Method for improving biomass, yield and nitrogen utilization rate of crops and iron-rich compound fertilizer

Abstract

The invention provides a method for improving biomass, yield and nitrogen utilization rate of crops and an iron-rich compound fertilizer.The method comprises the steps that an iron fertilizer is supplemented and applied to the crops, so that the microelement iron in the iron fertilizer can remarkably promote absorption and assimilation of the applied crops on mineral nutrition of the nitrogenous fertilizer, and the synergistic effect is achieved; wherein the application amount of the iron fertilizer to the crops is 0.37-0.74 kg per mu. And by adopting the method provided by the invention, the tillering number and nutrition absorption and utilization of crops can be enhanced according to a fertilization method of field crops and normal crop field management, so that the biomass, the yield and the nitrogen utilization rate of the crops are effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of crop fertilizers and fertilization, and in particular to a method for improving crop biomass, yield and nitrogen utilization rate, an application thereof and an iron-rich compound fertilizer. Background Art

[0002] Rice and wheat are important food crops, and their yield is the key to coping with the food crisis, and is also related to the national economy. With the increase in population, the reduction of cultivated land and the intensification of water shortage, the contradiction of food demand has become increasingly prominent, and it is urgent to increase the yield of rice and wheat.

[0003] At present, the application of chemical fertilizers is the main measure to increase the yield of rice and wheat, but the traditional compound fertilizer formula has low fertilizer efficiency. In order to pursue yield, people often blindly increase the amount of fertilizer. However, although the amount of fertilizer application has increased significantly every year, the growth of grain production has been slow. Excessive application of chemical fertilizers leads to fertilizer residues and acidification in the soil, causing residual fertilizers to be lost to rivers, lakes and oceans, causing serious environmental pollution and ecological imbalance, and also increasing the production cost of growing grain. At present, there is a common problem of excessive nitrogen fertilizer application but low utilization rate in fertilization. Therefore, improving the nitrogen utilization rate during fertilization is not only related to the vital interests of farmers, but also to food safety and environmental quality. Developing a fertilizer formula that can significantly increase yield and reduce costs is of great significance and good application prospects for achieving green and high yields of rice and wheat. Summary of the invention

[0004] In view of the above technical problems, the present disclosure provides a method for increasing crop biomass, yield and nitrogen utilization rate and an iron-rich compound fertilizer to at least partially solve the above technical problems.

[0005] In order to solve the above technical problems, the technical solutions provided by the present disclosure are as follows:

[0006] As a first aspect of the present disclosure, a method for increasing crop biomass, yield and nitrogen utilization efficiency is provided, comprising:

[0007] Applying iron fertilizer to crops can significantly promote the absorption and assimilation of nitrogen-containing fertilizer mineral nutrients by the crops, thus playing a synergistic role.

[0008] Among them, the application amount of iron fertilizer to crops is 0.37-0.74 kg per mu.

[0009] According to an embodiment of the present disclosure, the nitrogen-containing fertilizer is any kind of fertilizer.

[0010] According to an embodiment of the present disclosure, the molar concentration ratio of nitrogen in the nitrogen-containing fertilizer to iron in the iron fertilizer is 50:1-2.5, which is suitable for the improvement of any fertilizer.

[0011] As a second aspect of the present disclosure, there is provided an iron-rich compound fertilizer, comprising:

[0012] Nitrogen fertilizer, iron fertilizer;

[0013] Among them, the molar concentration ratio of nitrogen in the nitrogen fertilizer and iron in the iron fertilizer is 50:1-2.5, so as to increase crop biomass, grain yield and nitrogen utilization rate.

[0014] According to an embodiment of the present disclosure, the iron-rich compound fertilizer also includes: phosphorus fertilizer and potash fertilizer, so that the compound fertilizer is applied to the roots of the crop;

[0015] Among them, the molar concentration ratio of nitrogen in nitrogen fertilizer, phosphorus in phosphorus fertilizer and potassium in potash fertilizer is 50:15-25:8-15.

[0016] According to an embodiment of the present disclosure, the iron fertilizer includes: soluble free iron salt and / or chelated iron.

[0017] According to an embodiment of the present disclosure, the chelated iron includes any one or more of sodium ferric ethylenediaminetetraacetate, ferric ethylenediamine di-o-hydroxyphenyl acetate, ferric diethylenetriamine pentaacetate, ferric N-hydroxyethylethylenediamine triacetate, ferric ethylenediamine di-o-hydroxy-p-methylphenyl acetate, ferric iminodisuccinate, and ferric ethylenediamine disuccinate.

[0018] According to an embodiment of the present disclosure, the nitrogen fertilizer includes any one or more of sodium nitrate, calcium nitrate, ammonium nitrate, calcium ammonium nitrate, ammonium sulfate nitrate, and urea.

[0019] According to an embodiment of the present disclosure, the phosphate fertilizer includes any one or more of superphosphate, double superphosphate, calcium magnesium phosphate, and phosphate rock powder.

[0020] According to an embodiment of the present disclosure, the potash fertilizer includes any one or more of potassium chloride, potassium sulfate, potassium dihydrogen phosphate, sylvite, potassium magnesium salt, carnallite, potassium nitrate, and kiln dust potash fertilizer.

[0021] As a third aspect of the present disclosure, there is provided an application of the above-mentioned iron-rich compound fertilizer in increasing crop yield, comprising: supplementing the application of iron fertilizer to the crop during the tillering period of the crop;

[0022] Crops include any one or more of agricultural crops and cash crops.

[0023] According to an embodiment of the present disclosure, the crops are tillering crops, including rice, wheat, barley, millet, etc.;

[0024] Cash crops include forage, vegetables, and fruits;

[0025] The crop plant is a crop plant containing the OsNLP4 gene.

[0026] According to an embodiment of the present disclosure, the varieties of rice include wild-type rice and transgenic rice;

[0027] Wild rice includes japonica and indica;

[0028] The transgenic rice includes OsNLP4 overexpressing rice.

[0029] Based on the above technical scheme, the method for improving crop biomass, yield and nitrogen utilization rate and the iron-rich compound fertilizer provided by the present disclosure change the molar concentration ratio of iron in the compound fertilizer by supplementing the application of iron fertilizer and adjusting the application amount of iron fertilizer, balance the ratio of nitrogen in nitrogen fertilizer and iron in iron fertilizer, can strongly induce OsNLP4 gene protein to enter the cell nucleus, promote the absorption and utilization of nitrogen nutrition and rice tillering, thereby effectively improving crop biomass, grain yield and nitrogen utilization rate, and can fertilize the roots of crops. The fertilization method is simple to operate and the fertilizer cost is low. It can be widely applied to various crops and is easy to promote and use. DETAILED DESCRIPTION

[0030] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in conjunction with specific embodiments.

[0031] However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present disclosure. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0032] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise", "include", etc. used herein indicate the existence of features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0033] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification, and should not be interpreted in an idealized or overly rigid manner.

[0034] In the case of using expressions such as "at least one of A, B, and C, etc.", it should generally be interpreted in accordance with the meaning of the expression generally understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.). In the case of using expressions such as "at least one of A, B, or C, etc.", it should generally be interpreted in accordance with the meaning of the expression generally understood by those skilled in the art (for example, "a system having at least one of A, B, or C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0035] In current agricultural production, the phenomenon of blindly pursuing high crop yields and over-application and reliance on nitrogen fertilizers is common. However, with the increase in fertilizer application, the yield of crops has not been significantly improved. Instead, excessive fertilization has brought about a series of environmental pollution problems and increased planting costs. At present, one of the main reasons for this dilemma is the lack of a reasonable ratio of fertilizer nutrients, which leads to low fertilizer utilization.

[0036] During the research process of realizing the present disclosure, it was found that iron (Fe) is a trace nutrient element necessary for the normal growth and development of plants, and is an indispensable cofactor in many important cellular processes. It is not only an important component of iron-sulfur (Fe-S) clusters, heme and some ferritins, but also participates in physiological processes such as plant chlorophyll synthesis, respiration and redox reactions, and has a significant impact on crop yields and grain protein content. The iron content of compound fertilizers currently on the market is relatively low, and iron is only used as a trace element added to compound fertilizers. When plants need iron, additional iron fertilizers need to be added or sprayed. During the crop planting stage, additional manpower or material resources need to be consumed to add iron elements, which is very inconvenient.

[0037] In addition, iron has a synergistic utilization relationship with nitrogen, one of the main components of compound fertilizers. It can promote the nitrogen utilization efficiency of crops to increase crop yields. However, the iron content in conventional compound fertilizer formulas is not high, and this nutritional ratio cannot enable crops to obtain the best nutritional utilization effect. Therefore, it is necessary to improve the iron content in compound fertilizers to improve the fertilizer utilization efficiency of crops and the input cost of chemical fertilizers, providing a means of green and sustainable agricultural development.

[0038] In response to the above technical problems, the present disclosure provides a method for increasing crop biomass, yield and nitrogen utilization rate and an iron-rich compound fertilizer. By increasing the trace element iron in the fertilizer and balancing the nitrogen-iron ratio in the fertilizer, the biomass, yield and nitrogen utilization rate of crops can be significantly improved, and a guide is provided for the innovation of new compound fertilizer formulas and the iron-rich improvement of existing chemical fertilizers, so as to significantly improve the nitrogen utilization rate and yield of crops and reduce the application amount of nitrogen fertilizer.

[0039] In view of this, the present disclosure provides a method for increasing crop biomass, yield and nitrogen utilization rate and an iron-rich compound fertilizer. Specifically, as a first aspect of the present disclosure, a method for increasing crop biomass, yield and nitrogen utilization rate is provided, comprising:

[0040] Applying iron fertilizer to crops can significantly promote the absorption and assimilation of nitrogen-containing fertilizer mineral nutrients by the crops, thus playing a synergistic role.

[0041] Among them, the application amount of iron fertilizer to crops is 0.37-0.74 kg per mu, for example, it can be 0.37 kg per mu, 0.35 kg per mu, 0.7 kg per mu, etc.

[0042] According to an embodiment of the present disclosure, the nitrogen-containing fertilizer is any kind of fertilizer.

[0043] According to an embodiment of the present disclosure, the molar concentration ratio of nitrogen in the nitrogen-containing fertilizer to iron in the iron fertilizer is 50:1-2.5, which is suitable for the improvement of any fertilizer.

[0044] As a second aspect of the present disclosure, there is provided an iron-rich compound fertilizer, comprising:

[0045] Nitrogen fertilizer, iron fertilizer; wherein the molar concentration ratio of nitrogen in the nitrogen fertilizer to iron in the iron fertilizer is 50:1-2.5, so as to increase crop biomass, grain yield and nitrogen utilization rate.

[0046] According to the embodiments of the present disclosure, by adjusting and increasing the molar concentration of iron in compound fertilizer, synergistic utilization can be achieved with nitrogen, one of the main components of compound fertilizer, to induce the OsNLP4 gene in crops to enter cells, regulate genes in crop cells, and promote nitrogen utilization efficiency of crops under the action of Fe and N, so as to increase crop yields.

[0047] According to the embodiments of the present disclosure, the molar concentration ratio of nitrogen in nitrogen fertilizer and iron in iron fertilizer is 50:1-2.5, for example, it can be 50:1, 50:1.25, 50:1.5, 50:2, etc., but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable. The iron-enriched adjustment method is applicable to the improvement of all fertilizers, and by balancing the nitrogen-iron ratio of fertilizers, the crop biomass, grain yield and nitrogen utilization rate are increased.

[0048] According to an embodiment of the present disclosure, the iron-rich compound fertilizer also includes: phosphate fertilizer and potash fertilizer.

[0049] According to an embodiment of the present disclosure, the molar concentration ratio of nitrogen in nitrogen fertilizer, phosphorus in phosphorus fertilizer and potassium in potash fertilizer is 50:15-25:8-15. For example, the molar concentration ratio of nitrogen:phosphorus:potassium in compound fertilizer can be 50:15:8, 50:20:8, 50:25:10, 50:20:15, 50:25:10, etc., but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable. Among them, 50:20:10 can be preferred.

[0050] According to the embodiments of the present disclosure, the proportion formula of the iron-rich compound fertilizer can meet the needs of crops for the intake of various elements during the growth stage, simplify the fertilization process during planting, improve the fertilization efficiency, and effectively save manpower and material resources.

[0051] According to an embodiment of the present disclosure, the iron fertilizer includes: soluble free iron salt and / or chelated iron.

[0052] According to the embodiments of the present disclosure, the iron fertilizer may be either soluble free iron salt or chelated iron, preferably chelated iron. The iron ions in chelated iron are not easily precipitated, are absorbed by plants efficiently, and have a more stable fertilizer effect.

[0053] According to an embodiment of the present disclosure, the chelated iron includes any one or more of sodium ethylenediaminetetraacetate iron (EDTA-Fe), ethylenediamine di-o-hydroxyphenyl iron (EDDHA-Fe), diethylenetriamine pentaacetate iron (DTPA-Fe), N-hydroxyethylethylenediaminetriacetate iron (HEDTA-Fe), ethylenediamine di-o-hydroxy-p-methylphenyl iron (EDDHMA-Fe), iminodisuccinate iron (IDHA-Fe), and ethylenediamine disuccinate iron (EDDS-Fe).

[0054] According to an embodiment of the present disclosure, the nitrogen fertilizers include any one or more of sodium nitrate, calcium nitrate, ammonium nitrate, calcium ammonium nitrate, ammonium sulfate nitrate and urea, and other nitrogen-containing compounds may also be selected as needed.

[0055] According to the embodiments of the present disclosure, the phosphate fertilizers include any one or more of superphosphate, double superphosphate, calcium magnesium phosphate, and phosphate rock powder. Other phosphorus-containing compounds may also be selected as needed.

[0056] According to the embodiments of the present disclosure, the potash fertilizers include any one or more of potassium chloride, potassium sulfate, potassium dihydrogen phosphate, sylvite, potassium magnesium salt, carnallite, potassium nitrate, and kiln dust potash fertilizer. Other potassium-containing compounds may also be selected as needed.

[0057] It should be noted that nitrogen fertilizers, phosphorus fertilizers, potassium fertilizers and iron fertilizers are not limited to the types listed, and other fertilizers with the same properties and similar functions are also equally applicable.

[0058] As a third aspect of the present disclosure, there is provided an application of the above-mentioned iron-rich compound fertilizer in increasing crop yield, comprising: supplementing the application of iron fertilizer to the crop during the tillering period of the crop;

[0059] Crops include any one or more of agricultural crops and cash crops.

[0060] According to the embodiments of the present disclosure, applying a new type of iron-rich compound fertilizer to crops at an appropriate stage during the growth of crops can promote tillering of crops during the tillering period, increase the number of tillers of crops, and thus increase the yield of crops.

[0061] According to the disclosed embodiment, the crop plant is a crop plant containing the OsNLP4 gene.

[0062] According to the embodiments of the present disclosure, the OsNLP4 gene is a nitrogen efficient utilization gene that can efficiently utilize nitrogen in compound fertilizers, promote rapid root growth of crops, and significantly promote stem and leaf growth and the development of tiller primordium.

[0063] According to the embodiments of the present disclosure, the crops are tillering crops, including rice, wheat, barley, millet, etc.; the economic crops include forage, vegetables, and fruits.

[0064] According to an embodiment of the present disclosure, rice varieties include wild-type rice and transgenic rice; wild-type rice includes japonica rice and indica rice; transgenic rice includes OsNLP4 overexpressing rice.

[0065] According to an embodiment of the present disclosure, the type of japonica rice may be Zhonghua 11, Longgeng 31 or Xiushui 134, the type of indica rice may be 9311 or R527, and the transgenic rice may be of japonica rice Zhonghua 11 background.

[0066] According to the embodiments of the present disclosure, the compound fertilizer provided by the present disclosure is also applicable to other crops with tillering characteristics, not limited to the rice, wheat and their varieties listed in the present disclosure, and no further examples and limitations are given on the types and varieties of crops.

[0067] In order to make the purpose, technical solution and advantages of the present disclosure clearer and more specific, the technical solution and principle of the present disclosure are further explained through specific embodiments below. It should be noted that the following specific embodiments are only used as examples, and the protection scope of the present disclosure is not limited thereto.

[0068] The test materials and reagents used in the following examples, unless otherwise specified, can be obtained from commercial sources. Specific techniques or conditions not specified in the examples are conventional methods and can be carried out according to the techniques or conditions described in the literature in the field or according to the product instructions.

[0069] The japonica rice variety Zhonghua 11 (ZH11), the japonica rice variety Longjing 31 (LG31), the indica rice variety Xiushui 134 (XS134), the indica rice variety 9311, the indica rice variety R527, and the japonica rice variety Zhonghua 11 background OsNLP4 gene knockout mutant (nlp4-1) and OsNLP4 overexpression rice line (OE-9) were selected for field experiments. Among them, the mutant nlp4-1 was obtained by CRISPR / Cas9-based gene editing technology, and the overexpression line was obtained by Agrobacterium (EHA105) transformation and resistance screening. The experimental site was a place in Hefei City, Anhui Province.

[0070] Examples of embodiments of the present disclosure are as follows:

[0071] Example 1.

[0072] Research on iron-rich compound fertilizers to increase crop biomass:

[0073] In the experiment, four compound fertilizer formulas were optimized, and the compound fertilizers used are as follows:

[0074] (1) Ordinary compound fertilizer 1: 1mM KNO3+2mM NaH2PO4·2H2O+0.5mM K2SO4+0.05mM Fe(Ⅱ)-EDTA;

[0075] (2) Iron-rich compound fertilizer 1: 1mM KNO3+2mM NaH2PO4·2H2O+0.5mM K2SO4+0.2mM Fe(Ⅱ)-EDTA;

[0076] (3) Ordinary compound fertilizer 2: 5mM KNO3+2mM NaH2PO4·2H2O+0.5mM K2SO4+0.05mM Fe(Ⅱ)-EDTA;

[0077] (4) Iron-rich compound fertilizer 2: 5 mM KNO3 + 2 mM NaH2PO4·2H2O + 0.5 mM K2SO4 + 0.2 mM Fe(Ⅱ)-EDTA.

[0078] The experimental subjects were: the japonica rice variety Zhonghua 11 (ZH11), the OsNLP4 gene knockout mutant (nlp4-1) under the ZH11 background, and the rice line with overexpression of OsNLP4 (OE-9), and the ordinary compound fertilizer combination 1 of ZH11 was used as the control.

[0079] Each compound fertilizer was used to treat 24 rice plants, and three biological replicates (3×24 plants) were set up for the experiment. The vermiculite pot experiment was used, and the size of the pot was 15×15×15 cm 3 , one rice plant was planted in each pot, and each group of 6 pots was placed in a hydroponic box (size 60×40×20cm) filled with nutrient solution. 3 ), 10 liters of nutrient solution were added each time, for a total of 12 times. Samples were taken after the rice grew for 30 days, and the biomass was counted. The results of this experiment were analyzed by SPSS20.0 for significance analysis and correlation analysis. The significance analysis method used LSD and Duncan method in single factor variance, and the significance level was set to 0.05. The specific test results are shown in Table 1.

[0080] Table 1. Effects of different compound fertilizers on rice biomass during vegetative growth period

[0081]

[0082] Note: Letters a, b, c, d, e, f, g, and h indicate significant differences, p<0.05.

[0083] As shown in Table 1, the biomass of wild-type rice ZH11 was the highest when using iron-rich compound fertilizer 2, and the biomass increased by 2 times (200%) compared with the control group (ZH11, ordinary compound fertilizer 1). The biomass of OsNLP4 gene knockout mutant (nlp4-1) and OsNLP4 overexpression rice (OE-9) in iron-rich compound fertilizer 2 was also the highest. However, based on the comparison of the increase in the three rice materials in the iron-rich compound fertilizer group, the effect of OsNLP4 overexpression rice (OE-9) was the most obvious, with a biomass increase of 3.5 times (369%) compared with the control group.

[0084] It can be seen that the formula of iron-rich compound fertilizer 2 is the best formula that can significantly increase rice biomass in this experiment. The optimal ratio of nutrients in the iron-rich compound fertilizer is 5mM KNO3+2mM NaH2PO4·2H2O+0.5mM K2SO4+0.2mM Fe(Ⅱ)-EDTA. Under this ratio, the molar concentration ratio of nitrogen in the nitrogen fertilizer and iron in the iron fertilizer is 50:2. At this ratio, the effect on increasing the biomass of OsNLP4-overexpressing rice is most significant.

[0085] Example 2

[0086] Research on the effect of iron-rich compound fertilizer on increasing the number of effective tillers, yield and nitrogen utilization efficiency of rice:

[0087] The same compound fertilizer and experimental object as in Example 1 were used for planting and cultivation, and the yield-increasing effect of different nitrogen-phosphorus-potassium-iron compound fertilizer formulas on rice was compared. Samples were taken at the rice maturity stage, and the number of tillers, yield and nitrogen utilization rate (yield obtained per unit mass of nitrogen in the nutrient solution) were counted. SPSS20.0 was used to perform significance analysis and correlation analysis on the measurement results of this experiment. The significance analysis method selected LSD and Duncan method in single factor variance, and the significance level was set to 0.05. The specific experimental results are shown in Table 2, Table 3, and Table 4.

[0088] Table 2. Effects of different compound fertilizers on the number of rice tillers

[0089]

[0090] Note: Letters a, b, c, d, e, f, g, h, and i indicate significant differences, p<0.05.

[0091] Table 3. Effects of different compound fertilizers on rice yield

[0092]

[0093] Note: Letters a, b, c, d, e, f, g, h, and i indicate significant differences, p<0.05.

[0094] Table 4. Effects of different compound fertilizers on nitrogen utilization efficiency of rice

[0095]

[0096] Note: Letters a, b, c, d, e, f, g, h, and i indicate significant differences, p<0.05.

[0097] The experimental results in Table 2, Table 3, and Table 4 show that the use of iron-rich compound fertilizer 2 has the highest increase in the number of tillers per plant, yield, and nitrogen utilization rate of wild-type rice (Japonica rice variety Zhonghua 11, ZH11). Among them, since the rice plants only have compound fertilizers to provide nutrition throughout the growth period (vermiculite medium does not contain nutrients), in order to ensure obvious experimental effects, the cultivation process uses a fertilization level higher than field management, so the nitrogen utilization rate is lower than the average level of normal field management.

[0098] As can be seen from Tables 2 to 4, the number of tillers per plant of ZH11 rice treated with iron-rich compound fertilizer 2 increased by 2 times (200%), the yield increased by 10.44 times (1044%), and the nitrogen utilization rate increased by 1.28 times (128%) compared with the control group (ZH11, ordinary compound fertilizer 1). The number of tillers per plant, yield and nitrogen utilization rate of OsNLP4 gene knockout mutant (nlp4-1) rice treated with iron-rich compound fertilizer 2 were also the highest among all treatments, but lower than those of ZH11 rice lines treated with iron-rich compound fertilizer 2. The number of tillers, yield and nitrogen utilization rate of OsNLP4 overexpression rice (OE-9) treated with iron-rich compound fertilizer 2 increased the most among all combinations, increasing by 3.69 times (369%), 15.11 times (1511%) and 2.17 (217%) respectively compared with the control group (ZH11, ordinary compound fertilizer 1).

[0099] It can be seen that iron-rich compound fertilizer 2 is the best formula that can significantly increase the tiller number, yield and nitrogen utilization efficiency of rice. The optimal ratio of nutrients in the iron-rich compound fertilizer is 5mM KNO3+2mM NaH2PO4·2H2O+0.5mM K2SO4+0.2mM Fe(Ⅱ)-EDTA. Under this ratio, the molar concentration ratio of nitrogen in the nitrogen fertilizer and iron in the iron fertilizer is 50:2. At this ratio, the effect on increasing the biomass of OsNLP4-overexpressing rice is most significant, especially the tiller number of OsNLP4-overexpressing rice is significantly increased, thereby effectively improving the yield and nitrogen utilization efficiency of OsNLP4-overexpressing rice.

[0100] Example 3.

[0101] Study on the effect of iron-rich compound fertilizer on improving the effective tillering number, yield and nitrogen utilization efficiency of japonica rice varieties:

[0102] The same compound fertilizer and planting and cultivation method as in Example 1 were used, with the only difference being that the experimental objects were replaced by: japonica rice variety Longjing 31 (LG31), indica rice variety Xiushui 134 (XS134), indica rice variety 9311 and indica rice variety R527, to study the response of different rice types to iron-rich compound fertilizers.

[0103] Samples were taken at the rice maturity stage, and the tiller number, yield and nitrogen utilization rate (yield obtained per unit mass of nitrogen in the nutrient solution) were counted. SPSS20.0 was used to perform significance analysis and correlation analysis on the test results of this experiment. The significance analysis method used LSD and Duncan method in single factor variance, and the significance level was set to 0.05. The rice lines using ordinary compound fertilizer 1 were used as the control group, and the experimental results obtained are shown in Table 5, Table 6, and Table 7.

[0104] Table 5. Effects of different compound fertilizer ratios on the tillering number of wild rice

[0105]

[0106] Note: Letters a, b, c, d, e, f, g, h, i, and j indicate significant differences, p < 0.05.

[0107] Table 6. Effects of different compound fertilizer ratios on wild rice yield

[0108]

[0109] Note: Letters a, b, c, d, e, f, g, h, i, and j indicate significant differences, p < 0.05.

[0110] Table 7. Effects of different compound fertilizer ratios on nitrogen utilization efficiency of wild-type rice

[0111]

[0112] Note: Letters a, b, c, d, e, f, g, h, i, and j indicate significant differences, p < 0.05.

[0113] The experimental results in Tables 5 to 7 show that iron-rich compound fertilizers 1 and 2 significantly increased the tillering number, yield and nitrogen utilization rate of different rice varieties, and the effect of iron-rich compound fertilizer 2 was the most significant, although the increase varied among different rice varieties. This experiment shows that iron-rich compound fertilizer 2 is the best formula that can significantly increase the tillering number, yield and nitrogen utilization rate of rice in this experiment, and the ratio of nitrogen fertilizer and iron fertilizer in iron-rich compound fertilizer 2 has a significant effect on improving the tillering number, yield and nitrogen utilization rate of different rice varieties.

[0114] Example 4.

[0115] Research on the effect of iron-rich compound fertilizer on improving effective tillering number, yield and nitrogen utilization efficiency of wheat:

[0116] The same compound fertilizer and planting and cultivation method as in Example 1 were used, the only difference being that the experimental object was replaced by the wheat variety AN210.

[0117] Samples were taken at the maturity stage of wheat, and the tiller number, yield and nitrogen utilization rate (yield obtained per unit mass of nitrogen in the nutrient solution) were counted. The test results are shown in Tables 8 to 10. SPSS20.0 was used to perform significance analysis and correlation analysis on the test results of this experiment. The significance analysis method used LSD and Duncan method in single factor variance, and the significance level was set to 0.05. The specific experimental results are shown in Tables 8, 9 and 10.

[0118] Table 8. Effects of different compound fertilizer ratios on the tillering number of wheat

[0119]

[0120] Note: Letters a, b, c, d, e, f, g, h, i, j indicate significant differences, p < 0.05

[0121] Table 9. Effects of different compound fertilizer ratios on wheat yield

[0122]

[0123] Note: Letters a, b, c, d, e, f, g, h, i, j indicate significant differences, p < 0.05

[0124] Table 10. Effects of different compound fertilizer ratios on nitrogen utilization efficiency of wheat

[0125]

[0126] Note: Letters a, b, c, d, e, f, g, h, i, j indicate significant differences, p < 0.05

[0127] As shown in Tables 8, 9 and 10, the tillering number, yield and nitrogen utilization rate of wheat in the iron-rich compound fertilizer 2 treatment group were the highest among all combinations. However, the ordinary compound fertilizer 2 treatment group can also increase the yield and nitrogen utilization rate of wheat compared with the control group, which is slightly different from the change pattern of rice. Since the rice plants only have compound fertilizer to provide nutrition throughout the growth cycle (vermiculite medium does not contain nutrition), in order to ensure the obvious effect of the experiment, the cultivation process adopted a fertilization level higher than the field management, so the nitrogen utilization rate is lower than the average level of normal field management.

[0128] Based on the above embodiments, it can be seen that the iron-rich compound fertilizer formula disclosed in the present invention has a more significant yield-increasing effect on wild-type rice (such as japonica rice Zhonghua 11) than ordinary compound fertilizers; for transgenic rice (such as rice with overexpression of OsNLP4), because it contains more OsNLP4 protein, the iron-rich compound fertilizer disclosed in the present invention can induce more OsNLP4 protein to enter the cell nucleus to promote the absorption and utilization of nitrogen nutrients and promote rice tillering, so that the increase in the number of tillers, yield and nitrogen utilization rate is more significant than that of ordinary rice (such as japonica rice Zhonghua 11) under the same fertilization conditions.

[0129] In summary, compared with ordinary compound fertilizers, iron-rich compound fertilizers increase the proportion of iron nutrition, which can effectively increase the number of tillers, yields and nitrogen utilization rates of different types of crops (such as rice and wheat). The preferred ratio of iron-rich compound fertilizers for different crops can be further determined to significantly increase the yield and nitrogen fertilizer utilization rate of crops, and can be used to improve the molar ratio of each element in compound fertilizers containing different nitrogen, phosphorus, potassium and iron to achieve the effect of increasing production. Compared with iron-rich compound fertilizer 1, iron-rich compound fertilizer 2 increases the proportion of nitrogen nutrition, and is more effective in promoting the number of tillers, yield and nitrogen utilization rate of crops (such as rice and wheat). Iron-rich compound fertilizer 2 can be used as the most preferred compound fertilizer ratio for crops. According to the molar concentration ratio of the macroelements nitrogen, phosphorus, potassium and the trace element iron contained therein, the present disclosure sets a more suitable ratio range of the iron-rich compound fertilizer as 50:15-25:8-15:1-2.5 for the concentration ratio of nitrogen fertilizer, phosphorus fertilizer, potassium fertilizer and iron fertilizer, preferably 50:20:10:1-2.5.

[0130] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present disclosure. It should be understood that the above are only specific embodiments of the present disclosure and are not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, and iron-enriched improvements to existing fertilizers made within the spirit and principles of the present disclosure should be included in the scope of protection of the present disclosure.

Claims

1. A method for increasing crop biomass, yield and nitrogen utilization efficiency, comprising: Supplementing iron fertilizer to crops, so that the trace element iron in the iron fertilizer can significantly promote the absorption and assimilation of mineral nutrients in nitrogen-containing fertilizers by the crops, thus playing a synergistic role; The application amount of the iron fertilizer to crops is 0.37-0.74 kg per mu.

2. The method according to claim 1, wherein: The nitrogen-containing fertilizer is any kind of fertilizer.

3. The method according to claim 2, wherein: The molar concentration ratio of the nitrogen in the nitrogen-containing fertilizer to the iron in the iron fertilizer is 50:1-2.5, and is suitable for the improvement of any fertilizer.

4. An iron-rich compound fertilizer comprising: Nitrogen fertilizer, iron fertilizer; The molar concentration ratio of the nitrogen in the nitrogen fertilizer to the iron in the iron fertilizer is 50:1-2.5, so as to increase crop biomass, grain yield and nitrogen utilization rate.

5. The iron-rich compound fertilizer according to claim 4, further comprising: Phosphate fertilizer and potash fertilizer, so that the compound fertilizer can be applied to the roots of crops; Wherein, the molar concentration ratio of nitrogen in the nitrogen fertilizer, phosphorus in the phosphorus fertilizer and potassium in the potassium fertilizer is 50:15-25:8-15.

6. The iron-rich compound fertilizer according to claim 4, wherein: The nitrogen fertilizer includes any one or more of sodium nitrate, calcium nitrate, ammonium nitrate, calcium ammonium nitrate, ammonium sulfate nitrate, and urea; The iron fertilizer includes: soluble free iron salt and / or chelated iron; The chelated iron includes any one or more of sodium ferric ethylenediaminetetraacetate, ferric ethylenediamine di-o-hydroxyphenyl acetate, ferric diethylenetriamine pentaacetate, ferric N-hydroxyethylethylenediamine triacetate, ferric ethylenediamine di-o-hydroxy-p-methylphenyl acetate, ferric iminodisuccinate, and ferric ethylenediamine disuccinate.

7. The iron-rich compound fertilizer according to claim 5, wherein The phosphate fertilizer includes any one or more of superphosphate, double superphosphate, calcium magnesium phosphate, and phosphate rock powder; The potash fertilizer includes any one or more of potassium chloride, potassium sulfate, potassium dihydrogen phosphate, sylvite, potassium magnesium salt, carnallite, potassium nitrate, and kiln dust potash fertilizer.

8. An application of the iron-rich compound fertilizer according to any one of claims 4 to 7 in increasing crop yield, comprising: Supplemental iron fertilizer application to crops during the tillering stage; The crops include any one or more of agricultural crops and economic crops.

9. The use according to claim 8, wherein: The crops are tillering crops, including rice, wheat, barley, and millet; The cash crops include forage, vegetables, and fruits; Preferably, the crop is a crop containing the OsNLP4 gene.

10. The use according to claim 9, wherein: The rice varieties include wild rice and transgenic rice; The wild type rice includes japonica rice and indica rice; The transgenic rice includes OsNLP4 over-expressing rice.

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