施氮量对华南双季超级稻产量和干物质生产的影响

Effects of Nitrogen Rate on Grain Yield and Dry Matter for Double Cropping Super Rice in South China

以两优培九、Y两优1号、玉香油占和黄华占为材料,研究了施氮量对华南双季超级稻产量和干物质生产的影响。结果表明,施氮量对产量、有效穗数、每穗粒数和总颖花数的影响达显著水平,对结实率和千粒重的影响不显著,2011年N2（225 kg/hm^2）条件下的产量显著高于N1（112.5 kg/hm^2）,早、晚稻增幅分别为6.33%-13.39%和11.53%-25.06%,而2012年N1（161-176 kg/hm^2）和N2之间的产量差异不显著;与N0相比,增施氮肥可以显著增加干物质量,提高作物生长速率,但2012年N1和N2之间差异不显著。2年各品种N1的氮肥利用率要高于N2,其中氮肥偏生产力达到显著水平。因此,华南双季稻区早、晚稻在施氮量为161-176 kg/hm^2的条件下分别种植生育期较长和生育期较短的超级稻品种,可以在足够穗数的基础上增加每穗粒数或穗重并积累较多的干物质,从而有利于产量和氮肥利用率的提高。

In order to study the effect of nitrogen rate on grain yield and dry matter for double cropping super rice in South China,field experiments were conducted with Liangyoupeijiu, Yliangyou 1, Yuxiangyouzhan and Huanghuazhan as materials. The results showed that there was significant difference in effective panicles, grains per spike, spikelets per m2 and grain yield, however, there was no significant difference in grain filling rate and 1000-grain weight. Compared with N1 treatment, the grain yield of early rice and late rice cultivars in N2 treatment were significantly increased by 6.33%-13.39% and 11.53%-25.06% in 2011, respectively, but were no significant difference in 2012. On average, the highest or higher grain yield were attained by Y Liangyou 1 and Yuxiangyouzhan in early rice and late rice, respectively, and compared to late rice, the yield of early rice were increased by 4.58%-33.94%. Furthermore,the effective panicles had the highest contribution to grain yield, then grains per panicle. Compared with N0, increased nitrogen rate would significantly improve dry matter and crop growth rate, but there was no significant difference between N1 and N2 in 2012. How-ever, the N-use efficiency of N1 was higher than N2 for all cultivars in two years, and there was significant difference in partial factor productivity of applied nitrogen（PEP）. Therefore, in nitrogen rate of 161-176 kg/hm^2, the adoption of long and short growth period super rice cultivars as early rice and late rice, respectively, would improve grain yield and N-use efficiency due to increasing grains per panicle or panicle weight and dry matter based on enough effective panicles in South China.