Effects Of Reducing Water And Fertilizer On Soil Moisture And Nutrient, Crop Yield And Reasonable Irrigation Schedule Of Greenhouse

In recent years, the solar greenhouse cultivation has become the mainstay industry insome areas of northern China with the increasing of agriculture intensification levels.Fertigation technology is also developing rapidly in greenhouse cultivation.Currently, theresearch and development of water-saving irrigation and fertilization equipment has attractedpeople’s attention, but the study of the irrigation and fertilization techniques indicators havenot attracted enough attention. The water and fertilizer management of greenhouse productionis also very extensive, irrigation and fertilizeration inputs still up to2to3times than cropactual demand or even higher. Although many scholars had conducted a lot of research aboutwater requirements, irrigation amount, the maximum and minimum limit of the suitable soilmoisture and achieved some valuable results in greenhouse vegetable system. However, dueto soil type, climatic conditions, crop varieties and planting seasons are quite different inChina, there is a big difference in technical indicators of fertilization, irrigation quota and thefrequency of irrigation.Therefore, it is necessary to study the local water and fertilizermanagement techniques in greenhouse cultivation environment. In this paper, we selectedgreenhouse in Yang ling, Shaanxi province as research object. The goal of this study was todetermine the changes of soil water dynamics, yield and quality situation, nutrient balanceand accumulation characteristics in a greenhouse vegetable system of annual rotation oftomato and watermelon at three different irrigation and fertilization application rates for oneyear. For study area greenhouse rational fertilization and irrigation to provide scientific basis.Through the research we get the main conclusions as follows:1. Irrigation and fertilization reduced20%and40%on the basis of the local average level,0~50cm soil layer of moisture were adequate supplyment throughout the whole growingperiod of tomato and mini-watermelon, The soil water content in0~20cm and20~50cm soillayers in the local average fertigation and20%reduction treatment reached or exceeded thefield capacity after irrigation. It indicated that the water infiltrated below50cm soil layer, andit would result in nutrient leaching.The most of soil moisture of40%water and fertilizersaving treatment were in appropriate range, which was65%canopy water evaporation of tomato and41%of mini-watermelon.2. Compared to the conventional irrigation, reducing the water and fertilizer rates did notdecreased dry matter accumulation significantly, nutrients uptakes and yield of tomato andmini-watermelon, however, it increased irrigation utilization significantly,and the vitamin C,soluble sugar and organic acid content of tomato higer than conventional irrigation, thesoluble sugar content of mini-watermelon significantly increased.3. The appropriate irrigation quota in the whole stages of autumn-winter tomato were1057m3·hm-2, August to December irrigation quota were168,169,132,105and50m3·hm-2respectively, irrigation period was20to30days,8to13days,8to13days and20to30days,December and January irrigation depending on the weather. The appropriate irrigation quotain the whole stages of spring mini-watermelon were570m3·hm-2, February to April irrigationquota were150,150,135m3·hm-2respectively, irrigation period was30to35days,20to25days,10to15days respectively.4. Nutrient inputs more than crop demand significantly. After reducing the water andfertilizer40%in tomato season, soil total N, P and K nutrient surplus amount up to542kg·hm-2,637kg·hm-2,462kg·hm-2, nutrient inputs is3.88,10.95, and2.51times of thedemand of tomato.Watermelon season total N, P and K nutrient surplus amount up to34kg·hm-2,84kg·hm-2,871kg·hm-2, nutrient inputs is1.24,3.27, and5.84times of watermelondemand. If only saving irrigation without reducing fertilization, will accelerate soil saltaccumulation, reasonable rotation can reduce the excessive accumulation of nutrients in thesoil.5. Autumn-winter tomato suitable nitrogen, phosphorus and potassium fertilizer input is188kg·hm-2,64kg·hm-2,305kg·hm-2respectively. The spring mini-watermelon nitrogen,phosphorus and potassium fertilizer suitable input141kg·hm-2,37kg·hm-2,180kg·hm-2.