两种生态条件下氮素调控对不同栽培方式水稻干物质积累和产量的影响

Effects of nitrogen regulation on dry matter accumulation and grain yield of rice under different cultivation models and two kinds of ecological conditions

以Ⅱ优498水稻为试材,在温江和汉源两种生态条件下,研究了不同施氮量及氮肥运筹方式对宽窄行、三角形、扩行减株稀植和抛秧栽培4种栽培方式水稻干物质积累、产量及其构成因素的影响。结果表明,各栽培方式在两地最佳施氮量均为N 180 kg/hm2。在此施氮量下,宽窄行和三角形栽培氮肥运筹措施以基肥∶蘖肥∶穗肥比例为6∶3∶1最佳,扩行减株稀植栽培方式以5∶2∶3最佳,抛秧栽培温江点和汉源点分别为4∶1∶5和5∶2∶3最佳。不同栽培方式在温江点均可通过适宜的氮肥调控,提高群体颖花量和生物产量而获得高产;汉源点三角形栽培通过适宜的氮肥调控措施不仅生物产量极显著提高,还维持了较高的收获指数(H I),增产潜力显著高于其他栽培方式。此外,宽窄行栽培较扩行减株稀植栽培具有一定的边际效应,生态条件和氮肥调控措施的改变对其物质积累和产量的影响与后期群体大小和温光条件有关;抛秧栽培抽穗前干物质生产优势明显,在不同生态条件下采取适宜的氮肥后移措施来提高其抽穗后的干物质积累是其高产的关键。

The effects of nitrogen regulation on dry matter accumulation,grain yield and its components under different cultivations were studied in Wenjiang（WJ）and Hanyuan（HY）by using hybrid rice,Ⅱ-you 498.The cultivation models were wide-narrow row spacing cultivation,triangle cultivation,sparse planting by expanding spacing and reducing plant space,and scattered planting cultivation.The result indicates that the 180 kg/ha of nitrogen application is the optimum amount for all cultivation models.When the total nitrogen application amount is 180 kg/ha,the rational ratio of nitrogen application at the transplanting stage,tillering stage and booting stage is 6∶3∶1 under the wide-narrow row spacing cultivation and triangle cultivation,and is 5∶2∶3 under sparse planting by expanding spacing and reducing plant space.The ratios are 4∶1∶5 and 5∶2∶3 under scattered planting cultivation in WJ and HY,respectively.Each cultivation model is cable of obtaining high yield by increasing population spikelets and biomass yield under suitable nitrogen regulation in WJ.In HY,the biomass yield is significantly increased in the triangle cultivation under suitable nitrogen regulation,and the harvest index（HI） is high as well,so its potential yield is higher than those of other cultivation models.Compared to the sparse planting by expanding spacing and reducing plant space,the wide-narrow row spacing cultivation has a certain degree marginal effect,the effects of ecological condition and nitrogen regulation on dry matter accumulation and grain yield depend on crop population sizes at the late stage and conditions of temperature and light.The scattered planting cultivation has a great advantage in dry matter production before the heading stage,so increasing dry matter accumulation after the heading is key to get high grain yield by suitable postponing nitrogen measures under different ecological conditions.