漳河灌区水稻种植前后土壤养分变化研究

Variability of Soil Nutrients before and after the Rice Planting in Zhanghe Irrigation District

利用湖北漳河灌区典型试验区取样点上的土壤养分数据,运用经典统计学的有关理论分析了水稻种植前土壤养分的背景值。结果表明,试验区土壤氮元素供应较充分,土壤总氮和碱解氮的平均含量分别达到了1.140g/kg和107.980 mg/kg,但是试验区土壤磷元素相对缺乏,总磷和速效磷的含量分别仅有0.642 g/kg和16.619mg/kg,并且磷元素含量在区域内的变异性也很大。同时,对在区域内选取的3块典型田块的土壤养分在水稻种植前后的变化进行了对比分析,分析结果显示,土壤总氮和总磷在水稻种植后的含量平均降幅分别为26.28%和40.9%,统计学显著性检验证明氮元素减少不明显,而磷元素减少显著。结合地统计学的有关理论应用克里格空间插值,对取样点外区域土壤养分背景值进行了估计,并做出养分分布等值线图,为指导农户科学合理施肥,提高肥料利用效率和减轻农田面源污染提供参考。

This paper,according to the soil nutrient data of the sampling points in representative experimental area of Zhanghe irrigation system,Hubei Province,combined with the corresponding theory of classical statistics,has explored the background values of soil nutrient before rice planting.The result shows that nitrogen is sufficient in this area,with the average TN and available nitrogen content of 1.140 g/kg and 107.980 mg/kg,whereas,phosphorus in this area is relatively insufficient,with the average TP and available phosphorus content of only 0.642 g/kg and 16.619 mg/kg,and moreover,the variability of phosphorus is extremely high.Besides,the variability of soil nutrient before and after rice growth in three representative parcels selected in the experimental field is also analyzed,which reveals that the TN and TP content decreases separately by 26.28% and 40.9% after rice growth.By statistical significant test,it is proved that the loss of nitrogen is ignorable,while the loss of phosphorus is distinct in this process.At last,through space interpolation by Kriging method of geostatistics,the soil nutrients in the non-sampling areas are estimated,and the isoline maps of distribution of soil nutrients in the whole areas are made,which could be references to achieve efficient use of fertilizers and to prevent agricultural non-point source pollution.