摘要
从2000年10月到2004年4月,通过大田试验研究了半干旱黄土高原地区,苜蓿草地、苜蓿-作物轮作农田以及常规耕作农田中土壤有机碳、土壤全氮、土壤微生物生物量与土壤轻组物质的变化规律。结果表明,土壤轻组有机碳和氮含量苜蓿-作物轮作系统高于苜蓿草地。土壤微生物量碳和氮,以及它们占土壤有机碳和土壤全氮的比苜蓿-作物轮作系统高于常规耕作农田。土壤呼吸商苜蓿-作物轮作系统低于苜蓿草地和常规耕作农田。14年生苜蓿草地土壤微生物含量高,分解腐化植物碎片的能力高,但土壤有机物质利用不经济,3年中土壤全氮含量并无显著增加,这说明该系统较高的物质循环能力仅维持高的土壤肥力,而不能继续提高土壤肥力。苜蓿-作物用地系统不但能克服长时间种植苜蓿造成的物质循环的浪费,而且维持了良好的土壤肥力,促进了土壤氮素的有效利用。
A field experiment was conducted from October 2000 to Spring 2004 to examine soil microbial biomass C and N,soil light fraction C and N among the soils of alfalfa grassland, alfalfa-crop system, and conventional field systems（CS） in the semiarid loess plateau region of northwest China. The results showed that light fraction C and N pools of the alfalfa-crop rotation systems were higher than in alfalfa grassland. Microbial biomass C and N, as well as their ratios to the total in soils of the alfalfa-crop systems were higher than in conventional systems. Metabolic quotient was lower in the alfalfa-crop rotation systems than in 14-year-alfalfa grassland（AS14） and CS. The high soil microbial biomass, high decomposition ability for recently added plant material, but not utilizing the available resources more economically, indicated that high organic matter circulation in AS14 just kept soil fertility and didn＇t increase soil fertilizer. The alfalfa-crop rotation systems not only improved circulation of organic matter in 14-year-alfalfa grassland, but also maintained soil fertilizer over conventional farming system, and increased soil N utilization.
出处
《水土保持学报》
CSCD
北大核心
2006年第4期132-135,142,共5页
Journal of Soil and Water Conservation
基金
教育部重大科技创新基金
河南科技大学人才科学研究基金
关键词
苜蓿作物轮作
微生物生物量
轻组碳和氮
土壤有机碳
土壤肥力
alfalfa and crop rotation
microbial biomass
light fraction C and N
soil organic C
soil fertility
