白三叶草坪蒸散和光合蒸腾速率日变化研究

光合和蒸腾作用是植物的两个密切相关的生理过程,对于植物生长有着直接而重大的影响.在不同供水下,研究植物生理日变化时段性特征及其生理生态机理,对寻求提高作物水分利用效率具有积极的意义.该试验于天津经济技术开发区内测定了不同灌水处理下,白三叶的蒸散、光合蒸腾日变化,探求在特定地区植物生理日变化与土壤水分之间的关系,探讨草坪节水灌溉的途径.结果表明:不同灌水处理之间的白三叶蒸散日变化规律基本一致,其中从11:00—14:00这一阶段的蒸散值较大;水分条件对白三叶光合速率、蒸腾速率和气孔导度的影响非常大,都随灌水量增大而增大.

Diurnal changing features of ET, Pn, and Cs of Trifolium repens L.

As the two physiological processes of plants, photosynthesis and transpiration are not only related closely, but also have direct and significant effects on plant growth and development. Therefore, it is significant to promote water utilizing rate of plants to study the diurnal changing features of evapotranspiration and transpiration of plants as well as their physiological functions. The authors analyzed the diurnal changing features of evapotranspiration (ET), photisynthesis (Pn), and stomatal conductance (Cs) of Trifolium repens L. under four different irrigation treatments, to probe into the relationship between physiological diurnal changing features of plants and soil moisture. The results showed that, under four different irrigation treatments, the tendency of the ET diurnal change was conformable. The photosynthesis rate, transpiration rate and stomatal conductance increased along with irrigation treatments.