A biological conditioner for coastal saline soil improvement and crop growth promotion and application thereof

Abstract

The application discloses a kind of biological conditioner for coastal saline soil improvement and crop growth promotion and application, belong to soil improvement and crop cultivation technical field.The biological conditioner is made of small molecule organic carbon, polyglutamic acid, brown ball nitrogen-fixing bacteria BNCC192292 and bacillus amyloliquefaciens, and the compounding ratio of two kinds of bacterial agents is 1:1.The biological conditioner raw material is reasonable, and each raw material has specific function: small molecule organic carbon and polyglutamic acid can effectively increase soil organic matter content and total nitrogen content without increasing soil salt content, and are also good survival organic carriers of effective bacteria;Brown ball nitrogen-fixing bacteria and bacillus amyloliquefaciens can increase soil total nitrogen content and improve crop yield.The biological conditioner as a whole can not only significantly reduce soil salt content, promote crop germination, improve soil microbial activity and increase crop yield, but also has the advantages of sufficient raw materials, low cost, easy implementation, green environmental protection and the like.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of soil improvement and crop cultivation, and particularly relates to a biological conditioner for coastal saline soil improvement and crop growth promotion and application. BACKGROUND

[0002] The problem of saline soil is a relatively serious ecological and environmental problem. Coastal saline-alkali soil is an important part of saline soil, but this area is directly or indirectly affected by seawater or sea tide, and seawater is prone to backflow, so the salinization problem is particularly prominent. The high content of base ions and high pH stress in saline-alkali soil can cause soil fertility to decline, affect the growth of crop roots, hinder the absorption and utilization of water and nutrients by crops, inhibit the growth and development of crops, and lead to crop yield reduction. It is estimated that 1 / 3 of the food reduction is related to the reduction of soil organic matter and land degradation, which seriously affects the development of agriculture. Therefore, alleviating soil salinization and improving crop yield are of great significance to the high-quality development of agriculture.

[0003] Currently, the methods for improving saline-alkali soil mainly involve physical, chemical and biological three basic policies. Patent CN118077358A relates to a saline-alkali soil improvement method, which includes using a salt washing production line to reduce the pH of saline-alkali soil, using a batching production line to improve the soil, and subsequent planting and maintenance steps. The specific steps include soil cleaning, mud screening, water-soil separation, soil improvement, and saline-alkali land arrangement. Patent CN117521411A simulates a variety of crop generation schemes for saline-alkali soil through simulation, and proposes a method and device for improving saline-alkali soil by coordinating irrigation, drainage and fertilization, as well as an electronic device and a storage medium. These methods aim to improve the soil environment of saline-alkali soil and improve crop yield by optimizing the synergistic effect of irrigation, drainage and fertilization. However, there are many problems such as large labor intensity, high investment cost, short maintenance time, etc. Therefore, exploring saline-alkali soil improvement materials and methods that are simple in technology, low in cost and friendly to the environment is an important goal and direction for saline-alkali soil improvement.

[0004] As one of the main types of low-yield land in China, saline-alkali soil is widely distributed, and its carbon and nitrogen content is low, so the potential of increasing nitrogen and carbon sequestration in saline-alkali soil is huge. Studies have shown that adding organic matter can increase soil carbon and nitrogen storage, but different organic matters have different effects on improving saline-alkali land, and there are also some problems. For example, the types, sources and nutrient content of organic fertilizer differ greatly, and the application amount is not easy to control, and the fertilizer efficiency is slow, which is difficult to meet the needs of crop rapid growth; the planting and management of green manure crops require certain technology and experience, and the management is difficult and the crop growth cycle is long; the production cost of biochar is high, which is difficult to promote in a large area, and it is an alkaline substance, and the application technology in saline-alkali land improvement is not mature enough and needs further research and improvement. Zhao Huili et al. found that the application of desulfurization gypsum + straw can significantly increase the microbial nitrogen content and the proportion of large aggregates, but the composition of desulfurization gypsum contains sulfate, which may exacerbate the inhibition of nitrification, and the addition of straw will increase CO2 emission. The microorganisms in the microbial agent can reproduce in the soil, thereby improving the soil nutrient status, increasing the soil enzyme activity and microbial diversity, and providing a good living environment for crop growth. CN 118308114A discloses a biological soil conditioner for improving saline-alkali soil and a preparation method thereof. The conditioner is prepared from citric acid modified chitosan, biomass carbon nanotube, mixed straw powder, humic acid, urea, microbial agent and calcium dihydrogen phosphate, which can effectively adjust the soil pH, improve the microbial activity in the soil and promote the recovery of organic matter. However, the high salt content of saline-alkali soil poses a challenge to the survival and reproduction of microorganisms. Some microbial agents may not survive or function effectively in a high-salt environment, thereby affecting the improvement effect, and the low organic matter content is not conducive to the growth and reproduction of microorganisms. Although the microbial agent can supplement beneficial bacteria, its effect may be limited in an environment with low organic matter content.

[0005] Therefore, it is urgent to carry out more extensive control measures on the basis of the above measures. SUMMARY

[0006] To solve the above technical problems, the present application provides a biological conditioner for improving coastal saline soil and promoting crop growth. The conditioner is made of small molecular organic carbon, polyglutamic acid, azotobacter chroococcum bacterial agent and bacillus amyloliquefaciens bacterial agent, which has the advantages of sufficient raw materials, low cost, easy implementation and green environmental protection, can significantly reduce the salt content of soil, promote crop germination, improve soil microbial activity and increase crop yield.

[0007] To achieve the above purpose, the present application adopts the following technical solutions:

[0008] The application aims to provide a biological conditioner for coastal saline soil improvement and crop growth promotion, which is prepared by mixing small-molecule organic carbon liquid fertilizer, polyglutamic acid liquid fertilizer, Azotobacter chroococcum bacterial liquid and Bacillus amyloliquefaciens bacterial liquid.

[0009] Further, the active small-molecule organic carbon content in the small-molecule organic carbon liquid fertilizer is greater than or equal to 110 g / L.

[0010] Further, the polyglutamic acid content in the polyglutamic acid liquid fertilizer is 4-6%.

[0011] Further, the Azotobacter chroococcum is Azotobacter chroococcum BNCC192292.

[0012] Further, the effective viable bacterial count in the Azotobacter chroococcum bacterial liquid and the Bacillus amyloliquefaciens bacterial liquid is 2.0-2.5 x 10 8 cfu / ml.

[0013] Further, the volume ratio of the small-molecule organic carbon liquid fertilizer, the polyglutamic acid liquid fertilizer, the Azotobacter chroococcum bacterial liquid and the Bacillus amyloliquefaciens bacterial liquid is (1.2-1.3):(0.75-1.25):(0.75-1.25):(0.75-1.25).

[0014] Further, the volume ratio of the Azotobacter chroococcum bacterial liquid and the Bacillus amyloliquefaciens bacterial liquid is 1:1.

[0015] The second purpose of the application is to provide an application of the biological conditioner in coastal saline soil improvement and / or crop growth promotion.

[0016] Further, the application is an application in promoting crop germination.

[0017] Further, the application is an application in promoting crop growth and improving crop yield.

[0018] The soil conditioner in the application is obtained through multiple formula improvements and germination test verifications, and can improve soil nitrogen fixation capacity, balance soil nutrients, reduce soil salt content, reduce continuous cropping obstacles and improve crop yield and quality.

[0019] (1) It has the functions of reducing coastal soil salinization, increasing soil organic matter and improving crop yield.

[0020] (2) The raw materials are reasonably compounded, and each raw material has a specific function: small molecule organic carbon and polyglutamic acid do not increase soil salinity, but effectively increase soil organic matter content and total nitrogen content, and are good organic carriers for the survival of effective bacteria; brown azotobacter and amyloliquefaciens can increase soil total nitrogen content and increase crop yield.

[0021] (3) It is easy to apply in the field and is a farmer-friendly microbial fertilizer. Attached Figure Description

[0022] Figure 1 These are photographs of *Azotobacter brownii* grown in different salt concentrations in culture media in Example 1 of this invention after one day;

[0023] Figure 2 This is a schematic diagram showing the number of viable bacteria of *Azotobacter chrysogenum* after one day of growth under different salt concentrations in Example 1 of the present invention.

[0024] Figure 3 These are photographs of Bacillus amyloliquefaciens grown in different salt concentrations in culture media after one day, as shown in Example 2 of this invention.

[0025] Figure 4 This is a schematic diagram showing the number of viable bacteria of Bacillus amyloliquefaciens after one day of growth under different salt concentrations in Example 2 of the present invention;

[0026] Figures 5 to 7 These are photographs showing the germination of wheat seeds grown for 4 days under salt concentrations of 1%, 3%, and 5% in Example 4 of this invention.

[0027] Figures 8 to 10 These are photographs showing the germination of wheat seeds grown for 7 days under salt concentrations of 1%, 3%, and 5% in Example 4 of this invention. Detailed Implementation

[0028] The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the invention. Any modifications or substitutions made to the methods, steps, or conditions of the present invention without departing from the spirit and essence of the invention are within the scope of the invention. Unless otherwise specified, the products and equipment used in the following embodiments are commercially available, and the methods used are consistent with conventional methods unless otherwise specified.

[0029] The culture medium used in this invention:

[0030] LB solid medium: 10g tryptone, 5g yeast extract, 10g sodium chloride, 15g agar powder, 1000ml water.

[0031] LB liquid medium: 10g tryptone, 5g yeast extract, 10g sodium chloride, 1000ml water.

[0032] The raw materials used in the present application are as follows:

[0033] Small-molecule organic carbon fertilizer (active small-molecule organic carbon content ≥ 110 g / L, Beijing Aigelu International Agricultural Technology Co., Ltd.), polyglutamic acid fertilizer (polyglutamic acid content 5% (volume percentage), Beijing Aigelu International Agricultural Technology Co., Ltd.), Azotobacter chroococcum (BNCC192292, Beijing Jiyan Technology Co., Ltd.), Bacillus amyloliquefaciens (Hebei Xunwei Biological Technology Co., Ltd., Fertilizer Registration Certificate No.: Microbial Fertilizer (2021) Zhunzi (10647) No.).

[0034] The technical solutions of the present application will be further described in detail below in combination with examples.

[0035] Example 1: Salt tolerance determination of Azotobacter chroococcum BNCC192292

[0036] The strain was inoculated into 100 ml of LB liquid medium and cultured in a constant temperature incubator for 12 hours, and then inoculated into LB solid medium with salt concentrations (salinity adjusted by NaCl reagent) of 0%, 1%, 3%, 5%, 7%, 9%, and 11% in turn, and cultured at 29°C for 1 day. The culture dish photos are shown in Figure 1 , and the total number of single colonies on the culture medium was detected. The number of colonies is shown in Figure 2 .

[0037] As can be seen from Figures 1 to 2 , the number of colonies of Azotobacter chroococcum BNCC192292 is larger at 1% salt concentration, and the number of colonies is basically the same at 3% and 0% salt concentration.

[0038] Example 2: Salt tolerance determination of Bacillus amyloliquefaciens

[0039] The strain was inoculated into 100 ml of LB liquid medium and cultured in a constant temperature incubator for 12 hours, and then inoculated into LB solid medium with salt concentrations (salinity adjusted by NaCl reagent) of 0%, 1%, 3%, 5%, 7%, 9%, and 11% in turn, and cultured at 29°C for 1 day. The culture dish photos are shown in Figure 3 , and the total number of single colonies on the culture medium was detected. The number of colonies is shown in Figure 4 .

[0040] As can be seen from Figures 3 to 4 , the number of colonies of Bacillus amyloliquefaciens is larger at 1% salt concentration, and the number of colonies is basically the same at 3% and 0% salt concentration.

[0041] Example 3: Optimal compounding ratio of two bacterial agents under different salt concentrations

[0042] The two strains in Examples 1-2 were inoculated into 100 ml of LB liquid medium, and were cultured in a constant temperature incubator for 12 hours, and the OD600 was adjusted to 1. The two strains were mixed in a ratio of 1:1, 1:2 and 2:1 in LB liquid medium with a salt concentration of 1%, 3% and 5%, respectively, and were cultured in a constant temperature incubator at 29°C for 24 hours. The OD value was measured. The results are shown in Table 1.

[0043] Table 1 OD600 values of the two bacterial agents cultured under different salt concentrations

[0044]

[0045] The results in Table 1 show that under three salt stress conditions (1%, 3%, and 5%), the activity of the two bacteria combined was the largest when the ratio of Azotobacter chroococcum and Bacillus amyloliquefaciens was 1:1. Under 1% salt stress, the OD600 value of 1:1 was 1.94% and 10.06% higher than that of 1:2 and 2:1, respectively. Under 3% salt stress, the OD600 value of 1:1 was 6.07% and 0.15% higher than that of 1:2 and 2:1, respectively. Under 5% salt stress, the OD600 value of 1:1 was 3.34% and 1.51% higher than that of 1:2 and 2:1, respectively.

[0046] Example 4 Effect of the two bacterial agents combined on the growth of wheat under different salt concentrations

[0047] First, Azotobacter chroococcum and Bacillus amyloliquefaciens bacterial solutions were prepared, in which the effective viable count of Azotobacter chroococcum in the Azotobacter chroococcum bacterial solution was 2.39 x 10 8 CFU / mL, and the effective viable count of Bacillus amyloliquefaciens in the Bacillus amyloliquefaciens bacterial solution was 2.12 x 10 8 CFU / mL.

[0048] Then 24 treatments were set, each treatment with three repetitions. The 24 treatments were as follows: 1) water (CK); 2) Azotobacter chroococcum and Bacillus amyloliquefaciens liquid complex ratio 1:1 (10 mL:10 mL) inoculant (A1); 3) Azotobacter chroococcum and Bacillus amyloliquefaciens liquid complex ratio 1:2 (10 mL:20 mL) inoculant (A2); 4) Azotobacter chroococcum and Bacillus amyloliquefaciens liquid complex ratio 2:1 (20 mL:10 mL) inoculant (A3); 5) small molecule organic carbon fertilizer + polyglutamic acid fertilizer volume ratio 1.25:1 (12.5 mL:10 mL) conditioner (B); 6) small molecule organic carbon fertilizer + polyglutamic acid fertilizer + Azotobacter chroococcum liquid + Bacillus amyloliquefaciens liquid complex ratio 1.25:1:1:1 (12.5 mL:10 mL:10 mL:10 mL) conditioner (B1); 7) small molecule organic carbon fertilizer + polyglutamic acid fertilizer + Azotobacter chroococcum liquid + Bacillus amyloliquefaciens liquid complex ratio 1.25:1:1:2 (12.5 mL:10 mL:10 mL:20 mL) conditioner (B2); 8) small molecule organic carbon fertilizer + polyglutamic acid fertilizer + Azotobacter chroococcum liquid and Bacillus amyloliquefaciens liquid complex ratio 1.25:1:2:1 (12.5 mL:10 mL:20 mL:10 mL) conditioner (B3) under 1%, 3%, and 5% salt concentrations.

[0049] Then full and no pest size similar Cangmai 6002 wheat seeds were selected, put into 5 times the amount of water, and gently stirred for about 15 min. Washed with 75% ethanol for 30 seconds, then washed with ultrapure water, then soaked with 1% sodium hypochlorite for 15 minutes, and finally washed with ultrapure water. The washed wheat seeds were placed in a culture dish lined with qualitative filter paper, 10 seeds were placed in each culture dish, and a total of 10 milliliters of liquid was added to the culture dish. Put into a light incubator for 7 days, the light and dark time allocation is 1:2. Observe the germination and growth of wheat, the results are shown in Table 2. Figures 5 to 10

[0050] Table 2 Wheat germination rate (%) under different treatments

[0051]

[0052]

[0053] ​The results of Table 2 show that the germination rate of each treatment wheat is improved, wherein the effect of A1 treatment in single application of bacterial fertilizer is the most significant, the wheat germination rate of A1 treatment is increased by 10.81% compared with CK treatment, in the treatment of applying small molecule carbon fertilizer, polyglutamic acid fertilizer and different proportions of bacterial fertilizer, the effect of B1 treatment is the best, the wheat germination rate is increased by 14.87% compared with CK treatment. This shows that the compound bacterial fertilizer has a growth promoting effect on wheat germination, and the growth promoting effect is the most obvious when the compound ratio of azotobacter chroococcum and bacillus amyloliquefaciens is 1:1. The test shows that on the basis of applying organic fertilizer, applying compound bacterial agent also promotes the germination rate of wheat, and the wheat germination rate of B1 treatment is increased by 3.66% compared with A1 treatment. Therefore, the effect is the best when the compound ratio of azotobacter chroococcum and bacillus amyloliquefaciens in the compound bacterial fertilizer is 1:1.

[0054] Example 5 Influence of compound of four substances on yield of wheat and corn and soil index

[0055] The corn variety Weike 702 and the wheat variety Cangmai 6002 are used for the test, and the treatments are set as follows: (1) CK: control; (2) T1: small molecule organic carbon fertilizer (75L / hm 2 ) + polyglutamic acid fertilizer (60L / hm 2 ); (3) T2: azotobacter chroococcum liquid (75L / hm 2 ) + bacillus amyloliquefaciens liquid (75L / hm 2 ); (4) T3: small molecule organic carbon fertilizer (75L / hm 2 ) + polyglutamic acid fertilizer (60L / hm 2 ) + azotobacter chroococcum liquid (60L / hm 2 ) + bacillus amyloliquefaciens liquid (60L / hm 2 ). The effective viable count of azotobacter chroococcum and bacillus amyloliquefaciens liquid is the same as that in Example 4. The influence of each treatment on yield of wheat and corn and soil index in slightly salinized farmland (salt content 1.12g / kg) is shown in Table 3, and the influence of each treatment on yield of wheat and corn and soil water-soluble salt content in moderately salinized farmland (salt content 2.05g / kg) is shown in Table 4.

[0056] Table 3 Influence of each treatment on yield of wheat and corn and soil index in slightly salinized farmland (salt content 1.12g / kg)

[0057]

[0058] As shown in Table 3, compared with CK, each treatment increased the yield of wheat and corn and soil nutrients, and reduced the soil pH and salt content, wherein the effect of T3 treatment was higher than that of T1 and T2 treatments. The yield of wheat and corn of each treatment was increased by 0.79% to 7.90% and 6.46% to 9.30% respectively compared with CK, wherein the yield of T3 treatment was the highest, which was 5688.77 kg / hm 2 (wheat) and 12285.48 kg / hm 2 (corn). The pH and salt content of each treatment were reduced by 0.95% to 2.79% and 6.86% to 15.69% respectively compared with CK. The organic matter content of T1, T2 and T3 treatments was increased by 5.35%, 6.39% and 7.21% respectively compared with CK, and the total nitrogen was increased by 14.29%, 18.37% and 21.43% respectively. Compared with CK, the chlorophyll content of wheat and corn of T3 treatment was increased by 3.99% and 6.31% respectively.

[0059] Table 4 shows the effect of each treatment on the yield of wheat and corn and soil water-soluble salt content in a moderately salinized farmland (salt content 2.05 g / kg)

[0060]

[0061] As shown in Table 4, compared with CK, each treatment increased the yield of wheat and corn and soil nutrients, and reduced the soil pH and salt content. The yield of T3 treatment was the highest, which was 4772.98 kg / hm 2 (wheat) and 11289.35 kg / hm 2 (corn), which was increased by 29.04% and 14.43% respectively compared with CK; the pH and salt content were reduced by 0.81% to 2.90% and 3.03% to 9.09% respectively compared with CK;

[0062] The organic matter content of T1, T2 and T3 treatments was increased by 6.09%, 6.86% and 7.54% respectively compared with CK, and the total nitrogen was increased by 9.33%, 13.33% and 21.33% respectively. Compared with CK, the chlorophyll content of wheat and corn of T3 treatment was increased by 5.12% and 3.09% respectively.

[0063] The above examples only describe the preferred modes of the present application, and do not limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements to the technical solutions of the present application made by those skilled in the art shall fall within the protection scope determined by the claims of the present application.

Claims

1. A bioconditioning agent for improving coastal saline soil and promoting crop growth, characterized in that, Its raw material components include small molecule organic carbon, polyglutamic acid, azotobacter chrysogenum, and Bacillus amyloliquefaciens, and it is made by mixing small molecule organic carbon liquid fertilizer, polyglutamic acid liquid fertilizer, azotobacter chrysogenum liquid and Bacillus amyloliquefaciens liquid; The liquid fertilizer containing small molecule organic carbon has an active small molecule organic carbon content ≥110g / L; The polyglutamic acid liquid fertilizer contains 4-6% polyglutamic acid. The brown azotocin bacterium is BNCC192292; The effective viable counts of both the *Azotobacter chrysogenum* bacterial suspension and the *Bacillus amyloliquefaciens* bacterial suspension were 2.0~2.5×10⁻⁶. 8 cfu / ml; The volume ratio of the small molecule organic carbon liquid fertilizer, the polyglutamic acid liquid fertilizer, the azotobacter globosum bacterial solution, and the Bacillus amyloliquefaciens bacterial solution is 1.25:1:1:

1.

2. The application of the biological conditioner according to claim 1 in the improvement of coastal saline soil and / or the promotion of crop growth.

3. The application according to claim 2, characterized in that, The application described is in promoting crop germination.

4. The application according to claim 2, characterized in that, The application is in promoting crop growth and increasing crop yield.

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