Integrated Technology of Water and Fertilizer for vegetables in greenhouse

"dripping" vegetables in the greenhouse is actually an integrated technology of water and fertilizer, which integrates irrigation and fertilization. specifically, with the help of pressure system (or natural drop of topography), soluble solid or liquid fertilizer is made up of soluble solid or liquid fertilizer. according to the characteristics of soil nutrient content and fertilizer demand of vegetable types, the fertilizer liquid prepared together with irrigation water, supply water and fertilizer through the controllable pipeline system to make the water and fertilizer blend. Drip irrigation was formed through pipes and emitters, which infiltrated the root development area of vegetables uniformly, regularly and quantitatively, so that the soil of the main roots was always loose and suitable for water content. It is the most effective way of water-saving irrigation at present, and the utilization rate of water can reach 95%. Because there is not enough water between plants, weeds are not easy to grow, so the phenomenon of vegetables competing with weeds for nutrients is greatly reduced, and the work of weeding is also reduced. Because drip irrigation is easy to operate, high frequency irrigation can be carried out, and the outflow hole is very small, the flow rate is slow, each irrigation time is relatively long, and the change range of soil moisture is small. Therefore, it can be controlled that the soil in the root zone can be kept close to the humidity most suitable for vegetable growth for a long time. Drip irrigation belongs to micro-irrigation, in which water seeps into the soil slowly and evenly, which can maintain the soil structure and form a suitable soil water, fertilizer and thermal environment. 1. Drip irrigation equipment is mainly composed of water source, water pump, filter, flow and pressure regulator, fertilizer mixing box, fertilizer injector, pipeline system (main pipe, branch pipe and emitter) and other components. Places without tap water can be supplied with miniature electric pumps currently sold on the market. Drip irrigation requires a water supply pressure of 1 kilogram / square centimeter, which is equivalent to the pressure of a water column of more than 10 meters, so when setting up a water tower, its height should be higher than 10 meters. The simplest filter is a screen with more than 30 holes per square centimeter, which requires the removal of particles or impurities greater than 4.4 mm in diameter. The volume of the fertilizer mixing box is 0.5 to 1.0 cubic meters. In the winter greenhouse, drip irrigation pipes generally use two-stage type, that is, the main pipe and branch pipe. The emitter is installed directly on the branch pipe. The filter, flow (pressure) regulator and fertilizer mixing box should be installed at the head of the main pipe in the shed. If the water quality is good, and after a certain period of precipitation, the filter may not be used. The fertilizer solution can be injected into the fertilizer tank, and then hit the drip irrigation pipe with small water, or put into the pressure liquid storage tank. In the process of using drip irrigation, the dripping situation of each emitter should be checked frequently, and the abnormal situation should be adjusted in time. two。 The first method of operation is to irrigate clear water, first close the suction valve of the fertilizer applicator, then open the valve to the maximum, and then turn on the pressurized water source, and then irrigate. Second, when applying fertilizer and water, close the valve, turn on the switch of the straw of the fertilizer applicator, fix the filter at the bottom of the fertilizer solution bucket, and turn on the water source to fertilize. At the end of fertilization, turn off the switch on the straw and open the valve to continue irrigation in order to flush the residual fertilizer in the pipe. 3. Note: ① should control the system pressure well, and the system working pressure should be controlled within the prescribed standard range. ② filter is the key component to ensure the normal operation of the system, which should be cleaned frequently. If the filter screen is found to be damaged, it should be replaced in time. ③ emitter is easy to damage, should be carefully managed, gently rolled up when not in use, do not step on or drag on the ground. ④ strengthens management to prevent sundries from entering the emitter or water supply pipe. If you find sundries entering, you should open the clogging head and rinse it out in time. When the temperature in ⑤ greenhouse is too low in winter, corresponding measures should be taken to prevent frost cracking of plastic parts, water supply pipes and irrigators, etc. During ⑥ drip irrigation, it is necessary to slowly open the valve and gradually increase the flow rate to clean the air, reduce the impact pressure on the emitter and prolong its service life.