摘要
5年轮作和 1年水平沟耕作试验表明 :在不同的坡度上 ,与传统耕作法相比 ,水平沟减少产流 7% ,径流液铵态氮浓度提高 19% ,流失量达到 13.0 1kg/ (km2· a) ,比传统耕作多流失 1.11kg/ (km2· a) ;径流硝态氮浓度减少 2 7% ,比传统耕作减少 7.6 8kg/ (km2· a) ;径流硝态氮流失减少量和铵态氮增加量相差 6倍 ,水平沟可减少 6 .5 7kg/ (km2· a)矿质氮流失 ;水平沟拦截泥沙 2 5 %左右 ,泥沙中全氮富集率提高 13% ,土壤全氮流失 4 5 7kg/ (km2 · a) ,平均减少 18% ;一季黑豆和一季黄豆及两季黑豆和一季黄豆参与的 5年轮作周期 ,土壤侵蚀量仅为896 t/ (km2 · a)和 984 t/ (km2 · a) ,不及糜子和土豆参与轮作周期的 1/
Compared with conventional tillage, level trench might reduce 7% in average of runoff amount on different slope land, the ammonium concentration in runoff increases 19%, its loss amount reaches 13.01 kg/(km 2·a), also increases by 1.11 kg/(km 2·a), the nitrate concentration in runoff reduced 27%, its loss amount is 16.18 kg/(km 2·a) with reduction of 7.68 kg/(km 2·a), in conclusion, the soil available nitrogen loss in level trench might reduce 6.57 kg/(km 2·a) than that of conventional tillage. Level trench might retain 25% of soil loss, increase 13% of total nitrogen enrichment in sediment than that of conventional tillage, accordingly, soil nitrogen loss amount reaches 457 kg/(km 2·a), it also reduces 13% of nitrogen loss than that of conventional tillage. Five years' rotation experiments show the erosion modules of rotation systems with a season black soybean, a season soybean, and two seasons black soybean, a black soybean, reach 896 and 984 t/(km 2·a) respectively, their modules are twice less than that of rotation system with broom millet and potato.
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2002年第1期70-73,共4页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家重点基础研究发展规划项目 (G2 0 0 0 0 1860 5 )
国家杰出青年科学基金 (4 0 0 2 5 10 6)项目资助
