干旱区滴灌均匀系数和灌水量对土壤水氮分布的影响  

Effects of uniformity and irrigation amount of drip system on distributions of soil water and nitrogen in arid area

作　　者：关红杰[1] 李久生[1] 栗岩峰[1] 

机构地区：[1]中国水利水电科学研究院流域水循环模拟与调控国家重点实验室,北京100038

出　　处：《农业工程学报》2012年第24期121-128,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金项目(50979115)

摘　　要：研究新疆干旱区滴灌均匀系数和灌水量对土壤水氮分布的影响,为滴灌均匀系数设计与评价标准的修订和完善提供依据。供试作物为棉花,试验中滴灌均匀系数(Cu)设置0.65(C1)、0.78(C2)和0.94(C3)3个水平,灌水量设置充分灌水量的50%、75%和100%3个水平。结果表明,棉花生育期内根系层0～60cm土层含水率均匀系数保持在较高水平(0.80～0.97),滴灌均匀系数和灌水量及其交互作用的影响均未达到显著水平。土壤NO3--N含量均匀系数随时间和空间表现出较强的变化特征,在生育期内的变化范围为-0.27～0.92,且低于土壤含水率均匀系数;滴灌均匀系数和灌水量及其交互作用对NO3--N含量均匀系数的影响不显著。干旱区作物生育期降水量难以弥补灌水不均匀对水分分布造成的负面影响,滴灌均匀系数对棉花生育期内根系层土壤含水率均匀系数的影响强于初始含水率均匀性和灌水量。上述结果可供制定干旱区滴灌均匀系数标准时参考。Uniformity ratio is an important parameter in the design and operation of microirrigation systems, and a greater ratio might be of benefit to obtain a more uniform distribution of water and nutrients in the soil. However, the initial installation costs of systems with greater uniformity values are relatively high. Recent experimental researches in semi-humid and semi-arid regions indicated that the system uniformity had no significant influence on the distributions of soil water content and nutrients as well as crop growth and yield. However, the results are not necessarily applied to the arid regions where there is considerably less precipitation than in semi-humid and semi-arid regions. The effects of drip system uniformity and irrigation amount on the distributions of water and nitrate in soil were evaluated in arid environments of Xinjiang Uygur Autonomous Region, China, during the growing seasons of cotton in 2010 and 2011 to amend the current design and evaluation standards of drip system uniformity. Three Christiansen uniformity coefficients （Cu） of 0.65, 0.78, and 0.94 and three irrigation levels of 50%, 75%, and 100% of full irrigation were used. The lower Cu values of 0.65 and 0.78 were obtained by assembling the segments of drip tubes with six different nominal discharges （1.1, 1.4, 1.75, 2.1, 2.7, and 3.0 L/h at 0.1 MPa） randomly along the entire lateral, but a mean emitter discharge of 2.1 L/h at 0.1 MPa, which was similar to the mean emitter discharge of the high uniformity treatment （Cu=0.94）, was maintained for the assembled laterals. The distributions of the soil water content were measured from seven equally spaced access tubes located along a dripline using a TRIME-FM. Gravimetric samples of soil were collected regularly to determine the temporal and spatial distributions of nitrate in the experimental plots. A high seasonal mean uniformity coefficient of soil water content （0.80-0.97） within 0-60 cm depth was observed during both seasons. The effects of drip system uniformity a

关 键 词：土壤 水分 氮 滴灌 均匀系数 含水率 棉花 

分 类 号：S275.6[农业科学—农业水土工程] S152.7[农业科学—农业工程]