深松蓄水增量播种对旱地小麦植株氮素吸收利用、产量及蛋白质含量的影响

【目的】明确旱地麦田休闲期深松的蓄水效果,探索旱地小麦构建合理群体的最适播量,有利于寻求产量与品质同步提升的最佳耕作及播种技术途径。【方法】于2012—2014年在山西闻喜县开展大田试验,以休闲期深松与否为主区,以67.5、90、112.5 kg·hm-2共3个播量为副区,测定休闲期土壤水分、冬前群体分蘖数、植株各器官干物质量及含氮率、产量及其构成因素,研究休闲期深松蓄水调节播量对植株氮素吸收和利用、产量及籽粒蛋白质含量的影响。【结果】休闲期深松较对照休闲期土壤蓄水效率提高60%以上。深松较对照冬前群体分蘖数、越冬期植株干物质量和氮素积累量、开花前叶片和颖壳+穗轴积累氮素的运转量、开花后氮素积累量均显著增加。深松条件下增加播量,冬前群体分蘖数及越冬期植株干物质积累量显著增加,开花前各器官积累氮素的运转量增加,开花前叶片、颖壳+穗轴积累氮素的运转对籽粒的贡献率提高,但播量90 kg·hm-2与112.5 kg·hm-2两处理间差异不显著。深松较对照穗数、穗粒数显著提高,两年度分别增产26%—66%、17%—34%;而籽粒蛋白质含量降低,但播量90 kg·hm-2时降低不显著。深松条件下增加播量,穗数、千粒重、产量提高,但播量90 kg·hm-2与112.5kg·hm-2两处理间差异不显著;籽粒蛋白质含量及其产量均以播量90 kg·hm-2较高。深松较对照水分利用效率显著提高,两年度分别提高13%—22%、9%—16%;氮素吸收效率、氮肥生产效率显著提高,播量67.5 kg·hm-2和90 kg·hm-2时的氮素利用效率显著提高。深松后水分利用效率以播量90 kg·hm-2较高,且与其他两处理间差异显著,深松条件下增加播量,氮素吸收效率显著提高,氮肥生产效率提高,但播量90 kg·hm-2与112.5 kg·hm-2两处理间的氮肥生产效率差异不显著。此外,休闲期深松配套不同播量处理,产量和籽粒蛋白质产量均与开花前各器官积累氮素的运转量显著或极显著相关,且降水多的年份,与开花前颖壳+穗轴积累氮素的运转量相关性较高。降水较多的年份较降水较少的年份开花后氮素的积累量与产量相关性较高。【结论】旱地小麦休闲期深松蓄水配套播量90 kg·hm-2有利于形成冬前壮苗;有利于开花期各器官氮素积累,促进开花前叶片和颖壳+穗轴中积累的氮素向籽粒转移;有利于形成有效穗数,构建合理群体,提高产量、水分利用效率、氮素吸收效率和氮肥生产效率,实现旱地小麦产量与籽粒蛋白质含量同步提升。

Effects of Incremental Seeding Rate Under Sub-Soiling During the Fallow Period on Nitrogen Absorption and Utilization,Yield and Grain Protein Content in Dryland Wheat

【Objective】The objective of these experiments is to clarify the effects of sub-soiling during the fallow period(SS) on soil water storage, explore the optimum seeding rate for constructing rational community of dryland wheat, and find out the best tillage and seeding technique, which could improve yield and quality coordinately. 【Method】 Field experiments were carried out from 2012 to 2014 in Wenxi, Shanxi province, with or without SS as the main plots and three seeding rates (67.5, 90, 112.5 kg·hm^-2) as subplots. Soil water storage during the fallow period, community tiller amount of plants before winter, dry weight and nitrogen content in different organs of plant, the yield and its components were measured to assess effects of seeding rate under SS on plant nitrogen absorption and utilization, yield, and grain protein content. 【Result】 The soil water storage efficiency during the fallow period was improved by more than 60% under SS compared with CK. Plant community tiller amount before winter, dry weight and nitrogen accumulation in plant at wintering stage, pre-anthesis accumulated nitrogen translocation amount from leaf and glume+spike to grains and nitrogen accumulation in the whole plant after anthesis were significantly increased under SS compared with CK. Plant community tiller amount before winter, dry weight at wintering stage and pre-anthesis accumulated nitrogen translocation amount from vegetative organs to grains and the contribution of pre-anthesis accumulated nitrogen translocation amount from leaf and glume+spike to grains were increased with the increase of seeding rate under SS while no significant difference between the seeding rate of 90 kg·hm^-2 and 112.5 kg·hm^-2 was presented. Spike number and grain number per spike were significantly increased under SS compared with CK, meanwhile, the yield was improved by 26%-66% and 17%-34% in two growing years respectively. Grain protein content was decreased under SS compared with CK, however, no significant difference was observed between them under 90 kg·hm^-2 condition. Spike number, 1000-grain weight and the yield were increased with the increase of seeding rate under SS, however, there was no significant difference between seeding rate of 90 kg·hm^-2 and 112.5 kg·hm-2. In addition, the highest grain protein content and its yield were observed under the seeding rate of 90 kg·hm^-2 under SS. Water use efficiency was significantly improved by 13%-22% and 9%-16% in two growing years, respectively, under SS compared with CK. Nitrogen uptake efficiency and nitrogen productive efficiency were significantly improved, and nitrogen use efficiency was significantly improved under the seeding rate of 67.5 kg·hm^-2 and 90 kg·hm^-2 condition under SS compared with CK. The highest water use efficiency was significantly observed under the seeding rate of 90 kg·hm^-2 condition under SS. Nitrogen uptake efficiency and nitrogen productive efficiency were improved with the increase of seeding rate under SS, while nitrogen productive efficiency had no significant difference between the seeding rate of 90 kg·hm^-2 and 112.5 kg·hm^-2 treatments. Moreover, under the condition of SS combined with different seeding rates, the yield and grain protein yield have significant and very significant correlation with pre-anthesis accumulated nitrogen translocation amount from vegetative organs to grains after anthesis, especially with the glume + spike under the condition of more precipitation. And nitrogen accumulation after anthesis was more significantly correlated with the yield under the condition of more precipitation. 【Conclusion】 Sub-soiling during the fallow period plus the seeding rate of 90 kg·hm^-2 was not only beneficial to form the strong seedlings before winter for dryland wheat, increase nitrogen accumulation of various organs at anthesis, promote pre-anthesis accumulated nitrogen translocation from leaf and glume + spike to grains, form the effective spike number, construct plant rational community of dryland wheat, and improve yield, water use efficiency, nitrogen uptake efficiency and nitrogen productive efficiency, and ultimately achieve the coordinated improvement of yield and grain protein content.