基质配方和灌溉方式对生菜根系和产量的影响

Lettuce Yield and Root Distribution in Substrates under Drip Irrigation and Micro-sprinkler Irrigation

为筛选高产的生菜栽培基质配方及配套灌溉方式，根据滴灌和微喷灌水分在基质中的分布特点，研究了4种有机基质和2种灌溉方式下生菜产量和根长密度分布状况，分析了在滴灌和微喷灌条件下生菜根长密度剖面相对分布的异同，提出了生菜根长密度垂向分布模型及生菜产量和根长密度的关系模型。结果表明：滴灌处理在12cm以下基质层含水率明显高于上层基质，微喷灌处理基质水分主要集中在15am以上基质层且水分分布较均匀。复配基质栽培生菜的根长密度比纯醋糟基质高27％，且在剖面的垂直分布随深度增加而递减；微喷灌下生菜根系集中于表层（0—6cm），占71％以上，较滴灌有上移现象。复配基质栽培生菜产量比纯醋糟基质高10％。灌溉方式对生菜产量影响具有季节性，春季滴灌的生菜产量比微喷灌高22％以上，夏季滴灌的生菜产量比微喷灌低11％。选用复配基质进行栽培，春、夏季分别采用滴灌和微喷灌的方式最有利于生菜高产和根系的生长。

The lettuce yield and root distribution were studied in four cultivation substrates under drip and micro-sprinkler irrigation. And the vertical distribution model, lettuce yield and root length density model, and the differences and the similarities of root density relative distribution on profile were analyzed. The obtained results showed that the substrate moisture mainly distributed in lower level and evenly in 0 - 15 cm respectively under drip irrigation and micro-sprinkler irrigation. The lettuce root length density cultivated in compound substrates were higher 27% at least than that in pure vinegar cultivation. More than 71% of the root system was mainly distributed in shallow substrates （0 - 6 cm） under micro-sprinkler irrigation. The lettuce yield cultivated in compound substrates were higher 10% at least than that in pure vinegar cultivation, and was higher 22% at least than micro-sprinkler irrigation in spring, while it was lower 11% at least in summer.