不同水分处理下农田黑土水分特征

采用田间定位试验,利用中子仪原位监测土壤储水量的方法,研究3个水分处理下农田土壤水分特征.结果表明:受长期不同水分处理的影响,适宜水分处理0-110 cm土壤储水量最高,其次为自然降水处理,分别比干旱处理增加了23.4%和12.9%;在大豆生育期内,各水分处理土壤储水量的季节性变化均呈"减小-增加-减小-增加"的趋势,与大豆生育期内降雨分布密切相关;各处理大豆耗水量表现为适宜水分处理>自然降水处理>干旱处理,其值分别为459.4、420.3、326.4 mm;不同时段大豆耗水量表现为在无控水影响的时期(2008-05-01-2008-06-15)大豆耗水量处理间差异较小,而在控水时期差异较明显;从进水量与耗水量的比值可以看出,黑土调节土壤水分的能力较强;干旱处理、自然降水处理和适宜水分处理水分利用效率分别为3.9、4.8和5.4 kg·hm-2·mm-1,表明一般年份灌溉能够提高水分利用效率.

Effect of Water Treatment on Water Regime in Farmland Black Soil

A stationary field experiment was carried out to investigate effect of water treatment on farmland water regime,using a neutron probe.Results show that after a long-term experiment soil water storage in the 0-110 cm soil layer followed an order of suitable water treatment>rainfall treatment>dry treatment with the first two being 23.4% and 12.9%,respectively,higher than the last.During the soybean growing season,soil water storage in all the treatments displayed a trend of seasonal variation,such as declining-rising-declining-rising,which was closely related to rainfall distribution during the season.In terms of moisture consumption by soybean,the three treatments followed a decreasing order of suitable water treatment>rainfall treatment>dry treatment,and their value was 459.4,420.3,and 326.4 mm,respectively.Soybean water consumption varied slightly between treatments at all growth stages,during the period (2008-05-01-2008-06-15) when they were free of the influence of water control,but significantly in the period when they were under the influence of water control.The water-inflow/water-consumption ratio demonstrated that the black soil was quite high in capability of adjusting water regime.Water use efficiency of the dry treatment,the rainfall treatment and the suitable water treatment was 3.9,4.8 and 5.4 kg·hm-2·mm-1,respectively,indicating that irrigation could enhance water use efficiency in normal years in black soil.