土壤容重对土壤供氮能力及棉花吸收利用氮素的影响

本文应用~(15)N示踪法研究不同土壤容重对土壤供氮能力及棉花吸氮的影响。阐明了丘陵黄棕壤地区棉花低产的原因是棉田土壤容重过大,使土壤的供氮能力——A_N值显著下降,棉株对氮素养分的吸收量减少,而且延缓了氮素养分由营养器官向生殖器官的转运。降低土壤容重是挖掘丘陵黄棕壤地区棉田增产潜力的有效施施。

THE EFFECT OF SOIL VOLUMETRIC WEIGHT ON NITROGEN SUPPLYING ABILITY OF SOIL AND ABSORPTION,UTILIZATION OF NITROGEN BY COTTON

The study on nitrogen supplying ability ot soil and nitrogen absorption by cotton plant under different soil volumetric weight showed that the low cotton yield in yellow-brown soil with clay loam texture of hilly region was due to the heavy volumetric weight. In this case, soil nitrogen supplying ability-AN value and amount of nitrogen absorption by cotton plant were decreased.The translocation of nitrogen nutrient from vegetative organ to reproductive organ was delayed.Reducing the soil volumetric weight by tillage would be effective for increasing the yield and improving quality of cotton in yellow-brown soil of hilly region.