施氮量对杂交早稻T78优2155产量形成和氮素利用的影响

对杂交早稻T78优2155进行施氮量试验,结果表明:提高施氮量有利于促进分蘖,茎蘖数多,有效穗数也多;植株含氮量、每公顷吸氮量、百千克稻谷吸氮量都与施氮量呈线性正相关,稻谷产量与植株含氮量、每公顷吸氮量、百千克稻谷吸氮量均呈开口向下抛物线型关系,植株含氮量、吸氮量、百千克稻谷吸氮量偏低或过高均不利高产;干物质积累量、稻谷产量与施氮量都呈抛物线型关系,施氮量不足或偏高都不利于物质积累和水稻的高产;稻谷产量与干物质积累量也呈开口向下抛物线型关系,干物质过高也不利高产;氮肥当季利用率与施氮量呈抛物线型关系,施氮量不足或过高,均会降低氮肥利用率;杂交早稻T78优2155高产、高效、高氮肥利用率的适宜施氮量为每公顷纯氮160 kg左右.

Effects of Nitrogen Application Amount on the Yield Formation and Nitrogen Utilization in Spring Hybrid Rice T78 You 2155

Experiments were conducted to evaluate the effects of different levels of nitrogen application amount on the yield formation and nitrogen utilization in Spring hybrid rice T78 You 2155. The results showed that the increase of nitrogen application amount could promote tillering and increase the number of stems, tillers and effective panicle. The nitrogen concentration of plant organs, nitrogen uptake per hectare and nitrogen uptake by per 1 000 grams of rice were positively related to nitrogen application amount but curvedly related to rice yield, indicating that neither too high amount nor too low amount of them was beneficial to high yield. Both dry matter accumulation and rice yield had a curve relationship with nitrogen application amount, suggesting that neither too high nor too low amount of nitrogen application was helpful to dry matter accumulation or high yield of rice. Meanwhile, rice yield had a curve relationship with dry matter accumulation likewise, meaning that too high amount of the latter did no good to high yield. In addition, nitrogen utilization efficiency was linearly correlated to nitrogen application amount, implying that either too high or too low amount of nitrogen application would reduce its efficiency. Consequently, to ensure a high yield, high efficiency and high utilization rate for Spring hybrid rice T78 You 2155, the best amount of nitrogen applied in each hectare is about 160 kilograms.