旱作农业区土壤水分保蓄状态及其能量特征

在渭北旱地农田设置覆盖、耕翻等不同保蓄土壤水分处理,测不同层次土壤水分保蓄状况。结果表明:土壤含水量耕翻覆盖地>覆盖地>耕翻地>裸露休闲地。耕作层水分保蓄差异最为明显,但是在土层深度40~50cm处,耕翻过土壤含水量稍大于覆盖过土壤。同一土层土壤水分能量变化规律是土壤水势耕翻覆盖地>覆盖地>耕翻地>裸露休闲地,而同一土层土壤温度变化规律恰好与土壤水势相反,证明在影响土壤水势因素中,土壤水分的正效应>土壤温度;土壤温度日变幅明显是裸露休闲地和耕翻地大于覆盖地。

Soil water conservation and its energy characteristics

A field experiment was conducted to investigate the effect of different tillage methods on soil moisture regime.The results showed that soil water content was ranked as follows: Plow mulch>mulch>plow>fallow.The differences between them were greater for plowed layer of soil but in 40~50cm soil profile,soil water content of treatment plow slightly greater than treatment of mulch.Soil water potential at the same depth was ranked as follows: Plow mulch> mulch>plow>fallow.The reverse trend was found for soil temperature.This phenomenon proved that soil water content was the main factor to affect soil water potential.Diurnal change of soil temperature ranking from highest to lowest was fallow and plow>mulch and plow mulch.Soil temperature,water energy and water loss were lower or less for mulching than that for no mulching soils.The reason of this phenomenon was that the treatment of mulch shade the soil surface,then soil temperature was low.soil water potential was decreased,so soil water loss was decreased.The aim of soil water conservation was attained.