氮肥不同基追比例对水稻产量和氮素吸收利用的影响

以水稻"盛湘1号"为供试材料,在基础地力和施氮量相同的条件下,采用大田试验研究了氮肥不同基追比例对早稻产量和氮肥利用率的影响。结果表明:足够的分蘖肥能够通过促进植株分蘖数增多来提高早稻产量,平衡施用基-蘖-穗-籽肥则可通过增加有效穗数和籽粒数来保证水稻的高产;提高分蘖肥比例和穗肥比例以及平衡施用基-蘖-穗-籽肥均可以提高氮肥农艺利用率、氮肥生理利用率、土壤氮素依存率,但对氮肥偏生产力的影响不显著,与氮肥表观利用率呈现出负相关;氮肥不同基追分施比例处理间各时期植株体内氮素积累量差异显著,分蘖期、孕穗期和抽穗期是水稻吸收氮素养分的高峰期。

Effects of Different Ratios of Base to Topdressing for Nitrogen Fertilizer on Rice Yield and Nitrogen Absorption and Utilization of Rice

Filed experiments were conducted to study effects of different ratios of base to top dressing for nitrogen fertilizer on grain yield and N use efficiency of "Shengxiang 1" under the same soil basic fertility and nitrogen fertilizer rate.The results showed that adequate tillering fertilizer could increase yield by improving the tiller numbers of rice,while balanced fertilizer of base-tiller-panicle-granular fertilizer could increase yield by increasing number of effective panicles and grain.The fertilizer methods by improving the proportion of tillering fertilizer or panicle fertilizer,or balancing the application of base-tiller-panicle-granular fertilizer could promote N agronomic efficiency,physiological efficiency and dependency rate.But above methods had no significant effects on nitrogen partial factor productivity,and had negative effect on apparent nitrogen efficiency.There were significant differences among the amount of nitrogen accumulation in rice of each plant growing stages under different ratio of base to top dressing for nitrogen fertilizer.The peak periods of absorbing nitrogen appeared at tillering,booting or heading stage,therefore,the practice in rice production should balance base-tiller-panicle-granular fertilizer.