半旱地不同栽培模式及施氮下农田土壤养分表观平衡状况研究  

Net nutrient balance in soil under different cultivation pattern and nitrogen application rate in semiarid region

作　　者：刘瑞 戴相林 郑险峰 李生秀 周建斌 

机构地区：[1]四北农林科技大学资源环境学院,陕西杨凌712100

出　　处：《植物营养与肥料学报》2011年第4期934-941,共8页Journal of Plant Nutrition and Fertilizers

基　　金：国家“十一五”科技支撑计划课题(2008BADA4B09);国家自然科学基金重点项目(30230230);西北农林科技大学创新团队项目资助

摘　　要：以在陕西关中地区连续7年的夏玉米-冬小麦轮作体系定位试验为对象,采用养分投入量与作物养分携出表观平衡法分析了不同栽培模式及施氮量下土壤氮磷钾养分的平衡状况及其与土壤养分含量间的关系。结果表明,两种秸秆覆盖的模式(即覆草模式和垄沟模式)土壤氮磷钾养分的亏缺状况均较常规模式及控水模式低,说明秸秆还田在平衡土壤养分状况方面具有重要作用。当施氮量为每季N 120 kg/hm2时,土壤氮素基本达平衡状况;而施氮量达N 240 kg/hm2时,土壤氮素盈余量显著增加,平均达1471 kg/hm2。不同处理土壤氮平衡值与土壤0—2 m剖面累积的硝态氮以及土壤磷、钾的总平衡值与土壤有效磷及速效钾间呈极显著正相关,土壤氮平衡值每增加100 kg/hm2,0—2 m土壤剖面硝态氮累积量约增加38.3 kg/hm2;土壤磷、钾的平衡值每降低100kg/hm2,土壤有效磷和速效钾含量分别降低约3.5 mg/kg和1.0 mg/kg,说明农田养分平衡盈亏决定了土壤养分的消长规律。A 7-year＇s field experiment was used to study the effects of long-term cultivation pattern and nitrogen application rate on N,P and K nutrient net balances soil under maize-wheat rotation system,and their relationship with nutrient contents in soil was also evaluated.The results showed that the nutrient deficits in soils under the two patterns with straw additions,i.e.,mulching and furrow planting,were lower than that of conventional and water-controlling patterns,indicating that straw addition plays an important role in balancing the nutrients in soil.Nitrogen in soil added with 120 kg/ha of nitrogen fertilizer was near balance;when nitrogen fertilizer was increased to 240 kg/ha,nitrogen accumulation in soil increased significantly（averaged at 1471 kg/ha）.There were significantly positive relationships between nitrogen balance value in soil and nitrate accumulated in 0-2 m soil profile,and P and K balance values in soil and Olsen-P and available K in soil.The accumulated nitrate increased about 38.3 kg/ha when N balance in soil was increased at each 100 kg/ha.The deficit of each 100 kg/ha of P and K nutrients in soil,Olsen-P and available K in soils declined about 3.5 mg/kg and 1.0 mg/kg,respectively.It indicates the deficit and accumulation of available nutrients in soils was mainly determined by the nutrient balances in soil.

关 键 词：栽培模式 夏玉米-冬小麦轮作 施氮量 养分平衡 

分 类 号：S158.3[农业科学—土壤学] S318[农业科学—农业基础科学]