地力水平和播期对冬小麦籽粒产量及氮素利用率的影响

以泰农18为试材,在播种密度(基本苗)405.0万株/hm2条件下,研究两个不同地力水平和适度早播(10月1日)、适播(10月8日)和适度晚播(10月15日)对冬小麦籽粒产量和氮素利用率的影响。结果表明:高地力水平下小麦籽粒产量较高但氮素利用率偏低;同地力条件下,适当推迟播期,通过协调单位面积穗数和穗粒数,仍可维持与早播和适播条件下相当水平的籽粒产量;虽然推迟播期降低冬小麦氮素吸收效率,但可提高氮素利用效率,两者互补,所以适当推迟播期氮素利用率仍可维持与早播和适播相当的水平。因此,在不同地力水平下,适当推迟播期可以调控冬小麦冬前群体免受冷害和寒害的影响,维持较高的籽粒产量和氮素利用率。

Effects of Fertility Level and Sowing Date on Grain Yield and Nitrogen Use Efficiency of Winter Wheat

The cultivar Tainong 18 was sowed on three dates （ conventional sowing on October 8, early sowing on October 1 and delayed sowing on October 15） under low or high fertility level with plant density of 4.05 million/hm2.Under high fertility, higher grain yield but lower nitrogen use efficiency （NUE） was ob-served.Under the same fertility level , properly sowing later could maintain the grain yield equivalent to that of early and conventional sowing through coordinating spikes per unit area and grains per spike .Delayed sowing resulted in lower nitrogen uptake efficiency （ UPE ） but higher nitrogen utilization efficiency （ UTE ） , so the offset led to its equivalent NUE to the other sowing date treatments .Delayed sowing under both low and high fertility level could protect winter wheat from cold damage , so the higher grain yield and NUE could be main-tained.