覆膜和补施氮肥对晚播冬小麦冬前植株生长及群体质量的影响

Effects of filming and supplemental nitrogen fertilizer application on plant growth and population quality of late sowing winter wheat before winter

为解决我国北部冬麦区因播期推迟造成越冬前小麦苗情较弱的实际问题,于2019—2021年在中国农业科学院北京试验基地进行晚播试验,设3个播期:10月5日适期播种(S0)、10月15日适当晚播(S1)、10月25日过晚播(S2),以S0为对照,对晚播S1、S2采取覆膜和补施氮肥的调控措施,研究覆膜和补施氮肥对晚播小麦冬前群体质量、个体性状以及茎蘖生长的影响。结果表明:晚播不利于小麦冬前群体和个体质量的形成,以及茎蘖的生长。晚播覆膜增温可提高冬前群体总茎数,与不覆膜处理相比,适当晚播和过晚播覆膜处理提高了小麦冬前群体生长率和相对生长率,群体总茎数平均分别提高42.9%、148.4%;植株冬前叶龄增加,个体分蘖数平均分别增加1.6个和2.0个;覆膜增温延长主茎上第1分蘖至第3分蘖营养生长进程,提高苗期茎叶、分蘖节、根部可溶性糖含量以及叶片中生长素与玉米素核苷的比值(IAA/ZR),增加冬前群体总茎数。对各处理进行晚播苗情评价可得出,适期播种条件下均有利于2个不同分蘖力品种冬前群体综合质量的提高,其中,多穗型品种中麦8号在晚播覆膜条件下其晚播苗情较好,大穗型品种航麦501则在适当晚播无调控措施、适当晚播+补施氮肥、适当晚播+覆膜和过晚播+覆膜条件下其晚播苗情较好,同时2个不同分蘖力品种在晚播条件下对覆膜增温的响应存在差异。中麦8号在适期播种或晚播覆膜条件下更有利其冬前群体综合质量的提升,而航麦501在适期播种、适当晚播和过晚播覆膜条件下均有利于其晚播苗期质量的提高。补施氮肥则对晚播小麦冬前群体质量、个体性状和茎蘖生长无明显调控效应。综上所述,在晚播条件下,覆膜可有效改善小麦冬前群体和个体的综合质量,进一步促进茎蘖的生长。

In order to solve the actual problem of weaker wheat seedlings before overwintering due to the delayed sowing date in the winter wheat area of northern China,a late sowing experiment was carried out at the Beijing Experimental Base of the Chinese Academy of Agricultural Sciences from 2019 to 2021.Three sowing dates were set:sowing at the appropriate time on October 5th(S0),appropriate late sowing on October 15(S1),and too late sowing on October 25(S2).To study the effects of film mulching and supplemental application of nitrogen fertilizer on the population quality,individual traits and stems and tillers growth of late-sown wheat before winter,the late sowing S1 and S2 were treated with film mulching and nitrogen fertilizer regulating measures.The results showed that late sowing was not conducive to the formation of wheat population and individual quality before winter,and the growth of stems and tillers.Late sowing and mulching to increase temperature can increase the total number of stems and tillers in the population before winter.Compared with the treatment without mulching,mulching can increase the growth rate and relative growth rate of wheat before winter under the conditions of appropriate late sowing and too late sowing.The total number of stems and tillers in the population increased by 42.9%and 148.4%,respectively.The leaf age of the plant before winter increased,and the number of individual tillers increased on average by 1.6 and 2.0,respectively.Film mulching to increase the temperature prolonged the vegetative growth process of the first tiller to the third tiller on main stem,promoted cell growth,increased the soluble sugar content in the stems and leaves,tillering node,roots,and the ratio of IAA/ZR in leaves,and increased the total number of stems and tillers in population before winter.Evaluation of the seedling situation of each treatment for late sowing showed that under the condition of suitable sowing time,it was beneficial to improve the comprehensive quality of two different tillering ability cultivars before winter.Among them,Zhongmai 8 had better seedling situation under the condition of late sowing+film mulching,while Hangmai 501 also had better seedling situation under the condition of proper late sowing,proper late sowing+supplementary nitrogen fertilizer,proper late sowing+film mulching,and too late sowing+film mulching.Meanwhile,there were differences in the responses of two different tillering ability wheat cultivars to the temperature increase under the condition of late sowing+film mulching.It was more beneficial for Zhongmai 8 to improve the overall population quality before winter under the conditions of suitable sowing or late sowing+film mulching,while under the conditions of the appropriate sowing,appropriate late sowing and too late sowing+film mulching,it was beneficial to improve the quality of late sowing seedlings for Hangmai 501.Supplementary application of nitrogen fertilizer had no significant regulatory effects on popu-lation quality,individual traits and stems,and tillers growth of late-sown wheat before winter.In summary,under the condition of late sowing,film mulching can effectively improve the overall quality of wheat populations and individuals before winter,and further promote the growth of stems and tillers.