播期对麦(油)后直播棉产量、品质及氮磷钾利用的影响

Effects of sowing dates on lint yield, fiber quality, and use of nitrogen, phosphorus and potassium in cotton field-seeded after barley or oilseed rape harvest in Yangtze River Valley, China

为明确长江流域下游棉区麦(油)后直播棉生产的适宜播期,本研究以?中棉所50‘为材料,于2017-2018年进行大田试验,研究不同播期(5月15日、5月25日、6月4日、6月14日和6月24日)对直播棉产量、品质及养分利用的影响。结果表明,播期推迟,棉花生育进程推迟;花铃期日均温和日照时数降低、有效积温先升高后降低且以6月4日播期花铃期有效积温最高。可见,前3个播期棉花花铃期温光条件较好。棉株与生殖器官的生物量及氮磷钾累积量随播期推迟降低,且前3个播期的棉株生物量和养分累积进入较高速率累积期早于后2个播期的棉株。随着播期的推迟,直播棉成铃数与皮棉产量显著降低。与5月15日播期相比,其余4个播期直播棉的皮棉产量分别降低15.9%~16.9%、13.1%~16.9%、26.9%~33.5%、58.2~62.0%。100kg皮棉氮、磷和钾吸收量随播期推迟而增加,但养分利用效率降低。不同播期间,以6月4日和6月14日播期棉纤维综合品质较优。综上,本试验条件下,5月15日-6月4日是长江流域棉区麦(油)后直播棉获得较高产量的适宜播期,该播期内适当推迟播种有利于棉花优质纤维的形成。

This study aimed to evaluate the effects of sowing date on lint yield,quality,as well as nutrient uptake and use of cotton field-seeded after barley or oilseed rape harvest in the downstream Yangtze River Valley.Sowing dates were randomly assigned(15-May,25-May,4-June,14-June,and 24-June),using short-season cotton(CCRI 50)in fields in Nanjing,Jiangsu Province of China,between 2017 and 2018.The results showed that:with delayed sowing date,the growing process slowed,the daily mean temperature and sunshine hours were lower during the flowering and bolling stages,and the effective accumulated temperature increased until it reached a peak on the sowing date of 4-June.These trends suggested that temperature and sunshine were both higher before the sowing date of 4-June.The biomass and nitrogen,phosphorus and potassium accumulation of cotton plants and reproductive organs decreased with sowing date delay.The accumulation rate in biomass and nutrient peaked even earlier,on the sowing date of 15-May,25-May,and 4-June than on sowing date of 14-June and 24-June.As the sowing date was delayed,boll number and lint yield both decreased.Compared with the 15-May sowing date,the lint yields decreased by 13.1%-16.9%for sowing dates of 25-May and 4-June,and by 26.9%-33.5%and 58.2%-62.0%for sowing dates of 14-June and 24-June,respectively.Nutrient uptake of nitrogen,phosphorus,and potassium for 100 kg lint yield increased with sowing date delay,while the nutrient use efficiency decreased.The fiber quality w as better for sowing dates of 4-June and 14-June than for other sowing dates.In summary,sowing from 15-May to 4-June is suitable to achieve high yield in short-season cotton field-seeded after barley or oilseed rape harvest in the downstream Yangtze River Valley.Sowing later during this period would,on the other hand,lead to high fiber quality.