Method for improving tobacco field soil in high-altitude cold area

Abstract

The invention provides an improvement method for tobacco field soil in a high-altitude cold area, and belongs to the technical field of tobacco field soil improvement. The improvement method provided by the invention comprises the following steps: (1) in the later period of tobacco leaf picking or after tobacco leaf harvesting and soil preparation, spreading leguminous green manure, and after 10-30 days, spreading cruciferous green manure; 2, 25-35 days before tobacco transplanting, green manure is turned over and returned to the field, and meanwhile biochar is applied; and (3) preparing soil and ridging, applying a special fertilizer for tobacco, transplanting the tobacco, and applying a microbial agent when the tobacco is transplanted. According to the improvement method provided by the invention, the green manure green-pressing biomass can be remarkably improved, the soil fertility is improved, the activity and function of soil microorganisms are improved, the yield and quality of tobacco leaves are improved, the sustainable development of tobacco leaf production is promoted, and remarkable social benefits and economic benefits are generated.

Description

Technical Field

[0001] The invention relates to the technical field of agricultural soil improvement, and in particular to a method for improving tobacco field soil in high-altitude cold areas. Background Art

[0002] Liupanshui is also one of the main flue-cured tobacco production areas in Guizhou Province. In recent years, the area of ​​flue-cured tobacco cultivation has reached about 10.12 million mu, with an annual output of about 250,000 dan. However, investigations and studies have found that the tobacco fields in Liupanshui's tobacco area have a shallow plough layer and uneven nutrients. Liupanshui is located in a karst mountainous area, and the tobacco fields are mainly sloping dry land. The plough layer of tobacco fields is basically 10-12 cm, which is far lower than the 25 cm standard required for high-standard farmland in my country. This makes it difficult to meet the 25-30 cm ridge standard, which restricts the normal growth and development of the tobacco root system and tobacco plants.

[0003] Green manure is an important measure to increase soil organic matter and cultivate fertile arable layer. However, the Liupanshui tobacco area belongs to the karst mountainous area with low temperature and limited heat conditions. In addition, the traditional green manure in the Liupanshui tobacco area is mainly glossy purple flower vetch, which has a long growth period (about 240 days), resulting in low green biomass when transplanting flue-cured tobacco in late March. In addition, the Liupanshui tobacco area is currently mainly leguminous green manure. Existing studies have found that planting leguminous green manure in tobacco fields with high organic matter will increase nicotine content and increase the smell of flue-cured tobacco. In the case that climate factors cannot be changed by human factors, it is very important to use green manure varieties suitable for high-altitude cold areas to increase the aboveground biomass of green manure and improve the soil fertilization effect; in particular, it is very important to select suitable grass or cruciferous green manure and mix it with leguminous green manure to reduce the input of exogenous organic nitrogen and improve tobacco quality.

[0004] In addition, many tobacco fields in Liupanshui have been planted continuously for more than 10 years. Continuous cropping of flue-cured tobacco will lead to the deterioration of soil microbial flora and soil micro-environment, aggravate the allelopathic autotoxicity of the root system, and cause soil nutrient imbalance and reduced enzyme activity, which restricts tobacco growth and development and reduces tobacco yield and quality. The above problems combined have led to a year-on-year decline in the yield and quality of tobacco in Liupanshui. Therefore, how to eliminate obstacles and improve fertility in tobacco-growing soil, especially to propose scientific countermeasures for the unique problems in Liupanshui tobacco areas such as low green manure biomass, is an issue that needs to be solved urgently. Summary of the invention

[0005] The purpose of the present invention is to provide a method for improving tobacco field soil in high-altitude cold areas, which can significantly increase the green manure biomass, improve soil fertility, improve soil microbial activity and function, increase tobacco yield and quality, promote the sustainable development of tobacco production, and produce significant social and economic benefits.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a method for improving tobacco field soil in high-altitude cold areas, comprising the following steps:

[0008] (1) In the late stage of tobacco leaf picking or after tobacco leaf harvesting and land preparation, sow leguminous green manure seeds, and 10 to 20 days later, sow cruciferous green manure seeds;

[0009] (2) 25 to 35 days before tobacco transplanting, turn the green manure back into the field and apply biochar at the same time;

[0010] (3) Prepare the land and make ridges, apply tobacco-specific fertilizer, transplant tobacco, and apply microbial agents during tobacco transplanting.

[0011] Preferably, the leguminous green manure is the Yunnan early-maturing variety "Yunnan Early Potato No. 1", with a full growth period of 175 to 216 days and a sowing rate of 3 to 3.5 kg / mu. The leguminous green manure is sown on both sides of the ridge and both sides of the ridge ditch.

[0012] Preferably, the cruciferous green manure is a new green manure rapeseed variety "Zhonglvyou No. 1", with an average full growth period of 184.3 days and a sowing rate of 45-55g / mu; the cruciferous green manure is sown in the middle of the ridge.

[0013] Preferably, the biomass ratio of the leguminous green manure to the cruciferous green manure is 8-9:1-2.

[0014] Preferably, when the leguminous green manure or the cruciferous green manure is sown, the soil moisture content is controlled to be 60wt% to 80wt%.

[0015] Preferably, the high altitude refers to an altitude higher than 1800m, and straw is used for covering after the green manure sprouts, and the covering amount of the straw is 400-600kg / mu.

[0016] Preferably, the green manure is turned over and returned to the field in an amount of 1000-1500 kg / mu based on the weight of fresh grass. The green manure is processed into small segments with a length of 10-20 cm and then turned over and returned to the field at a turning depth of 20-30 cm.

[0017] Preferably, the application amount of the biochar is such that the organic carbon ratio of the green manure to the biochar is 9:1 to 7:3.

[0018] Preferably, the microbial agent is a straw rot-promoting agent containing Bacillus subtilis and Trichoderma harzianum, and the application amount is 15-18 kg / hm -2 .

[0019] The tobacco field soil improvement method in high-altitude cold areas based on mixed sowing of green manure provided by the present invention can significantly increase the green manure pressing biomass, improve soil fertility, improve soil microbial activity and function, increase tobacco leaf yield and quality, promote the sustainable development of tobacco leaf production, and produce significant social and economic benefits.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] 1. Product advantages: The growth period of the locally grown purple-flowered glossy-leafed sweet potato is as long as 240 days. The growth period of Yunguang Zaotiao No. 1 selected in this experiment is only 175-216 days, and the growth period of Zhonglvyou No. 1 is only 184 days. These two green manures have the advantage of a short growth period. Compared with the locally grown green manure varieties such as glossy-leafed sweet potato and rapeseed, the seeds of Yunguang Zaotiao No. 1 and Zhonglvyou No. 1 selected in this experiment have strong resistance to barrenness and cold. Yunguang Zaotiao No. 1 seeds also have strong drought resistance, and Zhonglvyou No. 1 seeds have strong antiviral properties. These two green manure varieties have basically overcome the shortcomings of traditional green manure varieties in Liupanshui Yan District, which have a low green yield due to a long growth period.

[0022] 2.Technical advantages:

[0023] 2.1 Mixed planting of green manure: Compared with the local single-planting of sweet potato and single-planting of rapeseed, the mixed planting of sweet potato and rapeseed significantly increased the fresh grass biomass of green manure. After being turned back into the field, the decomposition of green manure significantly increased the soil organic carbon content and thus improved soil fertility. On the other hand, compared with sweet potato, rapeseed contains a higher C / N ratio, and the decomposition of rapeseed brings in less organic nitrogen, reducing the input of exogenous organic nitrogen. Reducing nitrogen fertilizer is beneficial to increasing the quality of tobacco leaves. Therefore, this mixed planting method increases the local green manure planting method and improves the quality of tobacco leaves.

[0024] 2.2 Biochar addition: Compared with the local single-sowing vetch and single-sowing rapeseed planting methods, green manure mixed with biochar can regulate soil Ph and soil pore structure, promote the fixation of nutrients that are easily leached, and increase soil nutrient storage capacity. Biochar, as an inert carbon, is extremely difficult to decompose after entering the soil, and is then stored in large quantities in the soil. Green manure itself contains a large amount of easily decomposable carbon sources, and nutrients entering the soil are extremely easy to decompose and are then absorbed and utilized by crops. Therefore, green manure with biochar enriches the soil carbon pool.

[0025] 2.3 Biochar + microbial agent addition: Microbial agents are new green biofertilizers fermented from single or multiple beneficial microorganisms. The application of microbial agents can not only reduce the growth of pathogens and improve the structure of soil microbial communities, but also increase the effective nutrient content of soil and improve crop quality. Biochar is mostly alkaline and has a large specific surface area and high porosity. Adding biochar into the soil can not only increase the pH of acidic soil, but also maintain soil moisture and provide a good habitat for soil microorganisms. DETAILED DESCRIPTION

[0026] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0027] Example 1

[0028] 1. Test location: The test plot is located in Yanjing Village, Ajia Town, Shuicheng District (1900m above sea level). The soil texture is clay loam. The initial nutrient level of the soil is: soil organic carbon 24.18g / kg, alkaline nitrogen 163.92mg / kg, available phosphorus 53.24mg / kg, and available potassium 516.19mg / kg.

[0029] Green manure varieties: Light-leafed potato: "Yunguang Zaotiao No. 1", the whole growth period is 175 to 216 days;

[0030] Rapeseed seeds: "Zhonglvyou No. 1", the average full growth period is 184.3 days.

[0031] Biochar was purchased from Jiangsu Agnes Environmental Technology Co., Ltd.

[0032] The microbial agent is a straw decay-promoting agent, mainly containing Bacillus subtilis and Trichoderma harzianum, and was purchased from Shanghai Dajing Bioengineering Co., Ltd.

[0033] 2. Test steps:

[0034] 2.1 Green manure mixed sowing: After tobacco harvest and land preparation in early September, sow photorhizomes on both sides of the ridges and furrows of the tobacco field; sow rapeseed in the middle of the ridges in late September. After the rain, adjust the relative moisture content of the soil to about 70% and sow. After the seedlings emerge, cover with 400kg / mu of straw.

[0035] 2.2 Green manure turning and biochar addition: 28 days before tobacco transplanting, mix the green manure and turn it back to the field, the turning amount is 1000kg / mu for fresh samples, cut the light leaf vetch and rapeseed into 10-20cm small segments with a guillotine after yield measurement, evenly spread them in the field, use a small rotary tiller to turn it, the turning depth is 25cm, and appropriately increasing the tillage depth is conducive to the decomposition of green manure and the release of nutrients. At the same time, biochar is sprinkled to make the organic carbon ratio of green manure to biochar 9:1, that is, the ratio of activated carbon to inert carbon is about 9:1.

[0036] 2.3 Tobacco fertilizer application amount: 14 days after the green manure is turned over, the land is prepared and ridged to ensure that the green manure is fully decomposed. At the same time as ridged, 60kg / mu of tobacco-specific fertilizer (10-10-24N-P2O5-K2O) provided by Liupanshui Tobacco Company is applied. Since 1000kg / mu of green manure is returned to the field, the application amount of nitrogen fertilizer in chemical fertilizer can be reduced by 15%.

[0037] 2.4 Addition of microbial agents: Transplant tobacco under conditions of good soil moisture, and add straw rot-promoting agents at the same time, with an addition amount of 15kg / hm -2 .

[0038] 3. Experimental design: Eight treatments were set, including single sowing of sweet potato (A), single sowing of rapeseed (B), mixed sowing of sweet potato and rapeseed (8:2, C), mixed sowing of sweet potato and rapeseed (9:1, D), single sowing of sweet potato + soil conditioner (E), single sowing of rapeseed + soil conditioner (F), mixed sowing of sweet potato and rapeseed (8:2, G) + soil conditioner, and mixed sowing of sweet potato and rapeseed (9:1, H) + soil conditioner, with three replications for each treatment. The eight treatments were divided into four sowing methods: single sowing of sweet potato, single sowing of rapeseed, mixed sowing 1 (mixed sowing of sweet potato and rapeseed 8:2), and mixed sowing 2 (mixed sowing of sweet potato and rapeseed 9:1); and two soil fertilization methods: conventional fertilization, conventional fertilization + soil conditioner (biochar + biological agent).

[0039] Among them, when the mixed sowing ratio of glossy vetch and rapeseed is 8:2, the sowing amount of glossy vetch is 3.2kg / mu, and the sowing amount of rapeseed is 50g / mu. At this time, the amount of biochar used is 13kg / mu; when the mixed sowing ratio of glossy vetch and rapeseed is 9:1, the sowing amount of glossy vetch is 3.6kg / mu, and the sowing amount of rapeseed is 25g / mu.

[0040] 4. Results

[0041] 4.1 Effects of green manure mixing and soil conditioner addition on soil nutrient content at different stages

[0042] As shown in Table 1, during the vigorous growth period of tobacco, conventional fertilization + soil conditioner treatments increased the content of total phosphorus, available phosphorus and available potassium in the soil. The total phosphorus content in the soil was the highest in the sweet potato treatment, and the available phosphorus and available potassium contents in the soil were the highest in the rapeseed treatment. Comparing different sowing methods, the available phosphorus and available potassium contents in the soil of the mixed sowing treatment were higher than those of the sweet potato and rapeseed single sowing treatments, and the mixed sowing 2 treatment had the best effect.

[0043] Table 1 Effects of green manure mixing and adding soil conditioners on soil nutrient content during the vigorous growth period

[0044]

[0045] As shown in Table 2, during the tobacco topping period, conventional fertilization + soil conditioner treatments increased soil total phosphorus, total potassium and available phosphorus contents. The soil total phosphorus, total potassium and available phosphorus contents were the highest in mixed sowing treatment 2, and the lowest in rapeseed treatment. Comparing different sowing methods, the soil total phosphorus and total potassium contents in mixed sowing treatments were higher than those in potato and rapeseed single sowing treatments, and the mixed sowing 2 treatment had the best effect. The soil available phosphorus content in mixed sowing treatments was also higher than that in potato and rapeseed single sowing treatments, and the mixed sowing 1 treatment had the best effect.

[0046] Table 2 Effects of green manure mixed sowing and addition of soil conditioners on soil nutrient content during topping period

[0047]

[0048] As shown in Table 3, at the tobacco harvest period, conventional fertilization + soil conditioner treatments increased soil total phosphorus, alkaline nitrogen, available phosphorus and available potassium contents. The soil total phosphorus and available phosphorus contents were the highest in mixed sowing 2 treatment, and the soil alkaline nitrogen content and available potassium content were the highest in sweet potato treatment. Comparing different sowing methods, the soil total phosphorus, alkaline nitrogen, available phosphorus and available potassium contents in mixed sowing 2 treatment were higher than those in sweet potato and oilseed single sowing treatments, and only the alkaline nitrogen and available phosphorus contents in mixed sowing 1 treatment were higher than those in sweet potato and oilseed single sowing treatments.

[0049] Table 3 Effects of green manure mixing and adding soil conditioners on soil nutrient content during topping period

[0050]

[0051]

[0052] 4.2 Effects of green manure mixing and soil conditioner addition on agronomic traits of tobacco at different stages

[0053] Comparing the agronomic traits of tobacco at different growth stages (Table 4, Table 5 and Table 6), conventional fertilization + soil amendment treatments increased tobacco plant height, stem girth, maximum leaf length and maximum leaf width. The plant height, stem girth and maximum leaf length of tobacco were the highest in mixed sowing treatment 1, and the maximum leaf width was the highest in rapeseed treatment. Comparing different sowing methods, the trends in each growth stage were similar. The plant height of tobacco in mixed sowing treatment was higher than that in sweet potato and rapeseed single sowing treatments, and the effect of mixed sowing treatment 1 was the best. The stem girth and maximum leaf length of tobacco in mixed sowing treatment 1 were higher than those in sweet potato and rapeseed single sowing treatments, and the maximum leaf width of rapeseed single sowing treatment was higher than that in mixed sowing and sweet potato single sowing treatments.

[0054] Table 4 Effects of green manure mixing and soil conditioner addition on agronomic traits of tobacco during vigorous growth period

[0055]

[0056] Table 5 Effects of green manure mixed seeding and soil conditioner addition on agronomic traits of tobacco during topping period

[0057]

[0058]

[0059] Table 6 Effects of green manure mixing and soil conditioner addition on agronomic traits of tobacco at harvest

[0060]

[0061] 4.3 Effects of green manure mixing and soil amendment addition on the chemical composition of middle tobacco leaves after curing

[0062] As shown in Table 7, compared with the conventional fertilization treatment, the conventional fertilization + soil conditioner treatment increased the total nitrogen, total sugar, reducing sugar and total potassium content of tobacco leaves, increased the sugar-alkali ratio, nitrogen-alkali ratio and potassium-chlorine ratio of tobacco leaves, but reduced the salt-alkali and chlorine content of tobacco leaves, especially in the mixed sowing 1 treatment. Comparing the sowing methods, the total nitrogen and total potassium content of the mixed sowing 1 treatment was the highest, and the nitrogen-alkali ratio and potassium-chlorine ratio were also the highest, while the total nitrogen and total potassium content were the lowest in the oilseed single sowing treatment, and the nitrogen-alkali ratio and potassium-chlorine ratio were the lowest in the sweet potato single sowing treatment. The three indicators of total sugar, reducing sugar and sugar-alkali ratio in the oilseed single sowing treatment were significantly higher than those in the sweet potato single sowing treatment.

[0063] Table 7 Effects of green manure mixing and soil conditioner addition on the chemical composition of middle tobacco leaves after curing

[0064]

[0065] 4.4 Effects of green manure seeding and soil conditioner addition on the content of neutral aroma components in the middle part of flue-cured tobacco leaves

[0066] As shown in Table 8, the total amount of neutral aroma components, phenylalanine, carotenoids and neophytadiene in tobacco leaves treated with conventional fertilization + soil conditioner were higher than those in conventional fertilization, while the content of brown products and siberis-like substances in tobacco leaves were lower than those in conventional treatment. Comparing different sowing methods, the total amount of neutral aroma components, phenylalanine, carotenoids and neophytadiene in mixed sowing 1 treatment was the highest, followed by mixed sowing 1 and sweet potato treatments, and the rapeseed treatment was the lowest. In addition, the content of brown products and siberis-like substances in tobacco leaves was the highest in the sweet potato treatment, but the content of brown products was the lowest in the rapeseed treatment, and the content of siberis-like substances was the lowest in the mixed sowing 2 treatment.

[0067] Table 8 Effects of green manure mixing and soil conditioner addition on the content of neutral aroma components in the middle part of tobacco leaves after curing

[0068]

[0069]

[0070] 4.5 Effects of green manure intercropping and soil conditioner addition on the economic benefits of flue-cured tobacco

[0071] As shown in Table 9, the yield and output value of each treatment of conventional fertilization + soil conditioner were higher than those of each treatment of conventional fertilization, and the highest was in mixed sowing 1 treatment. Comparing the sowing methods, the yield and output value of mixed sowing 1 treatment were the highest under conventional fertilization, followed by mixed sowing 2 treatment, and the single sowing sweet potato treatment was the worst.

[0072] Table 9 Effects of green manure mixing and adding soil conditioners on the economic benefits of flue-cured tobacco

[0073]

[0074]

[0075] Comprehensive comparison of soil nutrient indicators showed that mixed sowing 2 combined with soil conditioners had the best effect on improving soil nutrient. However, by comparing the agronomic traits, economic traits, tobacco leaf quality and tobacco product quality of tobacco, mixed sowing 1 combined with soil conditioners had the best improvement effect. Single sowing of sweet potato or single sowing of rapeseed was not conducive to improving tobacco field soil and improving tobacco quality.

[0076] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for improving tobacco field soil in high altitude cold areas, characterized in that: The steps include: (1) In the late stage of tobacco leaf picking or after tobacco leaf harvesting and land preparation, sow leguminous green manure seeds, and 10 to 20 days later, sow cruciferous green manure seeds; (2) 25 to 35 days before tobacco transplanting, turn the green manure back into the field and apply biochar at the same time; (3) Prepare the land and make ridges, apply tobacco-specific fertilizer, transplant tobacco, and apply microbial agents during tobacco transplanting.

2. The improved method according to claim 1, characterized in that: The leguminous green manure is the Yunnan early-maturing variety "Yunnan Early Potato No. 1", with a full growth period of 175 to 216 days and a sowing rate of 3.0 to 3.5 kg / mu. The leguminous green manure is sown on both sides of the ridge and the ridge ditch.

3. The improved method according to claim 2, characterized in that: The cruciferous green manure is a new variety of green manure rapeseed "Zhonglvyou No. 1", with an average full growth period of 184.3 days and a sowing rate of 45-55g / mu; the cruciferous green manure is sown in the middle of the ridge.

4. The improved method according to claim 3, characterized in that: The biomass ratio of the leguminous green manure to the cruciferous green manure is 8-9:1-2.

5. The improved method according to claim 1, characterized in that: When the leguminous green manure or the cruciferous green manure is sown, the soil moisture content is controlled to be 60wt% to 80wt%.

6. The improved method according to claim 1, characterized in that: The high altitude refers to an altitude higher than 1800m. After the green manure sprouts, straw is used for covering, and the covering amount of the straw is 400-600kg / mu.

7. The improved method according to claim 1, characterized in that: The green manure is turned over and returned to the field in an amount of 1000-1500 kg / mu based on the weight of fresh grass. The green manure is processed into small segments with a length of 10-20 cm and then turned over and returned to the field at a turning depth of 20-30 cm.

8. The improved method according to claim 7, characterized in that: The application amount of the biochar is such that the organic carbon ratio of the green manure to the biochar is 9:1 to 7:

3.

9. The improved method according to claim 1, characterized in that: The microbial agent is a straw decay-promoting agent containing Bacillus subtilis and Trichoderma harzianum, and the application amount is 15-18 kg / hm -2 .

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