平原地区农田土壤养分变异与合理取样研究

Study on Soil Fertility Variability and Evaluation Using Sampling Techniques in Field of the Plain Areas

本文以随机抽样方法取样、土壤养分系统研究法评价土壤养分状况 ,研究了华北平原地区及浙江绍兴水网平原农田土壤养分变异特性。通过分析不同村地块、同村地块不同取样方( 10 0× 10 0 m2 )、同取样方不同农户地块土壤养分的差异 ,结果表明 ,经过多年实行以家庭承包分散经营为主的生产方式之后 ,土壤养分地域性的差异仍然大于不同农户经营的相邻地块间的差异 ,这便为区域性的土壤养分管理和合理推荐施肥提供了依据。通过对两个平原地区大约2 0 hm2 面积的粮田进行抽样调查和统计分析 ,结果显示 ,同一取样区域土壤养分变异不大 ,多数养分的频数分布在 1～ 2个分级范围。根据统计学原理进行抽样估计 ,在两个平原地区面积大约2 0 hm2 的粮田上 ,用随机取样方法选择 8个农户地块取样 ,从统计上来说基本能满足其土壤肥力评价要求。

Soil fertility variability in field of the plain areas was studies. The analysis showed that variation of the soil nutrients among fields of different villages was greatest, followed by variation among fields from the same village, with the relatively small variation found among plots managed for several years by different farmers within one field. The result indicated that there is no great difference in soil fertility properties among the adjacent plots. Therefore it is reasonable to practise small regional specific nutrient management. Sampling study on two domains with each around 20 hectares in field of the two plain areas for soil fertility evaluation showed that frequency of most of the nutrient elements was in one to two grading range and there is no great variability in soil nutrient in the same domain. It is believed that randomized selection of 8 samples for each domain of the plain areas is statistically enough to estimate the soil fertility.