Slow-release compound fertilizer and application thereof in tobacco planting

Abstract

The invention belongs to the technical field of fertilizer preparation and tobacco planting, and particularly relates to a slow-release compound fertilizer and application thereof in tobacco planting. The slow-release compound fertilizer contains slow-release nitrogen and slow-release potassium and can meet the requirement for nitrogen and potassium absorption of tobacco in the whole development period, and then fertilization is conducted only once in the tobacco planting process, and the requirement for nutrients of tobacco growth and development can be met without topdressing; compared with conventional fertilization, under the condition that the application amount of the slow-release compound fertilizer is reduced by 10% or more than 10%, the slow-release compound fertilizer can still meet the growth and development of tobacco in the whole growth period, improve the lodging resistance of tobacco plants, promote the growth and development of the tobacco and improve the yield and quality of the tobacco, so that the effects of saving cost and increasing income are achieved; moreover, the slow-release compound fertilizer can improve the pH value of soil, so that the content of organic matters is kept stable, the characteristics of soil aggregates are remarkably improved, the physical structure of the soil is improved, the microbial diversity is improved, and the soil improvement effect is obvious.

Description

Technical Field

[0001] The invention belongs to the technical field of fertilizer preparation and tobacco planting, and particularly relates to a slow-release compound fertilizer and application thereof in tobacco planting. Background Art

[0002] Tobacco is one of my country's important cash crops, and its planting area has always ranked first in the world. However, from the perspective of tobacco leaf quality and tobacco-growing soil changes, there is a certain downward trend overall, and the core reason for this downward trend is the problem of tobacco fertilization.

[0003] At present, conventional tobacco fertilizers are mostly composed of water-soluble compounds and organic fertilizers, and the quality of tobacco is improved through large-scale concentrated fertilization. However, this fertilization method cannot adapt to local conditions and reasonably apply chemical fertilizers, resulting in low fertilizer utilization. In addition, the application of traditional tobacco fertilizers is mostly calculated based on the total regional demand, and is applied through one-time fertilization or secondary topdressing, rather than releasing nutrients based on the fertilizer requirements of each period of tobacco growth and development, which easily leads to fertilizer waste. At the same time, the current fertilization plan mostly uses topdressing to meet the needs of tobacco growth and development, which greatly increases labor costs.

[0004] Furthermore, in the process of tobacco cultivation, tobacco farmers generally rely on the application of a single chemical fertilizer. The long-term excessive application of chemical fertilizers and the long-term continuous cropping phenomenon have led to serious soil compaction, acidification, and soil-borne diseases. The continuous fertilizer supply capacity has been seriously reduced, leading to problems such as poor tobacco growth and development, serious diseases and pests, and quality decline.

[0005] Therefore, current fertilizers cannot meet the requirements for yield, quality, cost savings, and improvement of the tobacco growing environment during tobacco growing. Summary of the invention

[0006] The object of the present invention is to provide a slow-release compound fertilizer and its application in tobacco planting, wherein the slow-release compound fertilizer can effectively promote the growth and development of tobacco and improve the quality of tobacco on the basis of reducing the amount of tobacco fertilizer applied, thereby achieving the effect of saving tobacco planting costs and increasing tobacco planting benefits.

[0007] The invention provides a slow-release compound fertilizer, which comprises the following nutrients in mass percentage: nitrogen, phosphorus and potassium compound nutrients ≥30%, organic matter ≥10.0%, free humic acid ≥7.0%, potassium oxide ≥16.0%, and active silicon ≥24%; the mass ratio of N, P2O5 and K2O in the nitrogen, phosphorus and potassium compound nutrients is 8:6:16.

[0008] Preferably, the slow-release compound fertilizer comprises the following raw materials in parts by weight:

[0009] 11.17-22.34 parts of urea, 12-24 parts of potassium silicate, 12.5-25 parts of potassium nitrate, 9.84-19.68 parts of monoammonium phosphate, 11.2-22.4 parts of potassium sulfate, 20-40 parts of attapulgite, and 11.29-22.58 parts of materials or products containing humic acid.

[0010] Preferably, the mass content of humic acid in the humic acid-containing material or product is 90%; and the urea includes slow-release urea.

[0011] Preferably, the nutrients in the preparation raw material are represented by N, P2O5 and K2O respectively, and are expressed in the form of N-P2O5-K2O, and the preparation raw material contains the following nutrients in percentage by mass: urea 46%-0%-0%, potassium silicate 0%-0%-20%, potassium nitrate 13.5%-0%-44.5%, monoammonium phosphate 11.8%-61%-0%, potassium sulfate 0%-0%-50% and attapulgite 0%-0%-0%.

[0012] Preferably, the pH value of the slow-release compound fertilizer is 7-8.

[0013] The present invention also provides application of the slow-release compound fertilizer described in the above technical solution in tobacco planting.

[0014] The present invention also provides the use of the slow-release compound fertilizer described in the above technical solution in one or more of promoting tobacco growth and development, improving tobacco quality, reducing tobacco fertilizer application, improving soil and improving tobacco's resistance to abiotic stress.

[0015] Preferably, the promoting the growth and development of tobacco includes promoting the growth and development of one or more of the tobacco root system, plant height, stem and leaves.

[0016] Preferably, improving tobacco quality includes improving tobacco appearance quality and / or increasing the content of chemical components in tobacco.

[0017] Preferably, the method for applying the slow-release compound fertilizer comprises: applying the slow-release compound fertilizer to the land before tobacco transplanting; the application method comprises broadcasting and / or strip application; the application amount is 60-70 kg / mu.

[0018] Beneficial effects:

[0019] The invention provides a slow-release compound fertilizer, which comprises the following nutrients in percentage by mass: nitrogen, phosphorus and potassium compound nutrients ≥30%, organic matter ≥10.0%, free humic acid ≥7.0%, potassium oxide ≥16.0%, and active silicon ≥24%; the mass ratio of N, P2O5 and K2O in the nitrogen, phosphorus and potassium compound nutrients is 8:6:16, and the content of each nutrient in the slow-release compound fertilizer is met by the preparation raw materials of 11.17-22.34 parts of urea, 12-24 parts of potassium silicate, 12.5-25 parts of potassium nitrate, 9.84-19.68 parts of monoammonium phosphate, 11.2-22.4 parts of potassium sulfate, 20-40 parts of attapulgite, and 11.29-22.58 parts of materials or products containing humic acid. The slow-release compound fertilizer of the present invention contains slow-release nitrogen (urea) and slow-release potassium (potassium silicate), which can meet the absorption of nitrogen and potassium by tobacco during the entire growth period, and thus only one fertilization is performed during the planting process of tobacco, and the nutrient demand of tobacco growth and development can be met without topdressing, especially the nutrient demand of growth and development during the vigorous growth period can be promoted; at the same time, compared with conventional fertilization, when the slow-release compound fertilizer is reduced by 10% or more, the growth and development of tobacco during the entire growth period can still be met, the lodging resistance of tobacco plants can be improved, and the growth and development of tobacco can be promoted, while the yield and quality of tobacco can be improved, so as to achieve the effect of saving costs and increasing benefits; furthermore, the slow-release compound fertilizer can increase the pH value of soil, so that the organic matter content remains stable, the soil aggregates are significantly improved, the microbial diversity is improved, and the soil improvement effect is obvious. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the embodiments are briefly introduced below.

[0021] Figures 1 to 3 The diagrams show the growth trend of the tobacco plant roots at the cluster stage (left) and 33 days after transplanting (right) in Example 3. DETAILED DESCRIPTION

[0022] The present invention provides a slow-release compound fertilizer, which comprises the following nutrients in mass percentage: nitrogen, phosphorus and potassium compound nutrients ≥30%, organic matter ≥10.0%, free humic acid ≥7.0%, potassium oxide ≥16.0%, and active silicon ≥24%; the mass ratio of N, P2O5 and K2O in the nitrogen, phosphorus and potassium compound nutrients is 8:6:16. As an embodiment, the content of active silicon in the present invention is calculated as silicon dioxide.

[0023] As an embodiment, the slow-release compound fertilizer of the present invention includes the following raw materials in proportion by weight: 11.17 to 22.34 parts of urea, 12 to 24 parts of potassium silicate, 12.5 to 25 parts of potassium nitrate, 9.84 to 19.68 parts of monoammonium phosphate, 11.2 to 22.4 parts of potassium sulfate, 20 to 40 parts of attapulgite, and 11.29 to 22.58 parts of materials or products containing humic acid. As an embodiment, the mass fraction of urea described in the present invention is 11.17-15.5 parts; the mass fraction of potassium silicate is 18-24 parts; the mass fraction of potassium nitrate is 12.5-20 parts; the mass fraction of monoammonium phosphate is 9.84-12.56 parts; the mass fraction of potassium sulfate is 11.2-16.2 parts; the mass fraction of attapulgite is 20-30 parts; the mass fraction of the material or product containing humic acid is 11.29-16.58 parts. As an embodiment, the mass content of humic acid in the material or product containing humic acid described in the present invention is 90%. As an embodiment, the urea described in the present invention is slow-release urea; the mass percentage of N, P2O5 and K2O in the urea is 46%-0%-0%; the slow-release urea can achieve slow-controlled release of nitrogen in the slow-release compound fertilizer. As an embodiment, the potassium silicate is a potassium silicate mineral fertilizer; the mass percentage of N, P2O5 and K2O in the potassium silicate mineral fertilizer is 0%-0%-20%; the potassium silicate can achieve slow and controlled release of potassium in the slow-release compound fertilizer. As an embodiment, the mass percentage of N, P2O5 and K2O in the potassium nitrate of the present invention is 13.5%-0%-44.5%; the potassium nitrate can increase the pH value of the soil in the slow-release compound fertilizer and assist in improving acidified soil. As an embodiment, the mass percentage of N, P2O5 and K2O in the monoammonium phosphate is 11.8%-61%-0%; the monoammonium phosphate in the slow-release compound fertilizer has the needs of the tobacco plants for the quick-acting nitrogen and quick-acting phosphorus nutrients in the early stage (0 to 15 days), which plays a role in the early growth and rapid development of the tobacco plants. As an embodiment, the potassium sulfate is a potassium sulfate compound fertilizer; the mass percentage of N, P2O5 and K2O in the potassium sulfate compound fertilizer is 0%-0%-50%; the potassium sulfate has the function of meeting the nutrient demand of tobacco plants for quick-acting potassium in the slow-release compound fertilizer. As an embodiment, the mass percentage of N, P2O5 and K2O in the attapulgite is 0%-0%-0%; the attapulgite has the function of fixing nutrients in the slow-release compound fertilizer to reduce nutrient loss, which plays an important role in promoting the formation of granular structure. As an embodiment, the humic acid is 90% humic acid; the mass percentage of N, P2O5 and K2O in the humic acid is negligible. The present invention does not specifically limit the source of the raw materials for preparation, and commercially available products can be conventionally selected on the basis of meeting the nutrient requirements of each raw material.

[0024] The slow-release compound fertilizer of the present invention has a certain effect of neutralizing acidified soil, can maintain the stability of soil organic matter content, increase the proportion of soil water-stable aggregates, improve soil physical properties, increase the variety of rhizosphere soil microorganisms and the abundance of beneficial microorganisms, and regulate soil acid-base balance.

[0025] The present invention also provides application of the slow-release compound fertilizer described in the above technical solution in tobacco planting.

[0026] The present invention also provides the use of the slow-release compound fertilizer described in the above technical solution in one or more of promoting tobacco growth and development, improving tobacco quality, reducing tobacco fertilizer application, improving soil and improving tobacco's resistance to abiotic stress.

[0027] As an embodiment, the method of promoting tobacco growth and development is to promote the growth and development of one or more of tobacco root system, plant height, stem and leaf. As an embodiment, the method of promoting tobacco root growth and development is to increase tobacco root volume, root vitality, root number, root dry weight and enhance root absorption and utilization of nutrients. As an embodiment, the method of promoting stem growth and development is to increase tobacco stem girth and / or stem dry weight. As an embodiment, the method of promoting tobacco leaf growth and development is to promote the growth and development of one or more of upper leaf, middle leaf and lower leaf of tobacco leaf; as another embodiment, the method of promoting tobacco leaf growth and development is to increase the number of effective leaves of tobacco leaf, increase the length of tobacco leaf, increase the width of tobacco leaf and increase the dry weight of tobacco leaf. As an embodiment, the method of improving tobacco quality includes improving tobacco appearance quality and / or increasing the content of tobacco internal chemical components; as another embodiment, the method of increasing the content of tobacco internal chemical components is to increase the potassium content in tobacco. As an embodiment, the soil improvement described in the present invention is to increase the soil pH value, increase the soil organic matter content, increase the soil aggregates and increase the microbial diversity. As an embodiment, the improvement of tobacco's resistance to abiotic stress described in the present invention is to improve tobacco's resistance to lodging.

[0028] As an embodiment, the method for applying the slow-release compound fertilizer of the present invention is: applying the slow-release compound fertilizer to the land before tobacco transplanting; the application method is broadcasting and / or strip application; the application amount is 60-70 kg / mu.

[0029] In order to further illustrate the present invention, the technical solution provided by the present invention is described in detail below in conjunction with the accompanying drawings and embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0030] Example 1

[0031] A formula of a slow-release compound fertilizer (hereinafter referred to as a slow-release integrated fertilizer for tobacco)

[0032] Preparation materials: humic acid, slow-release urea, potash fertilizer (potassium silicate, potassium nitrate, potassium sulfate), attapulgite and monoammonium phosphate.

[0033] Main nutrients: total nutrients (N+P2O5+K2O) ≥30% (8-6-16), organic matter ≥10.0%, free humic acid ≥7.0%, K2O ≥16.0%, active silicon (SiO2) ≥24%.

[0034] Table 1 Nutrient content of basic materials

[0035]

[0036] Table 2 Formula (calculated per 100 kg of compound fertilizer)

[0037]

[0038] Example 2

[0039] The preparation method of the slow-release integrated fertilizer for tobacco in Example 1 comprises the following steps:

[0040] Humic acid (mass content of 90%), slow-release urea, potash fertilizer (potassium silicate mineral fertilizer, potassium nitrate fertilizer, potassium sulfate compound fertilizer), attapulgite, and monoammonium phosphate are uniformly mixed according to the mass ratio of 11.17:24:12.5:9.84:11.2:20:11.29, and then added to a disc granulator for granulation, and then dried after granulation. The granulation process is prepared in accordance with the national standard | GB15063-2001.

[0041] Example 3

[0042] Effect of the Tobacco-specific Slow-Release Integrated Fertilizer Prepared in Example 2 on the Growth and Development of Flue-cured Tobacco

[0043] Demonstration and promotion experiments were conducted on representative soils and terrains in four tobacco-producing areas in Shandong. The soil fertility and conventional fertilization in the areas were consistent, and the variety was Zhongyan 301. Compared with local conventional fertilization (CK), the application amount of tobacco-specific slow-release integrated fertilizer (T) was calculated based on the conventional fertilization purity nitrogen content reduced by 12.5%. The CK treatment was applied according to the local conventional fertilization method. The T treatment was applied once before ridge formation and transplanting, and no topdressing was applied later. The distribution of tobacco-producing areas and the application of tobacco-specific slow-release integrated fertilizer are shown in Table 3.

[0044] Table 3 Distribution of tobacco producing areas and application of tobacco-specific slow-release integrated fertilizer

[0045]

[0046] The application method of the CK group is as follows: local conventional fertilization, the total nitrogen (N) applied per mu is 6.75kg, the total phosphorus (P2O5) is 6.75kg, and the total potassium (K2O) is 20.75kg, specifically: Sakufu (N: P2O5: K2O = 15:15:15) is used at a rate of 40kg per mu, potassium sulfate compound fertilizer (agricultural potassium sulfate produced by Liaoning Migao Chemical Co., Ltd., with a K2O content of 50%) is used at a rate of 28kg per mu, and microbial organic fertilizer (compound microbial fertilizer-Jinshuitu produced by ETS (Tianjin) Biotechnology Development Co., Ltd., with an organic matter content of 40wt.%, and 200 million active microorganisms / g) is applied at a rate of 31.77kg per mu.

[0047] T: Use the prepared tobacco-specific slow-release integrated fertilizer as base fertilizer, 75 kg per mu, and do not apply other base fertilizers (the total nitrogen (N) is 6 kg, the total phosphorus (P2O5) is 4.5 kg, and the total potassium (K2O) is 12 kg per mu).

[0048] In the following investigation process, the standard investigation was carried out in accordance with YC / T 142-2010. Ten tobacco plants with uniform overall growth were selected for investigation, and the average value was finally calculated.

[0049] 1. Investigation of agronomic traits during the clustering and flat-top stages

[0050] The effects of tobacco-specific slow-release integrated fertilizer on the growth and development of flue-cured tobacco at the cluster and flat-top stages are shown in Tables 4 and 5.

[0051] Table 4 Agronomic characteristics survey of flue-cured tobacco during the cluster period

[0052]

[0053]

[0054] Table 5 Survey on agronomic traits of flue-cured tobacco at flat-top stage

[0055]

[0056] It can be concluded from Tables 4 and 5 that there was no significant difference between the T treatment and CK in the four tobacco areas during the clustering stage, but at the flat-top stage, all agronomic traits of the T treatment were better than those of the CK.

[0057] Based on the above analysis, the slow-release integrated fertilizer for tobacco can fully exert its slow-release effect between the clustering stage and the flat-top stage, and can promote the growth and development of flue-cured tobacco, especially the growth and development of the upper leaves.

[0058] 2. Growth of tobacco plant roots

[0059] The root growth conditions in each production area 35 days after transplanting are shown in Table 6.

[0060] Table 6 Root growth status of tobacco plants 35 days after transplantation

[0061]

[0062] It can be concluded from Table 6 that the root volume and the number of primary lateral roots of each treatment showed that T>CK. Except for the Huangdao production area where there was no obvious difference in root growth between the two treatments, the root activity of the other three production areas was better in the T treatment than in CK.

[0063] Based on the above analysis, it can be seen that the slow-release integrated fertilizer for tobacco can promote the growth and development of the root system in the cluster stage, promote the vitality of the root system, and enhance the absorption and utilization of nutrients by the root system in the vigorous period (the comparison of the root system in the vigorous period is shown in the figure). Figures 1 to 3 shown), Figures 1 to 3 The left and right pictures in the figure show the growth of the tobacco plant roots at the cluster stage and 33 days after transplanting. Figures 1 to 3 The growth status of the tobacco plants can be intuitively seen, which can further improve the tobacco plants' resistance to lodging and avoid the situation in which the tobacco plants fall over due to unstable root systems in windy and rainy weather, thereby improving the tobacco plants' resistance to lodging.

[0064] 3. Dry matter accumulation of tobacco plants

[0065] The dry matter accumulation of flue-cured tobacco plants during the flat-top stage in each demonstration area is shown in Table 7.

[0066] Table 7 Dry matter accumulation of tobacco plants during the flat-top period

[0067]

[0068] It can be concluded from Table 7 that, compared with CK, except for stems, the dry weights of roots and leaves in the four production areas increased to varying degrees. The total weight of tobacco plants in T treatment increased compared with CK.

[0069] Based on the above analysis, the slow-release integrated fertilizer for tobacco can improve the growth and development of the root system of tobacco during the cluster stage; from the cluster stage to the flat-top stage, the slow-release integrated fertilizer for tobacco promotes the accumulation of dry matter in tobacco leaves, and is better than traditional tobacco fertilizers for the growth and development of the whole tobacco plant.

[0070] 4. Output value and benefits

[0071] According to the statistics of tobacco leaf yield and output value of each demonstration site (T group) in each tobacco-producing city, compared with the non-demonstration site (CK group), the average yield per mu increased by 7.7 kg, the output value per mu increased by about 227 yuan, and the average price of tobacco leaves increased by 0.17 yuan / kg. At the same time, the new tobacco-specific compound fertilizer reduced labor costs by 60 to 80 yuan / mu. (Note: Reduce fertilizer mixing by 0.2 people / mu / day; reduce topdressing by 1 to 2 times, about 0.3 people / mu / day, a total of about 0.5 people / mu / day). The above two items generate a total economic benefit of about 287 yuan / mu, as shown in Table 8.

[0072] Table 8 Comparison of tobacco leaf output and output value

[0073]

[0074]

[0075] 5. Appearance quality

[0076] According to the grading standards of Flue-cured Tobacco (GB 2635-1992), appearance evaluation experts (Tobacco Research Institute of Chinese Agricultural Sciences) score the appearance quality factors of tobacco leaves, such as color, maturity, leaf structure, identity, oil content, and chroma, on a 10-point scale. Finally, the average value of the scores given by the 10 experts is taken to assign different scores to each level of quality factors.

[0077] The upper leaves were graded B2F as the evaluation object, and the middle leaves were graded C3F as the evaluation object.

[0078] 5.1 The results of the investigation on the appearance quality of the upper leaves of flue-cured tobacco using the tobacco-specific slow-release integrated fertilizer are shown in Table 9.

[0079] Table 9 Survey results of appearance quality of upper leaves of flue-cured tobacco

[0080]

[0081] It can be concluded from Table 9 that compared with CK, except for Qingdao tobacco area, the oil quality of the upper leaves of flue-cured tobacco in T treatment in other production areas was improved; except for Rizhao tobacco area, the application of new tobacco-specific compound fertilizer in other production areas could improve the color quality of flue-cured tobacco; the application of new tobacco-specific compound fertilizer could improve the maturity and leaf structure quality in Qingdao tobacco area;

[0082] From the above analysis, it can be seen that although the application of tobacco-specific compound fertilizers has different effects on the appearance quality of upper leaves in various production areas, the appearance quality of upper leaves has been improved to varying degrees.

[0083] 5.2 The effects of tobacco-specific slow-release integrated fertilizer on the appearance quality of the middle leaves of flue-cured tobacco are shown in Table 10.

[0084] Table 10 Appearance quality of middle leaves of flue-cured tobacco

[0085]

[0086] It can be concluded from Table 10 that the color quality of the middle leaves of flue-cured tobacco in T treatment in Huangdao, Qingdao and Anqiu, Weifang is better than that in CK; compared with CK, the maturity quality of the middle leaves of flue-cured tobacco in T treatment in Huangdao, Qingdao is improved, and there is no obvious difference in other producing areas; the oil quality of the middle leaves of flue-cured tobacco in T treatment in each producing area is better than that in CK; T treatment in Juxian, Rizhao and Anqiu, Weifang improves the chromaticity quality of the middle leaves of flue-cured tobacco.

[0087] The comprehensive appearance quality indexes of the middle leaves of flue-cured tobacco in various producing areas show that the total scores of the T treatment are higher than those of the CK treatment. The above analysis shows that the application of tobacco-specific slow-release integrated fertilizer can improve the overall appearance quality of the middle leaves of flue-cured tobacco.

[0088] Based on the analysis of Sections 5.1 and 5.2, it can be seen that the application of slow-release integrated fertilizer for tobacco improves the appearance quality of the upper and middle parts of flue-cured tobacco leaves, thereby increasing the demand for purchasing grades, providing a guarantee for farmers' income growth and industrial raw material demand.

[0089] 6. Impact of potassium content in tobacco leaves

[0090] The potassium content in the upper, middle and lower leaves of the tobacco leaves that were cured at the flat-top stage is shown in Table 11 below.

[0091] Table 11 Detection of potassium content in tobacco leaves during the flat-top stage

[0092]

[0093]

[0094] It can be concluded from Table 11 that the slow-release integrated fertilizer for tobacco can significantly increase the intrinsic potassium (K2O) of the middle and upper tobacco leaves in the four producing areas. The potassium content of the upper tobacco leaves increased by 18% to 32.49%, with an average increase of 22.42%; the potassium content of the middle tobacco leaves increased by 11.68% to 32%, with an average increase of 22.97%; except for the 39.4% increase in the lower leaves of flue-cured tobacco in Feixian tobacco area of ​​Linyi, the potassium content of the lower leaves in the other three producing areas decreased. The decrease in potassium content in the lower leaves may be due to the fact that potassium is a mobile element. The lower leaves are the first mature old leaves, and the potassium element is lost in the lower leaves in the middle and late stages when there is heavy rain.

[0095] From the above analysis, it can be seen that the slow-release integrated fertilizer for tobacco can increase the potassium content of the middle and upper tobacco leaves by more than 20%, which is of great significance to promoting the appearance and internal quality of the middle and upper tobacco leaves.

[0096] 7. Soil improvement

[0097] 7.1 Sample collection

[0098] After the tobacco leaves were toppled, mixed test samples of 0-20 cm tillage layer and original soil were collected on the ridge according to the 5-point sampling method. The mixed test samples were naturally air-dried in a cool and ventilated place, and the physical and chemical properties of the soil were tested after sieving through a 1 mm aperture sieve. The original soil was gently broken into small pieces with a diameter of less than 1 cm along the natural structure, and plant residues, small stones, and earthworms were removed, and air-dried for later use.

[0099] 7.2 Soil fertility testing

[0100] The pH value, alkaline nitrogen, available phosphorus, organic matter and quick-acting potassium were determined by referring to the conventional soil agrochemical analysis.

[0101] 7.3 Soil structure testing

[0102] Soil aggregates were determined by referring to Zhou Hu's method [Zhou Hu, Lü Yizhong, Yang Zhichen, et al. Effects of conservation tillage on soil aggregate characteristics in the North China Plain [J]. Chinese Agricultural Science, 2007, 40(9): 1973-1979], and soil bulk density was determined using the ring knife method.

[0103] 7.4 Soil microbial detection

[0104] The determination was performed by high-throughput sequencing of microorganisms based on the Illumina HiSeq sequencing platform.

[0105] 7.5 Results Analysis

[0106] 7.5.1 Impact on soil nutrients

[0107] The results of the effects on soil nutrients are shown in Table 12 below.

[0108] Table 12 Impact on soil nutrients

[0109]

[0110] It can be concluded from Table 12 that compared with CK, T treatment can increase the pH value, organic matter and effective fast-acting nutrient content of tobacco-growing soil, alleviate soil acidification, and improve soil fertility.

[0111] 7.5.2 Impact on soil physical structure

[0112] The results of the impact on soil physical structure are shown in Table 13.

[0113] Table 13 Impact on soil physical structure

[0114]

[0115]

[0116] Note: R0.25 It is the percentage of aggregates larger than 0.25 mm in the soil.

[0117] It can be concluded from Table 13 that the T treatment reduced soil bulk density, promoted the formation of water-stable aggregates, improved soil physical properties such as air permeability and water retention, and was beneficial to the extension of the root system.

[0118] 7.5.3 Impact on Microbial Diversity in Tobacco-Growing Soil

[0119] The effects on soil microbial diversity in tobacco-growing areas are shown in Table 14.

[0120] Table 14 Impact on soil microbial diversity

[0121]

[0122] It can be concluded from Table 14 that the coverage of microbial detection samples in different production areas and different treatments is above 99%, which can accurately reflect the actual situation of samples with different treatments. The Simpson index, Shannon index and number of species of bacteria and fungi in tobacco-growing soil in T treatment are greater than those in CK treatment. T treatment can improve the richness of soil microbial species and the stability of tobacco-growing soil, especially it has a certain repair effect on the damage of microbial community diversity and community structure caused by continuous cropping obstacles.

[0123] The above results show that T treatment can improve the nutrients of tobacco-growing soil, reduce soil bulk density, promote the formation of tobacco-growing soil aggregates, improve the physical properties of tobacco-growing soil such as air permeability and water retention, and facilitate the extension of the root system. The application of this fertilizer can increase the richness of tobacco-growing soil microorganisms and improve the stability of tobacco-growing soil, especially repairing the damage to the diversity and community structure of microbial communities caused by continuous cropping obstacles.

[0124] It can be concluded from the above examples that the slow-release compound fertilizer of the present invention can effectively promote the growth and development of tobacco and improve the quality of tobacco on the basis of reducing the amount of tobacco fertilizer applied, thereby saving tobacco planting costs and increasing tobacco planting benefits, and at the same time can play a role in improving the soil.

[0125] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A slow-release compound fertilizer, characterized in that: The slow-release compound fertilizer includes the following nutrients in percentage by mass: nitrogen, phosphorus and potassium compound nutrients ≥30%, organic matter ≥10.0%, free humic acid ≥7.0%, potassium oxide ≥16.0%, and active silicon ≥24%; the mass ratio of N, P2O5 and K2O in the nitrogen, phosphorus and potassium compound nutrients is 8:6:

16.

2. The slow-release compound fertilizer according to claim 1, characterized in that: The slow-release compound fertilizer comprises the following raw materials in parts by weight: 11.17-22.34 parts of urea, 12-24 parts of potassium silicate, 12.5-25 parts of potassium nitrate, 9.84-19.68 parts of monoammonium phosphate, 11.2-22.4 parts of potassium sulfate, 20-40 parts of attapulgite, and 11.29-22.58 parts of materials or products containing humic acid.

3. The slow-release compound fertilizer according to claim 2, characterized in that: The mass content of humic acid in the humic acid-containing material or product is 90%; and the urea includes slow-release urea.

4. The slow-release compound fertilizer according to claim 2, characterized in that: The nutrients in the preparation raw material are represented by N, P2O5 and K2O respectively, and are expressed in the form of N-P2O5-K2O. The preparation raw material contains the following nutrients in percentage by mass: urea 46%-0%-0%, potassium silicate 0%-0%-20%, potassium nitrate 13.5%-0%-44.5%, monoammonium phosphate 11.8%-61%-0%, potassium sulfate 0%-0%-50% and attapulgite 0%-0%-0%.

5. The slow-release compound fertilizer according to any one of claims 1 to 4, characterized in that: The pH value of the slow-release compound fertilizer is 7-8.

6. Use of the slow-release compound fertilizer according to any one of claims 1 to 5 in tobacco planting.

7. Use of the slow-release compound fertilizer according to any one of claims 1 to 5 in one or more of promoting tobacco growth and development, improving tobacco quality, reducing tobacco fertilizer application, improving soil and improving tobacco's resistance to abiotic stress.

8. The use according to claim 7, characterized in that: The promoting tobacco growth and development comprises promoting the growth and development of one or more of tobacco root system, plant height, stem and leaves.

9. The use according to claim 7, characterized in that: Improving tobacco quality includes improving tobacco appearance quality and / or increasing the content of internal chemical components in tobacco.

10. The use according to any one of claims 7 to 9, characterized in that: The method for applying the slow-release compound fertilizer comprises: applying the slow-release compound fertilizer to the land before tobacco transplanting; the application method comprises broadcasting and / or strip application; the application amount is 60-70 kg / mu.

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