不同氮钾施用量对再生稻产量及其构成因素的影响

以两系杂交稻品种广两优676为材料,研究不同氮钾施用量对再生稻产量及其构成因素的影响。试验结果表明,头季达到最高产量的施氮、钾量分别为23.27、22.99g·m~(-2),相应的产量分别为1 152.9、1 159.0g·m~(-2),达到最佳经济收益的施氮、钾量分别为21.86、19.54g·m~(-2);再生季达到最高产量的施氮量为20.48g·m~(-2),相应产量为622.3g·m~(-2);达到最佳经济收益的施氮量为18.42g·m~(-2)。再生稻对氮素反应更灵敏,缺氮比缺钾减产更严重。在头季,有效穗数、株高均随氮、钾量的增加而提高;而每穗粒数与施氮量按钟形曲线先增后减,与施钾量呈直线相关;结实率随施氮量增加而降低。在再生季,随着促芽氮施用量的增加,有效穗数显著提高,而每穗粒数先升后降;在高氮条件下,结实率也有所降低;千粒重的差异则较小。

Effects of Different Nitrogen and Potassium Application Levels on Yield and Its Components of Ratoon Rice

The effects of different nitrogen (N)and potassium (K)application levels on yield and its components of ratoon rice were studied using a two-line hybrid rice combination Guangliangyou 676. The results indicated that N and K application levels of obtaining the highest yield in the first crop were 23.27 g · m-2 and 22.99 g · m-2 respectively,and reached the yield of 1 1 52.9 g·m-2 and 1 1 59.0 g·m-2 respectively. N and K application levels of achieving the best economic benefit in the first crop were 21.86 g · m-2 and 1 9.54 g m-2 respectively. N application level of obtaining the highest yield and the best economic benefit in the second crop was 20.48 g·m-2 and 18.42 g·m-2 respectively. These results showed that ratoon rice was more sensitive to nitrogen,and the lack of nitrogen would reduce more yield than that of potassium. Moreover,in the first crop,the number of effective panicle and plant height both increased with the increase of N and K application levels,the exhibited a bell-shaped curve correlation with N application level and a linear correlation with potassium application level. The seed setting rate decreased with the increase of N application level in the first crop. With the increase of nitrogen application level of promoting axillary buds in the second crop,the number of effective panicle significantly increased and the spikelets per panicle appeared a trend of first increasing and then reduction. Under the high nitrogen application level in the second crop,the seed setting rate slightly reduced and the difference of 1 000-grain weight was less.