不同种植方式下氮素营养对陆稻和水稻产量的影响

Effects of Nitrogen Nutrition on Grain Yield of Upland Rice and Paddy Rice under Different Cultivation Methods

以粳型陆稻中旱3号和粳型水稻扬粳9538为材料,设置裸地旱种和水种两种方式及低氮(LN,100kg hm-2)、中氮(NN,200kg hm-2)和高氮(HN,300kg hm-2)3种N素水平,比较研究了氮素营养对陆稻和水稻产量形成的影响。结果表明,旱种HN处理下陆稻和水稻的产量以及水种HN处理下水稻的产量较NN有所下降;但水种HN处理下陆稻的产量较NN增加;随施N量增加,水、陆稻在两种种植方式下穗数均增加,每穗粒数表现不一,结实率均下降,但陆稻降幅小于水稻,陆稻千粒重差异不显著,而水稻则显著下降。与水种相比,旱种条件下陆稻的千粒重无显著变化,而水稻千粒重则显著下降,水、陆稻旱种的结实率均有所提高,但陆稻的提高幅度大于水稻。与水稻相比,陆稻不定根数少,吸N能力低,分蘖能力弱,成穗数少、穗型小,产量较低。拔节至抽穗期不定根数的增幅大,叶片含N率下降慢,花后叶片含N率和剑叶叶绿素(SPAD)值下降快。陆稻光合生产力对水分胁迫的负响应小,对增施N素正响应大。表明陆稻和水稻对种植方式和N素的响应有明显差异。对陆稻和水稻的产量增产途径进行了讨论。

Upland rice and dry-cultivated paddy rice have been attracted more and more attention because of limited water resources in China. Researches on interaction between water and nitrogen supplies for crop resistance to drought stress has become the hot topic regarding regulation on nutritional physiology. However, there is little information available on effect of nitrogen （N） nutrition on grain yield and its components of upland rice and paddy rice under different cultivation methods. The objective of this study was to evaluate the difference between upland rice and paddy rice and interaction between cultivation methods and N levels. One upland rice cultivar Zhonghan 3 （japonica） and one paddy rice cultivar Yangjing 9538 （japonica） were grown under moist cultivation （MC, control） or bare dry-cultivation （DC） with three N levels, low amount of N （LN, 100 kg ha^-1）, normal amount of N （NN, 200 kg ha^-1）, and high amount of N （HN, 300 kg ha^-1）. The results showed that, compared with NN, the grain yield under HN was lower for both upland and paddy rice under DC and for paddy rice under MC, whereas higher for upland rice under MC. With the increase in N levels, upland rice and paddy rice showed higher productive tillers, more or fewer spikelets per panicle, lower percentage of ripened grains under two cultivation methods. However, the percentage of ripened grains was reduced more for paddy rice than for upland rice. There was no significant difference in 1 000-grain weight for upland rice among three N levels, whereas grain weight was reduced with the increase in N levels. Compared with MC, DC showed no significant difference in grain weight for upland rice, whereas a significant decrease for paddy rice. DC significantly increased the percentage of ripened grains for both upland and paddy rice, and that were more for upland rice than for paddy rice. Compared with paddy rice, upland rice showed less number of adventitious roots, lower nitrogen absorption ability and lower productive tillering ability, fewer pani- cles, fewer spikelets per panicle and lower grain yield. However, upland rice exhibited quicker increase in adventitious roots and slower declining in leaf nitrogen content from jointing to heading, and a faster declining speed in chlorophyll content （SPAD value） after flowering. Also, upland rice had less negative response to water stress and more positive response to N. The results suggest that the response to cultivation methods and N levels varies largely between upland rice and paddy rice. The approaches to increase the grain yield of both paddy and upland rice were discussed.