Nitrogen accumulation characteristics of high yielding population in late-sown wheat following rice

In order to understand the nitrogen accumulation characteristics of high yielding population in late-sown wheat following rice,a field experiment with a medium gluten wheat variety Yangmai 20as test material was carried out.The main results were as follows:Grain yield had a quadratic relationship with NAA at jointing sage and during the period from anthesis to maturity.Grain yield was significantly related to NAA at anthesis and maturity stages,and during the period from the beginning of over-winter to turning-green and from booting to anthesis,respectively.Increasing nitrogen translocation amount after anthesis was the key to high yield in late-sown wheat in rice-wheat cropping system.To achieve a grain yield greater than 7 500kg·hm-2 in late-sown wheat,the suitable NAA was 48-58kg·hm-2at jointing,higher than 191kg·hm-2at anthesis,and 257kg·hm-2 at maturity,the lowest nitrogen translocation amount after anthesis was 124kg·hm-2.