CN116686510A

CN116686510A - Soil testing formula fertilization method for improving growth and nutrient uniformity of flue-cured tobacco in continuous zone

Info

Publication number: CN116686510A
Application number: CN202310902848.2A
Authority: CN
Inventors: 徐兴阳; 李伟; 刘正玲; 邓世友; 王铎; 刘海; 赵虹龙; 杨宗云
Original assignee: Kunming Company of Yunnan Tobacco Co
Current assignee: Kunming Company of Yunnan Tobacco Co
Priority date: 2023-07-21
Filing date: 2023-07-21
Publication date: 2023-09-05

Abstract

The application discloses a soil testing formula fertilization method for improving the growth and nutrient uniformity of flue-cured tobacco in a continuous zone, which comprises the following steps: step S1: sampling a sampling farmer land block 'reference field' meeting the requirements in the connected sheet area; step S2: acquiring fertility levels of all plots in the continuous sheet area relative to the sampled farmer plots, measuring pH value, organic matters, quick-acting nitrogen, quick-acting phosphorus, quick-acting potassium, effective calcium, effective magnesium, effective boron, effective zinc, effective iron and effective molybdenum indexes of the sampled farmer plot soil, and making a fertilization scheme of a reference field, namely a 'one-to-one scheme'; step S3: deep ploughing and sunning upturned soil of all land areas; step S4: and determining fertilization countermeasures of other plots, namely ' one household one strategy ', according to the soil detection index level of each plot relative to a reference field '. The method can meet the precision requirements of 'one-piece one-occasion' and 'one-family one-occasion', and the growth uniformity of tobacco plants in each continuous land after fertilization according to the method is obviously improved.

Description

Soil testing formula fertilization method for improving growth and nutrient uniformity of flue-cured tobacco in continuous zone

Technical Field

The application relates to the technical field of flue-cured tobacco planting, in particular to a soil testing formula fertilization method for improving the growth and nutrient uniformity of flue-cured tobacco in a continuous zone.

Background

The scheme is formulated according to economic yield and internal quality targets of flue-cured tobacco, soil type texture, current situation of abundant soil nutrients, state of early cropping in spring and weather conditions in place and by combining fertilizer requirement characteristics of planted varieties.

However, along with the wide application of the flue-cured tobacco continuous planning and transplanting technology, the scheme needs to meet the fertilization requirement of the plots in the continuous region, but the problems of uneven fertility, uneven forward cropping and the like among the plots in the continuous region, so that after the fertilization scheme formulated by the existing method is used in the continuous region, the flue-cured tobacco in each plot grows unevenly, and the uniformity of the growth and quality of the flue-cured tobacco in each plot cannot be ensured.

The existing fertilization scheme is formulated according to the sampling result of the soil condition of each land in the continuous area, however, the fertilization scheme formulated according to the soil condition obtained by the existing sampling mode has the following defects due to the reasons of inconsistent soil fertility, inconsistent soil sampling requirements, limited soil samples and the like:

(1) The existing sampling method is a 5-point sampling method, and 5 soil samples are taken in a sampling unit according to 50 mu or 100 mu. However, the method does not explicitly require sampling points, only 5 points are required to be randomly or randomly selected in a sampling unit, the sampling unit often comprises a plurality of farmers' lands, each farmer has different land management capacities, so that the soil condition difference of each point in the sampling unit is large, and after the sampling points are randomly or randomly selected, the obtained result of each sampling point cannot effectively represent the real condition of each piece of soil in the sampling unit;

(2) After the soil nutrient detection result is obtained according to the existing sampling method, the basic condition of the area can only be represented, the formulated scheme can only be formulated in a mode of 'one-to-one mode', namely, the scheme is formulated for 50 mu or 100 mu after each connected area is divided, the fertilization scheme cannot be used for guiding a specific farmer to fertilize, the fertilization scheme cannot correspond to the respective lands of different farmers, and 'one-household-one strategy' cannot be realized;

(3) If each land or each household land is sampled respectively, the sampling cost is too high, the workload is too large, the sampling efficiency is lower, the timeliness of the soil detection result is poor, the soil detection result cannot be directly used for guiding the tobacco leaf production in the current year, and the soil detection result is difficult to realize in actual production.

According to the fertilizing scheme established by the existing sampling method, the requirements of different farmers on the land cannot be met after the application, and the uniformity of the growth of tobacco plants after the fertilization according to the scheme in a continuous zone cannot be ensured.

Disclosure of Invention

The application provides a soil testing formula fertilization method for improving the growth and nutrient uniformity of flue-cured tobacco in a continuous zone, which is used for solving the problem that sampling points are too sparsely distributed when a fertilization scheme is formulated in the prior art; the sampling unit is too large; the sampling result cannot represent the actual situation of each farmer land block; the sampling workload aiming at each peasant household land parcels is too large to implement; the technical problem that tobacco plants in all plots grow inconsistently after the obtained fertilization scheme is applied is caused.

The application provides a soil testing formula fertilization method for improving the growth and nutrient uniformity of flue-cured tobacco in a continuous zone, which comprises the following steps:

step S1: sampling the land block of the sampling farmer in the continuous sheet area, which is hereinafter referred to as a reference field, and sampling 5 points of the S-shaped or quincuncial land block, wherein the reference field land block simultaneously meets the following requirements:

1) The connecting piece area is positioned at the approximate center of the connecting piece area, and is formed into a gentle slope or a flat land;

2) The occupied area exceeds 2 mu, and the soil type is the same as most land blocks in the land areas;

3) The crops of great spring or small spring are planted before, and are the same as most land parcels in the continuous piece area;

4) Crop growth, at a moderate level within the tandem zone;

step S2: acquiring fertility levels of all plots in the continuous sheet area relative to the soil of the reference field, and measuring indexes of pH value, organic matters, quick-acting nitrogen, quick-acting phosphorus, quick-acting potassium, effective calcium, effective magnesium, effective boron, effective zinc, effective iron and effective molybdenum of the soil of the reference field in the continuous sheet area in the same time;

step S3: deep ploughing and sunning upturned soil of all land areas;

step S4: determining fertility level according to the detection index of the soil of the reference field, and preparing a 'one-piece-one-case' formula; determining relative soil detection indexes and fertility levels of other plots in the patch area according to the plot position, the soil layer thickness, the crop growth vigor and the lack of element expression, and comparing the relative soil detection indexes and fertility levels with a reference field, and determining fertilization countermeasures of each plot, namely 'one field one strategy';

step S5: the tobacco plant growth vigor of each land block is determined by acquiring the tobacco growth vigor, the thickness and the color of the stems and the color of the leaf surfaces within 15-25 days after transplanting, and is divided into the following grades and topdressing operation is carried out according to each grade:

strong growth potential: if the stems are thicker, the color of the stems and the leaves is dark green, and nitrogen fertilizer is not added;

growth vigor is moderate: if the thickness of the stems is medium and the colors of the stems and the leaves are green, applying N fertilizer 0.68-1.0 kg/mu in the root extending period for the nitrogen fertilizer sensitive varieties, and adding water for applying about 5-7.5 kg/mu of potassium nitrate; the other fertilizer-resistant varieties correspondingly increase the dosage by 1 to 1.5 times;

weak growth vigor: the stems are thin, the stems and leaves are light green, then the N fertilizer is applied to the nitrogen fertilizer sensitive varieties in the root extending period by 1-1.5 kg/mu, the potassium nitrate is reduced by about 8-11.0 kg/mu, and the water is added for 2 times for pouring; the other fertilizer-resistant varieties are correspondingly increased by 1 to 1.5 times.

Preferably, the fertility level grading standard in step S2 and the fertilization operation thereof are:

high fertility: the fertility level of a certain land block in the sheet area is higher than that of a reference field, and the nitrogen application amount is reduced according to the fertilizer tolerance of the planted variety: regulating the nitrogen application to be 1.5-2.5 kg/mu when planting the fertilizer-resistant varieties; when the sensitive varieties to the nitrogenous fertilizer are planted, the nitrogen application amount is regulated down by 0.5-1 kg/mu;

the fertility is equivalent: the fertility level of a certain land in the slice area is similar to that of a reference field, and the nitrogen application amount is referred to the reference field land;

the fertility is low: the fertility level of a certain land in the sheet area is lower than that of a reference field, and the nitrogen application amount is increased according to the fertilizer tolerance of the planted variety: the nitrogen application amount is regulated to be 1.5-2.5 kg/mu when the fertilizer-resistant varieties are planted; when the sensitive variety to the nitrogen fertilizer is planted, the nitrogen application amount is regulated to be 0.5-1 kg/mu.

Preferably, the soil detection index grading index:

pH value: the detection result is less than 4.5 and is strong acid; the detection result is that 4.5 to 5.5 is acid; the detection result is 5.5-7.5; the detection result is more than 8.0 and is strong alkali;

organic matter: the detection result is lower than 20 g/kg; the detection result is 20-35 g/kg; the detection result is 35-45 g/kg; the detection result is that the ratio of >45g/kg is too high:

quick-acting nitrogen: the detection result is lower than 65 mg/kg; the detection result is 65-120 mg/kg; the detection result is 120-150 mg/kg high; the detection result is that the concentration of the active ingredients is higher than 150 mg/kg;

quick-acting phosphorus: the detection result is lower than 100 mg/kg; the detection result is 100-300 mg/kg; the detection result is 300-400 mg/kg high; the detection result is >400mg/kg eutrophication;

quick-acting potassium: detection result <100 is low; the detection result is 100-300 mg/kg; the detection result is 300-400 mg/kg high; the detection result is >400, which is eutrophication;

effective calcium: the detection result is lower than 1500 mg/kg; the detection result is 1500-2000 mg/kg; the detection result is 2000-5000 mg/kg high; the detection result is higher than 5000 mg/kg;

effective magnesium: the detection result is lower than 100 mg/kg; the detection result is 100-250 mg/kg; the detection result is 250-400 mg/kg high; the detection result is that the eutrophication is carried out with the concentration of >400 mg/kg;

effective boron: the detection result is lower than 0.5 mg/kg; the detection result is 0.5-1.0 mg/kg; the detection result is 1.0-1.5 mg/kg; the detection result is over high, wherein the detection result is more than 1.5 mg/kg;

effective zinc: the detection result is lower than 2.0 mg/kg; the detection result is 2.0-3.0 mg/kg; the detection result is 3.0-4.0mg/kg high; the detection result is over high, wherein the detection result is more than 4.0 mg/kg;

effective iron: the detection result is lower than 0.2 mg/kg; the detection result is 0.2-0.3 mg/kg; the detection result is 0.3-2.0 mg/kg high; the detection result is 2.0mg/kg which is too high;

effective molybdenum: the detection result is lower than 10.0 mg/kg; the detection result is 10-20 mg/kg; the detection result is high at 20-50 mg/kg; the detection result was that the concentration was >50mg/kg, which was too high.

Preferably, step S2 further includes: and detecting the organic matters, alkaline hydrolysis nitrogen content, quick-acting phosphorus content, quick-acting potassium content, effective calcium content, effective magnesium content, effective boron content, effective zinc content, effective iron content and effective molybdenum content of the soil of the reference field.

Preferably, step S3 further includes: and (3) after more than 20 days before transplanting, the land blocks in the connected areas are uniformly deep-turned for a concentrated time, the depth is preferably 25-50 cm, and the upturned soil drying time is more than 15 days.

Preferably, step S3 further includes: and determining the dosage of three elements of nitrogen, phosphorus and potassium and organic materials of the flue-cured tobacco in the fertilization scheme according to the detection results of the organic matters, alkaline hydrolysis nitrogen content, quick-acting phosphorus content and quick-acting potassium content of the soil of the reference field.

Preferably, the determination of the amount of three elements of nitrogen, phosphorus and potassium and organic materials in the fertilization scheme is based on the following:

when the organic matter content is less than 20g/kg, 500-800 kg of decomposed farmyard manure or 100-300 kg of commercial organic fertilizer is added per mu; when the organic matter content is 20-35 g/kg, 200-500 kg of decomposed farmyard manure or 100-200 kg of commercial organic fertilizer is added per mu; when the organic matter content is more than 35g/kg, adding <200kg of decomposed farmyard manure or <100kg of commercial organic fertilizer per mu;

when the organic matter content is more than 40g/kg and the alkaline hydrolysis nitrogen content is more than 150mg/kg, the nitrogen application amount of the K326 nitrogen-resistant variety flue-cured tobacco is 1.5-4.5 kg/mu; the flue-cured tobacco of the variety sensitive to the N fertilizer is completely eradicated;

when the quick-acting phosphorus content is more than 40mg/kg, the nitrogen-phosphorus ratio is 1: calculating the phosphorus dosage at 0.5-1;

when the quick-acting potassium content is more than 200mg/kg, all varieties have a nitrogen-potassium ratio of 1: 2-3, calculating the potassium dosage;

more preferably, the dosage of three elements of nitrogen, phosphorus and potassium of flue-cured tobacco in the fertilization scheme is determined according to the following steps:

when the organic matter content is 30-40 g/kg and the alkaline hydrolysis nitrogen content is 120-150 mg/kg, the nitrogen application amount of K326 and the nitrogen-resistant variety flue-cured tobacco is 3.5-6.5 kg/mu, and the nitrogen-intolerant variety flue-cured tobacco is 2-2.5 kg/mu.

When the quick-acting phosphorus content is 20-40 mg/kg, the nitrogen-phosphorus ratio is 1:1, calculating the phosphorus consumption;

when the content of quick-acting potassium is 150-200 mg/kg, the nitrogen-potassium ratio is equal to that of flue-cured tobacco 1 which is not resistant to nitrogenous fertilizer: 3 to 5; other varieties 1:2 to 2.5 calculated dosage;

when the organic matter content is 20-30 g/kg and the alkaline hydrolysis nitrogen content is 60-120 mg/kg, the nitrogen application amount of the K326 nitrogen-resistant variety flue-cured tobacco is 5.5-8.5 kg/mu, and the nitrogen-intolerant variety flue-cured tobacco is 2.5-3.5 kg/mu;

when the quick-acting phosphorus content is 10-20 mg/kg, the nitrogen-phosphorus ratio is 1: calculating the dosage of 0.5-1;

when the content of quick-acting potassium is 100-150 mg/kg, the nitrogen-potassium ratio of the flue-cured tobacco of the variety intolerant to nitrogen fertilizer is 1:3 to 5; other varieties 1:2 to 2.5 calculated dosage;

when the organic matter content is less than 20g/kg and the alkaline hydrolysis nitrogen content is less than 60mg/kg, the nitrogen application amount of K326 and the nitrogen-resistant variety flue-cured tobacco is 7.5-9.5 kg/mu, and the nitrogen-resistant variety flue-cured tobacco is 4-6 kg/mu;

when the quick-acting phosphorus content is less than 10mg/kg, the nitrogen-phosphorus ratio is 1: calculating the phosphorus dosage at 0.5-1;

when the quick-acting potassium content is less than 100mg/kg, the nitrogen-potassium ratio of the flue-cured tobacco of the variety intolerant to nitrogen fertilizer is 1:3 to 3.5 percent; other varieties 1:2.5 to 3.0 calculated amount.

Preferably, step S1 comprises the steps of:

step S11: determining the fertilizing amount of the front crop of the reference field, and removing surface soil in the range of 8-10 cm from the land mass used as the front high fertilizing crop;

step S12: and determining the organic matter content and alkaline hydrolysis nitrogen content of the soil of the reference field, and removing surface soil within the range of 8-10 cm of the land if the organic matter content of the soil of the land exceeds 5% and the alkaline hydrolysis nitrogen exceeds 180 mg/kg.

Preferably, the front-crop spring or spring crop of the land parcels of the sampling farmers is gramineous crop; more preferably, the gramineous crop is corn, barley, wheat, highland barley.

Preferably, the step S4 includes the following operations:

step S41: determining that the trace element content in the soil of the land is low or eutrophication according to the result of the soil detection index of the reference field;

step S42: the fertilizer with low trace element content, or high trace element content, or eutrophication in the reference field soil is added into the plant activator, and is sprayed on the leaf surface from the vigorous period to the bud period for 2-3 times.

Step S43: the remaining field or farmer medium trace element embodiments are all performed with reference to "one-by-one" of the "benchmark field".

The application has the beneficial effects that:

1) The soil testing formula fertilization method for improving the growth and nutrient uniformity of the flue-cured tobacco in the continuous land provided by the application can meet the accuracy requirement of 'one family one strategy', and the growth uniformity of tobacco plants in each continuous land is improved after fertilization according to the method. The standard deviation of the plant height of the tobacco plants in the continuous zone after fertilization according to the method is only 7.1, and the standard deviation of the stem circumference is only 0.6; is far lower than 15.3 of plant height standard deviation and 1.7 of stem circumference standard deviation after fertilization according to the fertilization method formulated by the prior sampling method.

2) According to the soil testing formula fertilization method for improving the growth and nutrient uniformity of the flue-cured tobacco in the continuous zone, provided by the application, after fertilization according to the scheme obtained by the method, the moisture content and the nutrient component range of tobacco plant rhizosphere soil all meet the range requirements when alkaline hydrolysis nitrogen is 120-160 mg/kg, available phosphorus is 40-80 mg/kg and available potassium is 400-800 mg/kg in the period from the Tian Xianlei period to the central flower opening period of tobacco, so that the soil single nutrient component exceeding standard can be effectively avoided after fertilization according to the method, and the nutrient component balance of the tobacco planting soil can be effectively maintained.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions in the embodiments of the present application will be clearly and completely described in the following in conjunction with the embodiments of the present application.

The soil testing formula fertilization method for improving the growth and nutrient uniformity of flue-cured tobacco in a continuous zone provided by the application comprises the following steps: the method comprises 3 parts of preparing a base fertilizer scheme, preparing an additional fertilizer scheme and verifying nutrition deficiency of tobacco plants, wherein each part is divided into the following steps:

a first part: making a base fertilizer scheme

The first step: and (5) preprocessing special plots. For the plots of high-fertilizer crops such as vegetables and pseudo-ginseng and the like planted in the previous crop or N-element super-high-fertility plots (the organic matter content of the soil is more than 5 percent and the alkaline hydrolysis nitrogen is more than 170 mg/kg), the soil with the surface layer of 0-10cm is completely removed by mechanical modes and the like and is concentrated and stacked in a non-tobacco planting area. The special land parcels are cleaned, and the obtained extreme value can influence the accuracy and reliability of the finally obtained fertilization scheme when the soil is collected during sampling.

And a second step of: sampling fields/fields are selected. That is, the same land block of one peasant household is determined in the selected area to be sampled at 5 points of S shape or plum shape. The determination principle of the land block is as follows:

(1) The land block is positioned near the center position of the selected sheet area and is on the level close to surrounding cultivated land (mountain land or sloping land is near the middle position);

(2) Selecting farmers with larger area in the same land block;

(3) The type of the soil of the selected land is the same as that of the large area.

(4) The front cropping spring or the small spring of the land is selected to be the same as the large area of the slice area, and is preferably gramineous crops such as corn, barley, wheat, highland barley and the like;

(5) A plot having a medium level of land fertility (i.e., the crop growth is at a medium level within the plot) is selected.

And a third step of: recording the fertility level of each field/land in the sheet area relative to the sampled field/land, which is higher than that of the sampled field; equivalent to the sampling field; the level lower than the sampling field is low, and is classified into three levels of high, equivalent and low.

Fourth step: and (5) completing deep soil turning in the continuous zone at the same time. And (3) concentrating time, and uniformly deep-turning the land parcels in the continuous area, wherein the depth is preferably 30-40 cm.

Fifth step: and detecting indexes of pH value, organic matters, quick-acting nitrogen, quick-acting phosphorus, quick-acting potassium, effective calcium, effective magnesium, effective boron, effective zinc, effective iron and effective molybdenum of the soil.

Sixth step: and (5) application of a detection result. And (3) formulating a base fertilizer application scheme for flue-cured tobacco planting. By comparing the fertility with the 'sampled field/land', the field with high fertility (the fertilizer resistant variety is reduced by 1.5-2.5 kg/mu; the N fertilizer sensitive variety is reduced by 0.5-1 kg/mu), the fertility 'equivalent' refers to the 'sampled field/land', the fertility 'low' is properly increased by the N fertilizer (the fertilizer resistant variety is increased by 1.5-2.5 kg/mu; the N fertilizer sensitive variety is increased by 0.5-1 kg/mu).

Table 1: basis for judging fertility and abundant lack status of flue-cured tobacco in reference field

Table 2 "benchmark field" basis for judging the amounts of nitrogen, phosphorus and potassium of flue-cured tobacco

Note that: the pH value is in the range of 4.5-8.5; the N fertilizer sensitive varieties such as Hongda and Yunyan 300, and the rest varieties are fertilizer resistant varieties; the specific block needs to be properly adjusted in combination with the rotation condition of the previous 3 years.

A second part: making additional fertilizer scheme

A: the root topdressing scheme comprises the following steps:

and (3) during 15-25 days after planting, observing the growth vigor, the color of the stems and the color of the leaves of the flue-cured tobacco, and carrying out N fertilizer 'eccentric' management. The root topdressing amount can be divided into 3 grades according to the 3 grades of strong, medium and weak of the tobacco plant growth vigor.

First gear (strong growth): the stems are thicker, and the stems and the leaves are greenish. Then there is no need to apply additional N fertilizer.

Second grade (moderate growth): the thickness of the stems is medium, and the stems and the leaves are green. For the nitrogen fertilizer sensitive varieties, applying 0.68kg of N fertilizer per mu in the root extending period, and adding water for applying about 5kg of potassium nitrate per mu; the other fertilizer-resistant varieties correspondingly increase the dosage by 1 time.

Third gear (weak growth): the stems are thin, and the stems and the leaves are light green. For the nitrogen fertilizer sensitive varieties, topdressing 1 kg/mu of N fertilizer in the root extension period, which is about 8 kg/mu of potassium nitrate, and watering 2 times; the other fertilizer-resistant varieties correspondingly increase the dosage by 1 time.

B: an extra-root dressing/foliar dressing scheme:

the determination is made according to the abundant conditions of Ca-Mg-B-Zn-Mo-Fe in the attached Table 1. If there are medium trace elements at "low" level, the principle of "what is missing and what is being supplemented" is followed. The specific method is as follows;

the first step: determining elements of the missing element;

and a second step of: the fertilizer (such as zinc deficiency, zinc sulfate or chelated zinc EDTA-Zn) corresponding to the element deficiency is added into a plant activator, and the fertilizer can be sprayed on leaf surfaces for a long period of time until a bud period, and is continuously sprayed for 2-3 times.

The plant activator used in the embodiment is Yuan Tai Feng brand plant activator, contains humic acid water-soluble fertilizer, has effective viable count of 2.0 hundred million/ml or more and high nitrogen, and is used according to the use instruction of the product. The product execution standard is GB20287-2006. The main components of the product are shown in the following table:

total nitrogen (g/L)	Phosphorus (g/L)	Potassium (g/L)	Magnesium (g/L)	Humic acid content (g/L)
					3.8	0.6	6.4	4.9	0.05
Arsenic (mg/kg)	Mercury (mg/kg)	Lead (mg/kg)	Cadmium (mg/kg)	Chromium (mg/kg)
					0.4	0.1	0.2	0.2	0.4

Comparative example

Taking a traditional sampling method as a comparative example, determining a fertilization scheme and fertilizing according to the following steps:

1. that is, the conventional sampling operation method is to adopt an S-shaped or quincuncial sampling method in the continuous area, wherein five points are uniformly distributed in the continuous area, and the concept of a reference field is not adopted.

2. The comparative example or the comparative example shows malnutrition, which is manifested by overnutrition, malnutrition, or unbalanced nutrition.

And (3) optionally selecting sampling points in the continuous plots from the period of Tian Xianlei to the period of the central flower opening, sampling 6 points in which rhizosphere soil is uniformly distributed, and verifying the nutrition abundant and deficient condition of the tobacco plants in the field according to the detection result of the sampling soil so as to verify the practical effect of the fertilization method provided by the application.

Example 1 and comparative example providing methods each verify the nutrient-rich status of tobacco plants to determine the rationality of the "one-household one-strategy" fertilization strategy according to the following steps:

the first step: a diagnostic period is determined. And the bud stage of flue-cured tobacco to the central flower opening stage.

And a second step of: determining a diagnostic premise. By detecting the moisture content of the rhizosphere soil of the tobacco plant at this stage, if the moisture content of the soil is between 15 and 25 percent, the diagnosis result is considered to be effective, otherwise, the diagnosis result is not effective.

And a third step of: under the condition that the moisture content of rhizosphere soil meets 15-25%, 3 target fields (namely tobacco fields needing diagnosis) are randomly selected in the connected area. 3 tobacco plants with consistent growth are selected for each target field, a 6-point sampling method is adopted, each plant takes the soil in the rhizosphere range (namely, the soil in the plough layer with the target tobacco plants as the center and the surrounding soil in the transverse direction of 5-25 cm and the longitudinal direction of 0-20 cm is fully and uniformly mixed), and the soil is uniformly mixed into 1 soil sample. 3 target fields are sampled with 3 mixed samples to detect 3 indexes of alkaline hydrolysis nitrogen, available phosphorus and quick-acting potassium in soil.

Fourth step: determining a diagnostic index. The method adopts 'soil analysis technical Specification' to measure hydrolytic nitrogen, GB12297-1990 to measure soil available phosphorus, NY/T889-2004 to measure quick-acting potassium, and judges the nutrition status through the detection results of 3 indexes of alkaline hydrolytic nitrogen, available phosphorus and quick-acting potassium.

Fifth step: judging the nutrition status of the flue-cured tobacco. And judging the nutrient surplus and deficient conditions of the flue-cured tobacco according to the detection values of the 3 indexes.

Normal nutrition: when the alkaline hydrolysis nitrogen is 120-160 mg/kg, the available phosphorus is 40-80 mg/kg, and the quick-acting potassium is 400-800 mg/kg. The range is different to a certain extent due to the flue-cured tobacco varieties with different fertilizer requirements. Wherein, for flue-cured tobacco varieties with high fertilizer utilization rate (such as Hongda and Yunyan 300), each index needs to be adjusted by 20 units downwards to the upper limit; for fertilizer-resistant flue-cured tobacco varieties (such as K326, cloud smoke 87 and the like) with low fertilizer utilization rate, the upper limit value of each index can be selected.

Surplus nutrition: when any one of the above three indices exceeds its upper limit value, that index is considered to be overfed.

Deficiency of nutrition: when any one of the above three indicators is below its lower limit, the indicator is considered to be deficient in nutrition.

Sixth step: judging the nutrient uniformity of the tobacco plants in the connecting area. If 2 samples or 3 samples are judged to be 'normal nutrition', the uniformity of nutrients of the tobacco plants in the continuous zone is considered to be good, and the method is effective.

The results obtained are shown in the following table:

table 3: investigation result table of growth uniformity (mean value + -S) of flue-cured tobacco in Hongda continuous area

Note that: tobacco plant growth uniformity is expressed by an agronomic character index of tobacco plants in the open period of central flowers of tobacco fields, and a standard deviation (S) representing the discrete degree of the index.

As can be seen from the table, the average value of the plant height, the stem circumference, the waist leaf length, the waist leaf width and the leaf area of the tobacco plant in the Hongda section is obviously superior to that of the control section by adopting the method provided by the application, and the standard deviation (S) is obviously smaller. Therefore, the method obviously improves the growth uniformity of the tobacco plants.

The soil nutrition conditions of the method provided by the application and the method provided by the comparative example are counted according to the method, and the obtained results are shown in the following table:

table 4: investigation result table of nutrition uniformity of flue-cured tobacco in Hongda continuous area

Note that: the uniformity of tobacco plant nutrition is expressed by the rhizosphere soil from the bud-containing period to the bud-emergence period of the tobacco plant in the field, namely, normal nutrition, overnutrition and nutrition deficiency.

As can be seen from Table 4, the measured soil moisture of 3 fields (lands) was 15 to 25%, and the diagnosis result was considered to be effective. By adopting the method provided by the application, the indexes of alkaline hydrolysis nitrogen, available phosphorus and quick-acting potassium in 3 fields (lands) are all in the range of normal nutrition, and the uniformity of tobacco plant nutrients in the red large continuous area is good.

However, when the land is treated by adopting the method of the comparative example (the conventional method of the adjacent areas), only from the point of view of 1 index of alkaline hydrolysis nitrogen, two points cannot meet the requirement of regulating the upper limit of '120-160 mg/kg of alkaline hydrolysis nitrogen' by 20 units (the alkaline hydrolysis nitrogen is lower than 140 mg/kg), and the method provided by using the comparative example can cause overnutrition of tobacco plants in the adjacent comparative areas and nonuniform nutrition of each area.

Although the present application has been described with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described, or equivalents may be substituted for elements thereof, and any modifications, equivalents, improvements and changes may be made without departing from the spirit and principles of the present application.

Claims

1. The soil testing formula fertilization method for improving the growth and nutrient uniformity of the flue-cured tobacco in the continuous zone is characterized by comprising the following steps of:

4) Crop growth, at a moderate level within the tandem zone;

step S3: deep ploughing and sunning upturned soil of all land areas;

step S4: determining fertility level according to the detection index of the soil of a reference field, preparing a 'one-land-one-table', comparing the soil detection index and the fertility level of other plots in a land area according to the position of the plots, the thickness of the soil layer, the growth vigor of crops and the representation of lack of elements with the reference field, and determining fertilization countermeasures of each plot, namely 'one-land-one-strategy';

growth vigor is moderate: if the thickness of the stems is medium and the colors of the stems and the leaves are green, applying 0.68-1.0 kg of N fertilizer to each mu of the fertilizer in the root extension period, and pouring water to the fertilizer, wherein the thickness of the stems is about 5-7.5 kg of potassium nitrate; the other fertilizer-resistant varieties correspondingly increase the dosage by 1 to 1.5 times;

weak growth vigor: the stems are thin, the stems and leaves are light green, and then for the nitrogen fertilizer sensitive varieties, 1-1.5 kg of N fertilizer is applied to each mu in the root extension period, the amount of potassium nitrate is reduced to about 8-11.0 kg/mu, and the nitrogen fertilizer sensitive varieties are applied by adding water for 2 times; the other fertilizer-resistant varieties are correspondingly increased by 1 to 1.5 times.

2. The soil testing and formulated fertilization method for improving the growth and nutrient uniformity of flue-cured tobacco in a continuous zone according to claim 1, wherein the fertility level grading standard and the fertilization operation thereof in the step S2 are as follows:

3. The soil testing and formulated fertilization method for improving the growth and nutrient uniformity of flue-cured tobacco in a continuous zone according to claim 1, wherein the soil detection index grading index is as follows:

4. The soil testing and formulated fertilization method for improving the growth and nutrient uniformity of flue-cured tobacco in a continuous zone according to claim 1, wherein the step S2 further comprises: and detecting the organic matters, alkaline hydrolysis nitrogen content, quick-acting phosphorus content, quick-acting potassium content, effective calcium content, effective magnesium content, effective boron content, effective zinc content, effective iron content and effective molybdenum content of the soil of the reference field.

5. The soil testing and formulated fertilization method for improving the growth and nutrient uniformity of flue-cured tobacco in a continuous zone according to claim 4, wherein the step S3 further comprises: and (3) after more than 20 days before transplanting, the land blocks in the connected areas are uniformly deep-turned for a concentrated time, the depth is preferably 25-50 cm, and the upturned soil drying time is more than 15 days.

6. The soil testing and formulated fertilization method for improving the growth and nutrient uniformity of flue-cured tobacco in a continuous zone according to claim 4, wherein the step S3 further comprises: and determining the dosage of three elements of nitrogen, phosphorus and potassium and organic materials of the flue-cured tobacco in the fertilization scheme according to the detection results of the organic matters, alkaline hydrolysis nitrogen content, quick-acting phosphorus content and quick-acting potassium content of the soil of the reference field.

7. The soil testing and formulated fertilization method for improving the growth and nutrient uniformity of flue-cured tobacco in a continuous zone according to claim 5, wherein the determination of the amounts of three elements of nitrogen, phosphorus and potassium and organic materials in the flue-cured tobacco in the fertilization scheme is based on:

8. The soil testing and formulated fertilization method for improving the growth and nutrient uniformity of flue-cured tobacco in a continuous zone according to claim 1, wherein the step S1 comprises the following steps:

9. The soil testing and formulated fertilization method for improving the growth and nutrient uniformity of flue-cured tobacco in a continuous zone according to claim 1, wherein the front-cropping spring or spring crop of the land parcels of the sampling farmers is a gramineous crop; more preferably, the gramineous crop is corn, barley, wheat, highland barley.

10. The soil testing and formulated fertilization method for improving the growth and nutrient uniformity of flue-cured tobacco in a continuous zone according to claim 3, wherein the step S4 comprises the following operations: