为明确高海拔机插粳稻适宜施氮量,在海拔为1673 m的保山地区,以常规粳稻隆科16为试验材料,设施氮量为0、150、195、240、285和330 kg/hm26个处理,采用均衡施氮技术施用 (基肥:分蘖肥:促花肥:保花肥为0.25:0.25:0.25:0.25),系统研究了机插粳稻产量和产量结构、群体生长发育动态等指标.结果表明:施氮量在0~240 kg/hm2范围内,机插粳稻有效穗和产量随着施氮量的增加而增加,超过此施氮量产量和有效穗呈现出下降趋势;不施氮处理水稻的粒叶比和分蘖至抽穗阶段的净同化率最高,随着施氮量的增加分蘖至抽穗阶段水稻净同化率呈现下降趋势,粒叶比无显著差异,成穗率呈抛物线趋势;施氮量为240 kg/hm2处理,机插水稻在分蘖期以后的叶面积、光合势、群体生长率和干物质的积累量等指标表现最高,茎鞘的表观输出率最小.在保山地区机插粳稻的适宜施肥量为240 kg/hm2.%In order to study the optimal nitrogen rate of the mechanical transplanting japonica rice at altitudes as high as 1763 meters in Baoshan area,taking the regular japonica rice"Longke16"as the materials,the indexes including yield,yield produ-cing structure,growth etc. of the mechanical transplanting japonica rice were studied systematically. Six nitrogen levels were a-dopted,with amount of 0,150,195,240,285 and 330 kg/hm2 and N fertilizer was applied as basal dressing and triple top dressing with the ratio of 0.25:0.25:0.25:0.25,and the first top dressing was applied at tillering period and the other twice was applied to promote and sustain the spikelet. The results indicated that with the nitrogen content of 0 ~240 kg/hm2, the panicles and the yield of the mechanical transplanting japonica rice increased according to the increasing of the nitrogen amount, and decreased when the nitrogen amount exceeded. The spikelet per leaf area and the net assimilation rate from the stage of till-er to earing of the rice was the highest with no nitrogen fertilizer. And the net assimilation rate of the rice from the stage of tiller to earing decreased with the increasing of the amount of nitrogen, while the spikelet per leaf area didn't change obviously and the panicle rate exhibited parabolic trend. With the nitrogen level of 240 kg/hm2,the indexes of leaf area,photosynthetic po-tential,group growing rate and the accumulation of the dry matter of mechanical transplanting japonica rice were the highest at the tiller stage. And the apparent export rate of the stem-sheath was the lowest. In all 6 treatments,when the nitrogen level was 240 kg/hm2,the growth of machine transplanted japonica rice was the best,and the yield was the highest.
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