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为探明砂田土壤水、热状况乃至西瓜生长发育随覆砂年限的变化趋势,为提高中、老砂田的生产效率提供理论依据,本试验选取了5~40年砂田为研究对象,对其砂层含土量、砂层厚度、土壤水热效应及西瓜生长发育进行了研究。结果表明:铺砂年限每增加一年,砂层含土量平均增加0.6%左右,砂层厚度减少0.12cm左右;西瓜生育期内,10、15、20、30、40年砂田较5年砂田0~20cm土层积温分别降低了47.68、117.28、122.49、206.56、320.06℃;1m土层内土壤贮水量分别下降了11.74、33.15、39.31、51.99、57.3mm,表现出新砂田与中砂田较老砂田的增温、保墒效果均随着土层的加深递减,且该趋势在西瓜生育前期较强,中后期逐渐减弱。西瓜生育期随着铺砂年限的延长而延长,土壤水、热状况及西瓜产量、品质、水分利用效率均随着种植年限的延长而逐渐降低,以30年砂田为对照,5、10、15、20年砂田西瓜产量分别增加了170.91%、85.06%、58.76%、46.83%;西瓜含糖量分别提高了1.7%、1.6%、1.3%和0.8%;水分利用效率分别提高了83.48%、35.18%、35.35%和31.50%。
In order to find out the change trend of soil water, heat status and even watermelon growth and development with the sand cover age, the paper provides a theoretical basis for improving the production efficiency of middle and old sand fields. In this experiment, the sand fields from 5 to 40 years were selected as the research object, Soil layer thickness, sand thickness, soil water and heat effects and watermelon growth and development were studied. The results show that for each additional year of sand application, the soil content in sand layer increases about 0.6% on average, and the thickness of sand layer decreases about 0.12cm. During the growth period of watermelon, the content of sand in 10, 15, 20, 30, The accumulative temperature of 0-20 cm soil layer decreased by 47.68, 117.28, 122.49, 206.56 and 320.06 ℃, respectively. The soil water storage in 1m soil layer decreased by 11.74, 33.15, 39.31, 51.99 and 57.3 mm, The effects of warming and preserving soil moisture of sandy land decreased with the deepening of soil layer, and the trend was stronger in early stage of watermelon growth and gradually weakened in middle and late stage. The growth period of watermelon was prolonged with the prolongation of sanding time. The soil water and heat condition as well as the yield, quality and water use efficiency of watermelon gradually decreased with the extension of planting years. Compared with 30 years of sand field, 5,10,15 The watermelon yield increased by 170.91%, 85.06%, 58.76% and 46.83% respectively in the past 20 years; the sugar content of watermelon increased by 1.7%, 1.6%, 1.3% and 0.8% respectively; the water use efficiency increased by 83.48% and 35.18 %, 35.35% and 31.50%.