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以高产杂交稻组合两优培九和国稻6号为材料,设置基肥:分蘖肥:穗肥比例分别为50:30:20,60:10:30和40:20:40的不同氮肥管理,研究了强化栽培(SRI)条件下不同氮肥运筹对土壤微生物及植株氮素利用的影响。结果表明,强化栽培下每穗粒数增加,不同处理的结实率差异不明显,不施氮肥千粒重下降。强化栽培下穗肥施入增加,其土壤的铵态氮含量提高。土壤铵态氮以穗分化期最高,在孕穗期、开花灌浆期和成熟期的土壤铵态氮含量较低,基本不足20 mg kg-1;而土壤硝态氮含量穗分化期最低,各处理之间均不到4mg kg-1,而孕穗期达到20mg kg-1以上,开花灌浆期略有下降,成熟期土壤的硝态氮含量高。强化栽培能促进土壤细菌和放线菌数量增加。在穗分化期和孕穗期土壤微生物中放线菌含量最多,细菌次之,真菌量最少;灌浆期和成熟期细菌最多,放线菌次之,真菌量远低于前两者。细菌数以穗分化期较低,孕穗期快速上升,灌浆期略下降,成熟期最高。真菌量开花灌浆期低,成熟期高。土壤放线菌数量在穗分化后基本呈现下降的趋势。后期施氮对放线菌有一定的促进作用。另外,在等量的氮肥水平下,增施穗肥有利于提高籽粒的含氮量,水稻的氮吸收利用率品种间差异较大,强化栽培下两优培九品种氮吸收利用率提高。
High-yielding hybrid rice combinations, Liangyoupeijiu and Guodao 6, were used to study the effects of different nitrogen management practices, such as basal fertilizer: tillering fertilizer: panicle fertilizer ratio of 50: 30: 20,60: 10:30 and 40:20:40, Effect of Different Nitrogen Application on Soil Microbes and Nitrogen Utilization in Planting (SRI). The results showed that grain number per spike increased under intensified cultivation, the difference of seed setting rate was not obvious under different treatments, and the grain weight without nitrogen fertilizer decreased. Under the condition of intensive cultivation, the amount of ammonium nitrogen in soil increased with the increase of spike fertilizer application. Soil ammonium nitrogen had the highest spike differentiation stage and the soil ammonium nitrogen content was low at booting stage, flowering filling stage and mature stage, which was less than 20 mg kg-1, while the soil nitrate nitrogen content was the lowest during spike differentiation stage. Less than 4mg kg-1, while the booting stage reached more than 20mg kg-1, a slight decrease in flowering and filling stage, and high nitrate content in mature soil. Fortified cultivation can promote the increase of soil bacteria and actinomycetes. Actinomycetes were the most abundant in the soil microorganisms at the stage of spike differentiation and booting stage, followed by the bacteria, with the least amount of fungi. Bacteria were the most during the filling and maturing stages, followed by actinomycetes, and the fungal amount was much lower than the former two. The number of bacteria in spikes was lower, the booting stage increased rapidly, the filling stage decreased slightly and the maturity stage was the highest. Fungi flowering stage filling low, high maturity. The number of soil actinomycetes basically showed a downward trend after spike differentiation. Nitrogen late actinomycetes have a certain role in promoting. In addition, under the same amount of nitrogenous fertilizer, increasing the amount of spike fertilizer was beneficial to increase the nitrogen content of the grain, and the nitrogen absorption and utilization rate of rice varied greatly among cultivars. The nitrogen absorption and utilization rate of Liangyoupeijiu increased under intensive cultivation.