滴灌下不同灌水处理对马铃薯水氮运移及产量的影响

Effects of Different Irrigation Treatments on Water and Nitrogen Transport and Yield of Potato under Drip Irrigation

通过大田膜下滴灌试验,研究了不同灌水处理下马铃薯根区水分和硝态氮的运移规律以及不同灌水处理对马铃薯产量的影响,为宁夏干旱地区防止土壤中硝态氮淋移渗漏、提高土壤水肥利用效率提供理论依据。该试验以灌溉定额900、1 260、1 620 m^3/hm^2为变量,采用随机区组试验方法,试验结果表明:土壤含水率随着灌溉定额的增大而增加且随着土层深度的增加不断减少;随着灌水后天数的推移,各个处理不同深度土壤含水率不断降低;表层土壤(0～20 cm)含水率随着灌溉定额的增加而增大,30～40 cm土壤含水率不断降低,50～100 cm土壤含水率不断降低的幅度随着灌溉定额的增加而降低; 30～50 cm土层硝态氮含量低于0～20 cm土层的,60～100 cm土层硝态氮的含量在0.2 mg/kg基础上以0～0.11 mg/kg上下浮动;在该试验中,灌溉定额在一定范围内可以促进马铃薯产量的增加,但是当灌水量超过1 620 m^3/hm^2时,产量与灌水量呈负相关关系。试验条件下,灌溉定额为1 260 m^3/hm^2时,马铃薯产量最高,高达25.88 t/hm^2,不同深度土层含水率和硝态氮含量均为马铃薯生长发育对水分的最优需求。

The effects of different irrigation treatments on the water and nitrate nitrogen transport in potato root zone and the effects of different irrigation treatments on potato yield were studied through field sub-film drip irrigation experiment to provide a theoretical basis for the prevention of leaching and leakage of nitrate in soil and the improvement of soil water and fertilizer use efficiency in arid areas of Ningxia.The irrigation volume of 900,1 260 and 1 620 m^3/hm2 are selected as variables and the randomized block test method is used in the test.The test results show that the soil moisture content increases with the increase of irrigation quota and the depth of soil layer;with the process of the days after irrigation,the soil moisture content of different treatments decreases continuously;the water content of surface soil(0~20 cm)increases with the increase of irrigation quota,and the soil moisture content of 30~40 cm decreases continuously;the decreasing range of soil moisture content of 50~100 cm soil layer decreases with the increase of irrigation quota;the nitrate content of 30~50 cm soil layer is lower than that of 0~20 cm soil layer,and the content of nitrate nitrogen in 60~100 cm soil layer fluctuates from 0 to 0.11 mg/kg with the basis of the 0.2 mg/kg;irrigation amount can increase the yield of potato in a certain range,but when the irrigation water is more than 1 620 m^3/hm^2,the yield is negatively correlated with irrigation amount.Under the test condition,when the irrigation quota is 1 260 m^3/hm^2,the potato yield is the highest,up to 25.88 t/hm^2,and the soil moisture content and nitrate nitrogen content in different depths are the optimal water demand for potato growth and development.