播后镇压和冬前灌溉对冬小麦干物质转移和氮素利用效率的影响

Effect of Post-Sowing Soil Compaction and Pre-Winter Irrigation on Dry Matter Translocation and Nitrogen Use Efficiency of Winter Wheat

为明确播后镇压和冬前灌溉对高产冬小麦干物质和氮素转移及氮素利用效率的影响,以冬小麦品种石新828和石麦12为材料,采用裂区田间试验,于开花期和成熟期,测定不同器官的干物质和氮积累量和转移量、籽粒产量、蛋白质产量、氮吸收效率和氮肥生产效率。结果表明,冬灌和镇压处理下,2个品种开花期和成熟期的干物质积累量下降,开花前各营养器官干物质的转移量、转移率及对籽粒的贡献率均降低,但开花后籽粒中的干物质积累量增加。冬灌处理小麦成熟期的总干物质积累量和产量下降。冬灌处理下,石新828开花后籽粒中的氮积累量增加,开花后氮素对籽粒的贡献率提高,但各器官的氮转移量显著降低,籽粒氮积累总量显著减少,氮吸收效率下降;冬灌对石麦12成熟期籽粒氮素积累量影响不显著。与不镇压相比,镇压处理下,2个品种开花期的氮积累总量和不同器官中的氮积累量均降低,而成熟期各器官氮积累量及分配比例的差异均不显著。镇压处理与不镇压处理相比,2个品种开花前营养器官中的氮转移量、转移率和贡献率均降低,但是开花后的氮积累量及其对籽粒氮的贡献率提高,其中,镇压的石麦12开花前氮转移量、贡献率和开花后氮积累量、贡献率与不镇压的差异达显著水平;成熟期籽粒氮素积累量的差异不显著。建议在足墒播种条件下不必进行冬灌,应根据播种前后土壤和水分条件确定是否需要镇压。

In order to clarify the effects of post-sowing soil compaction and pre-winter irrigation on the translocation of dry matter and nitrogen and nitrogen use efficiency of high-yielding winter wheat, a field experiment was carried out, using two wheat cultivars, Shimai 12 and Shixin 828. The experi- ments were designed as split plots. The amounts of dry matter and nitrogen accumulation and translo- cation in different organs at anthesis and maturity, grain yield, grain protein content, nitrogen ab- sorption efficiency and nitrogen fertilizer production efficiency of wheat were determined. The results showed that under the treatments with pre-winter irrigation and post-sowing soil compaction, the a- mount of dry matter accumulation at anthesis and maturity of the two cultivars was decreased, and the amount and rate of pre-anthesis dry matter translocation from vegetative organs, and the contribution rate of pre-anthesis dry matter to grain weight of the two cultivars were also decreased, but post-an- thesis dry matter accumulation amount in grains of the two eultivars were increased. The dry matter accumulation of wheat plants at maturity and grain yield of the two cultivars were decreased under the treatments with pre-winter irrigation. The amount of post-anthesis nitrogen accumulation in grains was increased, and the contribution rate of post-anthesis nitrogen accumulation to grain nitrogen was increased in Shixin 828, but the translocation amount of pre-anthesis accumulated nitrogen to grain was significantly reduced, so that the total amount of grain nitrogen and nitrogen absorption efficiency was decreased. For Shimai 12, however, the effect of pre-winter irrigation on grain nitrogen accumu- lation amount at maturity was not significant. Comparing with the treatments without post-sowing compaction, the amount of nitrogen accumulation in different organs and whole plants of wheat with post-sowing compaction was reduced at anthesis in the two cultivars~ At maturity, however, the difference of nitrogen accumulation amount and distribution percentage in all organs of both cultivars was not significant. Compared with those without compaction, the translocation amount, transloca- tion rate and contribution rate to grain nitrogen of pre-anthesis accumulated nitrogen in vegetative or- gans were decreased, but the accumulation amount and contribution rate to grain nitrogen of post-an- thesis accumulated nitrogen were increased in the treatments with post-sowing compaction for both eultivars. For Shimai 12, all the differences of amount and contribution rate to grain nitrogen of pre and post-anthesis accumulated nitrogen were significant between the two treatments. The difference of nitrogen amount accumulated in grains at maturity was not significant. It is suggested that, pre-win- ter irrigation is unnecessary with adequate soil moisture when sowing of wheat. Whether post sowing compaction is needed should be determined according to pre- and post-sowing soil moisture of winter wheat.