Guan'gai paishui xuebao (Oct 2023)
The Effect of Controlled Drainage and Nitrogen Fertilization on Growth, Nitrogen Uptake and Yield of Cotton
Abstract
【Objective】 Soil nitrogen and groundwater table are two abiotic factors affecting crop growth in the middle and low reaches of the Yangtze River in Southern China. This paper aims to investigate the combined impact of nitrogen fertilization and controlled drainage on growth, nitrogen uptake and yield of cotton. 【Method】 The variety Jinghua Mian 112 was used as the model plant, and the experiment consisted of two drainage treatments: conventional drainage (FKS) and controlled drainage (KS). Each irrigation had five nitrogen treatments: applying 0 (N0), 90 (N1), 180 (N2), 270 (N3) and 360 kg/hm2 (N4) of nitrogen. In each treatment, we measured the leaf SPAD at fertility stage, plant height and leaves at blooming stage, dry matter accumulation in different organs at maturity stage, as well as nitrogen uptake, and yield of the cotton. 【Result】 Compared with FKS, controlled drainage combined with a reduction in nitrogen application significantly increased leaf SPAD and plant height at flowering stage, dry matter accumulation and nitrogen uptake at maturity stage, boll numbers per plant, boll weight per boll and yield at maturity stage. Reducing nitrogen application without implementing controlled drainage reduced cotton yield, while under controlled drainage, reducing nitrogen application from N4 to N3 did not give rise to a noticeable reduction in cotton yield. KS+N3 increased the dry matter mass, nitrogen uptake per unit dry matter, and total nitrogen uptake in the bud and boll, significantly. 【Conclusion】 Reducing nitrogen application currently used by farmers by 25% combined with a controlled drainage is not only beneficial to cotton growth and promotes dry matter accumulation, but also increases nitrogen uptake and its subsequent allocation to reproductive organs, thereby increasing cotton yield.
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