施氮量对四川盆地机播稻茬麦生长发育及氮素利用的影响

摘要

20102012年，在四川省广汉市开展了施氮量对机播稻茬小麦生长发育和氮素利用效率影响的研究，试验设置0、105、150、195 kg/hm24个施氮水平。结果表明，施氮量增加有利于稻茬麦分蘖力、有效穗数的提高以及单穗小穗数、穗粒数的增加，但对籽粒灌浆充实不利。不同年份和土壤质地，单产均以施氮量为150 kg/hm2时达到最高水平，继续增加氮素用量产量增幅变小进而下降。氮素供应量增加，植株氮素含量和积累量均有不同程度升高，但氮素农学利用率、氮素生产效率、氮素吸收效率、氮素利用效率等参数呈下降趋势，氮素收获指数、氮素表观回收率在各施氮处理间变幅相对较小。在四川盆地目前生产水平下，施氮150 kg/hm2可以获得较高的产量和经济效益。%The effects of different N application rates on the growth , development and N utilization of mechanical sowing wheat in rice-wheat cropping system were studied from 2010 to 2012 in Guanghan City , Sichuan Province . Four N rates were designed:0, 105, 150 and 195 kg/ha in the experiments.The results show that the increase of N rate is good for increasing the tillering ability , the numbers of effective spike , spikelet and grain per spike , but a bit of unfavorate to the grain filling .The highest yield were achieved when the N rate was 150 kg/ha in the two growing seasons and all the experimental sites with different soils textures ., When the N application rate were higher than 150 kg/ha, the yield increase less or even start to decline .Although the N accumulation and N content in the plants are continuing increase , the corresponding N agricultural use efficiency , N productivity efficiency , N uptake efficiency and N utilization efficiency are all declined , and the N harvest index and apparent N recovery efficiency have no significantly changes from 105 kg/ha to 195 kg/ha.Therefore, applying 150 kg/ha is recommended for higher yield and highest profit in the current production levels of Sichuan Basin .