滴灌土壤湿润区对棉花根形与生物量积累的影响

Influence of Soil Wetting Pattern under Drip Irrigation on Cotton Root Structure and Root Biomass Accumulation

基于桶栽棉花试验,分析了5个土壤湿润区处理下棉花5个生育阶段(苗期、蕾期、盛花期、盛铃期、吐絮期)的根形与根系生物量的增长规律。结果表明,窄深型土壤湿润区下的棉花根形紧凑,而宽浅型土壤湿润区下的棉花根形扩展;整个生育期内棉花根系生物量的积累过程符合"S"型增长曲线,且可用Gaussian Model拟合;滴灌土壤湿润区影响到棉花根系生物量的积累过程,在棉花苗期、蕾期,窄深型土壤湿润区对棉花根系生长有利,而在棉花花期、铃期,宽浅型土壤湿润区对棉花根系生长更为有利;随着土壤湿润区由窄深变得宽浅,进入吐絮期后的棉花根系衰减速度加快。

Bucket-culture experiments were conducted to analyze the growth characteristics of cotton root structure and root biomass in seedling stage, bud stage, flowering stage, boll stage, and boll opening stage under five different soil wetting pattern treatments. The results showed that the narrow and deep soil wetting pattern resulted in compact root structure, while wide and shallow soil wetting pattern led to extended root structure. The accumulative process of cotton root biomass in the whole growth period accorded with the ＂S＂ shaped growth curve and could be fitted by Gaussian Model. Soil wetting pattern could influence the accumulative process of cotton root biomass. In the seedling stage and bud stage, narrow and deep soil wetting pattern was favourable for cotton root growth while wide and shallow soil wetting pattern was more favourable for cotton root growth in the flowering stage and boll stage. With the soil wetting pattern changing from narrow and deep to wide and shallow, the decay rate of cotton root biomass became faster after boll opening stage.