苹果园表层与深层土壤水分的转换关系研究

2005年4-10月期间利用Trime土壤水分速测系统。测定苹果园内0-180cm范围内的土壤水分。建立了土壤水分随深度变化曲线及利用表层水分进行深层水分的预测模型。结果表明，0—50cm范围内土壤水分变化剧烈为强变异，50cm以下土壤水分变化随深度增加逐渐变弱星中等强度变异。0—10cm和0-30cm土层与深层水分的拟合效果较差，预测结果相对误差大于10％的占55．56％和50．00％。利用0-50cm土层水分进行深层水分预测时精度较高．预测结果中相对误差小于10％的占88．89％．最大相对误差为12．98％，且以经验关系的预测效果最为理想。故本地区进行深层水分预测的最佳表层土壤深度为0-50cm土层。

On Conversion Relation between Surface and Deep Soil Water of Apple Orchard

The soil water within 0-180cm was determined with Trime system from April to October in 2005. Curve between soil water and soil depth, and models using surface soil water to forecast deep soil water, were founded The results showed that the variance of 0-50cm soil water was strong,with increasing of soil depth, the variance of more than 50cm soil water became middling.Furthermore the corresponding effects of 0-10cm and 0-30cm and deep -soil water were worse,and the relative error of results more than 10% accounted for 55.56% and 50.00% respectively. The forecasting precision of 0-50cm layer was higher obviously than other layers, and the relative error of results less than 10% accounted for 88.89% and the biggest relative error was 12.98%, furthermore the forecasting effect of experience relation was best. As a result,the best surface depth of soil layer to forecast deep soil water was 0-50cm layer in this region.