不同土壤水分对滴灌春小麦生长、产量及水分利用效率的影响

以2000-2008年湖南省畜禽饲养量数据为基础,对湖南省畜禽粪尿年排放量进行统计,计算出粪尿污染物排放总量及污染物流入水体总量,并对养殖场排污水取样检测汞、砷、铜、锌金属离子的浓度和大肠杆菌、悬浮物、pH值。结果显示:湖南省2000-2008年间畜禽粪尿平均排放量达1.23×108t;化学耗氧量、生化耗氧量、氨氮、总氮和总磷排放量分别为2.95×106t、2.64×106t、2.75×105t、1.85×105t和6.54×105t;化学耗氧量、生化耗氧量、氨氮、总氮和总磷水体流失量分别为:3.63×105t、2.58×105t、6.22×104t、2.19×104t和1.56×105t,养殖场所排废水中以铜最高,锌、汞含量次之,未检出砷,4种金属元素在污水中平均含量分别为:铜0.18 mg/L,锌0.06 mg/L,汞0.05 mg/L,砷0 mg/L,大肠杆菌和悬浮物的平均含量均超过国家允许标准1.60倍(P<0.05)和12.78倍(P<0.01)。本文针对湖南省粪尿污染所处负荷状态,提出了相应的防控措施。

Effects of Different Soil Moisture on Growth,Grain Yield and Water Use Efficiency of Spring Wheat Under Drip Irrigation

A soil moisture controlled experiment under drip irrigation was conducted under the ecological and climatic conditions of South Xinjiang to study the effects of soil moisture on shoot growth, grain yield and water use efficiency(WUE) of spring wheat with tall variety of Xinchun 19 and dwarf variety of Xinchun 22 . The results indicated that the moisture-sensitive stage of spring wheat was at jointing to flowering stage and water deficit would significantly affect plant height, biomass, leaf area and yield components. In all water treatments, the soil relative moisture content of T2 at emergence to jointing, jointing to flowering and flowering to milk maturation being 65%-70%, 70%-75% and 65%-70%, respectively, showed a highest values of grain yield, WUE and harvest index(HI). The soil relative moisture content of T4 at emergence to jointing being 45%-50% and at other stages being the same as T2, was the secondary in grain yield, and its WUE, HI, number of kernels per spike and grain weight were no significant difference compared with T2, so T4 was economically feasible in deficit irrigation. Different genotypes had different response to soil moisture. Dwarf variety of Xinchun 22 was susceptible to soil moisture, and its water consumption of each treatment was below Xinchun 19, so it was a water saving cultivar. Studies showed that the suitable amount of drop irrigation for dwarf variety and tall variety in South Xinjiang were 318.86 mm -368.72mm and 394.52 mm -458.14mm respectively.