CN102144501A - Method of determining nitrogen fertilizer application in crops - Google Patents

Abstract

The invention discloses a method of determining nitrogen fertilizer application in crops, which can determine the nitrogen fertilizer application Nfert of the crops according to the quantitative relation of nitrogen fertilizer, soil nitrogen and nitrogen uptake by the crop at the crop root zone. The method can realize quick, accurate and quantitative nitrogen fertilizer application without testing the soil or plants, so that the cost for determining the nitrogen fertilizer application in the production is greatly saved.

Description

Determine the method for crop amount of nitrogen

Technical field

Agricultural technology field of the present invention relates in particular to a kind of method of definite crop amount of nitrogen.

Background technology

Determining to obtain in the agricultural production target output does not still break through so far in theory with the amount of nitrogen method that reduces environmental pollution.Although developed the fertilizing and determination method methods such as (as the rich scarce index method of soil fertility, nutrient balance methods) of paying attention to the biometric fertilizer response function method of field trial and biasing toward soil testing both at home and abroad, but these methods are to concern to determine amount of nitrogen according to input-output, basically with soil-be considered as "black box" as objects system.Do not touch the conversion of nitrogen between soil-crop-environment, the essential problem that flows and lose.

Based on definite method of fertilizer response function, can not resolve time and spatial variability in the application, belong to experience character.Definite method based on soil testing, at first run into the reliable test index problem of seeking, so far still do not find the practical index of fine reflection paddy field soil for nitrogen, although the dry farming system can be used the nitrate nitrogen reserves of root district soil layer as index, also there are problems such as spatial and temporal variation is big, mobility strong, the sampling and measuring error is big; Next is the problem that test value is converted into amount of application of nitrogen fertilizer, in this conversion process, need to introduce a series of parameter, uncertainty to these parameters selections, the fertilizing amount that often causes calculating does not meet reality, not even as expertise by so-called " bat head " definite consumption, limited these methods application in practice.Causing producing in the reality blindly, applied nitrogen causes problems such as serious environmental pollution.

Summary of the invention

(1) technical problem that will solve

The technical problem to be solved in the present invention is how a kind of method of definite crop amount of nitrogen is provided, to carry out realizing quickly and accurately the quantitatively amount of application of nitrogenous fertilizer under the situation of soil or plant test not needing.

(2) technical scheme

For solving the problems of the technologies described above, the invention provides a kind of method of definite crop amount of nitrogen, determine amount of nitrogen N according to the quantitative relation between nitrogenous fertilizer, Soil Nitrogen and the absorbed nitrogen by crop three of crop root zone to crop _Fert

Wherein, described method specifically may further comprise the steps:

S1, determine the amount of nitrogen sucking N on crop field top _Uptake, stalk amount of nitrogen sucking N _StrawAnd loss of nitrogen fertilizer N _Fert3

S2, utilize relational expression N _Fert=N _Uptake-N _Straw+ N _Fert3Determine amount of nitrogen N _Fert

Wherein, among the step S1, determine the amount of nitrogen sucking N on described crop field top according to the conversion coefficient of target output and hundred kilograms of seed acrial part amount of nitrogen sucking _UptakeTarget output and seed nitrogen content according to crop are determined seed amount of nitrogen sucking N _Grain, then according to relational expression N _Straw=N _Uptake-N _GrainDetermine stalk amount of nitrogen sucking N _Straw

Wherein, step S2 is replaced with following step: utilize relational expression N _Fert=(N _Uptake-N _Straw)/(1-Coeff) determined amount of nitrogen N _Fert, wherein, coefficient Coeff is according to described loss of nitrogen fertilizer N _Fert3Determine.

Wherein, described coefficient Coeff is 20%-35%.

Wherein, step S2 is replaced with following step: amount of nitrogen N _FertBe defined as the amount of nitrogen sucking N on crop field top _Uptake

(3) beneficial effect

The amount of nitrogen that the present invention determines according to the quantitative relation between crop root zone nitrogenous fertilizer, Soil Nitrogen and the absorbed nitrogen by crop three, under the situation that does not need to carry out the test of soil or plant, can realize the amount of application of quantitative nitrogenous fertilizer quickly and accurately, save the cost that is used for determining amount of nitrogen in producing greatly.

Description of drawings

Fig. 1 is the method flow diagram of the embodiment of the invention.

Embodiment

Below in conjunction with the drawings and specific embodiments, the present invention will be further described.

Conversion between crop root zone nitrogenous fertilizer, Soil Nitrogen and the absorbed nitrogen by crop and whereabouts are the cores that soil-do objects system nitrogen flows, quantitative relation between this three has determined the acquisition target output should use the problem of how much nitrogenous fertilizer (being also referred to as fertilizer nitrogen) in theory, to can be described as theoretical amount of nitrogen (be the crop amount of nitrogen of mentioning among the present invention to the amount of nitrogen of Tui Daoing thus, also abbreviate amount of nitrogen as, it is a theoretical value).Theoretical amount of nitrogen can be realized target output, keeps the soil nitrogen balance, reduces loss to greatest extent, reduce environmental pollution, has good society, economy and ecological environment benefit.

If there is the nitrogen input of fertilizer or biological nitrogen fixation form, the amount of application of fertilizer nitrogen should deduct this part.Certainly other forms of nitrogen input of soil-do also to exist in the objects system such as dried wet deposition, irrigation water are brought into, seed is brought into, abiotic fixed nitrogen, but not the main flow of nitrogen transformation and whereabouts, perhaps in some cases, some of these inputs seems important, but is not Universal Problems.

The present invention is based on above theory analysis, the amount of nitrogen according to the quantitative relation between crop root zone nitrogenous fertilizer, Soil Nitrogen and the absorbed nitrogen by crop three is determined specifically, as shown in Figure 1, may further comprise the steps:

S1, determine the amount of nitrogen sucking N on crop field top _Uptake, stalk amount of nitrogen sucking N _StrawAnd loss of nitrogen fertilizer N _Fert3

Obtain above-mentioned three amounts, at first will analyze three whereabouts of nitrogenous fertilizer:

After nitrogenous fertilizer enters soil-make objects system, three whereabouts are arranged, i.e. crop absorption, pedo relict and loss.The total absorbed nitrogen of crop is mainly from fertilizer and soil, again with seed form output farmland, with stalk form field also.Soil Nitrogen consumption mainly relies on residual nitrogenous fertilizer and straw-returning to obtain to replenish.

Three whereabouts of nitrogenous fertilizer can be represented with following formula:

N _fert＝N _fert1+N _fert2+N _fert3 (1)

In the formula: N _FertBe amount of nitrogen; N _Fert1Nitrogenous fertilizer for the crop absorption; N _Fert2Nitrogenous fertilizer for pedo relict; N _Fert3Be loss of nitrogen fertilizer.From the angle of protection environment, if adopt rational nitrogen fertilizer amount and application process, loss of nitrogen fertilizer N _Fert3That can fall is very low.Present a large amount of loss of nitrogen fertilizer and environmental pollutions in the production reality, excessive fertilization or fertilizing method are improper often causes.

The source of its less important definite absorbed nitrogen by crop:

The amount of nitrogen sucking on crop field top can be represented with following formula:

N _uptake＝N _grain+N _straw＝N _fert1+N _soil (2)

In the formula: N _UptakeAmount of nitrogen sucking for crop field top; N _GrainBe the seed amount of nitrogen sucking; N _StrawBe the stalk amount of nitrogen sucking; N _SoilBe the Soil Nitrogen amount that absorbs.Because the nitrogen that crop root absorbs is all the time in the soil inner loop, so do not consider within calculating.

Analyze the soil nitrogen balanced relationship once more:

Per season, crop all will absorb Soil Nitrogen, and giving back of the residual and stalk nitrogen of nitrogenous fertilizer should compensate the Soil Nitrogen that crop absorbs.To keep the nitrogen balance of soil itself.If the Soil Nitrogen storehouse can not get compensation, nitrogen fertility will reduce, the long-range improvement of soil fertility that is unfavorable for.Surpassed the absorption of crop to soil nitrogen if exogenous nitrogen is residual, nitrogen will be accumulated in soil, tends to cause a large amount of losses afterwards, contaminated environment.After ideal situation was one season of plantation crop, the Soil Nitrogen storehouse does not consume yet not to be increased, and made residual nitrogenous fertilizer and straw-returning nitrogen sum equal the Soil Nitrogen amount that crop absorbs, then:

N _soil＝N _fert2+N _straw (3)

To sum up, can derive the mathematic(al) representation of amount of nitrogen:

Can get by formula (2): N _Fert1=N _Uptake-N _Soil

Can get by formula (3): N _Fert2=N _Soil-N _Straw

In above two formula substitution formulas (1), then can derive theoretical amount of nitrogen N _FertFor:

N _fert＝N _uptake-N _soil+N _soil-N _straw+N _fert3

＝N _uptake-N _straw+N _fert3 (4)

Result of study to the nitrogenous fertilizer whereabouts shows, if adopt rational amount of nitrogen and application process, loss of nitrogen fertilizer N _Fert3Can fall very lowly.Inevitably loss of nitrogen fertilizer can be controlled in the 20%-35% scope, even can be lower.(4) formula can further be simplified to so:

N _fert＝(N _uptake-N _straw)/(1-Coeff) (5)

Wherein, Coeff is 20%-35%, is loss of nitrogen fertilizer.The coefficient of formula (5) 20%-35% can be adjusted with the different of weather conditions, fertilizing method according to the soil of locality.By (5) formula, can be more convenient calculate amount of nitrogen.

According to our a large amount of research data, under rational amount of nitrogen and application process:

$N_{\mathrm{fert}3}\≅N_{\mathrm{straw}}$

With following formula substitution (4) formula, then (4) formula can further be simplified to:

$N_{\mathrm{fert}}\≅N_{\mathrm{uptake}}---\left(6\right)$

Be the amount of nitrogen sucking that theoretical amount of nitrogen approximates acrial part, therefore can be amount of nitrogen N _FertBe defined as the amount of nitrogen sucking N on crop field top _UptakeIn order to prove under the field condition, obtain the target output amount of nitrogen and approximate the overground part amount of nitrogen sucking, in experiment, collected a large amount of field trial data of delivering, analyzed output, the amount of nitrogen sucking of acrial part and the relation between the suitable amount of nitrogen.In all tests, suitable amount of nitrogen is close with the amount of nitrogen sucking of acrial part.

Studies show that between the amount of nitrogen sucking on crop field top and the crop kernel output good positive correlation is arranged in a large number.Therefore, need only the target output of having determined a certain field piece according to local conditions, just can be by the conversion coefficient of hundred kilograms of seed acrial part amount of nitrogen sucking, the overground part amount of nitrogen sucking N when determining this target output _UptakeFor the specific crop of particular locality, the seed nitrogen content is generally determined, can obtain N by target output and seed nitrogen content _GrainThereby, can pass through N _Straw=N _Uptake-N _GrainObtain the stalk amount of nitrogen sucking.

To simply, the user can select for use according to parameter situation and the required precision grasped from complexity for above-mentioned formula (4), (5), (6).Theoretical amount of nitrogen does not need soil or plant test, as long as this area field trial or peasant household's data are gathered arrangement, drawing simple parameters can calculate, and has good practicability.For moving the excessive nitrogen phenomenon of executing of peasant household to a reasonable range, realize target output, keep the soil nitrogen balance, reduce loss to greatest extent, reduce environmental pollution and will play important effect.

Below illustrate implementation process of the present invention:

With North China Plain summer corn is example, and according to local working condition, the summer corn target output is set at about 8.5 tons of per hectares, and the conversion coefficient of per hundred kilograms of seed acrial part amount of nitrogen sucking is 2.23 kilograms, so the N of summer corn _Uptake=(8500/100) * 2.23=190kg N hm ^-2About.Under this yield level, summer corn seed nitrogen content is 1.35%, so N _Grain=8500*1.35%=115kg N hm ^-2, N then _Straw=N _Uptake-N _Grain=75kg N hm ^-2

If adopt rational amount of application of nitrogen fertilizer and application process, loss of nitrogen fertilizer N _Fert3That can fall is very low.In the practical application, the loss of nitrogen fertilizer rate in summer corn season is about 35%, N _Fert3Greatly about 67kg N hm ^-2About, try to achieve theoretical amount of nitrogen with formula (4) and be:

N _Fert=N _Uptake-N _Straw+ N _Fert3=190-75+67=182kg N hm ^-2About

Passing type (5) is tried to achieve theoretical amount of nitrogen:

N _Fert=(N _Uptake-N _Straw)/0.65=(190-75)/0.65=177kg N hm ^-2About

Passing type (6) is tried to achieve theoretical amount of nitrogen:

$N_{\mathrm{fert}}\≅N_{\mathrm{uptake}}\≅190\mathrm{kgN}{\mathrm{hm}}^{-2}$

The amount of nitrogen maximum that above-mentioned three formulas are calculated differs 13kg N hm ^-2Because absorbed nitrogen by crop is subjected to influence of various factors such as soil condition, climatic factor, other control measures of farmland, determine that amount of nitrogen should accept certain uncertainty.The per hectare uncertainty is acceptable at 15 kilograms with the planted agent.Reasonably amount of nitrogen more should be a narrower scope, minimumly can not influence target output, the highlyest can not cause a large amount of losses and contaminated environment.

As can be seen from the above embodiments, the amount of nitrogen that the present invention determines according to the quantitative relation between crop root zone nitrogenous fertilizer, Soil Nitrogen and the absorbed nitrogen by crop three, under the situation that does not need to carry out the test of soil or plant, can realize the amount of application of quantitative nitrogenous fertilizer quickly and accurately, save the cost that is used for determining amount of nitrogen in producing greatly.

Above embodiment only is used to illustrate the present invention; and be not limitation of the present invention; the those of ordinary skill in relevant technologies field; under the situation that does not break away from the spirit and scope of the present invention; can also make various variations and modification; therefore all technical schemes that are equal to also belong to category of the present invention, and scope of patent protection of the present invention should be defined by the claims.

Claims (6)

1. the method for a definite crop amount of nitrogen is characterized in that, determines amount of nitrogen N to crop according to the quantitative relation between nitrogenous fertilizer, Soil Nitrogen and the absorbed nitrogen by crop three of crop root zone _Fert

2. as claimed in claim 1ly determine the method for the amount of nitrogen of crop be is characterized in that described method specifically may further comprise the steps:

S1, determine the amount of nitrogen sucking N on crop field top _Uptake, stalk amount of nitrogen sucking N _StrawAnd loss of nitrogen fertilizer N _Fert3

S2, utilize relational expression N _Fert=N _Uptake-N _Straw+ N _Fert3Determine amount of nitrogen N _Fert

3. the method for definite crop amount of nitrogen as claimed in claim 2 is characterized in that, among the step S1, determines the amount of nitrogen sucking N on described crop field top according to the conversion coefficient of target output and hundred kilograms of seed acrial part amount of nitrogen sucking _UptakeTarget output and seed nitrogen content according to crop are determined seed amount of nitrogen sucking N _Grain, then according to relational expression N _Straw=N _Uptake-N _GrainDetermine stalk amount of nitrogen sucking N _Straw

4. as the method for claim 2 or 3 described definite crop amount of nitrogens, it is characterized in that, step S2 is replaced with following step: utilize relational expression N _Fert=(N _Uptake-N _Straw)/(1-Coeff) determined amount of nitrogen N _Fert, wherein, coefficient Coeff is according to described loss of nitrogen fertilizer N _Fert3Determine.

5. the method for definite crop amount of nitrogen as claimed in claim 4 is characterized in that, described coefficient Coeff is 20%-35%.

6. as the method for claim 2 or 3 described definite crop amount of nitrogens, it is characterized in that, step S2 is replaced with following step: amount of nitrogen N _FertBe defined as the amount of nitrogen sucking N on crop field top _Uptake

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