水肥处理对基质栽培西瓜生长、水分利用效率及光合特性的影响

Effects of Water and Fertilizer Coupling on Growth, Water Use Efficiency and Photosynthetic Characters of Watermelon Cultivated by Organic Substrate

探讨水肥耦合效应对基质栽培西瓜生长状况与水分利用效率的影响,为基质栽培西瓜的高效生产提供科学依据。本试验在田间温室条件下,基质栽培西瓜"苏蜜8号",通过设置3个水分梯度和4个施肥梯度,研究不同水肥处理对西瓜产量、光合特性和灌溉水分利用效率的影响。试验结果显示,在中水处理(整季60L)下,施肥量为N-P_2O_5-K_2O (20g-10g-30g)的养分供应下,西瓜产量和植株生物量达最高值。水分、肥料及二者交互作用对西瓜产量和植株地下部生物量的影响都达到了显著水平(P<0.05),且影响大小顺序为肥料作用>水分作用>交互作用。灌溉水分利用效率随灌溉量的增加水分利用效率降低,在同一水分条件下,适量增肥可提高灌溉水利用效率。水肥交互作用对西瓜不同生育期内叶片净光合速率的影响均达显著水平(P<0.05),但对叶片蒸腾速率只有在膨瓜期内影响较大,在苗期影响蒸腾速率的主要因子是灌水量。

This study aims at discovering the relations of water and fertilizer coupling with the growth and water use efficiency of watermelon cultivated by organic substrate in order to provide a theoretical basis for high-efficient production of watermelon in greenhouse. Watermelon variety ‘Sumi 8’ was used, three irrigation levels and four fertilization levels were designed. The results showed that maximum yield and plant biomass were obtained in middle irrigation level(60L) and (20-10-30)g (N-P2O5-K2O) fertilization level. There were strongly synergistic effects between water and fertilizer on yield and plant root biomass of watermelon (P<0.05), and the effects were in order of fertilization > water > interaction. Water use efficiency of watermelon was reduced with the increasing of irrigation levels, but increased with the increasing of fertilizer under the same irrigation levels. The interaction effects of water and fertilization on photosynthetic characters of watermelon leaves were significant in different growth periods (P<0.05), but only significant on transpiration rate in the expansion period of watermelon.