CN104429207B - Pitting field and hedgerow combined farming method and structure thereof - Google Patents

Abstract

The invention provides a compound farming method and its structure of field hedgerows, comprising: setting permanent slope protection ridges on the upper and lower edges of the sloping plots, and excavating and draining the outer sides of the ridges and the left and right sides of the sloping plots Side ditches are connected to each other to form slope drainage ditches; in the interior of the slope land, from top to bottom, excavate equal high-level retaining ditches at the critical slope length for rill erosion, and divide the slope land into several equal-length cultivated areas In the farming area, build ridges and ditches along the slope, along the slope drainage ridges, contour interception ditches and slope drainage side ditches to form a slope drainage network; along the slope drainage ridges and contour interception ditches are built along the same interval The field soil ridge in the drainage ditch area along the slope and the field soil ridge in the intercepting ditch area of contour are used to construct the field in the slope ditch area; the middle part of the farming plot is built with a horizontal slope ridge, and planting soil and water conservation plants on the ridge to build a ridge hedge. The composite mode designed by the invention is simple to operate, low in cost, and has obvious effect of controlling water and soil loss.

Description

A kind of compound cultivation method and its structure of field hedgerow

technical field

The invention relates to the technical fields of agricultural farming and soil erosion prevention on sloping farmland, and specifically designs a "district field + hedgerow" compound farming model and a construction method suitable for purple soil steep slope farmland in the upper reaches of the Yangtze River, especially in the Three Gorges reservoir area.

Background technique

The Three Gorges Reservoir area has an important strategic position in my country, especially in terms of social economy, ecological barrier and water security in the Yangtze River Basin. The terrain in the area fluctuates greatly, with a relative height difference of 2800m. Zhongshan Mountains account for 32.02% of the total land area of the region, low mountains account for 38.25%, hills account for 25.16%, and river valleys and flat dams account for 4.57%. The total land area is 55742km2. The existing cultivated land area in the reservoir area (Chongqing section) is 3,891,000 hm ² , of which more than 69% is purple soil slope farmland, and the slope area greater than 15° accounts for 53.87%, which is an important local cultivated land resource. The area is located in the humid subtropical monsoon climate zone, warm and humid, with an average annual precipitation of 1150mm, and more than 70% of the precipitation is distributed in summer and autumn. Heavy rainstorms are the main factors that induce soil erosion and soil erosion in the reservoir area. In addition, the Three Gorges Reservoir area has a long history of agricultural land reclamation activities, high population density, shortage of land resources, steep slopes, small and fragmented land plots, high reclamation rate and multiple cropping index, low soil erosion resistance, and serious soil erosion.

Entering the "post-Three Gorges" era, the research on soil and water conservation in the reservoir area is facing new requirements and challenges. The construction and operation of the Three Gorges Project and the resettlement of immigrants in the reservoir area have had and will have a significant impact on the ecosystem, surface processes and social economy of the reservoir area and the watershed; arable land is under unprecedented pressure. The resulting increasingly serious ecological and environmental problems, such as soil erosion and ecological environment degradation, have aroused widespread concern in the society and are becoming important research topics in the post-Three Gorges period.

There are many difficulties in implementing the slope-to-ladder project in the reservoir area. The labor cost is too high, the capital investment is large, and the renovation period is long; and the local mountains are high and steep, the surface is undulating, and the terrain is fragmented. The comprehensive slope terrace reconstruction project is in the reservoir area. Not suitable. The annual rainfall in the Three Gorges Reservoir area is concentrated from June to September, and soil erosion mainly occurs in several torrential rain events or heavy rain events. The local farming mode of digging ditches along the slope, ridging between ditches, and reciprocating up and down sowing has been implemented for a long time. The supporting cultivation along the slope with furrows and ridges on the whole slope resulted in too long water path on the slope surface, rapid water catchment, serious soil erosion on the slope surface and ridges and ridges, especially at the foot of the slope, and the ridges and ridges were eroded most violently, almost resulting in the exposure of purple parent rock. Therefore, the traditional farming method faces challenges such as serious soil erosion, loss of cultivated land assets, and high pressure on agricultural production increase; the local people also have the farming habit of picking sand and returning it to the field to avoid long-term soil erosion that causes thinning of the soil layer and barren soil , and even reduce agricultural production. Reciprocating all year round, a vicious cycle of "erosion-picking sand-erosion" has been formed.

At present, the pattern of sloping farmland in the reservoir area is basically fixed, and improving the farming mode of sloping farmland has become an effective method with simple operation, short cycle and obvious soil and water conservation benefits. Therefore, it is urgent to develop a water-conserving and erosion-reducing sloping farmland cultivation measure based on fully learning from local planting habits, so as to control slope soil erosion, prevent water and soil loss, reduce the sand-carrying rate of rivers in the reservoir area, and reduce water pollution in the reservoir area. load.

Contents of the invention

The purpose of the technology of the present invention is to provide a low-cost, easy-to-implement, and easy-to-promote technology that focuses on controlling the occurrence of rill erosion in sloping cultivated land, realizes the interception of surface runoff on slopes, promotes the in-situ deposition of silt, increases soil moisture, and "District field + hedgerow" slope compound farming mode and its structure for the purpose of soil cultivation.

The technical purpose of the present invention is achieved like this:

A compound farming model of field hedgerows and its structure, in which slope protection ridges (ridges) are set at the top of the upslope and at the foot of the downslope of the slope plot, which can be soil, gravel or a mixture of soil and gravel, designed It is a gravity-type permanent soil-retaining strong structure; the boundary of the plot is divided by the ridge, forming the outermost slope runoff structure of the slope plot, and providing a simple slope path for farmers to cultivate and walk in the field; the upper side of the ridge is The vertical surface and the lower slope surface are inclined surfaces, and plant hedges are planted on both sides of the ridge. Excavated drainage side ditches with a certain depth are set on the slope top, slope toe and left and right sides of the slope on the entire slope plot. The section is inverted and trapezoidal; several parallel intercepting ditches of equal height divide the slope plots to form slope farming plots with equal slope lengths, and ridges and ditches are built along the slope in each partition plot to form alternate cultivation of trenches and ridges on the transverse slope model. The configuration interval of interception ditch on the cross slope is twice the critical slope length of rill erosion on the actual cultivated slope. Down-slope drainage ditches, contour interception ditches and drainage side ditches together constitute the slope drainage network.

Ridge cropping field is a grid field or pit formed by ridges and ridges to intercept water and soil. The slope field structure is divided into two parts: a. Drainage along the slope and ditch field. The structure is designed to build horizontal ridges (hereinafter referred to as "district field ridges") at equal intervals from top to bottom in the ditch to form a series of transverse slopes. Retaining "wall", the distance between field ridges is inversely proportional to the slope; b Horizontal interception ditch field, the design position of field ridges is at the lower edge of the cultivated ridges along the slope (Figure 1). The structure and configuration principles of the field soil ridges in the districts are similar, and there are only differences in size: the cross-section design of the soil ridges are all inverted trapezoids with a wide top and a narrow bottom, and the structure size of the field soil ridges in the contour interception ditch area is larger than that in the drainage ditch area along the slope (Table 1); The field excavation depth in the contour intercepting ditch area can be appropriately increased, preferably 5-10cm deeper than the drainage ditch along the slope, which is proportional to the slope of the slope; the height of the field soil ridge in the drainage ditch area along the slope should be equal to the field surface It is advisable that the height of the field soil ridge in the intercepting ditch area of the contour level should be set at a height 5cm lower than the field surface.

Contour-height hedgerow configuration on the slope, as shown in Figure 1, the contour-level interception ditch cuts the plot into equal-slope-length farming plots, and the cross-slope in the middle of the farming unit between adjacent contour-level interception ditches is ridged. Open a farming area along the slope to form a small horizontal barrier ridge; the designed width of the ridge section is about 2/3 of that of the ridge cultivated along the slope, and the height of the ridge is set at the same level as the ridge cultivated along the slope, or it can be appropriately higher than that of the ridge cultivated along the slope. The ridge cultivated along the slope is about 5cm, and its height is proportional to the size of the slope. Soil and water conservation hedgerows are planted on the ridges on the slopes. The hedgerows can be perennial low-rooted crops (such as leeks), or seasonal food crops to alleviate the shortage of local cultivated land resources.

In the present invention, a "district field + plant hedge" compound farming mode and its structure are designed by matching the horizontal interception ditch on the slope surface, the ridge farming area along the slope, and the ridge plant hedge to form "one ditch, one ridge and one hedge" compound farming model on slopes.

The area of the Three Reservoirs has a large area of slope cultivated land, steep slope, and shortage of cultivated land resources; this area is located in the subtropical humid monsoon climate zone, and the rainfall is concentrated from June to September every year. The cultivated land suffers from serious water and soil erosion; in addition, the main cultivated soil in this area is shallow purple soil, which leads to serious water and soil erosion, reduced land fertility, and great pressure to increase agricultural production. The present invention fully considers the real conditions of high mountains and steep slopes in the region, and at the same time takes into account the farming habits of the local people for a long time, as well as the successful application experience of soil and water conservation measures for fields and ridges in ridge farming areas. The "district field + hedgerow" compound farming mode to control soil erosion on steep slopes in the reservoir area; on the basis of summarizing years of research experience in the occurrence and development of rill erosion on slopes, scientifically design the slope length of slope farming along slopes. . This farming mode is simple to operate, easy to implement, requires no external input, low cost, and easy to accept by farmers. It is of great significance to reduce soil erosion, control soil erosion, and protect regional cultivated land resources.

The beneficial effects of the present invention are:

1. Divide the land for easy farming.

In the design of a "district field + hedgerow" compound farming model, the side ditch for drainage on the slope, the ditch for drainage along the slope, and the interception ditch at the same height are connected to each other to form a complete cross-sectional drainage network, which can be quickly discharged from the surface in case of heavy rain. run-off. Secondly, setting up drainage ditches on the edge of the plot can remove the roots of weeds and nests of disease and insects on the edge of the plot and play a role in remote isolation. The horizontal interception ditch at the same height on the slope surface cuts the slope farmland into a number of farming units along the slope with equal lengths, which reduces the length of people’s slope cultivation. This structure fully combines the long-term farming habits of local people. It is more convenient to cultivate steep slopes along the slope, the length of the slope is shortened, and the labor intensity is low.

2. Block sand and accumulate soil, retain water and reduce erosion.

The field design of ridge cropping area plays a significant role in preventing soil erosion. The "district field + hedgerow" compound farming mode invented in this patent is different in the design of the district field, which is due to the fact that the area of slope farmland in the upper reaches of the Yangtze River is relatively large, and the area of steep slope farmland greater than 15 degrees is more . Therefore, the field soil ridge design in the area is higher and thicker, and the distance between the soil ridges is controlled within 50cm. The field longitudinal section of the unit area evolves from "flat straight line" → "U" type → "V" type as the slope increases. Such a design can effectively store precipitation, reduce the potential energy of rainwater on the slope, and promote the on-site deposition of sediment; the targeted configuration of the height of the fields in the drainage ditch area along the slope and the field ridge height in the intercepting ditch area at the same level can not only retain sand and store water, It can also eliminate excessive surface runoff, prevent waterlogging and erosion in ridges and ditches on slopes, and finally achieve the purpose of "water storage in light rain and sand retention in heavy rain" to control soil erosion.

3. Water storage and moisture conservation, ripe soil and fertilization.

The invention patent integrates the research and development of the compound farming mode of "sloping farmland ridge farming area + field ridge plant hedge". It is designed to dig deep the retaining ditch on the cross slope, plow and loosen the soil, and accelerate the weathering of purple parent rock into soil. Use "horizontal ridges + plant hedges" to cut off the runoff waterway on the slope, hinder and delay the water catchment on the slope, reduce the flow velocity, block the sand-carrying water flow layer by layer, and weaken the water energy; The water catchment path is too long, the slope confluence is strong, and the surface soil at the slope toe is severely eroded; at the same time, the hedgerow has the functions of canopy interception and root system soil consolidation, which also increases the shear resistance and scour resistance of the transverse slope ridge. Studies have shown that the "district field + hedgerow" compound farming mode takes into account the functions of controlling soil erosion and water storage and moisture conservation. When storing sediment, it promotes surface runoff and infiltration, increases soil moisture, and preserves water to form a soil "reservoir" to achieve the goal of water regulation and moisture conservation. and further reduce the long-term labor burden of "carrying sand back to the field" of local people.

4. The operation is simple, the counterfeiting is cheap, and it is good for promotion.

The three main structural units in the "district field + plant hedge" compound farming mode designed by the present invention are: slope water system, ridge farming area field and contour hedgerow, which are based on a large number of field investigations and fully combined with the local people's many years of farming habits and planting method based on a comprehensive induction. The design is simple and easy for farmers to master; there is no additional input and the cost is low. Several typical sloping land utilization methods in the Three Gorges Reservoir area at present, that is, large-area steep-slope terraced fields and small-area steep-slope horizontal terraces are applicable, and can be promoted on a large scale.

Description of drawings

Fig. 1 is the overall effect diagram of the field hedgerow farming mode and its structural slope of the present invention.

Fig. 2 is a schematic diagram of a longitudinal section along line I-I in Fig. 1 (sloping terraced field is an example).

Fig. 3 is a partial top projection view of the field hedgerow farming mode and its structural slope effect of the present invention.

Fig. 4 is a schematic cross-section along the line II-II of Fig. 3 showing the structure of the drainage ditches along the slope and the soil ridges in the district fields.

Fig. 5 is a schematic diagram of the field soil ridge structure along the III-III line longitudinal section in Fig. 3 .

detailed description

See Fig. 1 and Fig. 2, a kind of compound farming mode of "field hedgerow".

Figures 1 and 2 are the overall effect of the slope and the longitudinal section effect of the "district field + hedgerow" farming mode. The meanings of the symbols are: cultivated ridge along the slope (A), ridge hedgerow (B), sloping field surface (C), consolidated ridge at the edge of the plot (D), contour interception ditch (E), Field ridge (E ₁ ) in the contour interception ditch area, along-slope drainage ditch (F), field ridge in the down-slope drainage ditch area (F ₁ ), slope drainage side ditch (G), longitudinal section schematic line (I), Slope length (LS) of cultivated land on down slope.

①Water system layout on the slope. Permanent slope protection ridges (D) are set on the upper and lower edges of the slope plot. The upper side of the ridge is a vertical surface and the lower side is a slope surface. The slope is between 60-80 degrees. The outer side of the ridge and the slope surface Drainage ditches (G) are excavated on the left and right sides of the block, and are connected with each other to form a slope drainage ditch; inside the slope block, excavate a contour interception ditch (E) at the same interval (2LS) from top to bottom , and divide the slope land into several equal-length farming plots, excavate the down-slope drainage ditches (F) in the down-slope direction in each farming plot, and build the cultivated land ridges (A), the down-slope drainage ditches and the contour The retention ditches are connected and connected with the slope drainage side ditch to form a complete slope drainage network. ② Ridge farming area field design. Build the field ridge (F ₁ ) in the drainage ditch area along the slope and the field (E ₁ ) in the horizontal interception ditch area at a certain interval in the drainage ditch along the slope and the interception ditch at the contour, respectively, to form the ridge farming area along the slope and across the slope Fields, district field soil ridges need to be compacted. ③ Contour ridge plant hedges. Build a cross-slope blocking ridge along the middle part of the farming plot between two adjacent contour intercepting ditch, and plant a hedgerow with higher soil and water conservation benefits on the ridge to form a cross-slope contour ridge (B). Ridge length (LS) is the critical slope length for rill erosion at the corresponding slope.

Referring to Fig. 4 and Fig. 5, the structural parameters of a field hedgerow compound farming mode.

Figures 4 and 5 are respectively the detailed structural technical parameters of the slope drainage ditches and field ridges along the II-II and III-III lines in Figure 3, wherein the structural technical parameters represented by each symbol are respectively: the width of the bottom of the ridge (W ₁ ), the width of the ridge on the whole field (W ₂ ), the top width of the cross-section of the field ridge in the district (w ₁ ), the bottom width of the cross slope of the field ridge in the district (w ₂ ), the depth of the ridge below the field surface (H ₁ ), and the land above the field surface Ridge height (H ₂ ); top width (w ₃ ) of the longitudinal section of the field ridge, bottom width of the longitudinal section of the field ridge (w ₄ ), height of the ridge (h ₁ ), and distance between the bottom of the ridge (S).

The overall design of the field soil ridge in the area is an inverted trapezoid in the horizontal direction and a positive trapezoid in the vertical direction along the slope. The soil ridge is excavated and built on the slope surface in the ditch, and the soil ridge needs to be compacted; the design height of the field soil ridge in the drainage ditch area along the slope is flush with the field surface, etc. The design height of the field soil ridge in the high-ridge intercepting ditch area is preferably 5cm lower than the field surface, and the depth is 5-10cm greater than the drainage ditch along the slope; the field spacing is inversely proportional to the slope, and the height of the field soil ridge is proportional to the slope. As the slope increases, it evolves from "flat straight line" → "U" type → "V" type. The structural section of the ridge cultivated along the slope is in an inverted "U" shape, and the width of the ridge above the level of the field shrinks rapidly; the designed width of the ridge profile of the contoured plant fence is about 2/3 of that of the ridge cultivated along the slope, and the design height is greater than that of the cultivated ridge The height is 5-10cm, and the hedge configuration can be perennial, low, root-intensive crops (such as leeks), or seasonal food crops to alleviate the shortage of local cultivated land resources.

Relying on the Soil and Water Conservation and Environment Research Station of the Three Gorges Reservoir Area of the Chinese Academy of Sciences, we have carried out long-term field research and experimental research on the benefits of water and soil conservation. Integrating the key technologies for the control of rill erosion on part of the slope farmland, fully considering the planting habits of the local people on the slope farmland, on this basis, developed the "district field + hedgerow" compound farming model and its build technology. This technology forms the field pattern of the ridge farming area by digging the intercepting ditches at the same height, shallow drainage ditches along the slope, and building "field soil ridges" in the ditch; constructing horizontal ridges in the middle of the down-slope farming unit, and configuring plant hedges. together to achieve the goal of soil erosion control. And obtained the empirical value of the technical parameters of the "district field + hedgerow" farming model construction (see Table 1).

Table 1 Technical parameters for the construction of the "district field + hedgerow" model

Claims (3)

1. a kind of area field plant hedge is combined the methods of cultivation, it is characterised in that at the top of domatic plot is gone up a slope, descending foot setting shield The hillside fields ridge（D）, the gravity-type for being designed as soil, rubble or soil plus rubble mixed materials forever keeps off native competent structure；Drawn with field bund Point boundary of land block, forms domatic plot outermost and retains slope runoff construction, and provides and a kind of facilitate peasant field to cultivate walking Simple domatic path；Field bund upside for vertical plane, lower side slope be inclined plane, equal planting plants hedge inside and outside field bund； The outside of bank protection field bund and the domatic plot left and right sides arrange the excavation gutter of certain depth（G）；Inside domatic plot with Same intervals build contour level ditch of runoff harvesting（E）, contour level ditch of runoff harvesting cross section is trapezoidal in shape；Some parallel contour water Flat intercepting drain splits the domatic farming cell of the lengths of grade such as domatic plot, formation, makees ground along hill start straight plowing in each farming cell Ridge（A）And digging is built along slope furrow drain（F）, form the alternate tillage system reform in ditch ridge；Contour level ditch of runoff harvesting configuration space is actual There is critical plane method in farming Rill Erosion（LS）2 times；It is common along slope furrow drain, contour level ditch of runoff harvesting and gutter With composition slope drainage network；It is the lattice field or hole interception water and soil formed with alley plus furrow ridge that domatic ridge tillage and pitting field builds Construction, be divided into two large divisions：A is built at equal intervals laterally along slope draining from top to down along slope furrow drain area field in furrow The furrow area field low bank of earth between fields（F₁）, a lot of horizontal wall inscription gear soil " wall " is formed, area field low bank of earth between fields spacing size is inversely proportional to the gradient；The high water such as b Flat intercepting drain area field, the contour level ditch of runoff harvesting area field low bank of earth between fields（E₁）Design attitude makees alley lower edge in each straight plowing；Liang Zhong areas field It is similar that the low bank of earth between fields constructs and configure principle, cross section design be top width bottom it is narrow fall shape it is trapezoidal, vertical section design is the narrow bottom width in top Trapezoid；Contour level ditch of runoff harvesting area field low bank of earth between fields construction size is 1.5 times of suitable slope furrow drain area field low banks of earth between fields, waits high level to cut Stream ditch cutting depth is more than along slope furrow drain depth（H₁）5-10 cm, and with the gradient increase and deepen；Along slope furrow drain area The rational height of the field low bank of earth between fields flushes field face, and contour level ditch of runoff harvesting area field low bank of earth between fields rational height should be less than the cm of field face 5.

2. a kind of area field plant hedge according to claim 1 is combined the methods of cultivation, it is characterised in that domatic contour ground ridge-planting Thing hedge（B）Configuration mode is as follows：With lengths of grade such as contour level ditch of runoff harvesting cutting plot formation（2LS）Farming cell, adjacent Cultivating unit middle part horizontal wall inscription ridging between contour level ditch of runoff harvesting, forms a small-sized domatic field bund of laterally blocking；Field bund section sets Count width and make the 2/3 of alley width for straight plowing, ridge high setting is flushed with straight plowing as alley, or be higher by straight plowing and make alley 5cm or so, it is highly directly proportional to gradient size；Water is planted on horizontal wall inscription alley and protects plant hedge, plant hedge configuration can be perennial Short heave root system crop, or be this season cereal crops alleviating local cultivated land resource contradiction in short supply.

3. a kind of structure of the compound methods of cultivation of area field as claimed in claim 1 or 2 plant hedge is realized, it is characterised in that by Contour level ditch of runoff harvesting（E）, straight plowing make alley（A）And field bund plant hedge（B）Composition, constitutes the slope of " hedge of one ridge of a ditch one " The compound farming structure in arable land.