CN110326470A - It is a kind of for varieties in saline-alkali areas vegetables production collection rain every salt form heliogreenhouse - Google Patents

Abstract

The invention provides a rain-collecting and salt-isolation solar greenhouse for vegetable production in saline-alkaline areas. The greenhouse in the invention includes a front wall and a back wall, and a greenhouse film is arranged between the front wall and the back wall. A skylight device is provided on the top of the rear wall, and the skylight device is connected with the valgus movable rear slope, and a triangular support is fixed on the rear wall; an inclined soil slope is provided on the outer side of the front wall, and the inclined soil slope and the Water storage grooves are arranged between the front walls; rainwater collection pipes are arranged on the rear wall; water collection pipes are arranged underground in the greenhouse. The rain-collecting and salt-separating solar greenhouse disclosed by the invention can simultaneously realize fresh water supply and in-situ soil effective utilization, and combine rain-collecting technology and salt-reducing technology to form an integrated technical system, which is convenient and effective. The invention discloses a movable rear slope design, which has the advantages of being able to collect rain, being convenient to open, reducing humidity in the greenhouse, and not affecting normal vegetable production.

Description

A rain-collecting and salt-separating solar greenhouse for vegetable production in saline-alkaline areas

technical field

The invention belongs to the technical field of agricultural production, and in particular relates to a rain-collecting and salt-isolation solar greenhouse used for vegetable production in saline-alkali areas.

Background technique

Land resources are the foundation of agricultural production, but soil salinization limits the efficient development of agriculture and the effective use of land resources. In my country, saline-alkali land is widely distributed, especially in coastal cities and islands, where the saline-alkali land is huge, and the soil has high salinity, which makes it impossible to grow a series of agricultural products such as vegetables and fruits with high output value. At present, traditional solar greenhouses are mainly used in saline-alkali land, and vegetables are produced after the soil is improved. The back slope is a fixed brick wall structure, which cannot be rotated or opened. In addition, the phenomenon of saline-alkali corrosion of the structure of agricultural facilities is very serious, and the firmness and safety of the facilities cannot be guaranteed. At the same time, most of the saline-alkali areas have problems of uneven distribution of water resources and lack of fresh water for irrigation. As a result, fresh fruits and vegetables in saline-alkaline areas can only be supplied by transportation from other places, while the shortage of local high-quality products has formed a structural contradiction in the supply of fruit and vegetable products. In order to meet people's demand for the quality level of fruits and vegetables, it has become a mainstream trend to produce and supply fresh and live products that are not resistant to storage and transportation. In order to solve the problems of soil salt damage and fresh water shortage in coastal saline-alkali areas, the following researches have been mainly carried out so far:

1. Solve the problem of soil salt damage

Aiming at the problem of high salinity in soil in saline-alkaline areas, it was found that setting up a salt barrier in the soil can break the soil structure, affect the capillary system, change the trajectory of water and salt migration, and effectively inhibit the soil from returning to salt. The use of plastic film mulching, straw mulching, sand and gravel mulching, and compound organic material mulching can improve the hydrothermal state of the cultivated layer soil, increase water retention capacity, and reduce surface evaporation, thereby achieving the effect of inhibiting salt migration and increasing yield. However, the application of this method has high costs such as material costs, transportation costs for salt-isolated materials, and a large amount of human labor.

The underground pipe salt drainage technology is also mostly used to reduce salt in saline-alkali soil. By laying underground pipes, when flushing saline-alkali soil, the speed of salt washing can be accelerated, so that high-saline soil can be melted smoothly. However, in this method, there are serious problems of soil salt return and re-migration of salt in the later stage. Therefore, it is difficult to reduce soil salinity only by using the underground pipe salt drainage technology alone.

2. Solve the problem of fresh water shortage

The total amount of water resources in China is rich, about 2.8 trillion m ³ , ranking sixth in the world. However, due to the large population in China, the per capita water resource allocation is small, which is only 28% of the world's per capita water resources, ranking 125th in the world. According to the statistics of relevant departments, China's current water shortage is 40 billion m ³ , which is a serious water shortage and should be highly valued by the people of our country.

In the case of the overall shortage of water resources in China, the water used for agricultural irrigation is correspondingly reduced or even insufficient. If you rely solely on tap water to irrigate farmland, the cost is relatively expensive. According to the water supply price issued by the Qingdao Municipal Price Bureau, the water consumption per cubic meter will increase to 2.5-7 yuan per cubic meter. Not equal; groundwater exploitation is one of the methods to solve the problem of water use, but it is limited by resource conditions, and its exploitation must comply with the corresponding rules and regulations. However, over the years, over-exploitation has led to poor water quality and poor ecological environment; seawater desalination technology, It is an open-source incremental technology to realize the utilization of water resources, but high cost has always been the key factor limiting its popularization and application. Currently, the cost of seawater desalination in China is about 4-8 yuan/m ³ . Therefore, building water cellars and storage tanks to collect natural rainwater is an important measure to solve such problems.

Contents of the invention

The object of the present invention is to provide a rain-collecting and salt-isolation solar greenhouse for vegetable production in saline-alkaline areas, which combines the design of the rain-collecting structure of the solar greenhouse, the design of the soil-salt-isolation structure, and the research on salt-reduction technology, and collects fresh water, isolates soil The exchange of salt between layers, the use of fresh water for leaching, and the reduction of soil salt content in the plow layer are integrated to form a set of comprehensive technology models. At the same time, fresh water supply and effective use of in-situ soil are realized. The problem of unequal distribution of fresh water resources provides a new solution to normalize the soil of facilities in saline-alkali areas and ensure the effect of unrestricted conventional growth of crops, so as to solve the problems raised in the above-mentioned background technology.

In order to achieve the above-mentioned purpose of the invention, the present invention adopts the following technical solutions to achieve:

A rain-collecting and salt-isolation solar greenhouse for vegetable production in saline-alkaline areas, the greenhouse includes a front wall and a rear wall, a greenhouse film is arranged between the front wall and the rear wall, and a skylight is arranged at the top of the rear wall device, the skylight device is connected with the valgus movable rear slope, and a triangular support is fixed on the rear wall; an inclined soil slope is provided on the outside of the front wall, and a A water storage groove; a rainwater collection pipe is provided on the rear wall; a water collection pipe is provided underground in the greenhouse, and the water storage groove and the rainwater collection pipe are connected to the underground reservoir in the center of the greenhouse through the water collection pipe; The soil surface in the greenhouse is provided with a slope from the back wall to the front wall, the soil surface is provided with a salt barrier plate, and the salt barrier plate is provided with a salt discharge pipe, and the salt discharge pipe is excavated. buried in the upper layer of soil.

Further, the triangular support includes an internal support and an external support, the upper end of the internal support is connected to the greenhouse film, the upper end of the external support is used to support the opened movable back slope, and the lower end of the internal support and the external support are fixed Set in the middle of the back wall.

Further, a reinforcement stack is provided under each set of triangular supports, and one end of the reinforcement stack is fixed on the ground, and the other end of the reinforcement stack withstands the external support.

Further, the back slope of the eversion activity adopts a board with a layer of color steel tile board superimposed on the PC board.

Further, a drainage pipe is provided on the inside of the front wall, and the drainage pipe communicates with the brine well, and a soil retaining board is arranged between the salt discharge hidden pipe, the upper soil and the drainage pipe.

Further, a water pump is provided at the bottom of the water outlet area of the water storage tank, and a filter net is provided around the water outlet of the water storage tank and the water pump.

Further, the shape of the inclined soil slope is a right-angled triangular prism, and the length of the sloped soil slope is the same as that of the front wall, and the width is 2 to 5 meters. The slope at one end is 4%~6%.

Further, the distance between the salt-separating board and the ground surface is 50-70 cm, and the salt-separating board is spliced by XPS boards.

Further, the salt discharge concealed pipe is a polyvinyl chloride corrugated pipe, the diameter of the polyvinyl chloride corrugated pipe is 100-120mm, the aperture of the hole on the polyvinyl chloride corrugated pipe is 18-20mm, and the hole distance 150~170mm.

Further, a truss is fixed on the top of the rear wall, and the skylight device is fixed on the truss.

Further, the inclined soil slope is covered with a plastic film.

Further, a filtering device is set up in the center of the reservoir.

Compared with the prior art, the advantages and positive effects of the present invention are: Based on the obvious problems of lack of fresh water for irrigation and high salt content in the soil in saline-alkali areas, the present invention designs a new type of solar greenhouse structure, that is, a rain-collecting and salt-isolation solar greenhouse , covering the comprehensive technical methods of collecting fresh water, isolating the exchange of salt between soil layers, and using fresh water leaching to reduce the salt content of plow layer soil. The structure design and application of the rain-collecting and salt-separating solar greenhouse include three aspects: the design of the rain-collecting structure of the greenhouse, the design of the salt-separating structure of the greenhouse, and the method for reducing salinity and alkalinity in saline-alkali soil in situ. Using this design method, the two purposes of fresh water supply and in-situ soil salinity reduction can be realized simultaneously, and the rain collection technology and the salt reduction technology can be combined to form an integrated technical system, which is convenient and effective.

(1) The rain-collecting and salt-separating solar greenhouse disclosed by the present invention can realize the two purposes of fresh water supply and in-situ soil effective utilization at the same time, and combines rain collecting technology and salt reduction technology to form an integrated technical system, which is convenient and effective. By washing salt and separating salt, the soil EC of the plow layer can be reduced to below 3ms.cm ^-1 , and vegetable production can be carried out.

(2) The design of the slope behind the activity has the advantages of collecting rain, being convenient to open, reducing the humidity in the greenhouse, and not affecting the normal vegetable production. In the period of high temperature and high humidity, opening the active back slope can promote the ventilation of the greenhouse, increase the ventilation area, and promote gas exchange. In particular, the soil can quickly return to normal soil moisture after irrigation and reduce the occurrence of pests and diseases.

(3) Original soil cultivation. Different from soilless cultivation technology, it does not use cultivation substrate, but uses saline-alkali in-situ soil to reduce costs and improve land utilization. The design of the salt barrier structure is used in conjunction with the salt drainage technology of the hidden pipe to reduce the salt content of the soil to a normal range, so that vegetables, fruits and other agricultural products can be cultivated normally.

Description of drawings

Fig. 1 is the structural representation of rain-collecting and salt-isolation type solar greenhouse of the present invention;

Fig. 2 is a side view of the rain-collecting and salt-isolation solar greenhouse according to the present invention;

Fig. 3 is a schematic diagram of the rear slope structure of the rain-collecting and salt-isolation type solar greenhouse according to the present invention;

Fig. 4 is a structural schematic diagram of a fully open roof-turning skylight device for a greenhouse according to the present invention;

Fig. 5 is a structural schematic diagram of the rain collection structure design of the present invention;

Fig. 6 is a schematic structural view of the reservoir of the present invention;

Fig. 7 is a schematic diagram of the rainwater accumulation flow according to the present invention;

Fig. 8 is the structural representation of the design of the salt barrier structure of the present invention;

Fig. 9 is a design and layout diagram of the salt discharge underground pipe according to the present invention;

Fig. 10 is a schematic diagram of the brine flow according to the present invention;

Among them, 1 is a rainwater collection pipe, 2 is a water storage tank, 201 is a water inlet pipe, 202 is an outlet pipe, 203 is a filter device, 3 is an inclined soil slope, 4 is a salt discharge hidden pipe, 5 is a soil retaining plate, and 6 is a collector. Water pipeline, 7 is a salt water well, 8 is a water control valve, 9 is a drainage pipe, 10 is a water pump, 11 is a salt barrier, 12 is a walkway, 13 is a crop layer, 14 is an active back slope, 15 is a triangular support, 151 is an internal support, 152 is an external support, 16 is a reinforced stack, 17 is a greenhouse full-opening roof-turning skylight device, 171 is a gear, 172 is a rack, 173 is a worm gear reducer, 174 is a gear motor, and 175 is the main Transmission shaft, 176 is connecting rod transmission shaft, 177 universal joints, 178 is torque distributor, 18 is rear wall, 19 is front wall, 20 is water storage groove, and 21 is greenhouse film.

Detailed ways

The technical solutions of the present invention will be further described in detail below in conjunction with specific embodiments.

Example 1 A rain-collecting and salt-separating solar greenhouse for vegetable production in saline-alkaline areas

The rain-collecting and salt-isolation type solar greenhouse used for vegetable production in saline-alkali areas provided by this embodiment, as shown in Figure 2, the greenhouse includes a front wall 19, a rear wall 18 and a greenhouse film 21, and the front wall 19 is located in the south Side, the rear wall 18 is located on the north side, as shown in Figure 2, the south and north directions described in the embodiment of this specification and the accompanying drawings of the specification are consistent with the south and north directions marked in Figure 2 . The structural design of the solar greenhouse includes the design of the rain-collecting structure of the greenhouse and the design of the soil-salt isolation and salt-reduction structure of the greenhouse.

1. Design of greenhouse rain collection structure

The purpose is to flush the in-situ saline-alkali soil with fresh water to reduce the salt content to meet the needs of vegetable growth. Due to the high cost of running water, the rear slope of the greenhouse is designed as a movable outward structure, so as to expand the rain collection area and increase the rain storage capacity. Horizontal and vertical rainwater collection pipes 1 are set up on the back wall 18 of the greenhouse, and the movable rear slope 14 is opened, and rainwater flows into the underground storage tank 2 along the rainwater collection pipe 1, and is used for soil washing salt water or agricultural irrigation water. In addition, the opening of the slope 14 behind the greenhouse can also promote indoor ventilation, avoid the high temperature and high humidity cultivation environment, and reduce the occurrence of diseases and insect pests (as shown in Figure 1). At the same time, there are three rain collection modes in the design activities: the back slope rain collection, the front roof rain collection and the inclined soil slope rain collection. The rainwater passes through the water collection pipe 6 and collects rainwater in three ways (as shown in Figure 2).

(1) Slope rain collection mode after the event

①The back slope of the activity

The material selection of the movable back slope 14 adopts the combination of PC board and color steel tile board, which is beneficial to standardized engineering construction. The light transmittance of the PC board is high, and its light transmittance can reach up to 89%. Compared with the cement back slope, it provides a good light environment for crop growth and fully meets the lighting needs of crop growth. In addition, PC board is light and high-strength, with a density of 1.18-1.22g/cm ³ , and its impact resistance is 250-300 times that of glass; it has strong anti-aging performance, and the loss of light transmission after 10 years is only 6%. The present invention selects a conventional PC board with a thickness of 8mm as the movable back slope 14. In order to prevent the PC material from being too thin, and there will be gaps at the junction with the wall and the front roof, the insulation performance of the solar greenhouse cannot be guaranteed when the vegetables are overwintered. A layer of color steel tiles is superimposed on the board to ensure that the indoor temperature meets the needs of crop growth.

The color steel tile has high strength and low thermal conductivity, λ≤0.041w/mk, which can effectively maintain the indoor temperature; the density is 1.0-1.4g/cm3, and the weight is equivalent to 1/30 of the brick wall. Based on the characteristics of good thermal insulation performance, light weight and easy installation, the color steel tile board is very suitable as a superimposed movable board. The present invention utilizes 840-type color steel tiles, the thickness of which is 0.8mm, and the length and width are determined according to the actual conditions of the greenhouse, and are often used as roof waterproof building materials. The combined load of the PC plate and the color steel tile plate is less than the weight of the load carried by the back wall 18 of the solar greenhouse.

The active back slope 14 of the solar greenhouse is designed based on the idea of collecting rainwater during the summer rainfall period and alleviating the indoor temperature and humidity during the high temperature and hot summer period. It is mainly used for rain collection or high temperature heat dissipation in summer. The advantage is that it is easy to move and bears less weight. During winter production in Shandong Province, in case the temperature cannot meet the growth of crops, thermal insulation curtains or heating facilities can be added inside the greenhouse to increase the temperature. In the season when no heat preservation is required, only PC boards can be used as the material of the movable back slope 14, which can reduce the shading of the original brick wall and increase the light.

The design of slope 14 behind the activity is one of the core structures of the solar greenhouse rain collection model design. The present invention designs the rear slope of the greenhouse as a movable valgus form (as shown in Figure 3), and utilizes the existing greenhouse full-open roof valgus skylight device 17 to realize the opening of the movable rear slope 14 (as shown in Figure 4), and the bottom of the valgus movable rear slope 14 The end is connected with the eversion skylight device 17 on the fully open roof of the greenhouse, and the gear motor 174 drives the gear 171 to rotate. Flip out 120°. Simultaneously for guaranteeing the stability of greenhouse, the triangular support 15 of steel structure is set up at back wall 18, can fully stand against on the triangular support 15 after the movable rear slope 14 is opened. In case of bad weather (strong wind), the active rear slope is not opened; in high temperature or rainy periods, the active rear slope 14 is opened to collect rainwater and promote ventilation.

②Window opening system

The design of the movable rear slope 14 of the present invention adopts the currently commonly used roof-turning sunroof device 17 (as shown in Figure 4) for greenhouses with fully open roofs, which has weak window opening resistance and high transmission stability. Considering the load-bearing of the back wall 18 of the greenhouse and the safety and stability of the entire solar greenhouse, the present invention adopts the existing torque distribution continuous window opening system, and the number of motors used is small and the use economy is high.

According to the research, the active rear slope 14 is mainly affected by the weight of the rear slope, the wind force and other factors during the opening and closing process. In this case, factors such as the force situation and the transmission load are less than the load bearing capacity of the greenhouse itself, and the power, quantity and position of the geared motor 174 meet the needs when the active rear slope 14 is opened and closed.

A steel structure truss is fixedly arranged every 10-15 meters in the east-west direction of the greenhouse, and the truss is fixedly arranged on the top of the rear wall 18 of the greenhouse, and the truss is arranged in the north-south direction. The greenhouse full-opening roof-turning skylight device 17 is installed on the truss, and the greenhouse full-opening roof-turning skylight device 17 is connected with the movable rear slope 14, so as to realize the opening and closing of the movable rear slope 14. The skylight device 17 is turned over so that the active rear slope 14 of the solar greenhouse is opened to 120°. The rainwater collection pipe 1 is installed on the back wall 18, and the rainwater flows into the underground storage tank 2 along the rainwater collection pipe 1 of the greenhouse back wall 18; the bottom of the triangle support 15 is fixedly arranged in the middle of the vertical height of the back wall 18, and the The triangular support 15 includes an internal support 151 and an external support 152. The upper part of the internal support 151 is connected with the greenhouse film 21. The upper part of the external support provides power after the movable rear slope 14 is opened. The internal support 151 and the external support 152 The middle connection point is fixedly set in the middle of the rear wall 18; in order to ensure the safety of the greenhouse load, external support is given, and a reinforcement pile 16 is set up, installed upwards from the ground, one end is fixed on the ground, and the other end withstands the external support 152; in order to ensure safety performance, the The back wall 18 of the greenhouse is equipped with triangular supports 15 of steel structure with a distance of 10-15 meters, so that after the movable back slope 14 is opened to a specified angle, the frame leans on the triangular supports 15 to reduce the stress on the solar greenhouse. The triangular support 15 is fixed on the south side of the truss. In order to ensure the stress of the triangular support 15 and the stability of the rear wall 18 of the greenhouse, reinforcing piles 16 are set up under each set of triangular supports 15 to increase the bearing capacity (as shown in Figure 3).

③Design of the reservoir

The reservoir 2 is used to store the rainwater collected by the movable back slope 14 and the inclined soil slope 3 . Set up a long 30m underground in the center of the greenhouse, wide 5m, deep 3m reservoir 2, filter device 203 is set up in the central position of the reservoir 2, the reservoir 2 is divided into two parts, the water inlet area and the water outlet area, and the water inlet The area is provided with a water inlet pipe 201, and the water outlet area is provided with an outlet pipe 202, as shown in Figure 6. Because rainwater may carry impurities such as various fine particles and dust in the soil during the process of naturally falling to the ground, in order to use relatively clean rainwater when flushing the soil, the present invention utilizes the gravity of rainwater to remove floating dust. It naturally settles to the bottom of the reservoir 2, and then passes through the filter device 203 set up to filter fine impurities to obtain clean rainwater.

In addition, when building the water storage tank 2 , a water pump 10 needs to be dug deep at the bottom of the water outlet area to place the water pump 10 and pump out the underground water to supply water upward. The water outlet end of the water pump 10 and the surroundings of the water pump 10 are provided with filter screens for secondary filtering of impurities, as shown in FIG. 6 .

According to the conclusion of this salt washing process, when calculating the plow depth of one mu of land as 0.2 to 0.6 meters, it can be concluded that the designed rainwater collection area and the capacity of the reservoir can basically satisfy most vegetables such as cucumbers, peppers, and leaf lettuces. The needs of crop growth, but for deep-rooted vegetable crops such as burdock or saline-alkali areas with thick soil layers, the volume of the reservoir 2 needs to be calculated according to the annual rainfall.

(2) Rainfall collection mode on inclined soil slopes

①Incline soil slope design: An independent triangular structure in-situ saline-alkali soil slope is set up on the south side of the greenhouse (that is, the outside of the front wall 19), and is wrapped with an anti-seepage film to increase the rain storage area. In order to increase the accumulation of fresh water resources in the rainy season, an inclined soil slope 3 is set at a position 0.4 meters away from the south side of the solar greenhouse and the front wall 19, and a water storage ditch 20 is excavated between the inclined soil slope 3 and the front wall 19. Rainwater flows into the reservoir 2 through the water collecting pipe 6 . The present invention designs inclined earth slope 3 north-south width h to be 3 meters, and the east-west length is consistent with the length of the greenhouse front wall 19, and the slope is about 5%, and the shape is a right-angled triangular prism (as shown in Figure 5).

②Other designs: According to the design parameters of conventional rain pipes, DN400PVC water collection pipes 6 are used on the premise of meeting the rainwater flow rate. In order to prevent soil loss when it rains, the inclined soil slope 3 is fully covered with plastic film to promote the collection of rainwater. For different areas, such as severe saline-alkali areas, the area of the slope 3 can be doubled or directly extended to the front greenhouse rear wall 18 to fully increase the rain-collecting surface.

(3) Rain collection mode on the front roof of the greenhouse

Use the solar greenhouse film arc structure to collect rainwater. A DN400PVC rainwater collection pipe 1 is installed on the inner side of the rear wall 18, and a DN400PVC water collection pipe 6 is installed underground in the greenhouse (as shown in Figure 7). stand up.

The design of the rain collection mode of the greenhouse includes three methods: the rear slope rain collection mode, the front roof rain collection mode, and the inclined soil slope rain collection mode. The reservoir 2 is designed under the greenhouse, and each rain collection mode and the reservoir pass through the water collection pipeline. 6 are connected, and the collected fresh water all converges in the reservoir 2 in the greenhouse. The rain collection mode of the movable rear slope is to design the fixed back slope of the original greenhouse as a movable and outward structure, and use the rain collection pipe 1 arranged on the rear wall 18 to flow rainwater into the reservoir 2; the rain collection mode of the front roof The arched greenhouse film 21 is used to collect rainwater, and the water collection pipe 6 is connected to the reservoir 2; the rain collection mode of the inclined soil slope is to set up an independent triangular structure on the outside of the front wall 19 of the greenhouse. A water storage groove 20 is set up between the slope 3 and the front wall of the greenhouse 19, and the water storage groove 20 is connected to the water storage tank 2 by means of the water collection pipe 6; the rainwater flows into the water storage groove 20 along the slope of the slope 3, Then it enters the water collection pipe 6 and finally collects in the water storage tank 2 .

2. Soil salt barrier structure design

The in-situ saline-alkali soil salt reduction technology is to install a salt-discharging concealed pipe 4 device on the salt-separating plate 11 to accelerate the discharge of brine; the material of the salt-discharging concealed pipe 4 is polyvinyl chloride (PVC) corrugated pipe, which Material is sand filter material of 8cm, prevents clogging; Described salt-discharging concealed pipe 4 is placed close to the salt barrier plate 11, is laid along the natural slope direction of the soil, passes through the retaining plate 5, utilizes the three-way pipe structure, and Each salt row branch pipe is connected with the main salt discharge pipe, and the brine is directly discharged into the brine well 7 through the drainage pipe 9 (Fig. 8). The earth retaining plate 5 is made of extruded polystyrene material, and is wrapped with an engineering film to prevent the outflow of brine; the brine well 7 is designed to store brine outside the greenhouse. Using the fresh water collected, the amount of water is 3-5 times the volume of the soil in the plow layer, and the salt is washed 2-3 times, which can reduce the EC value of the in-situ saline-alkali soil to below 3ms.cm ^-1 , which basically meets the growth of vegetable crops need.

(1) Material selection of salt barrier board

The design of the soil salt barrier structure is to lay the salt barrier plate 11 in saline-alkali soil. The function of the salt-separating plate 11 is to block the movement of water and salt, and prevent the underground soil from returning to salt upwards. At the same time, the laying of the salt-separating plate 11 can reduce heat loss and increase the soil temperature. The salt barrier 11 is placed 50cm below the surface of the solar greenhouse. Since water irrigation is a necessary condition for crop growth, the accumulated irrigation may cause damage to the salt barrier 11. Therefore, the material of the salt barrier must be guaranteed It has high heat insulation and moisture resistance.

Extruded polystyrene board (XPS) has a compact and uniform closed-cell honeycomb structure, which makes it difficult to absorb water and has high compressive strength. At the same time, its thermal conductivity is low and its thermal insulation performance is good. The present invention designs the salt barrier plate 11 to be spliced by 12 XPS plates with a thickness of 50mm and a size of 5m*11m. In order to prevent possible phenomena such as corrosion and aging of the board, it is fully wrapped with an impermeable film before laying. The anti-seepage membrane is composed of polyethylene film and geotextile, which is corrosion-resistant, non-toxic, tasteless, has good anti-decomposition ability and strong stability.

(2) Laying method

Dig out all the saline-alkali soil in the solar greenhouse. It should be noted that when digging out the soil, the soil surface of the greenhouse must have a slope trend. The distance between the highest point on the north side of the excavated soil and the surface is 50 cm. High and low, easy to discharge salt water. Secondly, wrap a 5cm thick extruded polystyrene foam board with an impermeable film and put it into the greenhouse soil to block the migration of water and salt in the soil and prevent the lower soil from returning to salt. After that, the excavated saline-alkali When the original soil is backfilled in the greenhouse, it should be noted that the soil surface still needs to maintain a slope of 2.5% after backfilling. There are two reasons for choosing to lay the salt barrier plate 11 at a distance of 50 cm from the surface of the greenhouse. One is that the root system depth of conventional cultivated crops is 30 cm, and the other is that rotary tillers are often used to level the land in vegetable and fruit tree gardens. Generally, rotary tillers have a plowing depth of about 20 cm. , therefore, a distance of 50cm can ensure that the growth of crops is not affected (as shown in Figure 8).

3. Soil Salt Reduction Structure Design

(1) Material selection for salt reduction structure

The invention designs to use rainwater to wash saline-alkali soil to reduce its saline-alkali content. During the scouring process, in view of factors such as natural rainfall and the accumulation of salt in the upper layer, the salt content in the deep soil drops slowly, and the hysteresis phenomenon is obvious. Improve the effect of washing salt. The material selection of the underground pipe salt discharge device includes: the selection of pipe material and outsourcing filter material. According to the principles of corrosion resistance, good permeability, not easy to block pipes, and good for construction, the polyvinyl chloride (PVC) bellows are finally determined to have the advantages of high compressive strength, salt and alkali corrosion resistance, light weight, and easy installation. have. In addition, the permeable hole of the corrugated pipe needs to be drilled in the corrugated recess, which not only ensures that the brine is fully discharged, but also prevents the silt from clogging the pipe. The outer-dense and inner-sparse type is the best choice for the outsourcing material of the salt discharge concealed pipe 4. While ensuring the discharge of salt water and avoiding waterlogging, it can prevent soil particles from clogging the pipe. The present invention chooses a sand filter material with a thickness of about 8cm and wraps it tightly. The polyvinyl chloride corrugated pipe can effectively prevent fine soil particles from flowing into the salt discharge underground pipe 4 and cause silting.

(2) Laying method

Under normal circumstances, as the distance between the salt-discharging concealed pipes 4 decreases and the buried depth increases, the average drop rate of the groundwater level becomes faster and the amount of drainage and salt discharge increases. Tubes, with a spacing of 6m, according to the principle that the hole diameter is not greater than 1/2 of the original pipe diameter, and the minimum distance between two adjacent holes is not less than 7 times the hole diameter when the same corrugated pipe is opened, the hole diameter is determined to be 20mm. The hole distance is 150mm (Figure 9). The hidden salt discharge pipe 4 is placed close to the salt barrier plate 11, laid along the natural slope direction of the soil, passes through the soil retaining plate 5, and uses the three-way pipe structure to connect each salt discharge branch pipe with the main salt discharge pipe, and the salt water is directly Drain into brine well 7 (Fig. 10). The retaining plate 5 is made of extruded polystyrene material, wrapped with engineering film, with a thickness of 200mm.

The salt barrier structure of the greenhouse is to set up a salt barrier plate 11 structure in the greenhouse soil to block the migration of salt; the salt barrier plate 11 is arranged at a distance of 50 cm from the soil surface; the material selected for the structure of the salt barrier plate 11 is extruded polystyrene Styrene foam boards are spliced by 12 XPS boards with a thickness of 50 mm and a size of 5 m*11 m; It is composed of polyethylene film and geotextile.

The solar greenhouse rain collection structure includes: active rear slope rain collection mode, front roof rain collection mode and inclined earth slope rain collection mode, through the above three methods to increase the rain collection area, collect fresh water resources, and use it as soil washing salt water Or agricultural irrigation water. After the rainwater is collected, the saline-alkali soil is washed to reduce the salinity of the soil. The salt barrier structure is placed at a distance of 50 cm from the soil surface of the greenhouse to block water and salt migration and prevent the underground soil from returning to salt upwards. The salt-reducing structure is placed on the salt-separating structure, and is used to accelerate the discharge of the washing brine for flushing the saline-alkali soil, and avoid excessive salt retention. Through this design content, saline-alkali original soil cultivation can be realized, saving expenses; at the same time, the problem of water shortage can be effectively solved.

Example 2. Application of rain-collecting and salt-separating solar greenhouse

As shown in Figures 1 and 2, using this set of devices can solve the problems of poor fresh water resources and high salinity in soil for saline-alkali land. The present invention designs the rear slope to be a movable rear slope structure, which is composed of an everted movable rear slope rain collection structure, an inclined earth slope rain collection structure, a front roof rain collection structure, a water collection pipe 6 and a water storage tank 2. During natural rainfall, open the back slope 14 of the rain-collecting type solar greenhouse, and a part of the rainwater can directly wash away the saline-alkali soil, and the other part of the rainwater can be accumulated along the water-collecting pipe 6. Through three rain-collecting methods, the rainwater can be accumulated together and flow into the underground water storage together. Pool 2 is used as soil washing brine or agricultural irrigation water reserve. Before planting crops, the salt barrier structure and the salt reduction structure are applied to the saline-alkali soil; the salt barrier plate 11 is placed at a position 50 cm from the ground surface, and a hidden pipe salt discharge device is arranged close to the salt barrier plate 11 to block the migration of salt. Accelerate the drainage of brine. Using 3-5 times the amount of flushing water of the plow layer soil volume and 2-3 times of flushing times can reduce the EC value and pH value of the soil. After flushing the in-situ saline-alkali soil with fresh water such as collected rainwater, the placement of the salt barrier 11 prevents the water from migrating downward; This set of devices is expected to solve the problems of high salt content and lack of fresh water resources in saline-alkali greenhouse soil, so as to improve land utilization and expand the scope of cultivated land.

Taking the in-situ saline-alkali soil with an EC value of 12.3ms.cm ^-1 and a pH value of 7.8 as an example, use the collected rainwater to carry out 3-5 times the amount of plow layer soil and wash it 2-3 times. The measured data after application shows that : After being washed by rainwater, the EC value and pH value of the in-situ saline-alkali soil are greatly reduced, which can make the EC value of the in-situ saline-alkali soil basically meet the growth needs of salt-tolerant crops or drop below 3ms.cm ^-1 , eliminating soil Salt stress. As a result, most types of vegetables can be planted using the in-situ saline-alkali soil in the solar greenhouse, realizing the nearby supply of local vegetables and improving the utilization rate of saline-alkali land.

The present invention is aimed at the problem that the degree of salt damage is different in different areas, and the soil depth of the plow layer in situ is different, and the following corresponding methods are used to solve the problem:

① Severe salt damage area: expand the rain-collecting area of inclined soil slopes and increase the rain-collecting amount.

②The area where the main agricultural irrigation water is the Yellow River water: first use the nearby agricultural irrigation water to wash the saline-alkali soil, and then use the collected fresh water to wash again.

③Arid areas with very little rainfall: Under the premise of ensuring the cost, use tap water as a supplementary fresh water resource.

The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art can still understand the foregoing embodiments. Modifications are made to the technical solutions described, or equivalent replacements are made to some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions claimed in the present invention.

Claims (9)

1. A rain-collecting and salt-isolation solar greenhouse for vegetable production in saline-alkali areas, characterized in that: the greenhouse includes a front wall and a back wall, and a greenhouse film is arranged between the front wall and the back wall, and the A skylight device is provided on the top of the rear wall, and the skylight device is connected with the valgus movable rear slope, and a triangular support is fixed on the rear wall; an inclined soil slope is provided on the outer side of the front wall, and the inclined soil slope and the A water storage groove is provided between the front walls; a rainwater collection pipe is provided on the rear wall; a water collection pipe is provided underground in the greenhouse, and the water storage groove and the rainwater collection pipe connect with the central underground of the greenhouse through the water collection pipe. The reservoirs are connected; the soil surface in the greenhouse is provided with a slope from the back wall to the front wall, the soil surface is provided with a salt barrier, and the salt barrier is provided with a salt discharge pipe. The above-mentioned hidden salt discharge pipe is buried with the excavated upper layer of soil. 2. The rain-collecting and salt-isolation solar greenhouse for vegetable production in saline-alkaline areas according to claim 1, characterized in that: the triangular support includes an internal support and an external support, and the upper end of the internal support is connected to the greenhouse film , the upper end of the outer support is used to support the opened movable rear slope, and the lower ends of the inner support and the outer support are fixedly arranged in the middle of the rear wall. 3. The rain-collecting and salt-isolation solar greenhouse for vegetable production in saline-alkali areas according to claim 2, characterized in that: each set of triangular supports is provided with a reinforced pile, one end of which is fixed on the ground, and the other end is fixed on the ground. against external supports. 4. The rain-collecting and salt-isolation solar greenhouse for vegetable production in saline-alkaline areas according to claim 1, characterized in that: the back slope of the eversion activity is made of a PC board superimposed with a layer of color steel tiles. 5. The rain-collecting and salt-isolation solar greenhouse for vegetable production in saline-alkali areas according to claim 1, characterized in that: a drainage pipe is provided on the inner side of the front wall, and the drainage pipe communicates with the brine well, and the Soil retaining boards are arranged between the salt drainage pipes, the upper soil and the drainage pipes. 6. The rain-collecting and salt-isolation solar greenhouse for vegetable production in saline-alkali areas according to claim 1, characterized in that: a water pump is provided at the bottom of the water outlet area of the water storage tank, and the water outlet of the water storage tank and the water pump Set the filter around. 7. The rain-collecting and salt-isolation solar greenhouse for vegetable production in saline-alkali areas according to claim 1, characterized in that: the shape of the inclined soil slope is a right-angled triangular prism, and the length of the inclined soil slope and the front wall is Similarly, the width is 2-5 meters, and the slope of the inclined soil slope is 4%-6% from the end far away from the front wall to the end close to the front wall. 8. The rain-collecting and salt-separating solar greenhouse for vegetable production in saline-alkaline areas according to claim 1, characterized in that: the distance between the salt-separating board and the ground surface is 50-70 cm, and the salt-separating board is made of XPS board stitched together. 9. The rain-collecting and salt-isolation solar greenhouse for vegetable production in saline-alkaline areas according to claim 8, characterized in that: the salt discharge hidden pipe is a polyvinyl chloride corrugated pipe, and the pipe of the polyvinyl chloride corrugated pipe The diameter of the polyvinyl chloride corrugated pipe is 100~120mm, the hole diameter of the polyvinyl chloride corrugated pipe is 18~20mm, and the hole distance is 150~170mm.