摘要
金沙江干旱河谷区坡耕地固氮植物篱种植模式的研究结果表明 ,植物篱与农作物利用土壤水分的深度不同 ,植物篱在旱季主要利用 5 0 cm以下深层土壤水分来度过严酷的旱季 ,在雨季促进水分向深层土壤渗透 ,提高 0～ 15 0 cm土层贮水量 ;据剖面含水量的变异程度可将剖面分为 4个层次 :水分剧变层、水分渐变层、水分弱变层和水分稳定层 ,其中植物篱模式下剧变层为 0～ 30 cm,渐变层为 30～ 10 0 cm ,弱变层为 10 0～ 15 0 cm,稳定层在15 0 cm以下 ,而传统耕作坡地和裸坡地 (梯地 )分别为剧变层 0～ 30 cm,渐变层为 30～ 5 0 cm,弱变层为 5 0～ 12 0cm ,稳定层在 12 0 cm以下 ,渐变层厚度显著小于植物篱种植模式。植物篱模式提高系统中土壤水分周转库容 ,不仅有利于雨季调节地表径流 ,而且有利于旱季改善土壤水分条件。在时间上 ,一个旱季 -雨季周期内干热河谷坡耕地土壤水分动态可分为 3个时期 :水分消耗期。
Results are reported from on site study on soil moisture dynamics of slopeland, involving in the contour hedgerow/crop intercropping (ST1), hedgerow without crop(ST2), traditional crop cultivation (ST3) and bare slopeland (ST4), in dry valley area of Jinsha River. Hedgerow layer depleted soil moisture beneath 50cm during meta and anaphase of dry season, and promoted infiltration of rainfall into deep soil during rainy season, which leads to not only a significant reduction of surface flow in rainy season but a rather improvement of soil water regime of deep layers in monsoon and dry season. Soil profile of slopeland could be characterized by four layers, i.e. drastically changing layer (0~30cm), gradually changing layer (30~100cm), slightly changing layer (100~150cm) and stable layer (>150cm) for hedgerow system (ST1 and ST2), whereas drastically changing layer(0~30cm), gradually changing layer (30~50cm), slight changing layer (50~120cm) and stable layer (>120cm) for ST3 and ST4. The temporal dynamics of soil moisture could be characterized by three periods: depletion phase, complementarity phase, and stability phase during a dry season and rainy season circle.
出处
《水土保持学报》
CSCD
北大核心
2002年第A01期84-87,103,共5页
Journal of Soil and Water Conservation
基金
国际山地中心 (ICIMOD) ATSCFS(1991-2 0 0 1)项目
中国科学院知识创新工程西南基地
四川省青年科技基金
中科院成都地奥科学基金共同资助
关键词
干旱河谷
等高固氮植物篱
坡耕地
土壤水分
dry valley area
contour hedgerow system
sloping croplands
soil moisture
