几种农作措施对旱地土壤水分状况的影响

通过盆栽及田间试验 ,探讨了粗有机物质的两种不同施用方式以及不同耕作与覆盖措施对澄城旱地土壤水分状况的影响。结果表明 :在土壤中施用粗有机物质 ,兼有阻止上部土壤水分下渗与保蓄下部土壤水分两种作用 ;土壤水势与温度之间呈极显著的直线关系 ,其直线方程的斜率即为水势的温度效应 ,施用有机物质 ,尤其是集中施用 ,能降低下部土壤的水势温度效应值 ;在当地土壤、气候及技术水平等条件下 ,旋耕是目前比较适宜的蓄水保墒耕作方法 ,而免耕则不宜提倡 ;采用夏闲期并苗期秸秆覆盖 ,能有效提高耕层土壤水分的数量水平和能量水平 ;在某些情况下 ,能量指标比数量指标更适于用来表述土壤的水分状况。

Effects of Several Agricultural Measures on Soil Moisture Regime in Rainfed Farmland

Based on the pot incubation test and the field experiment,the effect of two application methods of raw organic material to soil and different measures of tillage and mulch upon the soil moisture regime in Chengcheng rainfed farmland were discussed. The results indicated that the application of raw organic material act both on reducing the downward infiltration of water from upper portion to lower portion of soil and on holding the moisture in lower soil,which have varying significance in different growing stages of crops. A straight line equation, the slope of which is just equal to the temperature effect on water potential,could be used to describe the most significant positive relation existing between soil water potential and temperature. The temperature effect in lower soil can be decreased by the organic material application, especially in concentration. Under the local condition of soil,climate and current techniques,the rotary tillage would be the suitable means of cultivation,while the zero tillage should not be advocated. The levels both of amount and energy of soil water were remarkably raised by adoption of mulch with straw in seedling stage as well as in summer fallow time in some cases. An energy index might be more suitable than a quantity index for expressing the soil moisture regime