CN103493693A - Method for determining furrow-ridge proportion suitable for furrow-ridge irrigation - Google Patents

Abstract

The invention provides a method for determining the furrow-ridge proportion suitable for furrow-ridge irrigation. The method comprises the steps of 1, initialization, 2, obtaining moist body spatial distribution values of irrigated water infiltration in different ridge width simulation scenes and an actual soil water content spatial distribution value, 3, conducting spatial discretization on furrow-ridge irrigation infiltration moist bodies, using requirements of crop growth for the root zone soil moisture as the target water content, and calculating the Euclidean distance between the actual soil water contents of a crop root zone in the different ridge width simulation scenes and the target soil water content according to the Euclidean distance formula, 4, determining the actual side direction infiltration distances in the different ridge width simulation scenes, and 5, comprehensively giving consideration to all parts to obtain the suitable ridge width. According to the method, on the condition that soil water motion parameters and farming technique parameters are known, only numerical simulation and model calculation are required to obtain the furrow-ridge proportion suitable for furrow-ridge irrigation, field tests are not required, and the method can be easily and conveniently determined.

Description

Furrow is irrigated definite method of suitable ditch, ridge ratio

Technical field

The present invention relates to the Agricultural Water-Soil Engineering field, particularly, relate to definite method that furrow is irrigated suitable ditch, ridge ratio.

Background technology

It is on ridge culture trench sowing plantation basis that furrow is irrigated, and by changing the ground micro-terrain, forms wide " furrow structure ", utilizes the irrigation ditch water delivery and, by the effect of soil hollow billet power, makes the moisture side be seeped into the ground irrigation method of wide ridge growth belt.It is only irrigated planting plant in ditch, and relies on the soil moisture side to ooze to realize the distribution of moisture between ridge, ditch, meet the crop water requirement of ditch, each growth belt of ridge, is to follow the pattern of farming adjustment and the side of pouring water that produces is oozed technology.

Furrow is irrigated the definite extremely important of suitable ditch, ridge ratio, and reasonably Crop Water Use Efficiency, than the obvious raising of regular meeting pour water efficiency and the uniformity, is improved in Gou, ridge, field simultaneously, saves agricultural water.Ridge is wide, and after pouring water and finishing, moisture is failed side and is seeped into soil moisture scarcity on Ti， ridge, ridge, and the soil water supply ability is low, and plant growth is impaired, and yield reducation even occurs here withering.Ridge is narrow, and after pouring water, the very fast side of moisture is seeped into the ridge body, crosses to infiltrate phenomenon, causes the irrigation water deep percolation serious, reduces the utilization ratio of pouring water.Therefore need definite furrow to irrigate suitable ditch, ridge ratio, with the raising quality of pouring water, optimize field farming technique parameter, for having under the plantation crops condition, promote between the furrow sewage farming theoretical support is provided, have important practical significance to improving furrow irrigation technique level.

Summary of the invention

For defect of the prior art, the purpose of this invention is to provide a kind of definite method that furrow is irrigated suitable ditch, ridge ratio.

Irrigate definite method of suitable ditch, ridge ratio according to furrow provided by the invention, comprise the steps:

Step 1: initialization step: set the different row spacing simulated scenario that furrow is irrigated; Obtain furrow irrigated soil Soil Water Movement Parameter; Determine furrow irrigation farming technical parameter, the farming technique parameter comprises the depth of water in ditch bottom width, ditch, ridge is high and limit, ridge and bottom of trench angle; And setting crop irrigation quantity;

Step 2: primary condition and the boundary condition of determining furrow irrigated soil Infiltration according to furrow irrigation farming technical parameter, furrow irrigated soil Soil Water Movement Parameter in step 1 is updated to furrow irrigated soil moisture movement equation, be in formula (1), formula (1) carried out to the golden finite element numerical of gal the Liao Dynasty and solve; On the crop irrigation quantity basis of setting, obtain wetting body values for spatial distribution and actual soil moisture content values for spatial distribution that pouring water of different row spacing simulated scenario infiltrated, wherein, formula (1) is:

$\frac{\∂\mathrm{\θ}}{\∂t}=\frac{\∂}{\∂x}\left(K\left(h\right)\frac{\∂h}{\∂x}\right)+\frac{\∂}{\∂z}\left(K\left(h\right)\frac{\∂h}{\∂z}\right)+\frac{\∂K\left(h\right)}{\∂z}$ Formula (1)

Wherein, θ is soil volumetric water content, the cm of unit ³/ cm ³, h is matric potential, the cm of unit, and t is the time of infiltrating, the min of unit, K (h) is unsaturated hydraulic conductivity, the cm/min of unit, x is abscissa, the cm of unit, z is vertical coordinate, the cm of unit;

Step 3: furrow Irrigation Infiltration wetting body is carried out to spatial discretization, the plant growth of take is target water content to the requirement of root region soil moisture, according to the Euclidean distance formula, be formula (2), calculate the actual soil moisture content of crop root zone in different row spacing simulated scenario and the Euclidean distance d between the target soil moisture content _ij:

${d_{\mathrm{ij}}}^2={\left(\underset{k=1}{\overset{m}{\mathrm{\Σ}}}{|{\mathrm{\θ}}_{\mathrm{ik}}-{\mathrm{\θ}}_{\mathrm{jk}}|}^2\right)}^{1/2}$ Formula (2)

Wherein, d _ijfor Euclidean distance, θ _ikfor treating judgment value, refer to the actual soil moisture content values for spatial distribution of certain row spacing simulated scenario, θ _jkfor desired value, refer to that plant growth is to the desired target water content values for spatial distribution of root region soil moisture, k=1 ... m is furrow Irrigation Infiltration wetting body spatial spreading number;

Step 4: the wetting body values for spatial distribution of infiltrating according to pouring water in described step 2 obtains the wetting body lateral infiltration distance of different row spacing simulated scenario, the horizontal wetting front front end and crossing of take infiltrates as boundary, determines the actual lateral infiltration distance of different row spacing simulated scenario;

Step 5: from corresponding actual lateral infiltration distance drop on the row spacing simulated scenario in the zone of reasonableness of setting, choose these row spacing simulated scenario the minimum of a value in the Euclidean distance between the actual soil moisture content of corresponding crop root zone and target soil moisture content, judge whether this minimum of a value is less than reasonable threshold value, further:

This minimum of a value of-Ruo is less than reasonable threshold value, according to the row spacing in the corresponding row spacing simulated scenario of this minimum of a value, determines that furrow irrigates suitable ditch, ridge ratio;

This minimum of a value of-Ruo is more than or equal to reasonable threshold value, dwindles the monopolization scope, returns to step 1 and is initialized.

Preferably, adopting the HYDRUS-2D simulation softward to carry out the golden finite element numerical of gal the Liao Dynasty to formula (1) solves.

Preferably, the primary condition that furrow irrigated soil moisture movement infiltrates is initial soil moisture content.

Preferably, the boundary condition that furrow irrigated soil moisture movement infiltrates is: during the furrow Irrigation Infiltration in ditch, in ridge, position is symmetry axis, is zero logical border, only considers the water infiltration process of 1/2 furrow specification section; The bottom of trench cross-section of river is for determining the head condition; In infiltration process, the ridge body covers and does not consider that Influence of Evaporation is the zero flux border; The border that connects two zero lower ends, logical border is the infiltration border.

Compared with prior art, the present invention, in the situation that known soil water movement parameter, farming technique parameter only need be calculated by numerical simulation and model, just can obtain furrow and irrigate suitable ditch, ridge ratio, and without carrying out field trial, the method for determining is easy.

The accompanying drawing explanation

By reading the detailed description of non-limiting example being done with reference to the following drawings, it is more obvious that other features, objects and advantages of the present invention will become:

Fig. 1 is principle schematic of the present invention;

The furrow specification boundary graph of Fig. 2 for being described by furrow irrigation farming technical parameter.

Embodiment

Below in conjunction with specific embodiment, the present invention is described in detail.Following examples will contribute to those skilled in the art further to understand the present invention, but not limit in any form the present invention.It should be pointed out that to those skilled in the art, without departing from the inventive concept of the premise, can also make some distortion and improvement.These all belong to protection scope of the present invention.

Irrigate definite method of suitable ditch, ridge ratio according to furrow provided by the invention, comprise the steps:

Step 1: initialization step: set the different row spacing simulated scenario that furrow is irrigated; Obtain furrow irrigated soil Soil Water Movement Parameter; Determine furrow irrigation farming technical parameter, the farming technique parameter comprises the depth of water in ditch bottom width, ditch, ridge is high and limit, ridge and bottom of trench angle; And setting crop irrigation quantity.

Step 2: furrow irrigated soil moisture movement equation is as follows:

$\frac{\∂\mathrm{\θ}}{\∂t}=\frac{\∂}{\∂x}\left(K\left(h\right)\frac{\∂h}{\∂x}\right)+\frac{\∂}{\∂z}\left(K\left(h\right)\frac{\∂h}{\∂z}\right)+\frac{\∂K\left(h\right)}{\∂z}---\left(1\right)$

In formula, θ is soil volumetric water content, the cm of unit ³/ cm ³, h is matric potential, the cm of unit, and t is the time of infiltrating, the min of unit, K (h) is unsaturated hydraulic conductivity, the cm/min of unit, x is abscissa, the cm of unit, z is vertical coordinate, the cm of unit.

The furrow specification boundary graph of being described by furrow irrigation farming technical parameter as shown in Figure 2.Determine primary condition and the boundary condition of furrow irrigated soil Infiltration according to furrow irrigation farming technical parameter, initial and boundary condition as shown in Figure 2; The primary condition that furrow irrigated soil moisture movement infiltrates is initial soil moisture content.The boundary condition that furrow irrigated soil moisture movement infiltrates is: during the furrow Irrigation Infiltration in ditch in (AB), ridge (CD) position be symmetry axis, be zero logical border, only consider the water infiltration process of 1/2 furrow specification section; The bottom of trench cross-section of river (AGF) is for determining the head condition; In infiltration process, ridge body covering (EF, ED) does not consider that Influence of Evaporation is the zero flux border; The boundary B C that connects two zero lower ends, logical border is the infiltration border.

The furrow irrigated soil Soil Water Movement Parameter of step 1 is updated to furrow irrigated soil moisture movement equation, and formula (1), adopt the HYDRUS-2D simulation softward to carry out the golden finite element numerical of gal the Liao Dynasty to formula (1) and solve; On the crop irrigation quantity basis of setting, obtain wetting body values for spatial distribution and actual soil moisture content values for spatial distribution that pouring water of different row spacing simulated scenario infiltrated.

Step 3: furrow Irrigation Infiltration wetting body is carried out to spatial discretization, the plant growth of take is target water content to the requirement of root region soil moisture, according to the Euclidean distance formula, be formula (2), calculate the actual soil moisture content of crop root zone in different row spacing simulated scenario and the Euclidean distance d between the target soil moisture content _ij:

${d_{\mathrm{ij}}}^2={\left(\underset{k=1}{\overset{m}{\mathrm{\Σ}}}{|{\mathrm{\θ}}_{\mathrm{ik}}-{\mathrm{\θ}}_{\mathrm{jk}}|}^2\right)}^{1/2}---\left(2\right)$

D in formula _ijfor Euclidean distance, θ _ikfor treating judgment value, refer to the actual soil moisture content values for spatial distribution of certain row spacing simulated scenario, θ _jkfor desired value, refer to that plant growth is to the desired target water content values for spatial distribution of root region soil moisture, k=1 ... m is furrow Irrigation Infiltration wetting body spatial spreading number.Euclidean distance is less, shows that actual soil moisture content and the mutual matching degree of target soil moisture content are good.

Step 4: the wetting body values for spatial distribution of infiltrating according to pouring water in described step 2 obtains the wetting body lateral infiltration distance of different row spacing simulated scenario, the horizontal wetting front front end and crossing of take infiltrates as boundary, determines the actual lateral infiltration distance of different row spacing simulated scenario.

Step 5: comprehensively take into account Euclidean distance and actual lateral infiltration Distance Judgment standard between the actual soil moisture content of crop root zone and target soil moisture content in different row spacing simulated scenario, Euclidean distance under certain row spacing is less, and the side of this row spacing is oozed distance rationally, and this row spacing is comparatively suitable accordingly.Otherwise, constantly adjust the row spacing scope of dwindling, repeat above-mentioned steps, finally definite furrow is irrigated suitable ditch, ridge ratio.

Particularly, from corresponding actual lateral infiltration distance drop on the row spacing simulated scenario in the zone of reasonableness of setting, choose these row spacing simulated scenario the minimum of a value in the Euclidean distance between the actual soil moisture content of corresponding crop root zone and target soil moisture content, judge whether this minimum of a value is less than reasonable threshold value, further:

This minimum of a value of-Ruo is less than reasonable threshold value, according to the row spacing in the corresponding row spacing simulated scenario of this minimum of a value, determines that furrow irrigates suitable ditch, ridge ratio;

This minimum of a value of-Ruo is more than or equal to reasonable threshold value, dwindles the monopolization scope, returns to step 1 and is initialized.

Above specific embodiments of the invention are described.It will be appreciated that, the present invention is not limited to above-mentioned specific implementations, and those skilled in the art can make various distortion or modification within the scope of the claims, and this does not affect flesh and blood of the present invention.

Claims (4)

1. a furrow is irrigated definite method of suitable ditch, ridge ratio, it is characterized in that, comprises the steps:

Step 1: initialization step: set the different row spacing simulated scenario that furrow is irrigated; Obtain furrow irrigated soil Soil Water Movement Parameter; Determine furrow irrigation farming technical parameter, the farming technique parameter comprises the depth of water in ditch bottom width, ditch, ridge is high and limit, ridge and bottom of trench angle; And setting crop irrigation quantity;

Step 2: primary condition and the boundary condition of determining furrow irrigated soil Infiltration according to furrow irrigation farming technical parameter, furrow irrigated soil Soil Water Movement Parameter in step 1 is updated to furrow irrigated soil moisture movement equation, be in formula (1), formula (1) is carried out to the golden finite element numerical of gal the Liao Dynasty to be solved, on the crop irrigation quantity basis of setting, obtain wetting body values for spatial distribution and actual soil moisture content values for spatial distribution that pouring water of different row spacing simulated scenario infiltrated, wherein, formula (1) is:

$\frac{\∂\mathrm{\θ}}{\∂t}=\frac{\∂}{\∂x}\left(K\left(h\right)\frac{\∂h}{\∂x}\right)+\frac{\∂}{\∂z}\left(K\left(h\right)\frac{\∂h}{\∂z}\right)+\frac{\∂K\left(h\right)}{\∂z}$ Wherein, θ is soil volumetric water content to formula (1), the cm of unit ³/ cm ³, h is matric potential, the cm of unit, and t is the time of infiltrating, the min of unit, K (h) is unsaturated hydraulic conductivity, the cm/min of unit, x is abscissa, the cm of unit, z is vertical coordinate, the cm of unit;

Step 3: furrow Irrigation Infiltration wetting body is carried out to spatial discretization, the plant growth of take is target water content to the requirement of root region soil moisture, according to the Euclidean distance formula, be formula (2), calculate the actual soil moisture content of crop root zone in different row spacing simulated scenario and the Euclidean distance d between the target soil moisture content _ij:

${d_{\mathrm{ij}}}^2={\left(\underset{k=1}{\overset{m}{\mathrm{\Σ}}}{|{\mathrm{\θ}}_{\mathrm{ik}}-{\mathrm{\θ}}_{\mathrm{jk}}|}^2\right)}^{1/2}$ Formula (2)

Wherein, d _ijfor Euclidean distance, θ _ikfor treating judgment value, refer to the actual soil moisture content values for spatial distribution of certain row spacing simulated scenario, θ _jkfor desired value, refer to that plant growth is to the desired target water content values for spatial distribution of root region soil moisture, k=1 ... m is furrow Irrigation Infiltration wetting body spatial spreading number;

Step 4: the wetting body values for spatial distribution of infiltrating according to pouring water in described step 2 obtains the wetting body lateral infiltration distance of different row spacing simulated scenario, the horizontal wetting front front end and crossing of take infiltrates as boundary, determines the actual lateral infiltration distance of different row spacing simulated scenario;

Step 5: from corresponding actual lateral infiltration distance drop on the row spacing simulated scenario in the zone of reasonableness of setting, choose these row spacing simulated scenario the minimum of a value in the Euclidean distance between the actual soil moisture content of corresponding crop root zone and target soil moisture content, judge whether this minimum of a value is less than reasonable threshold value, further:

This minimum of a value of-Ruo is less than reasonable threshold value, according to the row spacing in the corresponding row spacing simulated scenario of this minimum of a value, determines that furrow irrigates suitable ditch, ridge ratio;

This minimum of a value of-Ruo is more than or equal to reasonable threshold value, dwindles the monopolization scope, returns to step 1 and is initialized.

2. furrow according to claim 1 is irrigated definite method of suitable ditch, ridge ratio, it is characterized in that, adopts the HYDRUS-2D simulation softward to carry out the golden finite element numerical of gal the Liao Dynasty to formula (1) and solves.

3. furrow according to claim 1 is irrigated definite method of suitable ditch, ridge ratio, it is characterized in that, the primary condition that furrow irrigated soil moisture movement infiltrates is initial soil moisture content.

4. furrow according to claim 1 is irrigated definite method of suitable ditch, ridge ratio, it is characterized in that, the boundary condition that furrow irrigated soil moisture movement infiltrates is: during the furrow Irrigation Infiltration in ditch, in ridge, position is symmetry axis, be zero logical border, only consider the water infiltration process of 1/2 furrow specification section; The bottom of trench cross-section of river is for determining the head condition; In infiltration process, the ridge body covers and does not consider that Influence of Evaporation is the zero flux border; The border that connects two zero lower ends, logical border is the infiltration border.

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