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影响土壤水平衡的两个主要因子——潜在蒸发蒸腾和土壤持水能力可用计算机(EPIC)模型来估算.用EPIC模型估算潜在蒸发蒸腾有5种方法;估算土壤持水能力有4种方法.在美国选5个地区进行模拟试验,来测定因土壤和气候所引起的差异.在一个给定地区,用不同的潜在蒸发蒸腾和土壤持水能力模型测定的水渗透和N淋溶所出现的差异一致.然而,这5个地区的水渗透和N淋溶通常随当地气候和土壤情况而有较大变化,不随估算方法而变.
The two major factors influencing soil water balance-potential evapotranspiration and soil water holding capacity-can be estimated using a computerized (EPIC) model. There are five methods for estimating potential evapotranspiration using the EPIC model; and four methods for estimating soil water holding capacity. Simulations were conducted in five areas of the United States to determine differences due to soil and climate In a given area, water infiltration and N-leaching as determined by different potential evapotranspiration and soil water capacity models However, the water infiltration and N leaching in these five areas generally vary greatly depending on the local climate and soil conditions, and do not change with the estimation method.