Soil cover by crops and straw may improve water infiltration and reduce evaporation rate contributing to water conservation at top soil layer. This study was carried out at the experimental área of Soil Science Department, Santa Maria, RS, from May 1991 to May 1992. The objective was to evaluate the impact of winter cover crops on soil water conservation. After winter cover crops, maize was grown in no-tiliage system. The cover crops used as treatments were: legumes {Lathyrus sativus, Lupinus angustifolius and Vicia sativa) and oat (Avena strigosa). Fallow was used as the reference treatment. Soil water content was monthly measured. There was temporal variation of soil cover and moisture. They were closed related between each other. Oat conserved more water content along the studied period. Winter cover crops were significantiy efficient in conserving water as compared to fallow treatment.
soil moisture; temporal variation; soil cover; no-tiliage
