干旱季节渭北果园土壤水分时空变化特征

Characteristics of spatio-temporal variation of soil moisture in Weibei orchards in dry seasons

针对渭北旱塬干旱季节主要发生在春季到夏初,制约苹果早期生长发育的客观实际,对渭北旱塬苹果园和农田从3月初到5月底,0～100 cm土壤含水量时空变化进行了研究。结果表明:冬春季渭北果园土壤含水量明显高于农田,进入春季随着果树萌发并进入生长旺盛季节,果园土壤水分消耗较小麦农田更为明显,在0～100cm果园土壤耗水量显著,其中5月份0～60 cm土壤水分消耗更加明显。而农田土壤水分消耗层主要在0～30 cm。相对于农田而言,冬春季渭北果园土壤表现出极为明显的保墒性,有助于缓解春旱的威胁;而春季到夏初则表现为极为显著的土壤耗水性,土壤干燥化趋势明显,5月初为果园土壤水分管理的关键时期。

As the dry season occurs mainly in spring to early summer in Weibei area and restricts apple＇ s early growth, we study soil moisture content spatiotemporal characteristics in 0 - 100 cm soil layer from the early March to the end of May in Weibei dryland apple orchards and farmlands. The results indicate that the soil moisture content in Weibei orchards is obviously more than in farmlands in winter and spring. In spring, as fruiters sprout and grow fast, the soil moisture consumption of orchards is more than that of wheat farmlands, and orchard soil consumes water significantly in 0 ~ 100 em soil layer, but when May comes, the soil moisture consumption is majorly in 0 ~ 60 cm soil layers, while soil moisture consumption layer is mainly 0 - 30 cm in farmlands. Compared to the farmlands, Weibei orchards have more obvious moisture-preserving quality to ease the spring drought threat. However, soil moisture consumption shows very salient from spring to early summer, and the soil desiccation trend is clear, so early May is the key period to manage the orchard soil moisture.