为明确不同耕作和施氮模式对淮北砂姜黑土地区小麦产量及水分利用效率的影响,以烟农 19为试验材料,设置旋耕+氮肥基施(RW)、旋耕+氮肥后移(RA)、翻耕+氮肥基施(DW)和翻耕+氮肥后移(DA)共 4 个处理,开展了大田小区试验,考察不同处理下小麦花后光合特性、干物质积累、根系分布、水分利用效率(WUE)及产量的差异.结果表明,相同施氮模式下,翻耕较旋耕显著提升了小麦产量,增产的原因是穗数、穗粒数和粒重的显著增加;相同耕作模式下,氮肥后移(RA和DA)的产量较氮肥基施(RW和DW)分别提高了 25.54%和 17.94%.翻耕和氮肥后移均增强了花后旗叶抗氧化酶活性,降低了丙二醛含量,显著提高了旗叶叶绿素含量和净光合速率以及花后光合同化物积累对籽粒产量的贡献率和总干物质积累量.RA、DW、DA处理较 RW处理均显著提高了开花期 0~60 cm 土层的根长密度、根干重密度及 WUE,其中 WUE增幅分别为 21.35%、12.71%和 31.21%.综合来看,在淮北砂姜黑土地区采用翻耕结合氮肥后移的种植模式能延缓小麦花后旗叶衰老,维持叶片光合能力,增加群体干物质积累量,促进根系生长,实现产量和 WUE的协同提升.
A field experiment was conducted using Yannong 19 as the experimental material in order to clarity the effects of different tillage and nitrogen(N)fertilizer application patterns on wheat grain yield(GY)and water use efficiency(WUE)in the Shajiang black soil region of Huaibei.These pat-terns included with rotary tillage+all N fertilizer applied as basal dressing(RW),rotary tillage+N fertilizer postpone(RA),deep ploughing tillage+N fertilizer applied as basal dressing(DW),and deep ploughing tillage+N fertilizer postpone(DA).The effects of different treatments on post-anthesis photosynthetic characteristics of flag leaf,dry matter accumulation,root distribution,water use effi-ciency(WUE)and GY of wheat were examined in this study.The results showed that under the same N fertilizer application pattern,deep ploughing tillage significantly increased GY compared with that rotary tillage,and the reason for the increase was the significant increases in the spike number,grain number per spike and grain weight at maturity.Under the same tillage pattern,compare with the all N fertilizer applied as basal dressing treatment,the GY of N fertilizer postpone treatments increased by 25.54%and 17.94%,respectively.Both deep ploughing tillage and N fertilizer postpone signifi-cantly enhanced the activities of antioxidant enzymes and decreased the content of malondialdehyde in flag leaf after anthesis,increasing the chlorophyll content and net photosynthetic rate in flag leaf and improving the contribution rate of dry matter accumulation post anthesis to grain and the total dry matter accumulation.Compared with that RW,RA,DW and DA were significantly increased the root dry weight density in 0-60 cm soil layer at anthesis,and WUE,the WUE increased by 21.35%,12.71%and 31.21%,respectively.In conclusion,using deep ploughing tillage combined with N fertilizer post-pone could delay flag leaf senescence after anthesis,maintain its photosynthetic capacity,increase dry matter accumulation of population and promote root growth,achieving the synergistic improvement of wheat GY and WUE in Shajiang black soil region of Huaibei.