CN-122004024-A - Microbial compound fertilizer application method for desert grasslands

CN122004024ACN 122004024 ACN122004024 ACN 122004024ACN-122004024-A

Abstract

The invention discloses a microbial compound fertilizer application method for desert grasslands, and belongs to the technical field of agricultural fertilization. The method solves the problem that the application effect of the existing microbial fertilizer is unstable in harsh environments such as desert grasslands and the like, and is characterized by firstly collecting soil samples for physicochemical analysis, selecting an adaptive microbial strain based on analysis results and preparing a composite microbial agent, mixing the microbial agent with a bentonite carrier to prepare a microbial compound fertilizer, determining the fertilization depth and the fertilization dosage according to specific obstacle indexes (such as total petroleum hydrocarbon content) of the soil by adopting a grading adaptation process, primarily regulating and controlling the soil humidity, the temperature and the pH after fertilization, finally establishing a dynamic field management strategy based on fertilization effect feedback, and dynamically calculating and adjusting proper target values of the humidity and the temperature by periodically monitoring the change of key indexes of the soil, so that the soil microenvironment is continuously optimized according to the exertion condition of microbial fertilizer effects, and accurate fertilization and soil improvement are realized.

Inventors

MA HONGBIN
Han Bingfang
LI WEN
ZHOU YAO
LUO JUNSHENG
QIN WEICHUN
LIU CHAO
Ren Diehao
SHEN YAN
WANG GUOHUI

Assignees

宁夏大学

Dates

Publication Date: 20260512
Application Date: 20260407

Claims (7)

1. The microbial compound fertilizer application method for the desert grasslands is characterized by comprising the following steps of: Collecting a sample of polluted desert grassland soil, performing physicochemical analysis, and determining key indexes affecting soil quality and microbial activity, wherein the key indexes comprise a total petroleum hydrocarbon content index, a heavy metal content index, a microbial community diversity index, soil humidity, soil temperature and soil pH value in the soil; Step two, selecting an adaptive functional microorganism strain and a nutritional microorganism strain according to physicochemical analysis results, and culturing the selected strains under aseptic conditions to prepare a compound microorganism microbial agent, wherein the concentration range of each microorganism strain in the compound microorganism microbial agent is 1 multiplied by 10 6 ~1×10 8 CFU/g; Step three, mixing the compound microbial inoculant with carrier bentonite to obtain a microbial compound fertilizer, determining fertilization parameters by adopting a grading adaptation process based on the physicochemical analysis result of the step one, and applying the microbial compound fertilizer to the soil of the polluted desert grassland; The hierarchical adaptation process specifically comprises the following steps: According to the index of the total petroleum hydrocarbon content in the soil measured in the first step, different microbial inoculum carrier proportions, application depths and application amounts are adapted; When the index of the total petroleum hydrocarbon content in the soil exceeds 500 mg/kg, adopting a first adaptation grade, wherein the weight ratio of the composite microbial agent to the carrier bentonite is 1:1, the application depth is 15-20 cm, and the application amount is 300-400 kg/hm 2 ; When the index of the total petroleum hydrocarbon content in the soil is 200-500 mg/kg, adopting a second adaptation grade, wherein the weight ratio of the composite microbial agent to the carrier bentonite is 1:2, the application depth is 12-18 cm, and the application amount is 250-350 kg/hm 2 ; When the index of the total petroleum hydrocarbon content in the soil is lower than 200 mg/kg, adopting a third adaptation grade, wherein the weight ratio of the composite microbial agent to the carrier bentonite is 1:3, the application depth is 10-15 cm, and the application amount is 200-300 kg/hm 2 ; And fourthly, after the application operation is finished, preliminary regulation and control are carried out on the soil environmental conditions of the desert grasslands, the soil humidity is maintained in a field water holding range of 15-32%, the soil temperature is maintained in a range of 15-35 ℃, and the soil pH value is maintained in a range of 6.5-7.0.
2. The microbial compound fertilizer application method for desert grasslands according to claim 1, wherein in the second step, the adapted functional microbial strain and nutritional microbial strain are selected according to the physicochemical analysis result, and the specific selection method is as follows: At least one functional microorganism strain selected from the group consisting of Pseudomonas, nocardia, sphingomonas and Bacillus for the total petroleum hydrocarbon content index in the soil; Selecting at least one functional microorganism strain from bacillus, aspergillus, saccharomycete and penicillium aiming at the heavy metal content index; At least one vegetative microorganism strain selected from the group consisting of Aspergillus niger, bacillus mycoides, bacillus subtilis and azotobacter for the microbial community diversity index; Wherein the ratio of the number of viable bacteria of the total sum of the nutritional microbial strains and the selected functional microbial strains is 1:1-1:5.
3. The microbial compound fertilizer application method for the desert grassland according to claim 2, wherein the functional microbial strain is selected according to the total petroleum hydrocarbon content index in the soil measured in the first step, specifically, bacillus subtilis is selected when the total petroleum hydrocarbon content index in the soil is lower than 200 mg/kg, pseudomonas aeruginosa and bacillus subtilis with the viable count ratio of 1:1-1:3 are selected when the total petroleum hydrocarbon content index in the soil is in the range of 200-500 mg/kg, and pseudomonas aeruginosa, nocardia and Sphingomonas with the viable count ratio of 1:0.5:0.5-1:1:1 are selected when the total petroleum hydrocarbon content index in the soil is higher than 500 mg/kg; The functional microorganism strain is selected according to the heavy metal content index measured in the first step, and concretely comprises the steps of selecting saccharomyces cerevisiae when the heavy metal content index is lower than 20mg/kg, selecting aspergillus niger and bacillus mycoides with the viable count ratio of 1:1-1:2 when the heavy metal content index is within the range of 20-50 mg/kg, and selecting aspergillus niger, saccharomyces cerevisiae and penicillium with the viable count ratio of 1:0.5:0.5-1:1 when the heavy metal content index is higher than 50 mg/kg; The nutritional microorganism strain is selected according to the microbial community diversity index measured in the step one, specifically, aspergillus niger and azotobacter with the viable count ratio of 1:1-1:3 are selected when the microbial community diversity index is in the range of 0-1.5, bacillus mycoides and Bacillus subtilis with the viable count ratio of 1:1-1:2 are selected when the microbial community diversity index is in the range of 1.5-3.0, and Aspergillus niger, bacillus mycoides and Bacillus subtilis with the viable count ratio of 1:0.5:0.5-1:1:1 are selected when the microbial community diversity index is higher than 3.0.
4. The microbial compound fertilizer application method for desert grasslands according to claim 1, wherein the heavy metal pollution levels are classified according to the heavy metal content index measured in the first step, specifically: more than 50 mg/kg is the first grade, 20-50 mg/kg is the second grade, and less than 20 mg/kg is the third grade; and comparing the number corresponding to the heavy metal pollution level with the number corresponding to the level classified based on the total petroleum hydrocarbon content index in the soil, taking the level corresponding to the higher number to perform the mixing and applying process, and directly adopting the level to perform the mixing and applying process when the two values are the same.
5. The microbial compound fertilizer application method for the desert grasslands according to claim 1, further comprising the steps of establishing a dynamic field management strategy based on soil key index feedback, taking deviation of soil key index change conditions of a previous monitoring period relative to an expected target as core input, taking preliminary regulation and control environment parameters of the step four as references, dynamically calculating a suitable soil environment parameter target of the current period through a pre-established effect coefficient, and accordingly implementing corresponding field management measures, thereby forming a closed-loop continuous management flow for optimizing soil microenvironment, improving fertilizer utilization efficiency and promoting grassland ecological system recovery.
6. The microbial compound fertilizer application method for desert grasslands according to claim 5, wherein the specific process of the dynamic field management strategy is as follows: (a) Measuring the concentration of a target substance in the grassland soil every week, and continuously monitoring the soil humidity and the soil temperature; (b) Calculating the actual change rate V current of the concentration of the target substance in the current stage; (c) Comparing V current with a preset target change rate V target , and dynamically calculating a soil humidity control target range S val and a soil temperature control target range T val in the current week according to the following formulas on the basis of calculation of an arithmetic average value S cen of a soil humidity preliminary control range and an arithmetic average value T cen of a soil temperature preliminary control range in the fourth step: S val =S cen + k 1 ×(V target -V current ); T val =T cen + k 2 ×(V target -V current ); Wherein, k 1 and k 2 are adjustment coefficients calibrated in advance according to the soil type of the desert grassland; S val obtained through calculation is limited in a field water holding capacity range of 15-32%, T val is limited in a field water holding capacity range of 15-35 ℃, if S val is lower than 15% of field water holding capacity, 15% of field water holding capacity is taken, and if S val is higher than 32% of field water holding capacity, then 15 ℃ is taken, if T val is lower than a soil temperature lower limit of 15 ℃, and 35 ℃ is taken, and if T val is higher than a soil temperature upper limit of 35 ℃; Finally determining the soil humidity regulation target range S target in the current week as [ S val -ΔS, S val +DeltaS ], and the soil temperature regulation target range T target as [ T val -ΔT, T val +DeltaT ], wherein DeltaS and DeltaT are preset allowable fluctuation deviation absolute values, deltaS represents allowable fluctuation percentage relative to field water holding capacity, the value is 5%, and the value of DeltaT is 2 ℃; (d) Maintaining soil humidity in the range of S target and soil temperature in the range of T target by irrigation, drainage or covering measures; (e) Repeating the steps a to d every week, dynamically adjusting S target and T target according to the latest V current value, and forming continuous management based on feedback until the soil key index reaches the expected target; The target substances are substances corresponding to the total petroleum hydrocarbon content index and/or substances corresponding to the heavy metal content index in the soil measured in the first step.
7. The microbial compound fertilizer application method for desert grasslands according to claim 6, wherein the adjustment coefficients k 1 and k 2 are empirical values calibrated in advance according to the soil texture type of the desert grasslands; For sandy soil, the calibration value range of k 1 is 0.8 to 1.5, and the calibration value range of k 2 is 0.3 to 0.8; for loam soil, the calibration value range of k 1 is 1.0 to 2.0, and the calibration value range of k 2 is 0.5 to 1.2; For clay soil, k 1 has a calibration value in the range of 1.2 to 2.5 and k 2 has a calibration value in the range of 0.8 to 1.5.

Description

Microbial compound fertilizer application method for desert grasslands Technical Field The invention relates to the technical field of agricultural fertilization. More particularly, the invention relates to a microbial compound fertilizer application method for desert grasslands. Background Soil is the basis of agricultural production and ecological safety, and the quality of the soil is directly related to pasture growth, vegetation recovery and agricultural sustainable development. The beneficial microorganisms are utilized to improve soil and raise soil fertility, and are an important direction of modern agriculture and ecological agriculture. The microbial fertilizer can promote the transformation and circulation of nutrients, improve the physicochemical properties of soil and promote the availability of the nutrients through the vital activities of microorganisms. However, the microbial fertilizer is applied in severe environments such as polluted or degenerated desert grasslands, and the like, and the practical application effect of the microbial fertilizer still has a plurality of limitations, and is limited by multiple factors such as drought and little rain, severe temperature difference, soil impoverishment, pollutants and the like in the area, so that the stability and popularization value of the fertilizer efficiency are influenced. First, the colonization, activity and fertilizer efficiency of microorganisms in soil are exerted highly depending on the soil environmental conditions such as temperature, humidity, pH, etc. The desert grasslands have severe ecological environment and severe environmental fluctuation, and the growth and functional expression of microbial communities can be obviously influenced by the change of external conditions, so that the growth promotion and improvement effects are unstable and the efficiency is low. The prior art usually carries out disposable environmental parameter adjustment after fertilizer application or only depends on natural conditions to maintain, and lacks a mechanism for feeding back and regulating field management measures in real time according to soil moisture content, ground temperature and fertilizer efficiency. How to convert the dynamic monitoring data of soil environmental parameters into the key input of accurate water and fertilizer management decision is a core challenge for realizing stable improvement of the fertilization effect of desert grasslands. Secondly, when fertilization improvement is carried out on desert grasslands with different barrier substances (such as specific organic substances or heavy metals) or degradation degrees, the differences of soil background property, barrier concentration and texture structure are obvious. The prior art often uses a single bacterial manure formulation and a fixed application mode, and lacks a hierarchical adaptation process matched with soil characteristics, obstacle levels and improvement targets. This may lead to waste of resources due to excessive bacterial manure input in slightly obstructed soil, while in severely obstructed soil, the improvement effect is not up to standard due to insufficient concentration of bacterial agent, uneven distribution or insufficient contact. Because of the space heterogeneity and the diversity of obstacle types of the desert grasslands, a set of refined fertilization process standards which can flexibly adapt to different soil conditions are formulated, and are the difficulty of technical popularization and application. Thirdly, in terms of construction and application of the compound microbial fertilizer, the multifunctional improvement effect is often pursued by simply mixing a plurality of functional strains, but antagonism possibly existing among the strains is ignored. Incompatible strains are mixed and then applied to soil at the same time, so that the synergistic effect is difficult to form, and the overall function is reduced due to competitive inhibition, so that the expected effect of the fertilizer is affected. The prior art lacks an effective method for rapidly evaluating the compatibility of strains before fertilizer preparation and application, so that the effect of the compound bacterial fertilizer in practical application is uncertain. How to efficiently screen out the bacterial strain combination which can stably coexist and act synergistically in the soil of the desert grassland, and to prepare and apply the efficient compound microbial fertilizer according to the bacterial strain combination, is a key problem for improving the reliability of the fertilization effect. The existence of these problems limits the reliability of microbial fertilizers in soil improvement of desert grasslands (including grasslands where pollution or degradation disorders exist), environmental suitability and economy. Therefore, a set of more refined and systematic microbial compound fertilizer application methods and matched field management strategies need to