棉花膜下滴灌根系发育规律的研究

Study on Cotton Root Development and Spatial Distribution under Film Mulch and Drip Irrigation

研究了棉花常规灌溉、干播湿出和冬灌 +滴灌三种处理根系分布规律。结果表明 ,干播湿出棉花根量较少但须根量较大 ,根冠比较小 ,根系入土浅 ,生长发育提前。滴灌棉花浅层根系分布量增多 ,干播湿出尤其明显。地膜覆盖棉花膜内根系的分布量显著高于膜间的根系分布量。干播湿出棉花窄行根量较高 ,而常规灌溉和冬灌 +滴灌处理由于根系间对空间、养分和水分的竞争作用 ,窄行根系的分布量低于膜间和膜内根量之和。干播湿出在花铃期铃重、根系载铃量显著高于其它处理 ,生育期比其它处理提前 。

Cotton root spatial distribution was studied in 3 kinds of water regimes: conventional furrow irrigation (CI), winter storage irrigation plus drip irrigation (SCI) and drip irrigation (without winter storage irrigation, DI). Results showed that compared with CI and SCI treatments, the amount of root and root/canopy ratio in DI treatment was small, root depth was lower but the amount of fibre roots was larger and root development process was earlier than SCI and CI treatments. Drip irrigation induced more amount of root growing in upper part of soil, especially in DI treatment. The amount of root growing under film was larger than that growing under bare land. The amount of root growing in narrow cotton rows of DI treatment was larger than total amount of root growing in wide cotton rows and bare land whereas due to moisture, nutrition and spatial competitions among roots in narrow cotton rows, the amount of root growing undernarrow cotton rows was smaller than the total amount of root growing in wide cotton rows and bare land in SCI and CI treatments. The weight of boll and boll loading of DI treatment were much higher than other 2 treatments during blooming boll period, showed drip irrigation promoted cotton growth process and had superiority of increasing cotton yield.