CN102242543A - Water conservancy system for preventing and treating soil secondary salinization in greenhouses in coastal region - Google Patents

Abstract

The invention relates to soil salinization prevention technology, in particular, the invention relates to soil salinization prevention technology in multi-span greenhouses. A water conservancy system for the prevention and control of secondary salinization of soil in multi-span greenhouses in coastal areas, which includes: ditches are arranged in each facility greenhouse; rainwater collection pipes outside the facility greenhouses are all connected to a general water collection pipe; the general water collection pipe The ditch is connected to send rainwater into the ditch. The invention can conveniently and effectively delay or prevent secondary salinization of facility soil.

Description

A water conservancy system for the prevention and control of secondary salinization of soil in multi-span greenhouses in coastal areas

technical field

The invention relates to soil salinization prevention technology, in particular, the invention relates to a multi-span greenhouse soil secondary salinization prevention technology.

Background technique

Because protected cultivation can artificially control the conditions, thereby speeding up the growth of crops, increasing the yield of crops, and at the same time realizing all-weather, annual production, etc., protected cultivation has become an important mode of vegetable and fruit production in the world. However, due to being covered by greenhouses or greenhouses all year round, the water balance in the soil is different from that in the open-air cultivation mode, causing the salt and mineral nutrients in the lower soil to rise to the surface with the capillary, causing secondary salinization of the soil, and the decrease in soil salt content. Accumulation will cause the concentration of soil solution to be too high, causing "physiological drought" of crops, just like the "water shortage and drought" of crops caused by low soil moisture content, physiological drought will also cause crop yield reduction or even death. Therefore, the secondary salinization of facility soil has become an important obstacle to the sustainable development of facility agriculture.

At present, there are many measures for the prevention and control of secondary salinization of soil in multi-span greenhouses. Taking water conservancy measures as an example, they include: ① store light and compressed salt, and store precipitation around the greenhouse to promote soil desalination; Large-scale irrigation, flushing and leaching soil salt, and draining the irrigation area through the drainage system; ③ Drainage reduces the groundwater level to an appropriate depth. The commonly used drainage methods include open ditch drainage, hidden pipe drainage, and shaft drainage; Isolation layer and seepage pipe to discharge salt; ⑤ Combined use of surface water and groundwater, etc.

However, there are more or less disadvantages in these measures. To store desalination and pressure salt, it is necessary to build a special reservoir around the greenhouse. In addition, it is necessary to spend a lot of manpower, material resources and financial resources to dig a large hole to lower the guest soil, and to set up an isolation layer and a seepage pipe to discharge salt at the bottom, and it is impossible to achieve the desired effect. Although various methods can achieve certain effects, the "salt return" of greenhouse soil is highly repetitive, and the treatment and prevention of secondary salinization are not long-term, and it is difficult to fundamentally delay or prevent soil secondary salinization in facility greenhouses. Salinization problem.

Contents of the invention

The present invention aims to solve the above-mentioned defects, and provides a water conservancy system for preventing and controlling secondary salinization of soil in multi-span greenhouses in coastal areas. The invention conveniently and effectively delays the secondary salinization of facility soil, and further prevents the secondary salinization of soil.

The present invention is achieved like this,

A water conservancy system for the prevention and control of soil secondary salinization in multi-span greenhouses in coastal areas, which includes;

Ditches set up in facility greenhouses;

Freshwater collection pipes outside the facility shed to collect rainwater, all of which are connected to a single header;

The main water collecting pipe communicates with the ditch to send fresh water into the ditch.

The water conservancy system for the prevention and control of secondary salinization of soil in multi-span greenhouses in the coastal area also includes a buffer pool arranged outside the greenhouses, the buffer pool is provided with an inlet connected to the water collection main pipe, and a connection outlet of the ditch, and an overflow.

In the water conservancy system for the prevention and control of secondary salinization of soil in multi-span greenhouses in coastal areas, a float valve is provided at the overflow of the buffer pool.

In the water conservancy system for the prevention and control of secondary salinization of soil in multi-span greenhouses in the coastal area, the cross section of the ditch is an inverted trapezoid whose top side is wider than the bottom side, and its two sides are covered with sand Slate or non-woven fabric, the upper opening is covered with a removable cement slab for walking.

In the water conservancy system for the prevention and control of secondary salinization of soil in multi-span greenhouses in coastal areas, a ball float valve is arranged at the entrance of the ditch.

The water conservancy transformation method provided by the present invention is applicable to the prevention and treatment of secondary salinization of soil in multi-span greenhouses in coastal areas (shallow groundwater level). By digging water channels in the greenhouses, the water level in the water channels can be maintained at 80cm ± 5cm to ensure plowing. The source of soil moisture below the top layer replenishes the water lost due to surface evaporation. At the same time, based on the principle of osmosis, it promotes the balance between the salt in the soil and the salt in the water in the canal. In addition, arrange gaps between crop stubbles in summer to provide large amounts of fresh water for irrigation. , reduce soil salinity, then drain regularly. Therefore, it is convenient and effective to delay the secondary salinization of the facility soil, and then prevent the secondary salinization of the soil.

Description of drawings

Below, the present invention will be further described in conjunction with accompanying drawing:

Fig. 1 is the hydraulic system schematic diagram of the present invention;

Fig. 2 is a sectional view of A-A in Fig. 1 .

Detailed ways

Please refer to Fig. 1 and Fig. 2, the present invention is realized in this way: a kind of water conservancy system for the prevention and treatment of secondary salinization of multi-span greenhouse soil in coastal areas, it comprises;

The ditch 4 arranged in the facility greenhouse 1; the cross section of the ditch 4 is an inverted trapezoid with a top edge wider than the bottom edge, the hypotenuses on both sides are covered with sandstone boards 42 (or non-woven fabrics), and the upper opening is covered with a Removed cement slab 5 for walking.

The fresh water collection pipe 21 for collecting rainwater outside the facility greenhouse 1, they are all connected to a main water collection pipe 2;

The main water collecting pipe 2 communicates with the ditch 4 to send fresh water into the ditch 4 .

The water conservancy system for the prevention and control of secondary salinization of soil in multi-span greenhouses in the coastal area also includes a buffer pool 3 arranged outside the greenhouse 1, and the buffer pool 3 is provided with an inlet connected to the water collection main pipe 2 , an outlet connecting the ditch 4 and an overflow. A float valve 31, 41 is provided at the entrance of the ditch 4 and the overflow of the buffer tank 3 respectively.

Below is a specific embodiment of the present invention:

In a multi-span greenhouse of a horticultural field, water conservancy transformation is carried out according to the present invention. The underground water level of the horticultural site is buried at a depth of 1.5m±0.3m, and the average annual rainfall is 1062 mm, and the annual rainy days are about 133 days, with abundant rainfall.

Layout of fresh water collection pipes 21: According to the structure of the multi-span greenhouse 1, fresh water collection pipes 21 are arranged in the middle of the greenhouse 1 or on the edges around them. The inner diameter of the fresh water collection pipes 21 is 6 cm, and the fresh water collection pipes 21 are connected to drain rainwater. To the buffer pool 3 outside the facility greenhouse 1.

The structure of the buffer pool 3: on the premise of not hindering the transportation of materials into the greenhouse, the best assembly position of the rainwater collection pipe 21 is selected to build the buffer pool, and the rainwater collection pipes 21 can be collected into one main water collection pipe 2 and then passed into The buffer pool 3, the buffer pool 3 is 8 meters long, 5 meters wide, and 2 meters high. Connect to the overflow. Respectively install a water control valve 31,41 on these 2 pipelines simultaneously.

"Trapezoidal" canal: the upper bottom of the canal (cross section) is 1.8m, the lower bottom is 1.0m, and the depth is 1.5m; the inner wall of the canal is piled up with sandstone slabs 42 with good water permeability, and the water level in the canal is usually maintained at 80cm±5cm. It can be used as irrigation water. In seasons with little rain, lead fresh water into the canal, and change the water once a month at the same time. In summer, the stubble is arranged in the middle, flooded with flood water, washed with salt, and then drained. Cover movable cement board 5 above the water channel, be convenient to walk.

After 3 years of implementation, the trend of soil salinization in the facilities has been effectively curbed, and the changes in salinity in the soil are shown in Table 1:

Table 1 Effect of water conservancy improvement on soil salinity in facility greenhouses

After the water conservancy improvement, the total amount of soluble salt in the soil of the facilities decreased to 0.19% year by year. According to the "Soil Salinization Grading Index" (Wang Zunqin et al., 1993), the soil is mildly salinized. Under this condition, the vast majority of plants can be normal. grow.

The water conservancy transformation of multi-span greenhouses, combined with related facility crop fertilizer and water control, facility soil remediation and improvement technologies, can greatly slow down the speed of secondary salinization of the soil, and finally achieve effective prevention and control.

Claims (5)

1. A water conservancy system for preventing and controlling secondary salinization of multi-span greenhouse soil in coastal areas, characterized in that it comprises; Ditches set up in facility greenhouses; Freshwater collection pipes outside the facility shed to collect rainwater, all of which are connected to a single header; The main water collecting pipe communicates with the ditch to send fresh water into the ditch. 2. The water conservancy system for the prevention and treatment of secondary salinization of soil in a multi-span greenhouse in a coastal area according to claim 1, is characterized in that it also includes a buffer pool arranged outside the greenhouse, and the buffer pool is provided with a An inlet connected to the water main, an outlet connected to the ditch and an overflow. 3. The water conservancy system for the prevention and control of secondary salinization of soil in multi-span greenhouses in coastal areas according to claim 2, wherein a float valve is provided at the overflow of the buffer pool. 4. The water conservancy system for the prevention and treatment of secondary salinization of soil in multi-span greenhouses in coastal areas according to claim 1, wherein the cross section of the ditch is an inverted trapezoid whose top side is wider than the bottom side , its two side slopes are covered with sandstone boards or non-woven fabrics, and the upper opening is covered with removable cement boards for walking. 5 . The water conservancy system for the prevention and control of secondary salinization of soil in multi-span greenhouses in coastal areas according to claim 1 , wherein a ball float valve is provided at the entrance of the ditch.

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