摘要
常规耕作的水土流失造成紫色土坡耕地土层浅薄化、土壤养分贫瘠化、土壤干旱化及土壤结构劣化等土壤肥力退化问题。 1 984～ 1 996年长期田间试验结果表明 ,聚土免耕通过垄沟网状结构可保持水土 ,其多年平均径流与土壤侵蚀模数分别为 65 7.7m3hm- 2 和5 30 .0tkm- 2 ,而常规耕作的相应值分别为 1 75 4 .0m3hm- 2 和 31 2 2 .0tkm- 2 ,通过聚土与改土结合 ,聚土免耕活土层厚度平均增加 1 1 .8cm ,聚土免耕耕作技术还通过垄沟强化培肥降低土壤容重 ,增加土壤有机质及N、P、K含量 ,改善土壤理化性状 ,恢复土壤肥力。聚土免耕作物产量比平作高 1 5 %～ 30 %。 1 996～ 1 998年秸秆覆盖实验结果表明 ,秸秆覆盖增加土壤有机质和养分含量 ,改善并维持土壤结构。聚土免耕与秸秆覆盖结合有利于土壤养分活化、土壤结构形成与维护 ,是紫色土退化旱地肥力恢复与重建的关键技术。
Soil erosion, soil fertility d egeneration and land productivity loss are severe problems in hilly land of purp le soil under conventional. tillage. A long term field experiment was conducted during 1984 to 1996 to determine soil productivity in a typical hilly area of degraded upland of purple soil in Yanting, Sichuan province. Resu lts showed that a conservation tillage system with ridge furrow and seasonal no tillage (SNTRCS) increased topsoil depth by 11.8 cm over the conventional till age. Annual run off and soil loss were 657.7 m 3 hm -2 and 530.0 t km - 2 respectively, under conservation tillage, and 1 754.0 m 3 hm -2 and 3 12 2.0 t km -2 respectively, under conventional tillage. Soil structure and soi l physical, chemical and biological properties were also improved when conservat ion tillage was adopted. Mulching experiments from 1996～1998 showed that mulchi ng increase contents of organic matter and nutrients in the soil, which in turn improved and maintained soil structure. In conclusion, SNTRCS with mulching is s uitable for soil and nutrient conservation, and structure amelioration, conseque ntly for restoration of productivity in degraded hilly land of purple soil.
出处
《土壤学报》
CAS
CSCD
北大核心
2002年第5期743-749,共7页
Acta Pedologica Sinica
基金
中国科学院知识创新工程重大方向性项目 (KZCX2 41 3 )
国家自然科学基金 (4 960 1 0 0 9)
中国科学院"西部之光"人才培养项目资助
