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季节性干旱是南方红壤地区旱地农业生产中的主要障碍因素。本文报道了田间条件下作物土壤水势关系及其对干旱胁迫响应。结果表明ＳＰＡＣ中水势梯度为：叶气系统＞叶土系统＞７０ｃｍ以上土层，且约以１００倍左右递减，水势日变化结果表明免耕较常耕，窄垄较宽垄叶土水势差下降，水分胁迫更强；花生的耐旱性较强，大豆和玉米的则较弱；作物叶水势与土壤基质势呈正相关，可以用二项式表示。作物叶水势与不同土层土壤基质势关系表明，垄作处理作用层次更深，免耕处理仅与表层土壤基质势相关。土壤基质势和叶水势都随环境温度提高而降低；不同耕作制度改变了土壤温度和微气候，进而影响了水势的温度效应。结果说明高温和水分胁迫导致并加剧了红壤季节性干旱胁迫。
Seasonal drought is the main obstacle in dryland agricultural production in red soil region of southern China. This paper reports crop soil water potential under field conditions and its response to drought stress. The results showed that the gradient of water potential in SPAC was: leaf system> leaf soil system> 70cm above soil layer, and decreased about 100 times. The diurnal variation of water potential indicated no-tillage was more plowed, , Water stress is stronger; the drought resistance of peanut is stronger, while that of soybean and corn is weaker; the leaf water potential of crop is positively correlated with soil matrix potential, which can be expressed by binomial. The correlation between crop leaf water potential and soil matrix potential in different soil layers showed that the furrow layer treatment had a deeper level of action and the no-tillage treatment was only related to the surface soil matrix potential. Soil matrix potential and leaf water potential decreased with the increase of ambient temperature. Different farming systems changed soil temperature and microclimate, which affected the temperature effect of water potential. The results showed that high temperature and water stress caused and aggravated seasonal red soil drought stress.