不同灌溉方式对棉花根系分布的影响研究

Effect of Different Irrigation Methods on Cotton Root Distribution

设置痕量灌、逐日地下滴灌、膜下滴灌、常规地下滴灌和棉花地面灌(对照)等5种灌溉方式,研究不同灌溉条件下棉花根系的空间分布规律。结果表明:逐日地下滴灌、痕量灌对棉花根系干物质量积累的影响显著高于膜下滴灌、常规地下滴灌等滴灌方式,其中逐日地下滴灌处理根系干物质累积量大,水平分布均匀,更有利于根系生长。各处理棉花根系垂向分布范围在0~50 cm,主要聚集范围为0~20 cm、占总根重73.80~76.91,土层30~50 cm随着深度的增加根重占比逐渐减小,逐日灌水处理土壤横向剖面含水率相对其他处理变幅较小。根系水平方向范围在0~70 cm,各处理呈显著的向水性分布,且集中分布于膜下窄行与膜间,窄行根重占比相对膜间更大,但逐日地下滴灌处理水平方向分布较为均匀。综上所述采用逐日地下滴灌节水方式对棉花根系干物质积累更有利,根系水平分布更为均匀。

In this paper,five irrigation methods,including trace irrigation,daily subsurface drip irrigation,submembrane drip irrigation,conventional subsurface drip irrigation and cotton ground irrigation(control),were set up to study the spatial distribution of cotton roots under different irrigation conditions.The results showed that:the effects of subsurface drip irrigation and trace irrigation on dry matter accumulation of cotton roots was significantly higher than that of submembrane drip irrigation and conventional subsurface drip irrigation.Among them,daily subsurface drip irrigation was more beneficial to root growth because of its large dry matter accumulation and even horizontal distribution.The vertical distribution range of cotton roots in each treatment was 0~50 cm,and the main aggregation range was 0~20 cm,accounting for 73.80%~76.91%of the total root weight.The proportion of root weight in the soil layer of 30~50 cm decreased gradually with the increase of depth,and the water content in the transverse section of the soil treated with daily irrigation was less varied than that of other treatments.The horizontal direction of roots ranged from 0 to 70 cm,and each treatment was significantly water-oriented and concentrated in the narrow row and between the films.The root weight ratio of the narrow row was larger than that between the films.However,the horizontal direction distribution of daily subsurface drip irrigation treatment was relatively uniform.To sum up,the water-saving method of daily subsurface drip irrigation is more beneficial to dry matter accumulation and the root system is more evenly distributed.