滴灌灌水量对北京春茬露地生菜的影响研究

Research on Effects of Different Irrigation Amount on Spring Open Cultivation Lettuce in Beijing

为了探索春茬露地生菜滴灌条件下适宜的灌水量,设置了4种不同的滴灌灌水量处理,研究了不同灌水量对对生菜生长、品质和产量的影响,结果表明:在试验梯度范围内,不同的灌水量对生菜的株高、球径、Vc含量、硝酸盐含量等指标影响不显著,但极低水量处理的展开度、叶片数、单球重以及产量均显著低于高水处理。除可溶性固形物含量外,中水处理植株各指标均与高水处理差异性不显著。低水处理植株展开度、叶片数、单球重等指标与高水处理差异性不显著,但其可溶性固形物含量显著高于极低水量处理和高水处理,且该处理的水分生产效率达到最大,为33 kg/m^3。综合考虑植株生长、品质、产量和水分生产效率等要素,低水处理(实际灌水93.3 mm)最适宜春茬露地生菜的生产,其产量达到了41.96 t/hm^2。研究得出了春茬露地生菜各生育时期的作物系数,可以为实现春茬露地生菜滴灌施肥条件下的高效生产提供一定的科学依据。

In order to determine the suitable amount water application in lettuce under drip irrigation, 4 different treatments of water amount were set to study the impact of water amount on height, diameter, vitamin C and nitrate content in lettuce. The result showed that： within the threshold of 4 treatments, different water amount had no significant impact on height, diameter, vitamin C and nitrate content in lettuce, but the plot spike width, number of leaves, weight of single lettuce and yield in lowest amount of water were significantly lower than those in high amount of water; the indexes of lettuce under middle amount of water had no significant difference with that under high amount of water, except total soluble solids ; plot spike width, number of leaves, weight of single lettuce under low water amount had no significant difference with that under high water amount, but the total soluble solid was significantly higher than that under lowest water amount and high water amount, and the water used efficiency under low water treatment was the highest, up to 33 kg/m^3. Considering the factors of plant growth, quality, yield and water use efficiency etc., low water amount （93.3 ram） was the most suitable for lettuce grown in open field in spring, with the yield of 2 797 kg/hm^2. Also, the crop coefficients of lettuce in different growing stages were calculated, which couht give some instructions to lettuce production in open field in spring under drip irrigation.