Desert grassland grass interspecific synergistic agent and degraded grassland application method

Abstract

The invention discloses a desert grassland grass interspecific synergistic agent and a degraded grassland application method, and belongs to the technical field of plant synergist preparation. The application method of the desert steppe grass interspecific synergistic agent degraded grassland comprises the following steps that 1, grassland and gravel are cleaned, then ploughing and soil loosening are conducted, the depth is 10-15 cm, and land is leveled; step 2, mixing the synergist with the grass seeds according to a mixing ratio of 1g: 15g, then sowing the grass seeds in a drill sowing mode with the sowing depth of 1-2cm and the sowing quantity of 1-2kg / mu, and irrigating, moisturizing, detecting and evaluating the recovery effect. By means of the method, the biomass, density and coverage rate of grass can be effectively increased.

Description

Technical Field

[0001] The invention belongs to the technical field of synergistic enhancer preparation, and in particular relates to a desert steppe grass interspecific synergistic enhancer and an application method for degraded grassland. Background Art

[0002] As one of the most important ecosystems on Earth, grassland plays an irreplaceable role in maintaining ecological balance, protecting biodiversity and promoting sustainable development of animal husbandry. However, due to the combined effects of multiple factors such as overgrazing, unreasonable reclamation and climate change, desert grasslands are facing an unprecedented degradation crisis. This degradation not only leads to a decline in grassland productivity and biodiversity, but also exacerbates environmental problems such as land desertification and soil erosion, posing a serious threat to the ecological security and economic development of surrounding areas.

[0003] The degradation of desert grasslands is a complex process involving multiple aspects such as soil quality decline, vegetation structure change, and water utilization imbalance. Soil quality degradation is the basis of grassland degradation. Overgrazing and irrational use lead to a reduction in soil organic matter and structural damage, which in turn affects soil fertility and water retention capacity. Changes in vegetation structure are manifested in the reduction of high-quality forage and the spread of harmful and toxic plants, which further reduces the utilization value and ecological function of grasslands. At the same time, climate change, especially changes in rainfall patterns and rising temperatures, has exacerbated the fragility of grassland ecosystems, making grassland restoration and management more difficult.

[0004] In response to the degradation of desert steppes, traditional management methods often focus on single vegetation restoration or soil improvement measures, but these methods are often limited in effect in practical applications and are difficult to fundamentally solve the degradation problem. Therefore, exploring more comprehensive and efficient management technologies has become the focus of current research. Summary of the invention

[0005] The purpose of the present invention is to provide a desert steppe grass interspecific synergistic enhancer and a degraded grassland application method, so as to solve the technical problems of poor grass density, biomass and coverage in the prior art.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: The invention provides a desert steppe grass interspecific synergistic enhancer, which is composed of the following components in parts by weight: 50-65 parts of humic acid, 10-18 parts of microbial agents, 2-8 parts of minerals, 6-14 parts of composite chitosan, and 3-8 parts of modified gel, wherein the composite chitosan is prepared from chitosan, sodium azide, diglycolamine, sodium hydride, 3-bromopropyne, trifluoroacetic acid, ascorbic acid and activated carbon, and the modified gel is prepared from N,N-dimethylaminochloropropane hydrochloride, propane sultone, 1,2-dichloroethane, starch, acrylic acid, acrylamide and N,N'-methylenebisacrylamide.

[0007] Preferably, the microbial agent consists of one or more of Azospirillum, Pseudomonas, Bacillus subtilis, Bacillus subtilis, arbuscular mycorrhizal fungi and actinomycetes, and the mineral substance consists of one or more of potassium silicate, sodium silicate, apatite, superphosphate, potassium feldspar, potassium sulfate, calcium carbonate, calcium sulfate, borax, zinc sulfate, copper sulfate and montmorillonite.

[0008] Preferably, the method for preparing the composite chitosan comprises the following steps: S1: chitosan is placed in a container containing a mixed solution of acetic acid and N,N-dimethylformamide, stirred in an oil bath under a nitrogen atmosphere, and then sodium azide is added and stirred continuously. After the stirring is completed, the mixture is cooled, triphenylphosphine and carbon tetrabromide are added in sequence, stirred for reaction, and then methanol is added to quench the reaction, washed, and vacuum dried to obtain compound 1; S2: Add diglycolamine to a container containing chloroform, stir, then add chloroform containing di-tert-butyl dicarbonate to the container through a constant pressure dropping funnel, stir in an ice-water bath, and after the addition is complete, stir and react at room temperature. After the reaction is complete, wash, dry, filter, vacuum evaporate, and vacuum dry to obtain compound 2; add compound 2 to a container containing tetrahydrofuran, stir, then add sodium hydride, stir in an ice bath, and then slowly drop tetrahydrofuran containing 3-bromopropyne into the container through a constant pressure dropping funnel. After the addition is complete, remove the ice-water bath, stir and react at room temperature, then add anhydrous ethanol to quench the reaction, rotary evaporate, wash, dry, filter, purify, and vacuum dry to obtain compound 3; add compound 3 to a container containing dichloromethane, stir, then drop dichloromethane containing trifluoroacetic acid through a constant pressure dropping funnel, stir and react, vacuum evaporate, and vacuum dry to obtain compound 4; S3: Compound 1 is added to a container containing dimethyl sulfoxide, and then compound 4 is added, and stirring is continued. Subsequently, ascorbic acid, copper bromide and N,N-diisopropylethylamine are added, and the mixture is stirred under a nitrogen atmosphere for reaction. After the reaction is completed, the mixture is dialyzed and freeze-dried to obtain compound 5; S4: Add activated carbon to ultrapure water, stir ultrasonically, then add EDC and NHS to ultrapure water, stir to react, then add compound 5, continue stirring, wash, and dry to obtain composite chitosan.

[0009] In the above process, chitosan is first used as a raw material and modified with sodium azide to obtain compound 1, then diglycolamine and di-tert-butyl dicarbonate are subjected to an amidation reaction, followed by a substitution reaction with 3-bromopropyne, and then a reaction with trifluoroacetic acid to generate compound 4, and then compound 4 is reacted with compound 1 according to the Click reaction mechanism to prepare compound 5, and then compound 5 is reacted with activated carbon to prepare composite chitosan.

[0010] Preferably, in S1, the amount ratio of chitosan, acetic acid, N,N-dimethylformamide, sodium azide, triphenylphosphine and carbon tetrabromide is (0.3-0.45) g: (2-2.4) mL: (11-12.5) mL: (1-1.2) g: (1.3-1.5) g: (1.7-2.1) g, the oil bath stirring temperature is 80-85°C, the stirring time is 30-45 min, the continued stirring time is 4-6 h, and the stirring reaction time is 36-42 h.

[0011] Preferably, in S2, the dosage ratio of diglycolamine and di-tert-butyl dicarbonate is (3.63-3.85) g: (6.84-7.12) mL, the stirring time is 30-45 min, and the stirring reaction time at room temperature is 10-12 h; the dosage ratio of compound 2, sodium hydride and 3-bromopropyne is (2.1-2.23) g: (0.41-0.54) g: (1.81-1.93) g, the stirring time is 30-45 min, the ice bath stirring time is 10-15 min, and the stirring reaction time at room temperature is 4-6 h; the dosage ratio of compound 3 and trifluoroacetic acid is (5-7.5) g: (10-15) mL, and the stirring reaction time is 10-12 h.

[0012] Preferably, in S3, the dosage ratio of compound 1, dimethyl sulfoxide, compound 4, ascorbic acid, copper bromide and N,N-diisopropylethylamine is (0.052-0.064) g: (5-7.2) mL: (0.2-0.24) g: (0.06-0.09) g: (0.032-0.036) g: (0.23-0.35) mL, and the stirring time is continued for 30-45 m in, the stirring reaction time is 36-40h; in the S4, the amount ratio of activated carbon, ultrapure water, EDC, NHS and compound 5 is (0.6-0.92) g: (10-12) mL: (0.072-0.088) g: (0.012-0.018) g: (0.0011-0.0015) g, the stirring reaction time is 1-2h, and the stirring time is continued for 36-42h.

[0013] Preferably, the method for preparing the modified gel comprises the following steps: Q1: Add N,N-dimethylaminopropane chloride hydrochloride to a container containing deionized water, stir and mix, then add sodium hydroxide solution, let stand, take the upper layer of liquid, add propane sultone to 1,2-dichloroethane, stir and mix, drop the upper layer of liquid, continue the reaction, filter, wash, and dry to obtain intermediate A; Q2: Add starch to deionized water, stir to mix, then add sodium hydroxide, heat to react, then add intermediate A, continue to react, after the reaction is completed, cool, adjust the pH to neutral, precipitate, wash, vacuum dry to obtain intermediate B; add acrylic acid, acrylamide and N,N'-methylenebisacrylamide to distilled water, then add intermediate B, after magnetic stirring, adjust the pH, add potassium persulfate under nitrogen environment, heat to react, after the reaction is completed, soak, filter, wash, dry, crush, sieve to obtain modified gel.

[0014] In the above process, N,N-dimethylaminopropane chloride hydrochloride is firstly used to react with sodium hydroxide to obtain an upper liquid, and then the upper liquid is reacted with propane sultone to obtain an intermediate A. Subsequently, the intermediate A is used to modify the starch to obtain an intermediate B. Then, under the condition of potassium persulfate as an initiator, acrylic acid, acrylamide, N,N'-methylenebisacrylamide and the intermediate B are reacted to prepare a modified gel.

[0015] Preferably, in Q1, the dosage ratio of N,N-dimethylaminochloropropane hydrochloride, deionized water and sodium hydroxide solution is (30-33.2) g: (20-25) mL: (20-25) mL, the mass fraction of the sodium hydroxide solution is 40wt%, the dosage ratio of propane sultone, 1,2-dichloroethane and the upper liquid is (35-37.2) g: (150-200) mL: (12-16) mL, and the reaction time is 6-8h; in Q2, the dosage ratio of starch, deionized water, sodium hydroxide and intermediate A is (3-3.5) g: (6-8) mL: (8-12) mL: (1-1.3) g, the heating reaction temperature is 40-42°C, the reaction time is 1-2 h, and the continued reaction time is 4-6 h; the dosage ratio of acrylic acid, acrylamide, N,N'-methylenebisacrylamide, distilled water, intermediate B and potassium persulfate is (3-4.5) g: (3-4.5) g: (0.2-0.34) g: (25-30) mL: (0.8-1.2) g: (0.06-0.07) g, the heating reaction temperature is 65°C for 1 h, 75°C for 1 h and 85°C for 1 h.

[0016] Preferably, the method for preparing the interspecific synergistic enhancer of desert steppe grasses comprises the following steps: P1: humic acid and minerals are mixed, then composite chitosan is added, then microbial agents are added, and finally modified gel is added, and the mixture is stirred and mixed to obtain a mixture; P2: The mixture is homogenized, dried and granulated to obtain a desert steppe grass interspecific synergistic enhancer.

[0017] Preferably, the method for applying the desert steppe grass interspecific synergist to degraded grassland comprises the following steps: Step 1: Clear the grass, crush the stones, and then till the soil to a depth of 10-15cm to level the land; Step 2: Mix the enhancer with grass seeds in a ratio of 1g:15g, then sow in rows with a sowing depth of 1-2cm and a sowing amount of 1-2kg / mu, irrigate, moisturize, test, and evaluate the recovery effect.

[0018] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: The prepared composite chitosan and modified gel are simultaneously added to the interspecific synergistic enhancer of desert grassland grasses, which can effectively enhance the growth and development of grasses, thereby improving the restoration of desert grasslands. The addition of composite chitosan can enhance the activity of soil microorganisms, improve soil fertility, promote grass growth and improve the quality of grasses; the addition of modified gel can improve the water retention capacity of the soil, regulate the pH value of the soil, enhance the stability of the soil structure, and can also promote the development of the grass root system and improve the growth of the grass. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Example 1: This example discloses a method for preparing a composite chitosan, comprising the following steps: S1: 0.37 g of chitosan was placed in a container containing a mixed solution of 2.2 mL of acetic acid and 11.7 mL of N,N-dimethylformamide, and stirred in an oil bath at 85°C for 30 min under a nitrogen atmosphere. Then 1.1 g of sodium azide was added and stirring continued for 6 h. After the stirring was completed, the mixture was cooled, and 1.4 g of triphenylphosphine and 1.9 g of carbon tetrabromide were added in sequence. The mixture was stirred for 42 h, and then methanol was added to quench the reaction. The mixture was washed and dried in vacuo to obtain compound 1. S2: 3.74 g of diglycolamine was added to a container containing 30 mL of chloroform, stirred for 30 min, and then 30 mL of chloroform containing 6.96 g of di-tert-butyl dicarbonate was added to the container through a constant pressure dropping funnel, stirred in an ice-water bath, and after the addition was completed, stirred at room temperature for 12 h. After the reaction was completed, the mixture was washed, dried, filtered, vacuum evaporated, and dried in vacuo to obtain compound 2; 2.16 g of compound 2 was added to a container containing 100 mL of tetrahydrofuran, stirred for 35 min, and then 0.47 g of sodium hydride was added, stirred in an ice bath for 15 min, and then 1.86 g of 5 mL of tetrahydrofuran in 3-bromopropyne was slowly added dropwise to the container. After the addition was completed, the ice-water bath was removed, the reaction was stirred at room temperature for 6 h, and then anhydrous ethanol was added to quench the reaction, rotary evaporated, washed, dried, filtered, purified, and vacuum dried to obtain compound 3; 6.7 g of compound 3 was added to a container containing 100 mL of dichloromethane, stirred, and then 2 mL of dichloromethane containing 12.5 mL of trifluoroacetic acid was added dropwise through a constant pressure dropping funnel, the reaction was stirred for 12 h, reduced pressure rotary evaporated, and vacuum dried to obtain compound 4; S3: 0.058 g of compound 1 was added to a container containing 6.6 mL of dimethyl sulfoxide, and then 0.22 g of compound 4 was added, and stirring was continued for 35 min. Subsequently, 0.07 g of ascorbic acid, 0.034 g of copper bromide and 0.29 mL of N,N-diisopropylethylamine were added, and the reaction was stirred for 36 h under a nitrogen atmosphere. After the reaction was completed, the mixture was dialyzed and freeze-dried to obtain compound 5; S4: 0.71 g of activated carbon was added to 11 mL of ultrapure water, and ultrasonic stirring was performed. Then, 0.08 g of EDC and 0.015 g of NHS were added to the ultrapure water, and the reaction was stirred for 2 h. Subsequently, 0.0013 g of compound 5 was added, and stirring was continued for 36 h. The mixture was washed and dried to obtain composite chitosan.

[0021] This embodiment discloses a method for preparing a modified gel, comprising the following steps: Q1: Add 31.6 g of N,N-dimethylaminopropane chloride hydrochloride to a container containing 22.5 mL of deionized water, stir and mix, then add 22.5 mL of 40 wt% sodium hydroxide solution, let stand, take the upper layer liquid, add 36.6 g of propane sultone to 175 mL of 1,2-dichloroethane, stir and mix, dropwise add 14 mL of the upper layer liquid, continue the reaction for 7 h, filter, wash, and dry to obtain intermediate A; Q2: Add 3.25g starch to 7mL deionized water, stir to mix, then add 10mL sodium hydroxide, heat to 40℃ for 2h, then add 1.15g intermediate A, continue to react for 6h, after the reaction is completed, cool, adjust the pH to neutral, precipitate, wash, vacuum dry to obtain intermediate B; add 3.7g acrylic acid, 3.7g acrylamide and 0.27g N,N'-methylenebisacrylamide to 27.5mL distilled water, then add 1g intermediate B, after magnetic stirring, adjust the pH, add 0.065g potassium persulfate under nitrogen environment, heat to react, react at 65℃ for 1h, 75℃ for 1h and 85℃ for 1h, after the reaction is completed, soak, filter, wash, dry, crush, sieve to obtain modified gel.

[0022] The present embodiment discloses a desert steppe grass interspecific synergistic enhancer, which is composed of the following ingredients in parts by weight: 57 parts of humic acid, 14 parts of microbial agents, 5 parts of minerals, 10 parts of composite chitosan, and 5.5 parts of modified gel.

[0023] This embodiment discloses a method for preparing a desert steppe grass interspecific synergistic enhancer, comprising the following steps: P1: humic acid and minerals are mixed, then composite chitosan is added, then microbial agents are added, and finally modified gel is added, and the mixture is stirred and mixed to obtain a mixture; P2: The mixture is homogenized, dried and granulated to obtain a desert steppe grass interspecific synergistic enhancer.

[0024] This embodiment discloses a method for applying a desert grassland grass interspecific synergistic enhancer to degraded grassland, comprising the following steps: Step 1: Clear the grass, crush the stones, and then till the soil to a depth of 10-15cm to level the land; Step 2: Mix the enhancer with sheep fescue seeds in a ratio of 1g:15g, then sow them in rows with a sowing depth of 1-2cm and a sowing amount of 1-2kg / mu, irrigate, moisturize, test, and evaluate the recovery effect.

[0025] Example 2: This example discloses a method for preparing a composite chitosan, comprising the following steps: S1: 0.3 g of chitosan was placed in a container containing a mixed solution of 2 mL of acetic acid and 11 mL of N,N-dimethylformamide, and stirred in an oil bath at 85°C for 30 min under a nitrogen atmosphere. Then 1.2 g of sodium azide was added and stirring continued for 6 h. After the stirring was completed, the mixture was cooled, and 1.3 g of triphenylphosphine and 1.7 g of carbon tetrabromide were added in sequence. The mixture was stirred for 42 h, and then methanol was added to quench the reaction. The mixture was washed and dried in vacuo to obtain compound 1. S2: 3.63 g of diglycolamine was added to a container containing 30 mL of chloroform, stirred for 30 min, and then 30 mL of chloroform containing 6.84 g of di-tert-butyl dicarbonate was added to the container through a constant pressure dropping funnel, stirred in an ice-water bath, and after the addition was completed, stirred at room temperature for 12 h. After the reaction was completed, the mixture was washed, dried, filtered, vacuum evaporated, and dried in vacuo to obtain compound 2; 2.1 g of compound 2 was added to a container containing 100 mL of tetrahydrofuran, stirred for 35 min, and then 0.41 g of sodium hydride was added, stirred in an ice bath for 15 min, and then 1.81 g of 5 mL of tetrahydrofuran in 3-bromopropyne was slowly added dropwise to the container. After the addition was completed, the ice-water bath was removed, the reaction was stirred at room temperature for 6 h, and then anhydrous ethanol was added to quench the reaction, rotary evaporated, washed, dried, filtered, purified, and vacuum dried to obtain compound 3; 5 g of compound 3 was added to a container containing 100 mL of dichloromethane, stirred, and then 2 mL of dichloromethane containing 10 mL of trifluoroacetic acid was added dropwise through a constant pressure dropping funnel, the reaction was stirred for 12 h, reduced pressure rotary evaporated, and vacuum dried to obtain compound 4; S3: 0.052 g of compound 1 was added to a container containing 5 mL of dimethyl sulfoxide, and then 0.2 g of compound 4 was added, and stirring was continued for 35 min. Subsequently, 0.06 g of ascorbic acid, 0.032 g of copper bromide and 0.23 mL of N,N-diisopropylethylamine were added, and the reaction was stirred for 36 h under a nitrogen atmosphere. After the reaction was completed, the mixture was dialyzed and freeze-dried to obtain compound 5; S4: 0.6 g of activated carbon was added to 10 mL of ultrapure water, and ultrasonic stirring was performed. Then 0.072 g of EDC and 0.012 g of NHS were added to the ultrapure water, and the reaction was stirred for 2 h. Subsequently, 0.0011 g of compound 5 was added, and stirring was continued for 36 h. The mixture was washed and dried to obtain composite chitosan.

[0026] This embodiment discloses a method for preparing a modified gel, comprising the following steps: Q1: Add 30g of N,N-dimethylaminopropane chloride hydrochloride to a container containing 20mL of deionized water, stir and mix, then add 25mL of 40wt% sodium hydroxide solution, let stand, take the upper layer liquid, add 35g of propane sultone to 150mL of 1,2-dichloroethane, stir and mix, dropwise add 12mL of the upper layer liquid, continue the reaction for 7h, filter, wash, and dry to obtain intermediate A; Q2: Add 3.5g starch to 6mL deionized water, stir to mix, then add 8mL sodium hydroxide, heat to 40℃ for 2h, then add 1g intermediate A, continue to react for 6h, after the reaction is completed, cool, adjust the pH to neutral, precipitate, wash, vacuum dry to obtain intermediate B; add 3g acrylic acid, 4.5g acrylamide and 0.34g N,N'-methylenebisacrylamide to 25mL distilled water, then add 1.2g intermediate B, after magnetic stirring, adjust the pH, add 0.06g potassium persulfate under nitrogen environment, heat to react, react at 65℃ for 1h, 75℃ for 1h and 85℃ for 1h, after the reaction is completed, soak, filter, wash, dry, crush, sieve to obtain modified gel.

[0027] The present embodiment discloses a desert steppe grass interspecific synergistic enhancer, which is composed of the following ingredients in parts by weight: 50 parts of humic acid, 10 parts of microbial agents, 2 parts of minerals, 6 parts of composite chitosan, and 3 parts of modified gel.

[0028] This embodiment discloses a method for preparing a desert steppe grass interspecific synergistic enhancer, comprising the following steps: P1: humic acid and minerals are mixed, then composite chitosan is added, then microbial agents are added, and finally modified gel is added, and the mixture is stirred and mixed to obtain a mixture; P2: The mixture is homogenized, dried and granulated to obtain a desert steppe grass interspecific synergistic enhancer.

[0029] This embodiment discloses a method for applying a desert grassland grass interspecific synergistic enhancer to degraded grassland, comprising the following steps: Step 1: Clear the grass, crush the stones, and then till the soil to a depth of 10-15cm to level the land; Step 2: Mix the enhancer with sheep fescue seeds in a ratio of 1g:15g, then sow them in rows with a sowing depth of 1-2cm and a sowing amount of 1-2kg / mu, irrigate, moisturize, test, and evaluate the recovery effect.

[0030] Example 3: This example discloses a method for preparing a composite chitosan, comprising the following steps: S1: 0.45 g of chitosan was placed in a container containing a mixed solution of 2.4 mL of acetic acid and 12.5 mL of N,N-dimethylformamide, and stirred in an oil bath at 85°C for 30 min under a nitrogen atmosphere. Then 1 g of sodium azide was added and stirring continued for 6 h. After the stirring was completed, the mixture was cooled, and 1.5 g of triphenylphosphine and 2.1 g of carbon tetrabromide were added in sequence. The mixture was stirred for 42 h, and then methanol was added to quench the reaction. The mixture was washed and dried in vacuo to obtain compound 1. S2: 3.85 g of diglycolamine was added to a container containing 30 mL of chloroform, stirred for 30 min, and then 30 mL of chloroform containing 7.12 g of di-tert-butyl dicarbonate was added to the container through a constant pressure dropping funnel, stirred in an ice-water bath, and after the addition was completed, stirred at room temperature for 12 h. After the reaction was completed, the mixture was washed, dried, filtered, vacuum evaporated, and dried in vacuo to obtain compound 2; 2.23 g of compound 2 was added to a container containing 100 mL of tetrahydrofuran, stirred for 35 min, and then 0.54 g of sodium hydride was added, stirred in an ice bath for 15 min, and then 1.93 g of 5 mL of tetrahydrofuran in 3-bromopropyne was slowly added dropwise to the container. After the addition was completed, the ice-water bath was removed, the reaction was stirred at room temperature for 6 h, and then anhydrous ethanol was added to quench the reaction, rotary evaporated, washed, dried, filtered, purified, and vacuum dried to obtain compound 3; 7.5 g of compound 3 was added to a container containing 100 mL of dichloromethane, stirred, and then 2 mL of dichloromethane containing 15 mL of trifluoroacetic acid was added dropwise through a constant pressure dropping funnel, the reaction was stirred for 12 h, reduced pressure rotary evaporated, and vacuum dried to obtain compound 4; S3: 0.064 g of compound 1 was added to a container containing 7.2 mL of dimethyl sulfoxide, and then 0.24 g of compound 4 was added, and stirring was continued for 35 min. Subsequently, 0.09 g of ascorbic acid, 0.036 g of copper bromide and 0.35 mL of N,N-diisopropylethylamine were added, and the mixture was stirred for 36 h under a nitrogen atmosphere. After the reaction was completed, the mixture was dialyzed and freeze-dried to obtain compound 5; S4: 0.92 g of activated carbon was added to 12 mL of ultrapure water, and ultrasonic stirring was performed. Then 0.088 g of EDC and 0.018 g of NHS were added to the ultrapure water, and the reaction was stirred for 2 h. Subsequently, 0.0015 g of compound 5 was added, and stirring was continued for 36 h. The mixture was washed and dried to obtain composite chitosan.

[0031] This embodiment discloses a method for preparing a modified gel, comprising the following steps: Q1: Add 33.2 g of N,N-dimethylaminopropane chloride hydrochloride to a container containing 25 mL of deionized water, stir and mix, then add 20 mL of 40 wt% sodium hydroxide solution, let stand, take the upper layer liquid, add 37.2 g of propane sultone to 200 mL of 1,2-dichloroethane, stir and mix, dropwise add 16 mL of the upper layer liquid, continue the reaction for 7 h, filter, wash, and dry to obtain intermediate A; Q2: Add 3g of starch to 8mL of deionized water, stir to mix, then add 12mL of sodium hydroxide, heat to react at 40℃ for 2h, then add 1.3g of intermediate A, continue to react for 6h, after the reaction is completed, cool, adjust the pH to neutral, precipitate, wash, and vacuum dry to obtain intermediate B; add 4.5g of acrylic acid, 3g of acrylamide and 0.2g of N,N'-methylenebisacrylamide to 30mL of distilled water, then add 0.8g of intermediate B, after magnetic stirring, adjust the pH, add 0.07g of potassium persulfate under nitrogen environment, heat to react, react at 65℃ for 1h, 75℃ for 1h and 85℃ for 1h, after the reaction is completed, soak, filter, wash, dry, crush, sieve to obtain modified gel.

[0032] The present embodiment discloses a desert steppe grass interspecific synergistic enhancer, which is composed of the following ingredients in parts by weight: 65 parts of humic acid, 18 parts of microbial agents, 8 parts of minerals, 14 parts of composite chitosan, and 8 parts of modified gel.

[0033] This embodiment discloses a method for preparing a desert steppe grass interspecific synergistic enhancer, comprising the following steps: P1: humic acid and minerals are mixed, then composite chitosan is added, then microbial agents are added, and finally modified gel is added, and the mixture is stirred and mixed to obtain a mixture; P2: The mixture is homogenized, dried and granulated to obtain a desert steppe grass interspecific synergistic enhancer.

[0034] This embodiment discloses a method for applying a desert grassland grass interspecific synergistic enhancer to degraded grassland, comprising the following steps: Step 1: Clear the grass, crush the stones, and then till the soil to a depth of 10-15cm to level the land; Step 2: Mix the enhancer with sheep fescue seeds in a ratio of 1g:15g, then sow them in rows with a sowing depth of 1-2cm and a sowing amount of 1-2kg / mu, irrigate, moisturize, test, and evaluate the recovery effect.

[0035] Comparative Example 1: Compared with Example 1, in the preparation process of the desert steppe grass interspecific synergistic enhancer in Comparative Example 1, no composite chitosan is added, and other conditions remain unchanged.

[0036] Comparative Example 2: Compared with Example 1, in Comparative Example 2, during the preparation of the desert steppe grass interspecific synergistic enhancer, no modified gel was added, and other conditions remained unchanged.

[0037] Comparative Example 3: Compared with Example 1, in the preparation process of the desert steppe grass interspecific synergistic enhancer in Comparative Example 3, ordinary chitosan is used instead of composite chitosan, and other conditions remain unchanged.

[0038] Comparative Example 4: Compared with Example 1, in Comparative Example 4, intermediate A and intermediate B are not added during the preparation of the modified gel, and other conditions remain unchanged.

[0039] Experimental Example: The samples prepared according to Examples 1-3 and Comparative Examples 1-4 were applied to the planting process of Leymus chinensis, and a blank control group was set (no desert steppe grass interspecific synergist was applied during the planting process). The density, biomass and coverage of Leymus chinensis were tested. The test results are shown in Table 1:

[0040] It can be seen from the test results in Table 1 that the interspecific synergistic enhancers of desert steppe grasses prepared in Examples 1-3 of the present invention can effectively improve the density, biomass and coverage of Leymus chinensis. It can be seen from the comparison between Comparative Example 1 and Examples 1-5 that the addition of composite chitosan can effectively improve the density, biomass and coverage of Leymus chinensis; it can be seen from the comparison between Comparative Example 2 and Examples 1-5 that the addition of modified gel can effectively improve the density, biomass and coverage of Leymus chinensis.

[0041] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

[0042] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. Desert steppe grass interspecific synergistic enhancer, characterized in that: The invention is composed of the following components in parts by weight: 50-65 parts of humic acid, 10-18 parts of microbial agents, 2-8 parts of minerals, 6-14 parts of composite chitosan, and 3-8 parts of modified gel, wherein the composite chitosan is prepared from chitosan, sodium azide, diglycolamine, sodium hydride, 3-bromopropyne, trifluoroacetic acid, ascorbic acid and activated carbon, and the modified gel is prepared from starch, N,N-dimethylaminochloropropane hydrochloride, propane sultone, 1,2-dichloroethane, acrylic acid, acrylamide and N,N'-methylenebisacrylamide.

2. The desert steppe grass interspecific synergistic enhancer according to claim 1, characterized in that: The microbial agent is composed of one or more of Azospirillum, Pseudomonas, Bacillus colloidus, Bacillus subtilis, arbuscular mycorrhizal fungi and actinomycetes, and the minerals are composed of one or more of potassium silicate, sodium silicate, apatite, superphosphate, potassium feldspar, potassium sulfate, calcium carbonate, calcium sulfate, borax, zinc sulfate, copper sulfate and montmorillonite.

3. The desert steppe grass interspecific synergistic enhancer according to claim 1, characterized in that: The preparation method of the composite chitosan comprises the following steps: S1: chitosan is placed in a container containing a mixed solution of acetic acid and N,N-dimethylformamide, stirred in an oil bath under a nitrogen atmosphere, and then sodium azide is added and stirred continuously. After the stirring is completed, the mixture is cooled, triphenylphosphine and carbon tetrabromide are added in sequence, stirred for reaction, and then methanol is added to quench the reaction, washed, and vacuum dried to obtain compound 1; S2: Add diglycolamine to a container containing chloroform, stir, then add chloroform containing di-tert-butyl dicarbonate to the container through a constant pressure dropping funnel, stir in an ice-water bath, and after the addition is complete, stir and react at room temperature. After the reaction is complete, wash, dry, filter, vacuum evaporate, and vacuum dry to obtain compound 2; add compound 2 to a container containing tetrahydrofuran, stir, then add sodium hydride, stir in an ice bath, and then slowly drop tetrahydrofuran containing 3-bromopropyne into the container through a constant pressure dropping funnel. After the addition is complete, remove the ice-water bath, stir and react at room temperature, then add anhydrous ethanol to quench the reaction, rotary evaporate, wash, dry, filter, purify, and vacuum dry to obtain compound 3; add compound 3 to a container containing dichloromethane, stir, then drop dichloromethane containing trifluoroacetic acid through a constant pressure dropping funnel, stir and react, vacuum evaporate, and vacuum dry to obtain compound 4; S3: Compound 1 is added to a container containing dimethyl sulfoxide, and then compound 4 is added, and stirring is continued. Subsequently, ascorbic acid, copper bromide and N,N-diisopropylethylamine are added, and the mixture is stirred under a nitrogen atmosphere for reaction. After the reaction is completed, the mixture is dialyzed and freeze-dried to obtain compound 5; S4: Add activated carbon to ultrapure water, stir ultrasonically, then add EDC and NHS to ultrapure water, stir to react, then add compound 5, continue stirring, wash, and dry to obtain composite chitosan.

4. The desert steppe grass interspecific synergistic enhancer according to claim 3, characterized in that: In the S1, the amount ratio of chitosan, acetic acid, N,N-dimethylformamide, sodium azide, triphenylphosphine and carbon tetrabromide is (0.3-0.45) g: (2-2.4) mL: (11-12.5) mL: (1-1.2) g: (1.3-1.5) g: (1.7-2.1) g, the oil bath stirring temperature is 80-85°C, the stirring time is 30-45 min, the continued stirring time is 4-6 h, and the stirring reaction time is 36-42 h.

5. The desert steppe grass interspecific synergistic enhancer according to claim 3, characterized in that: In S2, the dosage ratio of diglycolamine and di-tert-butyl dicarbonate is (3.63-3.85) g: (6.84-7.12) mL, the stirring time is 30-45 min, and the stirring reaction time at room temperature is 10-12 h; the dosage ratio of compound 2, sodium hydride and 3-bromopropyne is (2.1-2.23) g: (0.41-0.54) g: (1.81-1.93) g, the stirring time is 30-45 min, the ice bath stirring time is 10-15 min, and the stirring reaction time at room temperature is 4-6 h; the dosage ratio of compound 3 and trifluoroacetic acid is (5-7.5) g: (10-15) mL, and the stirring reaction time is 10-12 h.

6. The desert steppe grass interspecific synergistic enhancer according to claim 3, characterized in that: In S3, the dosage ratio of compound 1, dimethyl sulfoxide, compound 4, ascorbic acid, copper bromide and N,N-diisopropylethylamine is (0.052-0.064) g: (5-7.2) mL: (0.2-0.24) g: (0.06-0.09) g: (0.032-0.036) g: (0.23-0.35) mL, and the stirring time is continued for 30-45 min. , the stirring reaction time is 36-40h; in the S4, the dosage ratio of activated carbon, ultrapure water, EDC, NHS and compound 5 is (0.6-0.92) g: (10-12) mL: (0.072-0.088) g: (0.012-0.018) g: (0.0011-0.0015) g, the stirring reaction time is 1-2h, and the stirring time is continued for 36-42h.

7. The desert steppe grass interspecific synergistic enhancer according to claim 1, characterized in that: The preparation method of the modified gel comprises the following steps: Q1: Add N,N-dimethylaminopropane chloride hydrochloride to a container containing deionized water, stir and mix, then add sodium hydroxide solution, let stand, take the upper layer of liquid, add propane sultone to 1,2-dichloroethane, stir and mix, drop the upper layer of liquid, continue the reaction, filter, wash, and dry to obtain intermediate A; Q2: Add starch to deionized water, stir to mix, then add sodium hydroxide, heat to react, then add intermediate A, continue to react, after the reaction is completed, cool, adjust the pH to neutral, precipitate, wash, vacuum dry to obtain intermediate B; add acrylic acid, acrylamide and N,N'-methylenebisacrylamide to distilled water, then add intermediate B, after magnetic stirring, adjust the pH, add potassium persulfate under nitrogen environment, heat to react, after the reaction is completed, soak, filter, wash, dry, crush, sieve to obtain modified gel.

8. The desert steppe grass interspecific synergistic enhancer according to claim 7, characterized in that: In Q1, the dosage ratio of N,N-dimethylamino chloropropane hydrochloride, deionized water and sodium hydroxide solution is (30-33.2) g: (20-25) mL: (20-25) mL, the mass fraction of the sodium hydroxide solution is 40wt%, the dosage ratio of propane sultone, 1,2-dichloroethane and the upper liquid is (35-37.2) g: (150-200) mL: (12-16) mL, and the reaction time is 6-8h; in Q2, the dosage ratio of starch, deionized water, sodium hydroxide and intermediate A is (3-3.5) g: (6- 8) mL: (8-12) mL: (1-1.3) g, the heating reaction temperature is 40-42°C, the reaction time is 1-2h, and the continued reaction time is 4-6h; the dosage ratio of acrylic acid, acrylamide, N,N'-methylenebisacrylamide, distilled water, intermediate B and potassium persulfate is (3-4.5) g: (3-4.5) g: (0.2-0.34) g: (25-30) mL: (0.8-1.2) g: (0.06-0.07) g, the heating reaction temperature is 65°C for 1h, 75°C for 1h and 85°C for 1h.

9. The desert steppe grass interspecific synergistic enhancer according to any one of claims 1 to 8, characterized in that: The preparation method of the desert steppe grass interspecific synergistic enhancer comprises the following steps: P1: humic acid and minerals are mixed, then composite chitosan is added, then microbial agents are added, and finally modified gel is added, and the mixture is stirred and mixed to obtain a mixture; P2: The mixture is homogenized, dried and granulated to obtain a desert steppe grass interspecific synergistic enhancer.

10. The desert steppe grass interspecific synergistic enhancer according to any one of claims 1 to 8, characterized in that: The method for applying desert steppe grass interspecific synergistic enhancer to degrade grassland comprises the following steps: Step 1: Clear the grass, crush the stones, and then till the soil to a depth of 10-15cm to level the land; Step 2: Mix the enhancer with grass seeds in a ratio of 1g:15g, then sow in rows with a sowing depth of 1-2cm and a sowing amount of 1-2kg / mu, irrigate, moisturize, test, and evaluate the recovery effect.

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