不同灌溉方式对棉花细根动态变化的影响研究

Growth and Senescence of Fine Roots of Cotton under Drip Irrigation Differ from Those under Flooding Irrigation

为了探明不同灌溉方式(滴灌、漫灌)对棉花细根动态变化的影响,利用CI-600植物根系生长监测系统,对2016年生长季内不同灌溉方式处理的棉花细根实施精准监测,获取了棉花细根根长、直径等相关数据,得到了现存量、生长速率(A)、死亡速率(D)及生死之比(RAD)等参数,研究了滴灌和漫灌条件下棉花细根生长、死亡及周转的差异。结果表明,不同灌溉方式下棉花细根现存量均呈"单峰"型变化曲线;在棉花生育期的前期,漫灌抑制了细根的生长,而在后期,滴灌促进了细根的死亡;滴灌棉花细根的A和D的最大值和平均值均高于漫灌棉花的;分析RAD发现,棉花生育期内细根动态表现为生死同步,且生长处于优势地位;滴灌棉花细根周转(0.88/0.67)高于漫灌棉花(0.77/0.61),与漫灌相比,滴灌使棉花根系的生命活动更加旺盛。

The development of plant roots depends on soil moisture,and this paper investigated experimentally how the fine roots of cotton respond to drip and flooding irrigations.The experiment was conducted in 2016 and the growth and senescence of the roots,including change in their lengths and diameters,were measured using theCI-600 root growth monitoring system,from which we calculated the growth rate（A）,the senescence rate（D）and the growth-senescenceratio（RAD）.The results showed that the biomass of the fine roots under the two irrigations reached a peak before declining drastically.Theflooding irrigation led to an early growth of the roots compared with the drip irrigation,while in the late growth stages,the roots senesce faster under drip irrigation than under flooding irrigation.The growth and senescencerates,both average and maximum,under drip irrigation were faster than under flooding irrigation.The RAD calculated from the data revealed that the roots grew and senesced simultaneously,althoughthe growth dominated over the senescence.The root turnover under drip irrigation was 0.88/0.67,slightly higher than that under flooding irrigation,which was 0.77/0.61.We also found that the roots under drip irrigation were more vigorous than those under flooding irrigation.