Selection Of Maize Varieties With Different Nitrogen Efficiency And Their Nitrogen Uptake And Utilization In Cinnamon Soil Area

Nitrogen is one of the essential elements for maize growth and development,which plays an important role in the formation of maize quality and yield.At present,there are still some problems in maize production,such as low nitrogen use efficiency and environmental pollution.Therefore,it is very important to select maize varieties with high nitrogen efficiency,apply fertilizer reasonably and improve nitrogen use efficiency for high and stable yield of maize and reduce environmental pollution.In this paper,nitrogen efficiency of 40 maize varieties was evaluated under low nitrogen and high nitrogen treatments,and nitrogen absorption and utilization characteristics of different nitrogen efficiency varieties in cinnamon soil area were further studied.The main results are as follows(1)Among the 40 maize hybrids with different genotypes,double high efficiency,double low efficiency,low nitrogen efficiency and high nitrogen efficiency accounted for 30%,27.5%,15% and 27.5% respectively;under low nitrogen condition,double efficiency type and low nitrogen efficiency type had higher 100 kernel weight,ear grain weight and dry matter accumulation;while under high nitrogen condition,double efficiency type and high nitrogen efficiency type had higher 100 kernel weight,ear grain weight and dry matter accumulation The sensitivity of grain yield,grain number per spike,100 grain weight,grain weight per spike and dry matter accumulation of double low efficiency and high nitrogen efficiency maize varieties were higher than that of double efficiency type and low nitrogen efficiency type.(2)In the range of N0-N180,the grain yield of maize increased significantly with the increase of nitrogen application rate;the yield of low nitrogen and high efficiency variety ZD958 at N270 had no significant difference with N180,which was10053 kg / hm2.SPAD,leaf area index,contribution rate of dry matter transport to grain,contribution rate of nitrogen transport to grain and nitrogen transfer rate of three leaves of stick were at N180 The highest dry matter accumulation,nitrate reductase activity(NR),glutamine synthetase activity(GS)and total nitrogen accumulation during silking stage and maturity stage were the highest under N270 treatment,but there was no significant difference between N270 treatment and N180 treatment,and had higher nitrogen use efficiency under low nitrogen treatment;the yield of high nitrogen efficient cultivar xy335 had no significant difference with N270 at N360,which was 10779 kg / hm2.The results showed that SPAD,leaf area index,total dry matter accumulation,contribution rate of dry matter transport to grain and nitrogen transport rate of trifolium corynetum were the highest in N270 treatment,which were significantly higher than those in N0,N90 and n180.The contribution rate of NR,GS activities,total nitrogen accumulation and nitrogen transport to grain reached the maximum at N360,but there was no significant difference between them.At the same time,it had high nitrogen use efficiency under high nitrogen treatment The results showed that the yield of double efficient cultivar ql368 had no significant difference with N180 at N270,which was 10623 kg / hm2.SPAD,total dry matter accumulation,contribution rate of dry matter transport to grain and N transport rate of Trifolium corynetum were the highest under N180 treatment,while the contribution rate of NR,GS activity and nitrogen transport to grain reached the maximum in N360 treatment,which had no significant difference with N270.Meanwhile,it had higher nitrogen under low nitrogen and high nitrogen treatment The yield of yd606 was9688.5kg/hm2 at N270,and SPAD,total dry matter accumulation,contribution rate of dry matter transport to grain and nitrogen transport rate of Trifolium corynetum reached the maximum under N270 treatment,while NR,GS activity,total nitrogen accumulation at maturity and contribution rate of nitrogen transport to grain reached the maximum under N360 treatment,with no significant difference compared with N270.The results showed that in cinnamon soil area,180 kg / hm2 of pure nitrogen was recommended for low nitrogen efficient varieties(such as ZD958)and double efficiency varieties(such as QL368),and 270 kg / hm2 for high nitrogen efficient varieties(such as XY335)and double low efficiency varieties(such as YD606).