不同绿肥复种及还田期对拉萨河谷农田土壤理化性状的影响

Effect of Different Multiple Planting of Green Manure and Returning Times on Soil Fertility in Farmland of Lhasa River Valley

为明确不同生长周期各绿肥品种还田后土壤养分效果差异,通过田间试验,设置不同还田期,测定不同豆科绿肥还田后不同时期土壤有机质、全氮、速效磷、速效钾含量的变化。结果表明,雪莎(H)、箭筈豌豆(J)、中青1号(Z)3种绿肥植物还田均能改善土壤肥力。其中,箭筈豌豆、复种60 d处理还田效果最明显。其N、P、K养分还田量最高,翻压还田后能有效地降低土壤容重;较对照处理,土壤有机质、全氮、速效磷含量分别增加了1.22 g/kg、0.05 g/kg、110.51 mg/kg。

In order to clarify the different effects of green manure varieties returning to the field after different growth cycles on soil nutrients,field experiments were conducted to determine the variation of soil organic matter,total nitrogen,available phosphorus and available potassium contents at different periods after returning to the field of green manure varieties.The results showed that the returning of three green manure varieties,fenugreek(H),common vetch(J)and Zhongqing No.1(Z)could improve soil fertility.The treatment of common vetch(J)variety after two months of multiple planting was the most obvious effect.It could supply more N,P,K nutrients to the soil,and could effectively reduce the soil bulk density.In addition,compared with the control treatment(fallow),the contents of organic matter,total nitrogen and available phosphorus in soil were increased by 1.22 g/kg,0.05 g/kg and 110.51 mg/kg.