极端干旱区滴灌条件下葡萄茎流变化规律研究

Experiments on variation of grape sap flow under drip irrigation in extremely arid areas

为探究极端干旱区滴灌葡萄植株茎流变化规律及其影响因素,本文采用Flow4-DL包裹式茎流计监测滴灌和沟灌条件下葡萄植株的茎流变化规律,研究了茎流速率的变化规律与气象因子的相互关系,以及日茎流量与参考作物蒸发蒸腾量之间的关系。研究结果表明:在晴天,葡萄植株茎流速率的日变化呈现双峰曲线;在阴天,葡萄植株茎流变化曲线呈现多峰型;通过对各环境因子与葡萄植株茎流进行偏相关分析,得到茎流与光合有效辐射、风速极显著相关,与饱和水汽压显著相关,与温度、湿度不显著相关,相关程度依次为:光合有效辐射>风速>饱和水汽压>空气湿度>空气温度;采用逐步删除法进行多元回归分析,得到茎流与光合有效辐射、风速、饱和水汽压具有较强的线性相关关系,回归方程达到极显著水平;滴灌和沟灌情况下日茎流量与参考作物蒸发蒸腾量呈显著线性相关关系,且沟灌的相关性高于滴灌。

To explore the variation law and affecting factors of grape sap flow under drip irrigation, the Flow4 - DL was used under furrow irrigation and drip irrigation in extremely an arid areas. The variation of sap flow rates, meteorological factors and relationship between daily sap flow and reference crop evapotranspiration were studied. The results showed that diurnal variation of grape sap flow rates displayed single peak curves in sunny day, and multi peaked curves in cloudy day. With partial correlation analysis to each environmental factor and sap flow, it was obtained that the sap flow was highly significantly correlated with photosynthetic active radiation and wind speed, significantly correlated with saturated vapor pressure, but not significantly correlated with air temperature and air humidity. The sequence of correlation degree was. photosynthetic active radiation 〉 wind speed 〉 saturated vapor pressure 〉 air humidity 〉 air temperature. The multiple stepwise regression analysis showed that there is a strong linear relationship between sap flow and photosynthetic ally active radiation, wind speed, saturated vapor pressure, and the regression equation achieved a highly significant level. It showed significant linear correlation between daily sap flow and reference crop evapotranspiration under furrow irrigation and drip irrigation, an.d the correlation degree of furrow irrigation was higher than that of drip irrigation.