黄土旱塬区苹果园土壤水分动态

Soil moisture dynamics of apple orchard in Loess Plateau dryland

选取黄土旱塬区盛果期果园,于2009—2013年对0~500 cm土层土壤含水量进行连续监测,了解其土壤水分动态变化规律.结果表明：平水年,苹果园耗水主要发生在0~300 cm土层;年降水量小于400 mm时,果树主要消耗300 cm以下土层土壤水分;受年降水量和苹果耗水的共同影响,200~300 cm土层是土壤水分的最大波动层;苹果园4—6月底季节性干旱明显,土壤水分的蓄积主要发生在7—10月中旬,该期的土壤蓄水能有效缓解下一年的春季干旱.

The soil moisture of 0-500 cm soil layer in a dryland orchard at its full fruit period was measured from 2009 to 2013 to explore the soil moisture dynamics. Results indicated that soil water consumption mainly occurred in the soil layer of 0-300 cm in normal rainfall year and below the 300 cm soil layer when the annual rainfall was less than 400 ram. The soil moisture in the 200-300 cm soil layer fluctuated most and was affected by rainfall and apple consumption. Seasonal drought usually happened between April and late June, while the accumulation of soil moisture mainly oc- curred in the rainy season from July to mid-October to alleviate the drought effectively in next spring.