Atreya Kishor, Sharma Subodh, Bajracharya Roshan M, Rajbhandari Neeranjan P
Alternative Development and Research Center (ADRC - Nepal), GPO Box 20078, Kathmandu, Nepal.
J Environ Manage. 2008 Aug;88(3):547-55. doi: 10.1016/j.jenvman.2007.03.017. Epub 2007 May 3.
In Nepal, soil erosion under maize (Zea mays) agro-ecosystems is most critical during the pre-monsoon season. Very few field experiments have been conducted on reduced tillage and rice straw (Oryza sativa) mulching, although these conservation approaches have been recommended. Thus, a five replicate field experiment was established in 2001 at Kathmandu University (1500 m above sea level) on land with 18% slope to evaluate the efficiency of reduced tillage and mulching on soil and nutrient losses and maize yield. The results showed non-significant differences among conservation approaches on runoff and maize yield. Mulching and reduced tillage significantly lowered annual and pre-monsoon soil and nutrient losses compared to conventional tillage. Soil organic matter (SOM) and nitrogen losses associated with eroded sediment were significantly higher in conventional tillage. However, due to limited availability and high opportunity cost of rice straw, reduced tillage would be a better option for soil and nutrient conservation without sacrificing economic yield in upland maize agro-ecosystems.
在尼泊尔，玉米（Zea mays）农业生态系统下的土壤侵蚀在季风前季节最为严重。尽管已推荐采用少耕和稻草（Oryza sativa）覆盖等保护性措施，但针对这些措施开展的田间试验却很少。因此，2001年在加德满都大学（海拔1500米）坡度为18%的土地上进行了一项有五次重复的田间试验，以评估少耕和覆盖对土壤及养分流失以及玉米产量的影响。结果表明，不同保护性措施在径流和玉米产量方面差异不显著。与传统耕作相比，覆盖和少耕显著降低了全年及季风前的土壤和养分流失。传统耕作中，与侵蚀泥沙相关的土壤有机质（SOM）和氮流失显著更高。然而，由于稻草供应有限且机会成本高，在不牺牲山地玉米农业生态系统经济产量的情况下，少耕对于土壤和养分保护而言是更好的选择。
