论文部分内容阅读
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。
Taking the 7-year summer maize-winter wheat rotation system positioning experiment in Guanzhong area of Shaanxi Province as an example, the balance of nitrogen, phosphorus and potassium in soil under different cultivation patterns and nitrogen application rates was analyzed by using nutrient input amount and apparent nutrient balance Status and its relationship with soil nutrient content. The results showed that the deficit status of NPK and potassium nutrition in the two straw mulching patterns (straw mulching pattern and furrow pattern) were lower than the conventional patterns and water control patterns, indicating that straw mulching plays an important role in the balance of soil nutrient status . When the nitrogen application rate was N 120 kg / hm2 per season, the soil nitrogen balance was basically reached. When the nitrogen application rate was N 240 kg / hm2, the soil nitrogen surplus increased significantly, with an average of 1471 kg / hm2. The results showed that there was a significant positive correlation between the total N balance and soil available P and available K in the 0-2 m section of soil with different treatments, and the soil nitrogen balance increased 100 kg / hm2, 0-2 m soil nitrate nitrogen accumulation increased about 38.3 kg / hm2; soil phosphorus and potassium balance for each reduction of 100kg / hm2, soil available phosphorus and available potassium decreased by about 3.5 mg / kg and 1.0 mg / kg, indicating that nutrient balance of farmland determines the growth and decline of soil nutrients.