香根草篱和稻草覆盖对红壤坡耕地土壤肥力的影响

香根草(Vetiveria zizanioides L.)篱和稻草覆盖是重要的水土保持措施。为揭示香根草篱和稻草覆盖对红壤缓坡旱地土壤肥力的影响,本研究于2011年设置了CK、香根草篱、稻草覆盖、香根草篱+稻草覆盖4个处理,并分析了2011年和2012年的花生产量、土壤有机质和氮磷钾养分变化,结果表明:各处理花生产量呈现出覆盖草篱+覆盖草篱、对照。与CK处理相比,覆盖和草篱+覆盖处理在2011年分别增产31.74%、15.23%,2012年增产59.39%、41.65%。香根草篱和稻草覆盖可以显著提高红壤坡耕地的有机质、碱解氮、有效磷和速效钾含量,但土壤全氮、全磷和全钾含量不存在显著增加。与2011年相比,虽然2012年草篱和覆盖措施的土壤碱解氮、有效磷和速效钾含量的增幅呈下降趋势,但在所有处理中均表现出草篱+覆盖处理的速效养分最高,这说明,虽然红壤坡耕地花生种植后土壤碱解氮、有效磷和速效钾含量明显下降,但草篱+覆盖可以在增加养分投入的同时有效维持和保蓄土壤速效养分。

Effects of Straw Mulching and Vetiver Hedge on Soil Fertility in Sloping Land of Red Soil

Vetiver grass (Vetiveria zizanioides L.) hedgerow and straw mulching are important measures for soil and water conservation. To study the effects of vetiver grass hedgerow and straw mulching on soil fertility in hilly land of red soil, one field experiment was set up in 2011 which included CK, vetiver grass hedgerow (VGH), straw mulching (SM), and vetiver grass hedgerow with straw mulching (VGH+SM). The results showed the grain yield of peanut was in order of SM > VGH+SM > VGH and CK. Compared with CK, the grain yield of SM and VGH+SM were increased by 31.74% and 15.23% in 2011, 59.39% and 41.65% in 2012, respectively. Vetiver grass hedgerow and straw mulching could significantly improve soil organic matter, alkali solution nitrogen, available phosphorus and potassium contents. The soil alkali-hydrolysable nitrogen, available phosphorus and available potassium in VGH+MS were higher than CK. However, the increment of soil organic matter and available nutrient were dropped with increasing of experimental years. It indicated that grass hedgerow and straw mulching can keep soil fertility and maintain soil available nutrients through adding straw input in sloping land of red soil.