Annual efficient nitrogen fertilizer utilization method for tobacco-rice system

Abstract

The invention provides an annual efficient nitrogen fertilizer utilization method for a tobacco-rice system, and belongs to the technical field of crop cultivation. The annual efficient nitrogen fertilizer utilization method comprises the steps that the transplanting density of tobacco / rice is increased, the nitrogen fertilizer application amount of the tobacco / rice is regulated and controlled, the transplanting density of the tobacco is increased by 6%-12% compared with the conventional transplanting density of the tobacco in a planting field, and the transplanting density of the rice is increased by 6%-24% compared with the conventional transplanting density of the rice in the planting field. The nitrogenous fertilizer application amount Y of the tobacco rice is equal to Y0 (1-AnX / average yield). According to the method, the local habitual transplanting density and the nitrogen application amount of the planting land are used as contrast, gradient nitrogen reduction is carried out in combination with the soil fertility level of the field parcels, meanwhile, appropriate densification and other measures are taken, the fertilizer utilization efficiency of unit yield is greatly improved, cost saving, fertilizer saving, high yield and efficiency improvement are synergistically achieved, and annual efficient utilization of the tobacco-rice system nitrogen fertilizer is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of crop cultivation, and in particular relates to a method for highly efficient year-round utilization of nitrogen fertilizer in a tobacco-rice system. Background Art

[0002] Tobacco-rice rotation is one of the main rotation patterns in the rice-growing areas of southern my country. It can improve the structure of soil microbial communities, effectively alleviate the obstacles of continuous tobacco cropping, and promote the combination of land use and land conservation. Developing the "tobacco-rice rotation" model can achieve "one field for two uses, double harvests in one year". By "using tobacco to promote rice and using tobacco to stabilize grain", it not only stabilizes the "golden leaves", holds the "grain bag", but also fills the "money bag", helping tobacco farmers increase their income and comprehensively revitalize the countryside.

[0003] Film covering, soil cultivation, and multiple topdressing are important means to achieve high tobacco yields. However, with the rapid transfer of rural labor to cities, the problem of labor shortage in tobacco production has become more and more serious. In order to pursue high yields, tobacco farmers have increased the application of nitrogen fertilizers such as urea and compound fertilizers. Although the labor cost has been greatly reduced, the quality of tobacco leaves has continued to decline, especially the proportion of high-quality tobacco leaves has dropped significantly, which seriously restricts the improvement of tobacco quality and efficiency. At the same time, the tobacco production season coincides with the rainy season. The nitrogen applied on the surface is easily lost through surface runoff and soil infiltration, resulting in waste of resources and harm to the ecological environment of farmland, and is not conducive to the weight loss and efficiency of subsequent rice crops. Generally speaking, the same type of soil's ability to retain chemical nutrients increases with the increase of fertility level. High-fertility soils have a higher nutrient pool capacity and stronger fertilizer nutrient retention capacity, and their fertilizer supply capacity, fertilizer utilization rate, and crop high yield potential are significantly stronger than low-fertility soils. In actual production, tobacco farmers are accustomed to applying fertilizers at a uniform rate, resulting in serious waste of nutrient resources.

[0004] In addition, there are also many problems with rice fertilization in the tobacco-rice rotation system. Influenced by traditional fertilization concepts, many farmers only apply fertilizer based on experience when planting rice, without fully considering the soil fertility, the fertilizer requirements of rice at different growth stages, and the impact of previous tobacco planting on soil nutrients, resulting in unreasonable fertilizer application. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a method for efficient year-round utilization of nitrogen fertilizer in a tobacco-rice system, which can greatly improve the fertilizer utilization efficiency per unit output, synergistically achieve cost saving, fertilizer saving, high yield and efficiency improvement, and realize efficient year-round utilization of nitrogen fertilizer in the tobacco-rice system.

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

[0007] A method for efficiently utilizing tobacco nitrogen fertilizer in a tobacco-rice system, comprising increasing the transplanting density of tobacco and regulating the amount of nitrogen fertilizer applied to tobacco;

[0008] The transplanting density of the tobacco is increased by 6% to 12% compared with the conventional tobacco transplanting density in the planting area;

[0009] The nitrogen fertilizer amount Y of the tobacco 烟 =Y 0烟 (1-A n烟 X 烟 / 2025); where Y 0烟 The conventional nitrogen fertilizer application amount of tobacco in the planting area, unit is kg / hm 2 ; A n烟 is the weight loss index under different soil fertility levels, low-yield field A 1烟 Assign 8%, middle-class field A 2烟 Assign 12%, high-yield field A 3烟 Assign 16%; X 烟 is the target yield of tobacco leaves, in kg / hm2 2 ; 2025 is the average tobacco leaf yield, unit is kg / hm 2 .

[0010] Preferably, the transplanting density of the tobacco is increased according to different soil fertility grades, with a 10% to 12% increase for low-yield fields, an 8% to 10% increase for medium-yield fields, and a 6% to 8% increase for high-yield fields.

[0011] More preferably, the low-yield field has a tobacco leaf yield of <1800kg / hm2. 2 The medium-yield field is 1800kg / hm 2 ≤Tobacco leaf yield≤2250kg / hm 2 The high-yield land is a tobacco leaf yield of >2250kg / hm 2 planting area.

[0012] Preferably, the nitrogen fertilizer is applied as base fertilizer in holes; it also includes mixed application of rapeseed cake fertilizer 450-750kg / hm 2 .

[0013] More preferably, the nitrogen fertilizer is applied in the form of a tobacco-specific base fertilizer with a nutrient content of N:P 2 O 5 :K 2 O=12:7:23.

[0014] The present invention also provides a method for efficient year-round utilization of rice nitrogen fertilizer in a tobacco-rice system, comprising increasing the transplanting density of rice and regulating the amount of nitrogen fertilizer applied to rice;

[0015] The transplanting density of the rice is increased by 6% to 24% compared with the conventional rice transplanting density in the planting area;

[0016] The nitrogen fertilizer amount Y of the rice 稻 =Y0稻 (1-A n稻 X 稻 / 7800); where Y 0稻 The conventional nitrogen fertilizer application amount for rice in the planting area, in kg / hm 2 ; A n稻 is the weight loss index under different soil fertility levels, low-yield field A 1稻 Assign 5%, middle-class field A 2稻 Assign 10%, high-yield field A 3稻 Assign 15%; X 稻 is the target yield of rice, in kg / hm 2 ; 7800 is the average yield of rice, in kg / hm 2 .

[0017] Preferably, the transplanting density of the rice is increased according to different soil fertility levels, with an increase of 18% to 24% for low-yield fields, 12% to 18% for medium-yield fields, and 6% to 12% for high-yield fields.

[0018] More preferably, the low-yield field has a rice yield of <6750kg / hm 2 The medium-yield field is 6750kg / hm 2 ≤Rice yield≤8250kg / hm 2 The high-yield field is a rice field with a yield of more than 8250 kg / hm2. 2 planting area.

[0019] Preferably, the nitrogen fertilizer is applied in a ratio of basal fertilizer: tillering fertilizer: ear fertilizer of 0:(6-4):(4-6).

[0020] The present invention also provides a tobacco-rice system nitrogen fertilizer year-round efficient utilization method. In the tobacco-rice year-round rotation, the tobacco nitrogen fertilizer efficient utilization method is adopted in the tobacco season, and the rice nitrogen fertilizer efficient utilization method is adopted in the rice season.

[0021] Compared with the prior art, the present invention provides a method for efficient utilization of nitrogen fertilizer in a tobacco-rice system throughout the year, which has the following beneficial effects:

[0022] (1) Tobacco uses a one-step fertilization method to apply basal fertilizer and topdressing fertilizer, eliminating the need for fertilizer for raising seedlings and topdressing, which greatly reduces labor costs and promotes tobacco cost reduction and efficiency improvement. Tobacco uses a one-step fertilization method to apply basal fertilizer and topdressing fertilizer as basal fertilizer, eliminating the need for fertilizer for raising seedlings and topdressing fertilizer. Compared with the traditional seven-step fertilization method, it can greatly reduce the number of fertilization times, which is conducive to promoting tobacco cost reduction and efficiency improvement in the context of labor shortage in rural areas.

[0023] (2) Tobacco fertilizer is used for rice. Precision application of rice ear fertilizer can promote efficient nutrient utilization throughout the year. Increasing potassium and controlling nitrogen are important fertilization strategies for improving tobacco leaf quality. The potassium content of tobacco-growing soil is relatively high, which can fully meet the potassium demand of subsequent rice crops. Therefore, only topdressing is applied to subsequent rice crops after transplanting. In addition, by reducing the proportion of rice tillering fertilizer and increasing the proportion of ear fertilizer, rice with few tillers and large ear groups is constructed, and the quality of individuals and groups is fully coordinated to achieve the synergy of rice fertilizer saving, high yield and increased efficiency.

[0024] (3) Classify and reduce seedlings, increase density scientifically, and achieve cost saving, fertilizer saving, high yield and increased efficiency in a coordinated manner. Classify and reduce seedlings in accordance with the principle of reducing more in high-yield fields and less in medium- and low-yield fields. At the same time, by increasing the transplanting density, increase the basic seedlings, reduce ineffective tillers, and improve the ear formation rate, effectively compensate for the loss of production caused by reducing seedlings, greatly improve the fertilizer utilization efficiency per unit of output, and achieve cost saving, fertilizer saving, high yield and increased efficiency in a coordinated manner. DETAILED DESCRIPTION

[0025] The present invention provides a method for efficient utilization of nitrogen fertilizer in a tobacco-rice system throughout the year. In the tobacco-rice annual rotation, the method for efficient utilization of nitrogen fertilizer in tobacco is used in the tobacco season, and the method for efficient utilization of nitrogen fertilizer in rice is used in the rice season to increase the yield of tobacco leaves and rice.

[0026] The tobacco nitrogen fertilizer efficient utilization method of the present invention comprises increasing the transplanting density of tobacco and regulating the amount of nitrogen fertilizer applied to tobacco;

[0027] The transplanting density of tobacco is increased by 6% to 12% compared with the conventional transplanting density of tobacco in the planting area; preferably, the transplanting density of tobacco is increased according to different soil fertility levels, with a low-yield field increasing by 10% to 12%, a medium-yield field increasing by 8% to 10%, and a high-yield field increasing by 6% to 8%. As an implementation method, the conventional transplanting density of tobacco in the planting area is 1.58×10 4 Plant / hm 2 , the transplanting density of tobacco in low-, medium- and high-yield fields is 1.74×10 4 ~1.77×10 4 Plant / hm 2 , 1.71×10 4 ~1.74×10 4 Plant / hm 2 , 1.67×10 4 ~1.71×10 4 Plant / hm 2 .

[0028] Nitrogen fertilizer amount for tobacco 烟 =Y 0烟 (1-A n烟 X 烟 / 2025); where Y 0烟 The conventional nitrogen fertilizer application amount of tobacco in the planting area, unit is kg / hm2 ; A n烟 is the weight loss index under different soil fertility levels, low-yield field A 1烟 Assign 8%, middle-class field A 2烟 Assign 12%, high-yield field A 3烟 Assign 16%; X 烟 is the target yield of tobacco leaves, in kg / hm2 2 ; 2025 is the average tobacco leaf yield, unit is kg / hm 2 .

[0029] In the present invention, it is preferred that tobacco nitrogen fertilizer is applied as base fertilizer in holes; it also includes mixed application of rapeseed cake fertilizer 450-750kg / hm 2 , preferably 600 / hm 2 It is further preferred that after the tobacco field is ridged, a hole is dug in the center of the ridge according to the density of tobacco planting, with a hole depth of 15 to 20 cm and a hole width of 18 to 22 cm, and nitrogen fertilizer and rapeseed cake fertilizer are mixed and applied in the hole. It is more preferred that the nitrogen fertilizer is applied in the form of tobacco-specific base fertilizer with a nutrient content of N:P 2 O 5 :K 2 O=12:7:23.

[0030] In the present invention, the above-mentioned low-yield field is preferably a field with a tobacco yield of <1800kg / hm2. 2 The medium yield is 1800kg / hm2 2 ≤Tobacco leaf yield≤2250kg / hm 2 The high-yield fields are tobacco leaf yields >2250kg / hm 2 planting area.

[0031] In the present invention, preferably in mid-to-late March, after the soil is soaked by 1 to 2 rainfalls, large tobacco seedlings with uniform growth are selected and transplanted on one side of the fertilization hole. At the same time, the soil near the tobacco seedlings is brought into the hole to cover the fertilizer (4 to 6 cm thick). It is forbidden to transplant in the middle of the fertilizer. No film is required after transplanting.

[0032] The rice nitrogen fertilizer year-round efficient utilization method of the present invention comprises increasing the transplanting density of rice and regulating the amount of nitrogen fertilizer applied to rice;

[0033] The transplanting density of rice is increased by 6% to 24% compared with the conventional transplanting density of rice in the planting area; preferably, the transplanting density of rice is increased according to different soil fertility levels, with an increase of 18% to 24% for low-yield fields, 12% to 18% for medium-yield fields, and 6% to 12% for high-yield fields. As an implementation method, the conventional transplanting density of rice in the planting area is 25.5×10 4 Hole / hm 2 , the transplanting density of tobacco in low-, medium- and high-yield fields is 30.1×10 4~31.6×10 4 Hole / hm 2 , 28.6×10 4 ~30.1×10 4 Hole / hm 2 , 27.0×10 4 ~28.6×10 4 Hole / hm 2 .

[0034] Nitrogen fertilizer application amount for rice 稻 =Y 0稻 (1-A n稻 X 稻 / 7800); where Y 0稻 The conventional nitrogen fertilizer application amount for rice in the planting area, in kg / hm 2 ; A n稻 is the weight loss index under different soil fertility levels, low-yield field A 1稻 Assign 5%, middle-class field A 2稻 Assign 10%, high-yield field A 3稻 Assign 15%; X 稻 is the target yield of rice, in kg / hm 2 ; 7800 is the average yield of rice, in kg / hm 2 .

[0035] In the present invention, it is preferred that rice nitrogen fertilizer is applied in a tillering fertilizer: ear fertilizer ratio of (6-4):(4-6); further preferred ratios of rice base fertilizer: tillering fertilizer: ear fertilizer in low-, medium- and high-yield fields are 0:6:4, 0:5:5, and 0:4:6, respectively; and more preferably, rice nitrogen fertilizer is applied in the form of urea.

[0036] In the present invention, the above-mentioned low-yield field is preferably a field with a rice yield of <6750 kg / hm2. 2 The medium yield is 6750kg / hm2 2 ≤Rice yield≤8250kg / hm 2 The high-yield fields are rice fields with a yield of >8250kg / hm 2 planting area.

[0037] In the present invention, the preferred rice irrigation method is to use thin water transplanting, shallow water tillering, field sunning to control weeding, moist heading, shallow water heading, alternating dry and wet filling, running watering during the yellow ripening period, and cutting off water for harvesting 7 to 10 days before harvest.

[0038] 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.

[0039] Example 1

[0040] A method for efficient utilization of nitrogen fertilizer in a tobacco-rice system throughout the year, comprising the following steps:

[0041] During tobacco season:

[0042] (1) Determine the soil fertility level of the planting site: tobacco leaf yield <1800kg / hm 2 The planting area is low-yield field, 1800kg / hm 2 ≤Tobacco leaf yield≤2250kg / hm 2 The planting area is medium-yield land, and the tobacco leaf yield is >2250kg / hm 2 The planting area is high-yield field.

[0043] (2) After the tobacco field is ridged, a hole is dug in the center of the ridge according to the density of tobacco planting. The hole is 17 cm deep and 20 cm wide. Then, a basal fertilizer (N:P 2 O 5 :K 2 O=12:7:23), rapeseed cake fertilizer 600kg / hm 2 Mix well and apply to the hole.

[0044] (3) Total nitrogen application amount of tobacco-specific basal fertilizer: Y 烟 =Y 0烟 (1-A n烟 X 烟 / 2025); where Y 0烟 The conventional nitrogen fertilizer application amount of tobacco in the planting area, unit is kg / hm 2 ; A n烟 is the weight loss index under different soil fertility levels, low-yield field A 1烟 Assign 8%, middle-class field A 2烟 Assign 12%, high-yield field A 3烟 Assign 16%; X 烟 is the target yield of tobacco leaves, in kg / hm2 2 ; 2025 is the average tobacco leaf yield, unit is kg / hm 2 .

[0045] (4) In mid-to-late March, after the soil has been soaked by 1-2 rainfalls, select large seedlings with uniform growth and transplant them on one side of the hole. At the same time, bring the soil near the seedlings into the hole and cover them with fertilizer (4-6 cm thick). Do not transplant them in the middle of the fertilizer. There is no need to cover them with film after transplanting.

[0046] The transplanting density of tobacco is as follows: the transplanting density of tobacco in low-, medium- and high-yield fields is increased by 10% to 12%, 8% to 10%, and 6% to 8% respectively compared with the conventional transplanting density.

[0047] After tobacco harvest, rice is rotated. During the rice season:

[0048] (1) Determine the soil fertility level of the planting site: rice yield <6750kg / hm2 2 The planting area is low-yield field, 6750kg / hm 2 ≤Rice yield≤8250kg / hm 2 The planting area is medium-yield land, and the rice yield is >8250kg / hm 2 The planting area is high-yield field.

[0049] (2) The transplanting density of rice is as follows: the transplanting density of rice in low-yield, medium-yield and high-yield fields is increased by 18%-24%, 12%-18% and 6%-12% respectively compared with the conventional transplanting density.

[0050] (3) Total nitrogen application amount for rice: Y 稻 =Y 0稻 (1-A n稻 X 稻 / 7800); where Y 0稻 The conventional nitrogen fertilizer application amount for rice in the planting area, in kg / hm 2 ; A n稻 is the weight loss index under different soil fertility levels, low-yield field A 1稻 Assign 5%, middle-class field A 2稻 Assign 10%, high-yield field A 3稻 Assign 15%; X 稻 is the target yield of rice, in kg / hm 2 ; 7800 is the average yield of rice, in kg / hm 2 ; In the form of urea, the ratios of base fertilizer: tillering fertilizer: ear fertilizer for rice in low-, medium- and high-yield fields are 0:6:4, 0:5:5 and 0:4:6 respectively.

[0051] (4) Rice irrigation adopts thin water transplanting, shallow water tillering, field sunning to control weeding, moist heading, shallow water heading, alternating dry and wet filling, running water irrigation during the yellow ripening period, and cut off water for harvesting 7 to 10 days before harvest.

[0052] Test Example 1

[0053] Table 1 shows the conventional fertilization pattern of tobacco in the planting area. Table 2 shows the optimized fertilization pattern and transplanting density of tobacco designed with the conventional fertilization pattern and transplanting density of tobacco in the planting area as the control. It can be seen that under the optimized fertilization pattern, the amount of nitrogen applied decreases with the increase of soil fertility. The average nitrogen application amount of low, medium and high yield fields is 184.3 kg / hm2 respectively. 2 、172.9kg / hm 2 、158.1kg / hm 2 , which are 5.5%, 11.3% and 18.9% lower than the traditional nitrogen application rate. As shown in Table 3, under the optimized fertilization mode and transplanting density, the average tobacco leaf yield is 1740.3 kg / hm2 、2237.0kg / hm 2 、2689.7kg / hm 2 , the yields of the optimized fertilization mode increased by 8.1%, 5.4% and 3.8% respectively compared with the traditional fertilization mode. The yield increase rate (the percentage of yield increase of the optimized fertilization mode relative to the traditional fertilization mode) showed a downward trend with the increase of soil fertility and yield, which shows that soil fertility is the key factor affecting tobacco yield. The yield increase of low-yield plots mainly depends on high nitrogen fertilizer input, while the yield increase of high-yield plots mainly depends on soil fertilizer supply, and its weight loss space is significantly greater than that of medium and low-yield plots. In addition, the optimized fertilization mode eliminates the seedling fertilizer and topdressing of the conventional fertilization mode. 75kg / hm2 is applied during the clustering period. 2 Potassium sulfate reduces the input of rural labor.

[0054] Table 1 Conventional fertilization pattern of tobacco planting area

[0055]

[0056]

[0057] Table 2 Optimized fertilization pattern and transplanting density design for tobacco

[0058]

[0059] Table 3 Effects of optimized tobacco fertilization pattern and transplanting density design on tobacco leaf yield

[0060]

[0061]

[0062] Table 4 shows the optimized fertilization pattern and transplanting density of rice designed with the conventional rice fertilization pattern and transplanting density as the control. It can be seen that under the optimized fertilization pattern of rice, the amount of nitrogen applied decreases with the increase of soil fertility. The average nitrogen application amount for low, medium and high yield fields is 82.4 kg / hm2, respectively. 2 、77.6kg / hm 2 、71.8kg / hm 2 , which are 3.9%, 9.7% and 17.3% lower than the traditional nitrogen application rate. As shown in Table 5, under the optimized rice fertilization mode and transplanting density, the average rice yield is 6599.7 kg / hm 2 、8009.7kg / hm 2 、9137.0kg / hm 2, the yields increased by 7.0%, 5.6% and 3.4% respectively compared with the conventional fertilization mode. The yield increase rate showed a downward trend with the increase of soil fertility and yield. This shows that under the conditions of nitrogen reduction, with the increase of soil fertility level, increasing the application ratio of ear fertilizer and transplanting density of post-smoking rice can still achieve yield increase, and soil fertility level is a key factor affecting rice yield. The yield increase of low-yield plots mainly depends on high nitrogen fertilizer input, while the yield increase of high-yield plots mainly depends on soil fertility, and its soil fertility reduction space is obviously greater than that of medium and low-yield plots.

[0063] Table 4 Optimized fertilization pattern and transplanting density design for rice

[0064]

[0065] Table 5 Effects of optimized rice fertilization pattern and transplanting density design on rice yield

[0066]

[0067] 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 efficiently utilizing tobacco nitrogen fertilizer in a tobacco-rice system, characterized in that: These include increasing tobacco transplanting density and regulating the amount of nitrogen fertilizer applied to tobacco; The transplanting density of the tobacco is increased by 6% to 12% compared with the conventional tobacco transplanting density in the planting area; The nitrogen fertilizer amount Y of the tobacco 烟 =Y 0烟 (1-A n烟 X 烟 / 2025); where Y 0烟 The conventional nitrogen fertilizer application amount of tobacco in the planting area, unit is kg / hm 2 ; A n烟 is the weight loss index under different soil fertility levels, low-yield field A 1烟 Assign 8%, middle-class field A 2烟 Assign 12%, high-yield field A 3烟 Assign 16%; X 烟 is the target yield of tobacco leaves, in kg / hm2 2 ; 2025 is the average tobacco leaf yield, unit is kg / hm 2 .

2. The method for efficient utilization of tobacco nitrogen fertilizer according to claim 1, characterized in that: The transplanting density of the tobacco is increased according to different soil fertility grades, with a 10% to 12% increase in low-yield fields, an 8% to 10% increase in medium-yield fields, and a 6% to 8% increase in high-yield fields.

3. The method for efficient utilization of tobacco nitrogen fertilizer according to claim 1 or 2, characterized in that: The low-yield fields are those with tobacco leaf yields less than 1800kg / hm2. 2 The medium-yield field is 1800kg / hm 2 ≤Tobacco leaf yield≤2250kg / hm 2 The high-yield land is a tobacco leaf yield of >2250kg / hm 2 planting area.

4. The method for efficient utilization of tobacco nitrogen fertilizer according to claim 1, characterized in that: The nitrogen fertilizer is applied as base fertilizer in holes; it also includes mixed application of rapeseed cake fertilizer 450-750kg / hm 2 .

5. The method for efficient utilization of tobacco nitrogen fertilizer according to claim 4, characterized in that: The nitrogen fertilizer is applied in the form of a tobacco-specific base fertilizer with a nutrient content of N:P2O5:K2O=12:7:

23.

6. A method for efficient utilization of rice nitrogen fertilizer throughout the year in a tobacco-rice system, characterized in that: These include increasing rice transplanting density and regulating the amount of nitrogen fertilizer applied to rice; The transplanting density of the rice is increased by 6% to 24% compared with the conventional rice transplanting density in the planting area; The nitrogen fertilizer amount Y of the rice 稻 =Y 0稻 (1-A n稻 X 稻 / 7800); where Y 0稻 The conventional nitrogen fertilizer application amount for rice in the planting area, in kg / hm 2 ; A n稻 is the weight loss index under different soil fertility levels, low-yield field A 1稻 Assign 5%, middle-class field A 2稻 Assign 10%, high-yield field A 3稻 Assign 15%; X 稻 is the target yield of rice, in kg / hm 2 ; 7800 is the average yield of rice, in kg / hm 2 .

7. The method for efficient utilization of nitrogen fertilizer in paddy fields throughout the year according to claim 6, characterized in that: The transplanting density of the rice is increased according to different soil fertility levels, with a low-yield field increasing by 18% to 24%, a medium-yield field increasing by 12% to 18%, and a high-yield field increasing by 6% to 12%.

8. The method for efficient utilization of tobacco nitrogen fertilizer according to claim 6 or 7, characterized in that: The low-yield fields are rice fields with a yield of less than 6750 kg / hm2. 2 The medium-yield field is 6750kg / hm 2 ≤Rice yield≤8250kg / hm 2 The high-yield field is a rice field with a yield of more than 8250 kg / hm2. 2 planting area.

9. The method for efficient utilization of nitrogen fertilizer in paddy fields throughout the year according to claim 6, characterized in that: The nitrogen fertilizer is applied at a ratio of basal fertilizer: tillering fertilizer: ear fertilizer of 0: (6-4): (4-6).

10. A method for efficient utilization of nitrogen fertilizer in tobacco-rice system throughout the year, characterized in that: In the tobacco-rice annual rotation, the tobacco nitrogen fertilizer efficient utilization method according to any one of claims 1 to 5 is adopted in the tobacco season, and the rice nitrogen fertilizer efficient utilization method according to any one of claims 6 to 9 is adopted in the rice season.

Images