, and directly planting cash crops has low survival rates and limited growth, making it difficult to meet the requirements of land reclamation and ecological restoration.

[0003] Sugarcane (Saccharum spp.), an important sugar and energy crop, boasts a high biomass, a well-developed root system, and tolerance to infertility. During its growth, sugarcane significantly improves soil physical structure and imports organic carbon through root exudates and litter, promoting soil aggregate formation. Crucially, the sugarcane rhizosphere is rich in a variety of functional microorganisms, including Bacillus, Chryseolinea, Paenibacillus, Lysinibacillus, Truepera, Variibacter, Mesorhizobium, and Brevibacillus. These microorganisms not only activate nutrients (such as phosphorus and potassium) immobilized in slag soil but also secrete exopolysaccharides and organic acids, promoting the cementation of mineral particles and accelerating the transformation of slag soil into soil.

[0004] In recent years, the "organic matter-plant-microbe" collaborative improvement model has gradually become a research hotspot for the reconstruction of degraded soils or non-arable land. Studies have shown that the addition of exogenous organic matter (such as decomposed livestock and poultry manure, biogas residue, green manure, etc.) can provide carbon sources and energy for microorganisms, stimulate the proliferation and metabolic activity of rhizosphere microbial communities, and thus improve nutrient recycling efficiency and soil structural stability. Applying this concept to the improvement of engineering waste soil, combined with the powerful root penetration of sugarcane and its ability to build a rhizosphere microecosystem, is expected to achieve the functional transformation of waste soil from an "inert matrix" to an "active tillage layer."

[0005] However, existing technologies often focus on the short-term regulation of the physical and chemical properties of slag soil using single amendments (such as chemical fertilizers or conventional organic fertilizers), ignoring the driving role of plant-microbe interactions in soil processes. In particular, there is a lack of systematic soilification solutions tailored to the specific characteristics of sugarcane, a high-biomass crop, and slag soil. Therefore, developing a soilification method for engineering slag soil based on a four-dimensional synergistic mechanism of "water and fertilizer regulation - organic matter input - sugarcane planting - root microbial activation" has important practical significance and innovative value for realizing slag soil resource utilization, promoting the green and sustainable development of the sugarcane industry, and building a "city-agriculture" circular economy system. Summary of the Invention

[0006] In view of this, the present invention aims to provide a method for converting construction waste soil into soil based on the synergy of water, fertilizer, organic matter and sugarcane. The method provided by the present invention can realize the conversion of construction waste soil into soil at low cost and high efficiency.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] The present invention provides a method for soilification of engineering waste soil based on the synergy of water, fertilizer, organic matter and sugarcane, comprising the following steps:

[0009] Step 1, cultivating sugarcane seedlings: transplanting the sugarcane tissue culture seedlings into a slag soil simulation matrix for cultivation, and selecting the qualified sugarcane seedlings;

[0010] Step 2, transplanting sugarcane seedlings: pre-treat the construction waste soil and then transplant the sugarcane seedlings; the planting depth of the sugarcane seedlings is 5-7 cm, and spray the rooting water and fertilizer 1 once on the day of planting;

[0011] 3-5 days before transplanting sugarcane seedlings, evenly spray rooting water and fertilizer 2 on the surface of pre-treated soil; before transplanting sugarcane seedlings, press 1×10 5 ~5×10 5 Spores kg -1 Soil inoculation with arbuscular mycorrhizal fungi;

[0012] Step 3: Dynamic gradient water and fertilizer management: Tillering period: spray tillering period water and fertilizer once every 14 days, with a dosage of 1.0L / m 2 ; Elongation period: spray the elongation period water and fertilizer once every 10 days, with a dosage of 1.2L / m 2 Maturity period: spray once every 21 days with water and fertilizer at a dosage of 0.8L / m 2 .

[0013] In a preferred embodiment of the present invention, in step 1, the preparation method of the slag simulated matrix is ​​as follows: air-dried engineering slag, quartz sand and sugarcane biochar in a mass ratio of (7-8) : (1-2) : (0.5-1.0) are mixed evenly, and then the bulk density is adjusted to 1.60 ± 0.05 g cm-3 , pH 6.8±0.2, organic matter ≤0.5% and saturated water content 22±2%.

[0014] In a preferred embodiment of the present invention, in step 1, the sugarcane tissue culture seedlings are transplanted into a slag-simulated soil substrate for cultivation, and qualified sugarcane seedlings are selected. Specifically, the sugarcane tissue culture seedlings with a rooting period of 30 days, a plant height of 8 to 10 cm, and a root length of ≥3 cm are selected, and after removing the culture medium residue, the seedlings are transplanted into the slag-simulated soil substrate at a transplanting depth of 2 cm. After culturing in the slag-simulated soil substrate under conditions of 16 hours of light, 28±1°C, and 70±5% relative humidity for 30 days, qualified sugarcane seedlings with a plant height growth rate of ≥50%, a root length growth rate of ≥40%, a chlorophyll SPAD value of ≥25, and a root activity of ≥100 μg TPF / g·h are selected.

[0015] In a preferred embodiment of the present invention, in step 2, the construction waste soil is pretreated, specifically: the construction waste soil is mechanically crushed to a particle size of ≤5 cm, while crushed stones with a particle size of >5 cm are screened out, and then the moisture content is adjusted to 60% of the field water holding capacity.

[0016] In a preferred embodiment of the present invention, in step 2, the application amount of the rooting water fertilizer 1 is 1.5-2.0Lm -2 ; The application rate of rooting water fertilizer 2 is 0.8–1.2Lm -2 ; The rooting water fertilizer 1 and the rooting water fertilizer 2 are the same;

[0017] The preparation method of the rooting water fertilizer 1 is as follows: using a composite bacterial agent 4 to ferment livestock and poultry manure to obtain a fermentation product 4; adding 40.001-0.003 wt% of sodium naphthaleneacetate, 0.1 wt% of potassium dihydrogen phosphate, 2 wt% of humic acid, 0.001 wt% of potassium indolebutyrate and 0.5 wt% of seaweed extract to the fermentation product to obtain the rooting water fertilizer 1;

[0018] By mass, the composite bacterial agent 4 includes 25-35 parts of Bacillus velezensis, 20-30 parts of Bacillus ammoniiphilus, 15-20 parts of Trichoderma reesei, 10-15 parts of Rhodopseudomonas palustris and 3-5 parts of sugarcane bagasse biochar.

[0019] In a preferred embodiment of the present invention, the preparation method of the tillering period water fertilizer is as follows: using a composite bacterial agent 1 to ferment livestock and poultry manure to obtain a fermentation product 1; adding zinc sulfate accounting for 10.05wt% of the fermentation product, 0.01wt% of ammonium molybdate and sodium malate to the fermentation product 1 to obtain the tillering period water fertilizer; the concentration of sodium malate in the tillering period water fertilizer is 0.5mmol / L;

[0020] Calculated by mass, the composite bacterial agent 1 includes 30-40 parts of Bacillus subtilis, 30-40 parts of Bacillus mucilaginosus, 15-20 parts of Trichoderma reesei, 10-15 parts of Rhodopseudomonas palustris and 3-5 parts of sugarcane bagasse biochar.

[0021] In a preferred embodiment of the present invention, the preparation method of the elongation period water fertilizer is as follows: using a composite bacterial agent 2 to ferment livestock and poultry manure to obtain a fermentation product 2; adding 20.3 wt% of potassium fulvic acid, 0.1 wt% of polyglutamic acid, potassium silicate, and fish protein to the fermentation product 2 to obtain the elongation period water fertilizer; the concentration of potassium silicate in the elongation period water fertilizer is 2 mmol / L, and the concentration of fish protein is 5 g / L;

[0022] Calculated by mass, the composite bacterial agent 2 includes 25-35 parts of Bacillus subtilis, 25-35 parts of Bacillus gelatinosa, 10-20 parts of Bacillus ammoniaphilus, 10-15 parts of Trichoderma reesei, 10-15 parts of Rhodopseudomonas palustris and 3-5 parts of sugarcane bagasse biochar.

[0023] In a preferred embodiment of the present invention, the method for preparing the mature stage water-fertilizer is as follows: using a composite bacterial agent 3 to ferment livestock and poultry manure to obtain a fermentation product 3; adding chitosan oligosaccharide accounting for 30.1 wt% of the fermentation product and 0.05 wt% of choline chloride to the fermentation product 3 to obtain the mature stage water-fertilizer;

[0024] Calculated by mass, the composite bacterial agent 3 includes 25-35 parts of Bacillus subtilis, 25-35 parts of Bacillus gelatinosa, 10-20 parts of Pseudomonas stutzeri, 10-15 parts of Trichoderma reesei, 5-10 parts of Rhodopseudomonas palustris and 3-5 parts of bagasse biochar.

[0025] In a preferred embodiment of the present invention, when dynamic gradient water and fertilizer management is carried out, the normalized vegetation index NDVI, the green light normalized difference vegetation index GNDVI, the normalized difference red edge vegetation index NDRE and the optimized soil adjustment vegetation index OSAVI are obtained every day by multi-spectral scanning of the engineering slag area by unmanned aerial vehicles, with a resolution of ≤5cm; three-layer soil volume water content θv monitoring is arranged at depths of 10cm, 30cm and 50cm, and the soil volume water content of the root layer is measured in real time and the effective water storage REW of the root layer is calculated;

[0026] Root zone effective water storage REW = Σ(θv × ΔZ) - WP; where WP is the theoretical wilting coefficient, which is preset according to the soil type (3% for gravel soil; 12% for loamy soil; 20% for clay soil; WP = the above coefficient × total root zone thickness. The total root zone thickness of newly planted sugarcane is measured on site or estimated empirically; the total root zone thickness of ratoon sugarcane is 150 cm); ΔZ is the depth;

[0027] The decision logic for determining the water and fertilizer management period is as follows:

[0028] a. When NDVI is monitored to rise for two consecutive times and NDVI ≥ 0.6 and REW > 45mm, it is determined that the sugarcane has entered the elongation period and the elongation dynamic mode is activated;

[0029] b. When NDVI steadily decreases or GNDVI ≥ 0.65 and ΔGNDVI < 0.005 / d for 5 consecutive days, switch to mature stage water and fertilizer;

[0030] c. If REW≤30mm, irrigation compensation is immediately started to make the water volume = 45mm - current REW;

[0031] d. Use the modified potassium deficiency index MKDI formula: MKDI = (NDRE × OSAVI) / GNDVI to determine whether the plant is under potassium deficiency stress, where:

[0032] 0.8≤MKDI≤11.0: normal potassium (K≥20g / kg);

[0033] 0.6≤MKDI<0.8: mild potassium deficiency (K 15–20 g / kg);

[0034] MKDI < 0.6: severe potassium deficiency (K < 15 g / kg);

[0035] When potassium is slightly deficient: the proportion of gelatinous Bacillus is increased by 10%, and if it is in elongation, the amount of potassium silicate added is increased by 0.2mmol / L;

[0036] When potassium is severely deficient: the proportion of gelatinous Bacillus is increased by 20%, and if it is in elongation, the amount of potassium silicate added is increased by 0.5mmol / L.

[0037] The present invention discloses the following technical effects:

[0038] (1) Breakthrough Improvement in Construction Waste Soil Improvement Efficiency: Through a sugarcane-microbe synergistic mechanism (root secretion of organic acids + bacterial activation of minerals), the organic matter content of construction waste soil is significantly increased within 90 days, shortening the improvement cycle to one-fifth of the traditional method (traditional methods require 3-5 years). The sugarcane root system is active, promoting the formation of waste soil aggregates and increasing soil porosity.

[0039] (2) Growth formula composite microbial agents and growth promotion and stress resistance enhancement: The existing technology usually uses a single strain or a universal composite microbial agent, which has the problems of single function and weak pertinence, especially in the harsh slag environment, the survival rate of the strain is low and the colonization effect is poor, making it difficult to effectively play the role of growth promotion and improvement. The present invention has made a breakthrough in tailoring four composite microbial agents (composite microbial agents 1-4) for different stages of sugarcane growth (rooting period, tillering period, elongation period, and maturity period). The composition and proportion of the strains are precisely designed to achieve the functions of strengthening root colonization, improving phosphorus and nitrogen fixation capacity, optimizing ammonia nitrogen utilization and enhancing stress resistance. At the same time, the microbial agent uses sugarcane bagasse biochar as a carrier to improve the adaptability and survival rate in poor slag, and is compounded with biostimulants such as seaweed extract, humic acid, and chitosan oligosaccharides to further activate the plant's stress resistance mechanism and nutrient absorption efficiency. This design achieves multi-factor synergistic enhancement, significantly improves the functional expression of the microbial agent in harsh environments, and solves the core pain points of traditional technology, which is weak pertinence and unstable effect.

[0040] (3) Efficient utilization and precise dynamic regulation of water and fertilizer resources: Existing irrigation and fertilization technologies are mostly based on experience or fixed schedules, which cannot respond to the actual conditions of crops and soil in real time, easily leading to resource waste or stress. This technology builds a phased gradient model for water and fertilizer management and monitors aboveground and underground conditions in real time to achieve intelligent dynamic regulation of crop water and fertilizer requirements, minimize water and fertilizer waste, and improve fertilizer efficiency and yield.

[0041] (4) Significant economic, environmental and social benefits: With livestock and poultry manure as the core raw material, a microbial-organic matter synergistic system is constructed, which significantly reduces the dependence on external chemical fertilizers and organic fertilizers, and the treatment cost is significantly lower than that of traditional methods; at the same time, it realizes the dual resource utilization of engineering waste and agricultural waste, turning waste into treasure, which is in line with the concept of circular economy and green development; its output value is not only reflected in the improved soil, but also creates significant economic value through the large-scale planting of sugarcane (which can be used in sugar production, energy and other fields), forming a virtuous cycle of ecological restoration and economic benefits; it has the potential for large-scale promotion with strong standardization and replicability, and provides innovative solutions for waste resource utilization and ecological restoration. DETAILED DESCRIPTION

[0042] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0043] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value within any stated value or stated range, and each smaller range between any other stated value or intermediate value within the stated range, is also encompassed within the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0044] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0045] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the invention. The description and examples are intended to be exemplary only.

[0046] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0047] In the present invention, the sugarcane biochar is obtained by a preparation method well known to those skilled in the art, such as a hydrothermal carbonization method, wherein sugarcane bagasse and water are mixed in a mass-to-volume ratio of 1:(6-8), placed in a high-pressure reactor, and reacted at 210-230° C. for 2-4 hours. After the reaction, solid-liquid separation is performed, the mixture is washed with clean water, dried at 105° C. to constant weight, and ground through a 100-mesh sieve to obtain the obtained biochar; the hydrothermal carbon has a pH of 5.5-7.0, an oxygen-to-carbon ratio (O / C) of 0.4-0.6, and a hydrogen-to-carbon ratio (H / C) of 0.8-1.0;

[0048] The seaweed extract is prepared by an alkaline extraction method. Seaweed powder is added to a 1-2% KOH solution at a ratio of 1:15-20 (w / v), stirred at 60-80°C for 2-4 hours, cooled, adjusted to a pH of 6-8, and centrifuged to obtain a clear supernatant; the solution is concentrated to a solid state in a vacuum concentrator (vacuum -0.08MPa, ≤60°C), and then spray-dried to obtain a seaweed polysaccharide extract.

[0049] In the present invention, the microorganisms involved (Bacillus velezensis, Bacillus ammoniaphilus, Trichoderma reesei, Rhodopseudomonas palustris, Bacillus subtilis, Bacillus gelatinous, Trichoderma reesei and Pseudomonas stutzeri) were purchased from the China Agricultural Microorganism Culture Collection Center.

[0050] Unless otherwise specified, the technical solutions described in the present invention are all conventional solutions in the field, and the reagents or raw materials used, unless otherwise specified, are purchased from commercial channels or have been disclosed.

[0051] In order to better understand the present invention, the content of the present invention is further illustrated below in conjunction with the examples, but the content of the present invention is not limited to the following examples.

[0052] Example 1

[0053] The No. 5 earthwork storage site at the Pinglu Canal Madao Hub, Section 11 of the Pinglu Canal waterway. 380 mu (approximately 16 acres) of Guitang No. 44 sugarcane is planted. Construction waste soil must be piled at least 50 cm high. This is dry farmland with red and yellow soil. (Planting began in March, and soil fertility reached Level 6 in July.)

[0054] The details are as follows:

[0055] Step 1: Mix air-dried construction waste soil (200 mesh), quartz sand, and bagasse biochar at a mass ratio of 8:2:1.0 and adjust the bulk density to 1.60±0.05g cm -3 , pH 6.8±0.2, organic matter ≤0.5%, and saturated moisture content 22±2% to obtain a homogenized slag soil simulated matrix. Sugarcane tissue culture seedlings with a rooting period of 30 days, a plant height of 8-10 cm, and a root length ≥3 cm were selected. After removing the culture medium residue, they were transplanted into a transparent plastic root canal with an inner diameter of 4 cm and a height of 60 cm. The root canal was filled with the slag soil simulated matrix to a transplanting depth of 2 cm. After culturing in the simulated matrix for 30 days under the conditions of 16 h of light, 28±1°C, and 70±5% relative humidity, the tissue culture seedlings with a plant height growth rate ≥50%, a root length growth rate ≥40%, a chlorophyll SPAD value ≥25, and a root activity ≥100 μg TPF / g·h were determined to be qualified varieties.

[0056] Step 2: Mechanically crush the construction waste soil to a particle size of ≤5cm, and screen out the gravel with a particle size >5cm. Adjust the moisture content to 60% of the field water holding capacity by spraying. Three days before planting the sugarcane tissue culture seedlings, evenly spray the surface of the waste soil with rooting water and fertilizer at a rate of 1.5–2.0L m -2 ; Transplant the stress-resistant sugarcane seedlings into the slag soil at a planting depth of 5–7 cm. Spray the rooting fertilizer again on the day of planting at a rate of 0.8–1.2 Lm -2 Before transplanting, the tissue culture seedlings were 1×10 5 ~5×10 5 Spores kg -1 Soil inoculated with arbuscular mycorrhizal fungi (Glomus etunicatum).

[0057] The preparation method of the rooting water fertilizer is as follows: after mixing the composite bacterial agent 4 with livestock and poultry manure (the amount of the composite bacterial agent is 4wt% of the livestock and poultry manure), fermenting (injecting air into the liquid manure through an aeration disk to promote the proliferation and metabolism of aerobic microorganisms, maintaining the fermentation temperature at 30°C-35°C, and fermenting for 72-75 hours) to obtain a fermentation product 4; adding sodium naphthaleneacetate, which accounts for 40.003wt% of the fermentation product, 0.1wt% of potassium dihydrogen phosphate, 2wt% of humic acid, 0.001wt% of potassium indolebutyrate, and 0.5wt% of seaweed extract to the fermentation product to obtain the rooting water fertilizer 1;

[0058] Calculated by mass, the composite bacterial agent 4 includes 35 parts of Bacillus velezensis, 30 parts of Bacillus ammoniaphilus, 15 parts of Trichoderma reesei, 15 parts of Rhodopseudomonas palustris and 5 parts of sugarcane bagasse biochar.

[0059] Step 3. Finally, based on the drone spectrum and online soil moisture data, dynamic gradient water and fertilizer management is carried out during the sugarcane growth cycle to promote sugarcane growth and further secretion of organic acids by the sugarcane roots to improve the soil. Tillering period: spray tillering period water and fertilizer once every 14 days, with a dosage of 1.0L / m 2 ; Elongation period: spray the elongation period water and fertilizer every 10 days, the dosage is 1.2L / m 2 Maturity period: Spray the maturity period water and fertilizer every 21 days, with a dosage of 0.8L / m 2 .

[0060] The preparation method of the tillering period water fertilizer is as follows: mixing the composite bacterial agent 1 with livestock and poultry manure (the amount of the composite bacterial agent 1 is 4wt% of the livestock and poultry manure), fermenting (injecting air into the liquid manure through an aeration disk to promote the proliferation and metabolism of aerobic microorganisms. Maintaining the fermentation temperature at 35°C-38°C for 72-75 hours) to obtain a fermentation product 1; adding zinc sulfate accounting for 10.05wt% of the fermentation product, 0.01wt% of ammonium molybdate and sodium malate to the fermentation product 1 to obtain the tillering period water fertilizer; the concentration of sodium malate in the tillering period water fertilizer is 0.5mmol / L;

[0061] Calculated by mass, the composite bacterial agent 1 includes 35 parts of Bacillus subtilis, 35 parts of Bacillus gelatinosa, 15 parts of Trichoderma reesei, 10 parts of Rhodopseudomonas palustris and 5 parts of sugarcane bagasse biochar.

[0062] The preparation method of the elongation-period water fertilizer comprises: mixing a composite bacterial agent 2 with livestock and poultry manure (the amount of the composite bacterial agent 2 is 4 wt% of the livestock and poultry manure), fermenting (injecting air into the liquid manure through an aeration plate to promote the proliferation and metabolism of aerobic microorganisms. The fermentation temperature is maintained at 35° C.-38° C. and the fermentation is carried out for 72-75 hours) to obtain a fermentation product 2; and adding potassium fulvic acid accounting for 20.3 wt% of the fermentation product, 0.1 wt% of polyglutamic acid, potassium silicate, and fish protein to the fermentation product 2 to obtain the elongation-period water fertilizer; the concentration of potassium silicate in the elongation-period water fertilizer is 2 mmol / L, and the concentration of fish protein is 5 g / L.

[0063] Calculated by mass, the composite bacterial agent 2 includes 30 parts of Bacillus subtilis, 35 parts of Bacillus gelatinosa, 10 parts of Bacillus ammoniaphilus, 10 parts of Trichoderma reesei, 12 parts of Rhodopseudomonas palustris and 3 parts of sugarcane bagasse biochar.

[0064] The preparation method of the mature-stage water-fertilizer comprises: mixing a composite microbial agent 3 with livestock and poultry manure (the amount of the composite microbial agent 3 is 4 wt% of the livestock and poultry manure), fermenting (injecting air into the liquid manure through an aeration plate to promote the proliferation and metabolism of aerobic microorganisms. The fermentation temperature is maintained at 35° C.-38° C. and the fermentation is carried out for 72-75 hours) to obtain a fermentation product 3; and adding chitosan oligosaccharide accounting for 30.1 wt% of the fermentation product and 0.05 wt% of choline chloride to the fermentation product 3 to obtain the mature-stage water-fertilizer;

[0065] Calculated by mass, the composite bacterial agent 3 includes 25 parts of Bacillus subtilis, 30 parts of Bacillus gelatinosa, 20 parts of Pseudomonas stutzeri, 12 parts of Trichoderma reesei, 10 parts of Rhodopseudomonas palustris and 3 parts of bagasse biochar.

[0066] During dynamic gradient water and fertilizer management, drone multispectral scanning flights were used daily to collect data from the construction waste soil area, including the Normalized Difference Vegetation Index (NDVI), Green Normalized Difference Vegetation Index (GNDVI), Normalized Difference Red Edge Vegetation Index (NDRE), and Optimized Soil Adjusted Vegetation Index (OSAVI), with a resolution of ≤5cm. Three-layer soil volumetric water content (θv) monitoring was performed at depths of 10cm, 30cm, and 50cm, to measure the root zone soil volumetric water content in real time and calculate the root zone effective water storage (REW).

[0067] Root zone effective water storage REW = Σ(θv×ΔZ)-WP; where WP is the theoretical wilting coefficient, which is preset according to the soil type; ΔZ is the depth;

[0068] The decision logic for determining the water and fertilizer management period is as follows:

[0069] a. When NDVI is monitored to rise for two consecutive times and NDVI ≥ 0.6 and REW > 45mm, it is determined that the sugarcane has entered the elongation period and the elongation dynamic mode is activated;

[0070] b. When NDVI steadily decreases or GNDVI ≥ 0.65 and ΔGNDVI < 0.005 / d for 5 consecutive days, switch to mature stage water and fertilizer;

[0071] c. If REW≤30mm, irrigation compensation is immediately started to make the water volume = 45mm - current REW;

[0072] d. Use the modified potassium deficiency index MKDI formula: MKDI = (NDRE × OSAVI) / GNDVI to determine whether the plant is under potassium deficiency stress, where:

[0073] 0.8≤MKDI≤11.0: normal potassium (K≥20g / kg);

[0074] 0.6≤MKDI<0.8: mild potassium deficiency (K 15–20 g / kg);

[0075] MKDI < 0.6: severe potassium deficiency (K < 15 g / kg);

[0076] When potassium is slightly deficient: the proportion of gelatinous Bacillus is increased by 10%, and if it is in elongation, the amount of potassium silicate added is increased by 0.2mmol / L;

[0077] When potassium is severely deficient: the proportion of gelatinous Bacillus is increased by 20%, and if it is in elongation, the amount of potassium silicate added is increased by 0.5mmol / L.

[0078] The parameters of engineering waste soil before and after treatment are shown in Table 1:

[0079] Table 1

[0080]

[0081]

[0082] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for soilification of engineering waste soil based on the synergy of water, fertilizer, organic matter and sugarcane, characterized in that: The following steps are involved: Step 1, cultivating sugarcane seedlings: transplanting the sugarcane tissue culture seedlings into a slag soil simulation matrix for cultivation, and selecting the qualified sugarcane seedlings; Step 2, transplanting sugarcane seedlings: pre-treat the construction waste soil, and then transplant the sugarcane seedlings; the planting depth of the sugarcane seedlings is 5-7 cm, and spray the rooting water and fertilizer 1 once on the day of planting; 3-5 days before transplanting sugarcane seedlings, evenly spray rooting water and fertilizer 2 on the surface of pre-treated soil; before transplanting sugarcane seedlings, press 1×10 5 ~5×10 5 Spores kg -1 Soil inoculation with arbuscular mycorrhizal fungi; Step 3: Dynamic gradient water and fertilizer management: Tillering period: spray tillering period water and fertilizer once every 14 days, with a dosage of 1.0L / m 2 ; Elongation period: spray the elongation period water and fertilizer once every 10 days, with a dosage of 1.2L / m 2 Maturity period: spray once every 21 days with water and fertilizer at a dosage of 0.8L / m 2 .

2. The method for converting engineering waste soil into soil based on the synergy of water, fertilizer, organic matter and sugarcane according to claim 1, characterized in that: In step 1, the preparation method of the slag simulated matrix is ​​as follows: air-dried construction slag, quartz sand and sugarcane biochar are mixed uniformly in a mass ratio of (7-8) : (1-2) : (0.5-1.0), and then the bulk density is adjusted to 1.60 ± 0.05 g cm -3 , pH 6.8±0.2, organic matter ≤0.5% and saturated water content 22±2%.

3. The method for converting engineering waste soil into soil based on the synergy of water, fertilizer, organic matter and sugarcane according to claim 1, characterized in that: In the step 1, the sugarcane tissue culture seedlings are transplanted into a slag soil simulated substrate for cultivation, and qualified sugarcane seedlings are selected. Specifically, the sugarcane tissue culture seedlings with rooting for 30 days, plant height of 8-10 cm, and root length of ≥3 cm are selected, and after removing the culture medium residue, the seedlings are transplanted into the slag soil simulated substrate at a transplanting depth of 2 cm; after culturing for 30 days in the slag soil simulated substrate under conditions of 16 hours of light, 28±1°C, and 70±5% relative humidity, qualified sugarcane seedlings with plant height growth rate of ≥50%, root length growth rate of ≥40%, chlorophyll SPAD value of ≥25, and root activity of ≥100 μg TPF / g·h are selected.

4. The method for converting construction waste soil into soil based on the synergy of water, fertilizer, organic matter and sugarcane according to claim 1, characterized in that: In step 2, the construction waste soil is pretreated, specifically: the construction waste soil is mechanically crushed to a particle size of ≤5 cm, while crushed stones with a particle size of >5 cm are screened out, and then the moisture content is adjusted to 60% of the field water holding capacity.

5. The method for converting construction waste soil into soil based on the synergy of water, fertilizer, organic matter and sugarcane according to claim 1, characterized in that: In step 2, the application amount of rooting water fertilizer 1 is 1.5–2.0 L m -2 ; The application rate of rooting water fertilizer 2 is 0.8–1.2Lm -2 ; The rooting water fertilizer 1 and the rooting water fertilizer 2 are the same; The preparation method of the rooting water fertilizer 1 is as follows: using a composite bacterial agent 4 to ferment livestock and poultry manure to obtain a fermentation product 4; adding sodium naphthaleneacetate, which accounts for 0.001-0.003 wt% of the fermentation product 4, 0.1 wt% of potassium dihydrogen phosphate, 2 wt% of humic acid, 0.001 wt% of potassium indolebutyrate, and 0.5 wt% of seaweed extract to the fermentation product 4 to obtain the rooting water fertilizer 1; Calculated by mass, the composite bacterial agent 4 includes 25-35 parts of Bacillus velezensis, 20-30 parts of Bacillus ammoniaphilus, 15-20 parts of Trichoderma reesei, 10-15 parts of Rhodopseudomonas palustris and 3-5 parts of sugarcane bagasse biochar.

6. The method for converting construction waste soil into soil based on the synergy of water, fertilizer, organic matter and sugarcane according to claim 1, characterized in that: The preparation method of the tillering period water fertilizer comprises: fermenting livestock and poultry manure using a composite bacterial agent 1 to obtain a fermentation product 1; adding zinc sulfate accounting for 10.05 wt% of the fermentation product, ammonium molybdate and sodium malate accounting for 0.01 wt% of the fermentation product to the fermentation product 1 to obtain the tillering period water fertilizer; the concentration of sodium malate in the tillering period water fertilizer is 0.5 mmol / L; Calculated by mass, the composite bacterial agent 1 includes 30-40 parts of Bacillus subtilis, 30-40 parts of Bacillus gelatinosa, 15-20 parts of Trichoderma reesei, 10-15 parts of Rhodopseudomonas palustris and 3-5 parts of sugarcane bagasse biochar.

7. The method for converting construction waste soil into soil based on the synergy of water, fertilizer, organic matter and sugarcane according to claim 1, characterized in that: The preparation method of the elongation period water fertilizer comprises: fermenting livestock and poultry manure using a composite bacterial agent 2 to obtain a fermentation product 2; adding 20.3 wt% of potassium fulvic acid, 0.1 wt% of polyglutamic acid, potassium silicate, and fish protein to the fermentation product 2 to obtain the elongation period water fertilizer; the concentration of potassium silicate in the elongation period water fertilizer is 2 mmol / L, and the concentration of fish protein is 5 g / L; Calculated by mass, the composite bacterial agent 2 includes 25-35 parts of Bacillus subtilis, 25-35 parts of Bacillus gelatinosa, 10-20 parts of Bacillus ammoniaphilus, 10-15 parts of Trichoderma reesei, 10-15 parts of Rhodopseudomonas palustris and 3-5 parts of sugarcane bagasse biochar.

8. The method for converting construction waste soil into soil based on the synergy of water, fertilizer, organic matter and sugarcane according to claim 1, characterized in that: The preparation method of the mature-stage water-fertilizer comprises: fermenting livestock and poultry manure with a composite bacterial agent 3 to obtain a fermentation product 3; adding chitosan oligosaccharide accounting for 30.1 wt% of the fermentation product and 0.05 wt% of choline chloride to the fermentation product 3 to obtain the mature-stage water-fertilizer; Calculated by mass, the composite bacterial agent 3 includes 25-35 parts of Bacillus subtilis, 25-35 parts of Bacillus gelatinosa, 10-20 parts of Pseudomonas stutzeri, 10-15 parts of Trichoderma reesei, 5-10 parts of Rhodopseudomonas palustris and 3-5 parts of bagasse biochar.

9. The method for converting construction waste soil into soil based on the synergy of water, fertilizer, organic matter and sugarcane according to claim 1, characterized in that: During dynamic gradient water and fertilizer management, daily drone multispectral scanning flights were used to collect data from the construction waste soil area, including the Normalized Difference Vegetation Index (NDVI), the Green Normalized Difference Vegetation Index (GNDVI), the Normalized Difference Red Edge Vegetation Index (NDRE), and the Optimized Soil Adjusted Vegetation Index (OSAVI), with a resolution of ≤5 cm. Three-layer soil volumetric water content (θv) monitoring was performed at depths of 10 cm, 30 cm, and 50 cm, measuring the root zone soil volumetric water content in real time and calculating the root zone effective water storage (REW). Root zone effective water storage REW = Σ(θv×ΔZ)-WP; where WP is the theoretical wilting coefficient, which is preset according to the soil type; ΔZ is the depth; The decision logic for determining the water and fertilizer management period is as follows: a. When NDVI is monitored to rise for two consecutive times and NDVI ≥ 0.6 and REW > 45mm, it is determined that the sugarcane has entered the elongation period and the elongation dynamic mode is activated; b. When NDVI steadily decreases or GNDVI ≥ 0.65 and ΔGNDVI < 0.005 / d for 5 consecutive days, switch to mature stage water and fertilizer; c. If REW≤30mm, irrigation compensation is immediately started to make the water volume = 45mm - current REW; d. Use the modified potassium deficiency index MKDI formula: MKDI = (NDRE × OSAVI) / GNDVI to determine whether the plant is under potassium deficiency stress, where: 0.8≤MKDI≤1.0: normal potassium; 0.6≤MKDI<0.8: mild potassium deficiency; MKDI<0.6: severe potassium deficiency; When potassium is slightly deficient: the proportion of gelatinous Bacillus is increased by 10%, and if it is in elongation, the amount of potassium silicate added is increased by 0.2mmol / L; When potassium is severely deficient: the proportion of gelatinous Bacillus is increased by 20%, and if it is in elongation, the amount of potassium silicate added is increased by 0.5mmol / L.

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