山地烟区土壤养分变异及测土施肥合理取样密度

Soil Nutrients Variation and Rational Sampling Density for Soil Testing and Fertilization Recommendations in Mountainous Tobacco Planting Areas

分析了山地烟区不同尺度区域及取样密度条件下土壤属性指标的变异,探讨了实施测土施肥的土壤合理取样密度。结果表明,不同的土壤属性指标在不同尺度条件下的变异系数和偏移量差别很大,土壤pH的变异系数和偏移量较小,而且随取样尺度的变化也不明显;土壤速效磷等养分的变异系数和偏移量较大,且随着尺度的变小而明显降低。在90%的置信水平和10%以内相对误差条件下,根据Cochran针对区域随机取样而提出的最佳取样计算公式得到研究区域土壤碱解氮、速效磷、速效钾、交换性镁、有效锌的合理取样密度分别为1.21、0.22、1.01、0.93、0.32 hm2采集1份土样;考虑采样成本和烟草施肥的实际,在实施测土施肥的过程中采样密度可以降低到0.52 hm2采集1份土样。

Soil property and nutrients variation under different scale and sampling density in mountainous tobacco planting area were analyzed,and rational sampling density for soil testing and fertilization recommendations was studied.Results showed that,in different scale,large differences of variation coefficient and offset were observed among the soil properties or the contents of nutrients.For soil pH value,the variation coefficient and offset were relatively low,and changed rather small with the sampling scale.Whereas,the variation coefficients and offsets of soil available P and other nutrients were relatively higher,and decreased with the sampling scale.Under the confidence of 90% and relative error of 10%,rational sampling density for soil available N,available P,available K,exchangeable Mg and available Zn in soil testing and fertilization recommendations was 1.21,0.22,1.01,0.93 and 0.32 hm2 per sample,respectively.Taking sampling cost and tobacco fertilization status,0.52 hm2 per sample was suggested to be practical.