草地雀麦对北京山区石灰性褐土水土保持作用的研究

北京山区石灰性褐土草地雀麦播种后第2a,研究了其主要生物学特性对土壤物理性质及坡地水土流失的影响.结果表明,草地雀麦种植1a后,4月份返青,7月份地表覆盖度可达85%以上,8月份植株密度最大,地上、地下生物量为2322.6 kg/hm2和5623.0 kg/hm2,且0-10 cm地下生物量是草地雀麦地下水土保持功能发挥的主要部分.北京地区石灰性褐土土壤侵蚀的主要形式是坡面地表径流流失,降雨与植物生物学特性是坡地土壤侵蚀的主要影响因素,且不同因素作用大小表现为:地表径流量＞降雨量＞降雨强度＞坡度＞植被盖度＞植被高度＞植株密度.草地雀麦种植第2a,可以明显改善石灰性褐土土壤物理性质,减小土壤容重2.4%～9.8%,降低土壤紧实度,提高土壤入渗率,坡地地表年径流损失量与土壤侵蚀模数仅为13.5 mm和105.2 t/(km2·a),保水固土能力达到65.4%和98.1%,水土保持效果显著.

Effects of Bromus Riparius on Soil and Water Conservation on Slope with Calcareous Cinnamon Soil in Beijing

Experiment was conducted to study the effects of Bromus riparius on soil and water conservation on the slope with calcareous cinnamon soil in Beijing by analyzing the relation to main biological characters and soil and water loss for a year.Bromus riparius turned green in April and its cover was over 85% in July.In August,their overground and underground biomasses at the highest plant density were 2 322.6 and 5 623.0 kg/hm²,respectively,and the root amount in 0? 10 cm soil layer was important to prevent soil and water loss.T he main form of soil erosion on the slope with the calcareous cinnamon soil in Beijing was surface runoff.Rainfall and biological characters were two major factors to soil erosion on the slope.T he order of factors was surface runoff> rainfall> rainfall intensity> slope degree> vegetation cover> vegetation height> tiller density according to their effects to soil erosion.After one year Bromus rip arius,the physical properties of the calcareous cinnamon soil were significantly improved.Soil bulk density was deduced by 2.4% ~ 9.8%,soil compaction was decreased,and infiltration capacity was promoted.T he yearly amount of surface runoff loss and soil erosion modulus on the slope were reduced to 13.5 mm and 105.2 t/(km²? a) and the capacity of soil and water conservation reached 65.4 % and 98.1%,respectively.Grass planting on the slope with the calcareous cinnamon soil has great significance in soil and water conservation.