A method for improving nitrogen and phosphorus utilization efficiency in red soil and its application

Abstract

The present invention relates to a method for improving nitrogen and phosphorus utilization efficiency in red soil and its application. The method comprises applying microalgae cell sap to the red soil; the microalgae include Scenedesmus and / or Chlorella. The present invention develops a novel method and strategy for improving nitrogen and phosphorus utilization efficiency in red soil. This method and strategy is simple to implement and is suitable for cultivating various crops in red soil. It also significantly improves nitrogen and phosphorus utilization efficiency in red soil and crop yields.

Description

Technical Field

[0001] The invention belongs to the technical field of agriculture, and relates to a method for improving the utilization efficiency of nitrogen and phosphorus in brick red soil and an application thereof, and particularly relates to a method for improving the utilization efficiency of nitrogen and phosphorus in brick red soil and an application thereof in improving the yield of crops planted in brick red soil. Background Art

[0002] Nitrogen and phosphorus are crucial soil nutrients, crucial for maintaining crop yields. Brick red soil, a deep red soil developed through intense iron-aluminization and bioaccumulation, derives its name from its color, which resembles burnt red bricks. Brick red soils enjoy favorable hydrothermal conditions and have long been important crop production areas in southern my country. However, nitrogen and phosphorus use efficiencies in brick red soils are generally low, with nitrogen utilization rates around 30% and phosphorus utilization rates around 20%. These low nitrogen and phosphorus utilization rates limit their development and utilization.

[0003] The low nitrogen and phosphorus utilization efficiency of brick red soil is closely related to its characteristics, such as low pH and weak water and fertilizer retention capacity. Improving the physical and chemical properties of brick red soil through technical means, thereby improving the nitrogen and phosphorus utilization efficiency of brick red soil, is an important way to improve the productivity of brick red soil arable land. Improving the nitrogen and phosphorus utilization efficiency of brick red soil can be achieved by improving the soil pH, increasing the soil microbial biomass, and increasing the soil organic matter content. Microorganisms are important reservoirs of soil nitrogen and phosphorus. Excess nitrogen and phosphorus applied to the soil can be absorbed and stored by soil microorganisms and then re-enter the soil environment as the microorganisms die and are absorbed and utilized by crops. Applying organic fertilizers can improve the soil's water and fertilizer retention capacity, promote nitrogen and phosphorus fixation, extend nitrogen and phosphorus turnover time, and improve nitrogen and phosphorus utilization efficiency. Summary of the Invention

[0004] In view of the deficiencies in the prior art, the object of the present invention is to provide a method for improving the nitrogen and phosphorus utilization efficiency of brick red soil and its application, and specifically to provide a method for improving the nitrogen and phosphorus utilization efficiency of brick red soil and its application in increasing the yield of crops grown in brick red soil.

[0005] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a method for improving nitrogen and phosphorus utilization efficiency in red soil, the method comprising: applying microalgae cell sap to the red soil; the microalgae comprising Scenedesmus and / or Chlorella.

[0007] The present invention creatively discovered that applying cell sap of Scenedesmus and / or Chlorella to brick red soil can significantly improve the brick red soil's utilization efficiency of nitrogen and phosphorus. Scenedesmus and / or Chlorella convert atmospheric CO2 into organic carbon through photosynthesis and input it into the soil, which can improve the soil's water and fertilizer retention capacity, promote nitrogen and phosphorus fixation, extend nitrogen and phosphorus turnover time, and improve nitrogen and phosphorus utilization efficiency; at the same time, they can also secrete a large amount of active nutrients and hormones, significantly promoting the increase of microbial biomass in the brick red soil. As a storage reservoir of soil nitrogen and phosphorus, microorganisms can absorb and store excess nitrogen and phosphorus in their bodies, and then re-enter the soil environment as they die and are absorbed and utilized by crops; in addition, the application of microalgae cell sap to acidic brick red soil can also neutralize soil acidity and improve nitrogen and phosphorus utilization.

[0008] The present invention develops a new method strategy for improving the nitrogen and phosphorus utilization efficiency of brick red soil. The operation and implementation of this method strategy are very simple, and it is suitable for planting brick red soil of various crops. It is very effective in improving the nitrogen and phosphorus utilization efficiency of brick red soil and crop yield.

[0009] Preferably, the microalgae cell fluid includes active microalgae cell fluid and / or inactivated microalgae cell fluid, preferably active microalgae cell fluid.

[0010] The present invention also found that both active microalgae cell fluid and inactivated microalgae cell fluid can improve the nitrogen and phosphorus utilization efficiency of red soil. Compared with inactivated microalgae cell fluid, active microalgae cell fluid is more significant in the above effect.

[0011] The Scenedesmus or Chlorella used in the method of the present invention is not limited to a specific algae strain. Any Scenedesmus or Chlorella can achieve the above-mentioned effects to varying degrees. The following specific Scenedesmus and Chlorella are more preferred.

[0012] Preferably, the Scenedesmus sp. is the Scenedesmus sp. with a deposit number of GDMCC No. 63703, which is named Scenedesmus sp. CJ and is deposited in Guangdong Provincial Microbial Culture Collection Center.

[0013] Preferably, the Chlorella is the Chlorella with a preservation number of GDMCC No. 63704, named Chlorella sp. ZJ, and is preserved in Guangdong Provincial Microbial Culture Collection Center.

[0014] Preferably, the microalgae cell concentration in the microalgae cell solution is (1×10 6 )-(1×10 8 ) / mL, for example (1×10 6 ) / mL, (5×10 6 ) / mL, (8×10 6 ) / mL, (1×10 7 ) / mL, (5×10 7) / mL, (8×10 7 ) / mL, (1×10 8 ) pieces / mL, etc. Other specific point values ​​within this numerical range can be selected and will not be described here one by one.

[0015] Preferably, the application amount of the microalgae cell solution is 100-200 kg / mu, for example, 100 kg / mu, 120 kg / mu, 140 kg / mu, 160 kg / mu, 180 kg / mu, 200 kg / mu, etc.

[0016] Preferably, the microalgae cell fluid is prepared by the following method:

[0017] The microalgae are inoculated into a culture medium and cultured under light;

[0018] Preferably, the culture temperature is 25-35°C, for example, 25°C, 26°C, 27°C, 28°C, 29°C, 30°C, 31°C, 32°C, 33°C, 34°C, 35°C, etc.

[0019] Preferably, the intensity of the light is 2000-12000 Lux, for example, 2000 Lux, 4000 Lux, 5000 Lux, 6000 Lux, 7000 Lux, 8000 Lux, 10000 Lux, 12000 Lux, etc.

[0020] Preferably, the culture medium is BG-11 medium.

[0021] The formula of the BG-11 culture medium includes: NaNO3 0.5-1.5g / L, K2HPO4 0.02-0.06g / L, MgSO4·7H2O 0.05-0.1g / L, CaCl2·2H2O 0.01-0.05g / L, citric acid 0.002-0.01g / L, ammonium ferric citrate 0.002-0.01g / L, EDTA 0.0005-0.001g / L, Na2CO3 0.01-0.03g / L, H3BO4 0.001-0.005g / L, MnCl2·H2O 0.001-0.003g / L, ZnSO4·7H2O 0.0001-0.0005g / L, CuSO4·5H2O 0.00005-0.0001g / L, Na2MoO4·2H2O 0.0001-0.0005g / L, Co(NO3)2·6H2O 0.00002-0.00008g / L; the solvent is deionized water.

[0022] In a second aspect, the present invention provides application of the method for improving nitrogen and phosphorus utilization efficiency in red soil according to the first aspect in improving the yield of crops grown in red soil.

[0023] Preferably, the application method comprises: spraying the microalgae cell solution onto the soil surface in batches during the growth period of the crops.

[0024] Preferably, the application method comprises: spraying the microalgae cell solution onto the soil surface 2-4 times (eg, 2 times, 3 times, or 4 times) during the growth period of the crops.

[0025] Preferably, the crops include rice or pepper.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The present invention creatively discovered that applying cell sap of Scenedesmus and / or Chlorella to brick red soil can significantly improve the brick red soil's utilization efficiency of nitrogen and phosphorus. Scenedesmus and / or Chlorella convert atmospheric CO2 into organic carbon through photosynthesis and input it into the soil, which can improve the soil's water and fertilizer retention capacity, promote nitrogen and phosphorus fixation, extend nitrogen and phosphorus turnover time, and improve nitrogen and phosphorus utilization efficiency; at the same time, they can also secrete a large amount of active nutrients and hormones, significantly promoting the increase of microbial biomass in the brick red soil. As a storage reservoir of soil nitrogen and phosphorus, microorganisms can absorb and store excess nitrogen and phosphorus in their bodies, and then re-enter the soil environment as they die and are absorbed and utilized by crops; in addition, the application of microalgae cell sap to acidic brick red soil can also neutralize soil acidity and improve nitrogen and phosphorus utilization.

[0028] The present invention develops a new method strategy for improving the nitrogen and phosphorus utilization efficiency of brick red soil. The operation and implementation of this method strategy are very simple, and it is suitable for planting brick red soil of various crops. It is very effective in improving the nitrogen and phosphorus utilization efficiency of brick red soil and crop yield. DETAILED DESCRIPTION

[0029] In order to further illustrate the technical means and effects adopted by the present invention, the technical solutions of the present invention are further described below in conjunction with the preferred embodiments of the present invention, but the present invention is not limited to the scope of the embodiments.

[0030] The Scenedesmus involved in the following content is the Scenedesmus with the deposit number GDMCC No. 63703, named Scenedesmus sp. CJ, deposited in Guangdong Provincial Microbial Culture Collection Center, the deposit date is August 1, 2023, and the deposit address is 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou.

[0031] The Chlorella involved in the following content is the Chlorella with the preservation number GDMCC No. 63704, named Chlorella sp. ZJ, and deposited in the Guangdong Provincial Microbial Culture Collection Center on August 1, 2023. The preservation address is 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou.

[0032] Preparation Example 1

[0033] This preparation example provides a Scenedesmus cell solution, and the preparation method is as follows:

[0034] Scenedesmus was collected from the microalgae culture greenhouse of Zhanjiang Biomass Power Plant of Guangdong Energy Group. 5% of the cells were inoculated into BG-11 liquid culture medium. The flue gas from the power plant was used as the carbon source. The culture was carried out at 30°C and a light intensity of 4000 Lux. The absorbance of the culture medium was measured by a spectrophotometer. The absorbance of the culture medium was used to reflect the biomass of the microalgae. When the concentration of the microalgae cells reached 2×10 7 When the microalgae solution reached 100 μg / mL, the microalgae solution was harvested.

[0035] The composition of BG-11 liquid culture medium is as follows: NaNO3 1.00 g / L, K2HPO4 0.04 g / L, MgSO4·7H2O0.075 g / L, CaCl2·2H2O 0.036 g / L, citric acid 0.006 g / L, ammonium ferric citrate 0.006 g / L, EDTA 0.001 g / L, Na2CO3 0.02 g / L, H3BO4 0.00286 g / L, MnCl2·H2O0.00181 g / L, ZnSO4·7H2O 0.000222 g / L, CuSO4·5H2O 0.000079 g / L, Na2MoO4·2H2O 0.00039 g / L, Co(NO3)2·6H2O 0.000049g / L; the solvent is deionized water.

[0036] Preparation Example 2

[0037] This preparation example provides a Chlorella cell solution, and the preparation method is as follows:

[0038] Chlorella vulgaris was collected from the microalgae cultivation greenhouse of the Zhanjiang Biomass Power Plant of Guangdong Energy Group. 5% of the microalgae was inoculated into BG-11 liquid culture medium. The flue gas from the power plant was used as the carbon source. The culture was carried out at 35°C and a light intensity of 8000 Lux. The absorbance of the culture medium was measured by a spectrophotometer. The absorbance of the culture medium was used to reflect the biomass of the microalgae. When the microalgae cell concentration reached 2×10 7 When the microalgae solution reached 100 μg / mL, the microalgae solution was harvested.

[0039] The composition of BG-11 liquid culture medium is as follows: NaNO3 1.00 g / L, K2HPO4 0.04 g / L, MgSO4·7H2O0.075 g / L, CaCl2·2H2O 0.036 g / L, citric acid 0.006 g / L, ammonium ferric citrate 0.006 g / L, EDTA 0.001 g / L, Na2CO3 0.02 g / L, H3BO4 0.00286 g / L, MnCl2·H2O0.00181 g / L, ZnSO4·7H2O 0.000222 g / L, CuSO4·5H2O 0.000079 g / L, Na2MoO4·2H2O 0.00039 g / L, Co(NO3)2·6H2O 0.000049g / L; the solvent is deionized water.

[0040] Application Example 1

[0041] This application case investigates the effects of microalgae cell sap on nitrogen and phosphorus utilization efficiency and rice yield in red soil:

[0042] (1) Soil sample collection: Soil samples (typical brick red soil) were collected from the fields of the experimental base of the Zhanjiang Research Center of the South China Seed Research Institute of the Guangdong Academy of Sciences. After removing stones and plant roots, the soil samples were air-dried and passed through a 4 mm sieve for later use.

[0043] (2) Experimental groups: There were five treatments: 1) blank control group (only water); 2) group treated with the living cell solution of Scenedesmus saliva (1.8 g / kg soil); 3) group treated with the living cell solution of Chlorella vulgaris (1.8 g / kg soil); 4) group treated with the living cell solution of equal volumes of Scenedesmus saliva and Chlorella vulgaris (1.8 g / kg soil); 5) group treated with the inactivated cell solution of equal volumes of Scenedesmus saliva and Chlorella vulgaris (1.8 g / kg soil).

[0044] (3) Experimental method: Prepare culture pots, take 4 kg of the soil sample prepared in step (1) from each pot, and then plant rice according to the potted experimental method for rice planting. Add the same amount of chemical fertilizer to each pot as base fertilizer. According to the treatment settings of (2) above, spray the soil surface with clean water, active microalgae cell solution, and inactivated algae solution three times in proportion. The active cell solution of Scenedesmus and the active cell solution of Chlorella are the products prepared in Preparation Example 1 and Preparation Example 2, respectively. The microalgae are inactivated by ultrasonic crushing. The microalgae solution is placed in an ultrasonic crusher for ultrasonic treatment (algae solution volume: 100 mL; treatment time: 20 min; power setting: 70%). Each treatment is repeated three times. After the rice matures, collect rice plants and soil samples respectively, and analyze and determine the soil nitrogen use efficiency, soil phosphorus use efficiency, and rice yield.

[0045] Soil nitrogen use efficiency: According to the following formula E N =(N p +Ns ) / (F N +N so )×100 for calculation, where E N is nitrogen use efficiency, N p is the nitrogen content of rice after harvest, N s is the soil nitrogen content after harvest, F N is the nitrogen content in the basal fertilizer, N so is the soil nitrogen content before planting;

[0046] Soil phosphorus utilization efficiency: According to the following formula E P =(P p +P s ) / (F P +P so )×100 for calculation, where E P is phosphorus utilization efficiency, P p is the phosphorus content of rice after harvest, P s is the soil phosphorus content after harvest, F P is the phosphorus content in the basal fertilizer, P so is the soil phosphorus content before planting;

[0047] Among them, the nitrogen content of soil and fertilizer: determined by the semi-micro Kelvin method GB 7173-1987;

[0048] Among them, the phosphorus content of soil and fertilizer: determined by spectrophotometry GB 7852-1987;

[0049] Among them, the nitrogen content of rice: determined by sulfuric acid-hydrogen peroxide digestion method NY / T 2017-1011;

[0050] Among them, the phosphorus content of rice: determined by spectrophotometry NY / T 2017-1011;

[0051] The results are shown in Table 1:

[0052] Table 1

[0053]

[0054] As shown in Table 1, the method of the present invention significantly improved soil nitrogen and phosphorus utilization and boosted rice yield compared to the blank treatment. Compared to the inactivated microalgae solution, the activated microalgae solution demonstrated superior benefits in these areas. Furthermore, the combined use of Scenedesmus and Chlorella was superior to either Scenedesmus or Chlorella alone.

[0055] Application Example 2

[0056] This application case studies the effects of microalgae cell sap on nitrogen and phosphorus utilization efficiency and pepper yield in red soil:

[0057] (1) Soil sample collection: Soil samples (typical brick red soil) were collected from the fields of the experimental base of the Zhanjiang Research Center of the South China Seed Research Institute of the Guangdong Academy of Sciences. After removing stones and plant roots, the soil samples were air-dried and passed through a 4 mm sieve for later use.

[0058] (2) Experimental groups: There were five treatments: 1) blank control group (only water); 2) group treated with the living cell solution of Scenedesmus saliva (1.8 g / kg soil); 3) group treated with the living cell solution of Chlorella vulgaris (1.8 g / kg soil); 4) group treated with the living cell solution of equal volumes of Scenedesmus saliva and Chlorella vulgaris (1.8 g / kg soil); 5) group treated with the inactivated cell solution of equal volumes of Scenedesmus saliva and Chlorella vulgaris (1.8 g / kg soil).

[0059] (3) Experimental method: Prepare culture pots, take 4 kg of the soil sample prepared in step (1) from each pot, and then plant peppers according to the potted experimental method for pepper planting. Add the same amount of chemical fertilizer to each pot as base fertilizer. According to the treatment settings of (2) above, spray clean water, active microalgae cell solution, and inactivated algae solution on the soil surface three times in proportion. The active cell solution of Scenedesmus and the active cell solution of Chlorella are the products prepared in Preparation Example 1 and Preparation Example 2 respectively. The microalgae are inactivated by ultrasonic crushing. The microalgae solution is placed in an ultrasonic crusher for ultrasonic treatment (algae solution volume: 100 mL; treatment time: 20 min; power setting: 70%). Each treatment is repeated three times. After the peppers mature, collect pepper plants and soil samples respectively, and analyze and determine the soil nitrogen use efficiency, soil phosphorus use efficiency and rice yield.

[0060] Soil nitrogen use efficiency: According to the following formula E N =(N p +N s ) / (F N +N so )×100 for calculation, where E N is nitrogen use efficiency, N p is the nitrogen content of pepper after harvest, N s is the soil nitrogen content after harvest, F N is the nitrogen content in the basal fertilizer, N so is the soil nitrogen content before planting;

[0061] Soil phosphorus utilization efficiency: According to the following formula E P =(P p +P s ) / (F P +P so )×100 for calculation, where E P is phosphorus utilization efficiency, P p is the phosphorus content of pepper after harvest, P s is the soil phosphorus content after harvest, FP is the phosphorus content in the basal fertilizer, P so is the soil phosphorus content before planting;

[0062] Among them, the nitrogen content of soil and fertilizer: determined by the semi-micro Kelvin method GB 7173-1987;

[0063] Among them, the phosphorus content of soil and fertilizer: determined by spectrophotometry GB 7852-1987;

[0064] Among them, the nitrogen content of pepper is determined by sulfuric acid-hydrogen peroxide digestion method NY / T 2017-1011;

[0065] Among them, the phosphorus content of pepper: determined by spectrophotometry NY / T 2017-1011;

[0066] The results are shown in Table 2:

[0067] Table 2

[0068]

[0069] As shown in Table 2, the method of the present invention significantly improved soil nitrogen and phosphorus utilization and boosted pepper yield compared to the blank treatment. Compared to the inactivated microalgae solution, the activated microalgae solution demonstrated superior benefits in these areas. Furthermore, the combined use of Scenedesmus and Chlorella was superior to either Scenedesmus or Chlorella alone.

[0070] The applicant declares that the present invention is illustrated by the above-described embodiments, but the present invention is not limited to the above-described embodiments. This does not mean that the present invention must rely on the above-described embodiments in order to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent replacements for raw materials in the present invention, additions of auxiliary ingredients, and selection of specific methods, etc., fall within the scope of protection and disclosure of the present invention.

[0071] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the scope of protection of the present invention.

[0072] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. A method for improving nitrogen and phosphorus utilization efficiency in red soil for increasing pepper yield in red soil, characterized in that: The method comprises: applying microalgae cell slurry to red soil; the microalgae include Scenedesmus and Chlorella; the amount of the microalgae cell slurry applied is 100-200 kg / mu; the concentration of microalgae cells in the microalgae cell slurry is (1×10 6 )-(1×10 8 ) cells / mL; the microalgae cell fluid is active microalgae cell fluid; The Scenedesmus is a Scenedesmus with a deposit number of GDMCC No. 63703, which is named Scenedesmus sp. CJ, deposited in Guangdong Provincial Microbiological Culture Collection; The chlorella is a chlorella with a preservation number of GDMCC No. 63704, named Chlorella sp. ZJ, and is preserved in the Guangdong Provincial Microbial Culture Collection Center.

2. The use according to claim 1, characterized in that The microalgae cell solution is prepared by the following method: The microalgae were inoculated into the culture medium and cultured under light.

3. The use according to claim 2, characterized in that The culture temperature is 25-35° C., and the light intensity is 2000-12000 Lux.

4. The use according to claim 2, characterized in that The culture medium is BG-11 culture medium.

5. The use according to claim 1, characterized in that The application method comprises: during the growth period of pepper, spraying the microalgae cell liquid on the soil surface in batches.

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