Peanut no-tillage planting method

Abstract

The invention discloses a no-tillage peanut planting method, which relates to the technical field of peanut planting, and is characterized in that soil is not disturbed after rice in the last season is harvested, rice stubbles cover the surface of the soil, rice roots are left in the soil, shallow ploughing and weeding are performed before sowing, and single-grain direct sowing of peanuts is adopted. According to the method, the physicochemical properties of soil are improved through no-tillage, the community abundance of soil microorganisms and the abundance of soil nitrification function microorganisms are promoted, conversion of soil nitrogen is improved, absorption and utilization of nitrogen by plants are promoted, and therefore accumulation of volatile flavor substances of peanuts is promoted.

Description

Technical Field

[0001] The present invention relates to the technical field of peanut planting, and more specifically, it relates to a peanut no-tillage planting method. Background Art

[0002] Peanut is a kind of nut crop with rich yield and wide consumption in China. It is also one of the main oil crops and cash crops in China. In recent years, the planting area has been stable at 65 million - 75 million mu, and the annual output is 15 million - 18 million tons. The industrial development of peanut planting is not only related to the increase of farmers' income, but also of great significance to ensuring the national edible oil security.

[0003] Peanut is praised as "plant meat" by people, with an oil content as high as 50%, excellent quality and a delicate fragrance. There are more than 140 natural aromatic substances in peanuts, mainly including: β-sitosterol, maltol, 2-acetyl-1-pyrroline (2-AP) and volatile aldehydes and ketones. In order to achieve the accumulation of natural aromatic substances in peanuts, the present invention proposes a peanut no-tillage planting method. Summary of the Invention

[0004] The purpose of the present invention is to provide a peanut no-tillage planting method to achieve the accumulation of natural aromatic substances in peanuts.

[0005] The above technical purpose of the present invention is achieved through the following technical solutions: A peanut no-tillage planting method, without disturbing the soil after the previous season's rice harvest, covering the soil surface with rice stubble, leaving the rice roots in the soil, shallow tilling and weeding before sowing, and directly sowing single-seed peanuts.

[0006] The present invention is further set as: The shallow tillage depth is 4 - 6 cm.

[0007] The present invention is further set as: The row spacing of the single-seed direct sowing is 30 cm, and the plant spacing is 20 cm.

[0008] In summary, the present invention has the following beneficial effects: The present invention improves the physical and chemical properties of the soil through no-tillage, promotes the community abundance of soil microorganisms and the abundance of soil nitrifying functional microorganisms, improves the transformation of soil nitrogen, promotes the absorption and utilization of nitrogen by plants, and thus promotes the accumulation of volatile flavor substances in peanuts. Brief Description of the Drawings

[0009] Figure 1 is the peanut field planting situation in the present invention (wherein, a is the actual picture of peanut planting, b is the physical picture of the static - greenhouse gas collection box);

[0010] Figure 2 is the relative content of volatile compounds in peanut kernels under different tillage treatments in the present invention;

[0011] Figure 3 It is the score scatter plot of the OPLS-DA model in the present invention;

[0012] Figure 4 It is the heat map of differential volatile compounds and VIP value map of peanut kernels under different tillage treatments in the present invention;

[0013] Figure 5 It is the heat map of the abundance of Rhizobium in peanut roots under different tillage treatments in the present invention;

[0014] Figure 6 It is the correlation heat map of the potential relationship between key microorganisms, nitrification functional genes and soil environmental factors in peanut soil in the present invention (where a is the key microorganism and soil environmental factor, b is the nitrification functional gene and soil environmental factor; blue and red respectively represent the positive correlation and negative correlation between two variables (**P<0.01, *P<0.05));

[0015] Figure 7 It is the Mantel test of peanut quality and yield with soil physical and chemical factors and key microorganisms in the embodiment of the present invention (where a is pH, b is total nitrogen, c is nitrate nitrogen, d is ammonium nitrogen, e is CH4 cumulative emission, f is CO2 cumulative emission, g is N2O cumulative emission, h is Proteobacteria, i is Nitrospirae, j is Gemmatimonadetes, k is β-Proteobacteria, l is δ-Proteobacteria, m is Anaerovibrio, n is Anaeromyxobacteraceae, o is Myxococcales, p is AOA-amoA, q is AOB-amoA, r is Burkholderia, s is Bradyrhizobium). Specific Embodiments

[0016] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0017] Example 1: No-tillage

[0018] After the previous season of rice harvest, the soil is not disturbed, the rice stubble covers the soil surface, and the roots remain in the soil. Weed by shallow tillage at 5 cm before sowing. Also use single-seed direct seeding with a row spacing of 30 cm and a plant spacing of 20 cm. Repeat in 3 plots, and the area of each plot is 15 m 2 . The field management during the whole growth period is carried out with reference to the peanut field cultivation regulations

[0019] Comparative Example 1: Conventional ploughing

[0020] Before sowing, weed and prepare the land. Deeply plow the land to 30 cm. Sow directly with single seeds, with a row spacing of 30 cm and a plant spacing of 20 cm. Repeat in 3 plots, and the area of each plot is 15 m 2 . The field management during the whole growth period shall be carried out with reference to the peanut field cultivation regulations.

[0021] Experimental results:

[0022] I. Effects of different tillage treatments on peanut flavor substances

[0023] 1.1 Effects of different tillage treatments on peanut volatile flavor compounds

[0024] The types and contents of volatile flavor substances in peanut kernels determine the peanut flavor type. In this experiment, HS-SPME-GC-MS was used to detect 6 fresh peanut kernel samples of conventional tillage and no-tillage treatments, and a total of 344 flavor volatile substances were detected, including 52 alcohols, 49 terpenes, 46 ketones, 42 esters, 28 hydrocarbons, 25 aldehydes, 16 acids, 8 amines, 8 ethers, 6 aromatic hydrocarbons, 6 phenols, 48 heterocyclic compounds, 6 nitrogen-containing compounds, 2 sulfur-containing compounds and 2 halogenated hydrocarbons. According to the relative contents of volatile compounds, alcohols, aldehydes and ketones are the main volatile compounds in peanut kernels, followed by heterocyclic compounds and esters ( Figure 2 ). Compared with conventional tillage, the no-tillage treatment significantly increased the relative content of peanut esters by 12.03% (P<0.05), increased the relative contents of aldehydes, heterocyclic compounds, esters, terpenes, hydrocarbons, ethers, nitrogen-containing compounds, phenols, acids, sulfur-containing compounds and halogenated hydrocarbon compounds, and decreased the relative contents of ketones, amines and aromatic hydrocarbon compounds, but the difference between the no-tillage treatment and conventional tillage was not significant (P>0.05).

[0025] Alcohol compounds had the highest relative content, accounting for 34.80%-37.48% of the total detected flavor components, and were the main volatile compounds in the fresh peanut kernel flavor. Among them, the relative contents of 1,2-butanediol, 2,3-butanediol, (Z)-2-penten-1-ol, (E)-2-penten-1-ol, and 3,3-dimethyl-1-butanol were relatively high and were the main volatile substances. (Z)-2-penten-1-ol had a "fruity" flavor, and (E)-2-penten-1-ol had a "mushroom" flavor. Aldehyde compounds were the second most abundant volatile compounds, accounting for 18.45%-18.86% of the total volatile compounds. Among them, the relative contents of hexanal, 2-hexenal, (E)-2-hexenal, 3,3-dimethyl-2-oxobutanal, and cyclohexylmethanal were relatively high and were the main volatile substances. Hexanal and (E)-2-hexenal had "green grass" and "fresh" flavors. Ketones ranked third in the total amount of peanut flavor components, accounting for 15.06%-15.20% of the total flavor components. Among them, the relative contents of dihydro-2-methyl-3(2H)-furanone, 3-methyl-2-cyclohexen-1-one, 4-heptanone, 4-methyl-2,3-pentanedione, and 2,2,3-trimethylcyclobutanone were relatively high and were the main volatile substances. Dihydro-2-methyl-3(2H)-furanone, 3-methyl-2-cyclohexen-1-one, and 4-methyl-2,3-pentanedione had "sweet", "nutty", and "fatty" flavors.

[0026] To further analyze the differential substances in the fresh peanut kernel flavor of the two tillage treatments, orthogonal partial least squares-discriminant analysis (OPLS-DA) was used for analysis. The results are shown in the figure ( Figure 3 ). The two tillage treatments were clearly separated, indicating that there were significant differences in the volatile flavor compounds of fresh peanut kernels under different tillage treatments. Variable Importance in Projection (VIP) was used to evaluate the contribution degree of each variable to sample discrimination. According to the criteria of VIP>1 and P<0.05, 23 volatile flavor substances with significant differences were screened, including 6 heterocyclic compounds, 3 alcohols, 3 aldehydes, 3 acids, 2 terpenes, 2 hydrocarbons, 1 amine, 1 nitrogen-containing compound, 1 ketone, and 1 ester ( Figure 4)。Compared with conventional tillage, no-till treatment significantly increased the contents of terpenoids and heterocyclic compounds (P<0.01). Among them, the contents of (E,E)-2,6-nonadienal and (E,Z)-2,6-nonadienal increased extremely significantly by 33.65% (P<0.01), the contents of 2-butyl-3,5-dimethylpyrazine, 6-nitro-2-methylpyridine, (R)-5-isoxazolecarboxylic acid-4,5-dihydro-5-methyl methyl ester, tetrahydro-3a-methyl-1,3-dithiol [4,5-b] furan, 1-acetylpyrrolidine, 3-butyl-2,5-dimethylpyrazine, (E)-5-nonenal, α-2-propenylbenzyl alcohol, 2,6-dimethyl-7-octene-2,6-diol, 1,2-diacetylhydrazine, 2-methylbutyric anhydride, 3-isopropyl-6-methyl-2-cyclohexen-1-one, piperitone, 3-ethyl-3-methyldecane, 1-ethyl-2-propylcyclohexane, (E)-8-methyl-3,7-nonadien-2-one, and ethyl 2-mercaptopropionate increased significantly by 27.92%, 26.21%, 34.13%, 26.52%, 40.37%, 27.92%, 10.07%, 23.23%, 24.61%, 38.80%, 12.00%, 21.53%, 21.53%, 14.81%, 13.48%, 19.82%, and 33.53% (P<0.05), respectively. The contents of propylene glycol and formamide decreased extremely significantly by 5.19% (P<0.01), and the contents of 4-methylvaleric acid and 2-methylvaleric acid decreased significantly by 20.09% (P<0.05).

[0027] 1.2 Effects of Different Tillage Treatments on the Contribution Values of Main Aroma Substances in Peanuts

[0028] Volatile metabolites exhibit different aroma characteristics, but not all flavor compounds can affect the overall flavor of peanuts. Only volatile compounds with concentrations exceeding their respective odor thresholds can be detected by humans (Yin et al., 2022). Generally, the larger the rOAV value, the higher the contribution of the flavor substance to the overall flavor. Volatile compounds with rOAV ≥ 1 have a direct impact on the overall flavor of peanut kernels (Liu et al., 2022). In this experiment, a total of 196 volatile flavor substances were detected in the fresh peanut kernels of the two treatments (Appendix A). There were 93 volatile flavor substances with rOAV ≥ 1 in the conventional tillage, and 99 volatile flavor substances with rOAV ≥ 1 in the no-tillage treatment, indicating that they made significant contributions to the flavor characteristics of peanut kernels. Among them, the rOAV value of alcohol flavor compounds had the highest proportion, accounting for 69.48% - 21.99% of the total flavor. The rOAV value of α,α,4-trimethyl-3-cyclohexene-1-methanethiol was the highest in the no-tillage treatment, reaching 5,749,341.81; the rOAV value of ketone flavor compounds ranked second, accounting for 30.28% - 77.46% of the total flavor. The rOAV value of dihydro-2-methyl-3(2H)-furanone was the highest in the conventional tillage, with an rOAV value of 2,425,957.43. The rOAV value of key active flavor compounds of aldehydes ranked third, accounting for 0.18% - 0.40% of the total flavor. The rOAV values of (E,Z)-2,6-nonadienal and hexanal were the highest in the no-tillage treatment, both being 2,318.10.

[0029] In the fresh peanut kernels under different tillage treatments, a total of 3 significantly different volatile flavor substances were screened through VIP > 1, P < 0.05 and rOAV ≥ 1, namely (E,Z)-2,6-nonadienal, (E,E)-2,6-nonadienal, and (E)-5-nonenal. (E,Z)-2,6-nonadienal has a "cucumber flavor", and (E,E)-2,6-nonadienal has flavors such as "umami", "citrus", "cucumber", and "melon". These three volatile flavor substances are important volatile flavor substances that form the flavor of peanuts.

[0030] II. Effects of Different Tillage Treatments on Peanut Roots

[0031] As shown in Table 1, different tillage treatments had significant effects on peanut roots. Compared with conventional tillage, the no-tillage treatment extremely significantly increased the number of peanut root nodules by 36.11% (P < 0.01), increased the root length of peanuts by 8.64%, the root surface area by 10.60%, and the root volume by 29.82%, but there was no significant difference between the no-tillage treatment and conventional tillage (P > 0.05).

[0032] In the soil metagenomic data of this experiment, a total of 34 species of rhizobia were screened (Appendix B). Compared with conventional tillage, no-tillage treatment extremely significantly increased the abundance of Burkholderia by 39.55%, extremely significantly decreased the abundance of Bradyrhizobium by 52.19% (P<0.01), increased the abundance of Bartonella by 3045.23%, the abundance of Cupriavidus by 49.47%, the abundance of Ochrobactrum by 574.30%, the abundance of Herbaspirillum by 83.51%, the abundance of Sinorhizobium by 25.15%, the abundance of Allorhizobium by 175.14%, the abundance of Pararhizobium by 64.15%, the abundance of Mycoplana by 69.75%, the abundance of Pseudorhizobium by 40.00%, the abundance of Rhodobium by 15.41%, the abundance of Methylobacterium by 5.62%, the abundance of Microvirga by 8.11%, the abundance of Pseudomonas by 24.30%, the abundance of Cohaesibacter by 71.35%, and the abundance of Hyphomicrobium by 531.11%, decreased the abundance of Beijerinckia by 41.87%, the abundance of Aurantimonas by 2.50%, the abundance of Devosia by 76.64%, the abundance of Ensifer by 32.07%, the abundance of Agrobacterium by 3.45%, the abundance of Neorhizobium by 74.46%, the abundance of Rhizobium by 11.33%, the abundance of Shinella by 38.77%, the abundance of Ciceribacter by 61.00%, the abundance of Gellertiella by 100%, the abundance of Georhizobium by 71.91%, the abundance of Liberibacter by 100%, the abundance of Xanthobacter by 81.43%, the abundance of Azorhizobium by 67.60%, the abundance of Methylocystis by 10.61%, the abundance of Mesorhizobium by 25.30%, and 86.The abundance of Phyllobacterium was 22%, but there was no significant difference between the no-tillage treatment and the conventional tillage treatment (P > 0.05)(. Figure 5 )

[0033] In summary, the no-tillage treatment significantly affected the formation of peanut root nodules and the abundance distribution of rhizobia, especially increasing the abundance of Burkholderia and decreasing the abundance of Bradyrhizobium. These changes may have important effects on peanut yield and soil structure.

[0034] Table 1 Effects of different tillage treatments on peanut roots

[0035]

[0036] Note: Different letters in the table indicate significant differences between treatments (P < 0.05).

[0037] III. Effects of different tillage treatments on nitrogen accumulation and yield of peanuts

[0038] 3.1 Effects of different tillage treatments on dry matter accumulation and nitrogen accumulation of peanuts

[0039] Peanut dry matter accumulation is the basis of kernel yield. Different tillage treatments had a significant impact on peanut dry matter accumulation (Table 2). Among different tillage treatments, the dry matter accumulation in each organ of peanuts showed the order of pod > leaf > stem > root > peg. Compared with conventional tillage, the no-tillage treatment extremely significantly increased the root dry matter accumulation by 63.37%, the leaf dry matter accumulation by 44.73%, the peg dry matter accumulation by 48.74%, and the whole-plant dry matter accumulation of peanuts by 41.51% (P < 0.01), and significantly increased the stem dry matter accumulation by 40.44% and the pod dry matter accumulation by 37.12% (P < 0.05). This indicates that no-tillage is beneficial to the dry matter accumulation of peanut plants.

[0040] Table 2 Effects of different tillage treatments on dry matter accumulation in each organ of peanuts

[0041]

[0042] Note: Different letters in the table indicate significant differences between treatments (P < 0.05).

[0043] The effects of different tillage treatments on nitrogen accumulation in peanuts were significant (Table 3). Among different tillage treatments, the nitrogen accumulation in various organs of peanuts showed the order of pods > leaves > stems > roots > pegs. Compared with conventional tillage, no-till treatment significantly increased the nitrogen accumulation in roots by 132.87%, in leaves by 61.40%, in pegs by 56.74%, and in the whole peanut plant by 58.38% (P<0.01), and significantly increased the nitrogen accumulation in pods by 54.24% (P<0.05). This indicates that no-till is beneficial to nitrogen accumulation in peanut plants.

[0044] Table 3 Effects of different tillage treatments on nitrogen accumulation in various organs of peanuts

[0045]

[0046]

[0047] Note: Different letters in the table indicate significant differences between treatments (P<0.05).

[0048] 3.2 Effects of different tillage treatments on peanut yield and yield components

[0049] The effects of different tillage treatments on peanut yield and yield components were significant (Table 4). Compared with conventional tillage, no-till treatment significantly increased the peanut pod yield by 40.48%, the kernel yield by 65.76%, and the kernel extraction rate by 15.80% (P<0.01), significantly increased the total number of fruits per plant by 38.48% and the 100-kernel weight by 3.68% (P<0.05), and decreased the 100-pod weight by 0.41%, but the difference between no-till treatment and conventional tillage was not significant (P>0.05). From the perspective of yield components, the main reason for the increase in peanut yield under no-till treatment was the increase in peanut pod yield and kernel yield, and the decrease in 100-pod weight. In summary, no-till treatment can increase peanut yield.

[0050] Table 4 Effects of different tillage treatments on peanut yield and yield components

[0051]

[0052] Note: Different letters in the table indicate significant differences between treatments (P<0.05).

[0053] IV. Effects of no-till soil physical and chemical properties and microorganisms on peanut flavor quality

[0054] Heatmap of the correlation between the abundances of key microbial fungi and soil factors ( Figure 6a), The abundance of Bradyrhizobium was significantly negatively correlated with pH value (P<0.01). The abundance of Nitrospira was significantly positively correlated with the ammonium nitrogen content and significantly negatively correlated with the nitrate nitrogen content (P<0.05). The abundance of Gemmatimonadetes was significantly positively correlated with the cumulative N2O emissions (P<0.01), significantly positively correlated with the total nitrogen content, ammonium nitrogen content and cumulative CH4 emissions (P<0.05), and significantly negatively correlated with the cumulative CO2 emissions (P<0.01). The abundance of Deltaproteobacteria was significantly positively correlated with the total nitrogen content, cumulative CH4 emissions and cumulative N2O emissions (P<0.05), and significantly negatively correlated with the nitrate nitrogen content (P<0.01); the abundance of Anaerovibrio was significantly positively correlated with the ammonium nitrogen content (P<0.01), significantly positively correlated with the cumulative CH4 emissions (P<0.05), and significantly negatively correlated with the nitrate nitrogen content (P<0.05); the family Anaeromyxobacteraceae was significantly positively correlated with the ammonium nitrogen content (P<0.01), significantly positively correlated with the cumulative CH4 emissions (P<0.05), and significantly negatively correlated with the nitrate nitrogen content (P<0.05); the abundance of Myxococcales was significantly positively correlated with the ammonium nitrogen content and cumulative CH4 emissions (P<0.01), significantly positively correlated with the total nitrogen content and cumulative N2O emissions (P<0.05), and significantly negatively correlated with the nitrate nitrogen content (P<0.01).

[0055] Heatmap of the correlation between the abundance of nitrification functional genes and soil factors( Figure 6 b). In peanut soil, the abundance of AOA-amoA gene was significantly positively correlated with the cumulative N2O emissions (P<0.01), significantly positively correlated with the total nitrogen, ammonium nitrogen and cumulative CH4 emissions (P<0.05), significantly negatively correlated with the cumulative CO2 emissions (P<0.01), and significantly negatively correlated with the nitrate nitrogen (P<0.05). The abundance of AOB-amoA gene was significantly positively correlated with the ammonium nitrogen content and cumulative N2O emissions (P<0.05), and significantly negatively correlated with the nitrate nitrogen content (P<0.01).

[0056] The results of Mantel test showed that( Figure 7) In peanut soil, the amino acid components were extremely significantly positively correlated with the abundances of Proteobacteria and Betaproteobacteria (P<0.01), and significantly positively correlated with total nitrogen content, cumulative CH4 emissions, cumulative CO2 emissions, cumulative N2O emissions, the abundance of Gemmatimonadetes, the abundance of Anaerolineaceae, the abundance of Anaeromyxobacteraceae, the abundance of AOA-amoA gene, and the abundance of Burkholderia (P<0.05). The fatty acid components were extremely significantly positively correlated with cumulative CH4 emissions, the abundances of Proteobacteria and Betaproteobacteria (P<0.01), and significantly positively correlated with total nitrogen content, ammonium nitrogen content, the abundance of Nitrospirae, the abundance of Anaerolineaceae, the abundance of Anaeromyxobacteraceae, and the abundance of Myxococcales (P<0.05).

[0057] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

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[0070] Appendix B Effects of Different Tillage Treatments on the Relative Abundance of Rhizobia in Peanut Soil

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[0072]

Claims

1. A no-till planting method for peanuts, characterized in that: After the previous season's rice harvest, the soil is not disturbed, the rice stubble covers the soil surface, and the rice roots remain in the soil. Before sowing, shallow tillage is carried out to remove weeds, and single-seed direct seeding of peanuts is adopted.

2. The peanut no-till planting method according to claim 1, characterized in that: The depth of the shallow tillage is 4 - 6 cm.

3. The peanut no-tillage planting method according to claim 1, characterized in that: The row spacing of the single-seed direct seeding is 30 cm, and the plant spacing is 20 cm.

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