施氮量对不同水稻品种氮肥利用率与农艺性状的影响

为探明施氮量对不同水稻品种产量、氮肥利用率和农艺性状的影响,以适合江苏省种植的12个中粳稻（含籼/粳杂交稻）品种为材料,大田种植,设置0N（全生育期不施氮）、200N（全生育期施纯氮200kg/hm ²）和360N（全生育期施纯氮360kg/hm²）3个施氮量处理,研究各品种产量、氮肥利用率和一些农艺性状的差异。结果表明：甬优2640在3个施氮水平产量均最高,库容量大是其高产的主要原因。其他品种产量对氮肥响应的表现不一。在较低氮（0N、200N）条件下,淮稻13号和武运粳30的产量较高,宁粳1号和扬粳4038的产量较低。在高氮（360N）条件下,宁粳1号和扬粳4038产量较高。在较低施氮量条件下,产量和氮肥利用率较高的品种具有较高的干物质积累量、茎蘖成穗率、叶面积指数、粒叶比及群体生长速率,这些指标可作为筛选氮高效品种的农艺性状指标。

Effects of Nitrogen Rates on the Nitrogen Use Efficiency and Agronomic Traits of Different Rice Cultivars

The objective of the study was to understand the effects of nitrogen (N) rates on grain yield, N use efficiency (NUE), and agronomic traits of different rice cultivars. Twelve japonica rice cultivars (including indica/ japonica cultivars) suitable for planting in Jiangsu Province were field planted. Three N rates, 0N (no N application), 200N (200kg/hm ²) and 360N (360kg/hm ²) were applied in the experiment. The performances of grain yield, NUE and some agronomic traits were investigated. The results showed that the indica/japonica hybrid Yongyou 2640 had the highest grain yield among 12 tested cultivars under the three N application rates, mainly due to its large sink capacity. The response of grain yield to N rates varied with cultivars except for Yongyou 2640. Under the lower N rates (0N and 200N), the cultivars of Huaidao 13 and Wuyunjing 30 exhibited a higher yield, whereas the cultivars of Ningjing 1 and Yangjing 4038 produced a lower grain yield and NUE. However, a higher grain yield was observed for Ningjing 1 and Yangjing 4038 under a higher N rate (360N). The cultivars showed a higher grain yield and NUE under a lower N rates possessed a higher dry matter accumulation, more productive tillers, larger leaf area index, greater grain-leaf ratio and crop growth rate. These traits could be used as indexes in selecting a N-efficient rice cultivar.