磷肥减施对玉米根系生长及根际土壤磷组分的影响.pdf

磷肥减施对玉米根系生长及根际土壤磷组分的影响 陈磊;云鹏;高翔;卢昌艾;刘荣乐;汪洪 【摘要】[Objectives]Winter wheat-summer maize rotation is the most common agricultural production system in the North China Plain. Excessive phosphorus (P) fertilization in wheat is concerned in this area, which might result in low fertilizer use efficiency and potentially pressure on the environment. The objective of this paper was to investigate the possibility and potential of reducing application rate of P fertilizer in winter wheat- summer maize crop rotation systems.[Methods]A field experiment was conducted on fluvo aquic soil in Hengshui City, Hebei Province. Four rates of P2O5 application rate of 0, 112.5, 150.0 and 187.5 kg/hm2 were set in winter wheat. After harvest of wheat, summer maize was planted without tillage. The grain yields, biomass and P content in above ground parts of maize were investigated; Root analysis system WinRHIZO was used to determine the root length and diameter; and the contents of different fraction of soil P were analyzed at harvest.[Results]Compared to current farm’s P2O5 input rate of 187.5 kg/hm2, the maize grain yield, total root length, average root diameter and soil Olsen-P contents were not significantly affected in treatment of P2O5112.5 and 150.0 kg/hm2 for three years’ period. Under no P fertilizer application treatment, the maize yield and soil available P contents in the third year started to decline, the organic P contents in the rhizosphere soils were lower than in the non- rhizosphere soils in 2009 and 2010 year; the amounts of moderately labile organic P in soils were higher at maize seedling and mature stage than at other growth stages in 2008. When less P fertilizer was applied, moderately labile organic P contents in rhizosphere soils were remarkably lower than in non-rhizosphere at maize seedling stage. The concentrations of Ca2-P, one of inorganic P forms in soils, declined during maize growth season. The contents of Ca10-P, Ca8-P, O-P