摘要
深施肥能提高旱地作物的水肥利用效率,是作物增产的重要技术途径之一,但目前对其营养生理机制,尤其是从旗叶生态化学计量特征的角度缺乏系统研究分析.本研究采用桶栽定量控制试验的方法,在 2021-2022 年以'陇春 35 号'为供试品种,设置 30 cm深施肥(D30)、15 cm浅施肥(D15)和不施肥(CK)3 个处理,研究不同处理对春小麦挑旗至灌浆期春小麦旗叶碳(C)、氮(N)、磷(P)含量及生态化学计量特征(C/N、C/P、N/P)的影响,揭示春小麦旗叶养分含量及生态化学计量特征对旗叶 SPAD 值、Pn、地上部干物质积累、地上部生长速率、产量形成的影响.结果表明,灌浆期D30旗叶C/N值较D15和CK分别降低2.1%～6.4%、5.4%～10.2%;C/P值分别降低3.8%～5.2%、5.4%～6.0%;2021 年N/P值分布提高 1.4%和 4.1%,2022 年N/P值分别降低 1.6%和 0.2%.灌浆期D30 旗叶SPAD值较D15 和CK分别提高 1.8%～6.5%、15.5%～18.2%;Pn分别提高 21.6%～27.0%、28.5%～36.6%.扬花至灌浆期D30 地上部生长速率较 D15 和 CK 分别提高 22.1%～41.2%、68.4%～80.8%.成熟期 D30 地上部干物质积累量较 D15 和 CK 分别提高10.6%～11.1%;产量分别提高 15.7%～16.0%、46.5%～49.3%.D30 氮肥贡献率较D15 提高 46.6%～52.4%;氮肥偏生产力提高 15.7%～16.0%;氮肥农学效率提高 69.6%～76.7%.相关性分析表明,灌浆期春小麦旗叶 C、N、P含量与旗叶SPAD值、Pn、地上部干物质积累呈正相关;旗叶生态化学计量特征与旗叶SPAD值、Pn、干物质积累呈负相关.因此,在干旱条件下 30 cm深施肥通过提高春小麦挑旗至灌浆期旗叶C、N、P含量,延缓扬花期后旗叶N、P含量的降低,优化旗叶生态化学计量特征,降低N、P对春小麦旗叶光合作用的限制,提高春小麦旗叶Pn和地上部生长速率,并且延缓旗叶衰老,促进产量增加.
Abstract
Deep fertilization can improve the water and fertilizer use efficiency of dryland crops,which is one of the important technical ways to increase crop yield,but there is a lack of systematic research on its nutritional physiological mechanism,espe-cially from the perspective of ecological stoichiometric characteristics of flag leaves.In this study,three treatments,30 cm deep fertilization(D30),15 cm shallow fertilization(D15)and no fertilization(CK)were conducted in 2021 and 2022 with'Longchun 35'as the test cultivar.The effects of different treatments on the contents of carbon(C),nitrogen(N),phosphorus(P),and eco-logical stoichiometric characteristics(C/N,C/P,N/P)of spring wheat flag leaves from booting to filling stage were studied.The effects of nutrient content and ecological stoichiometric characteristics of flag leaves on SPAD value,Pn,shoot growth rate,dry matter accumulation,and yield formation of flag leaves in spring wheat were revealed.The results showed that the C/N value of D30 flag leaves at the grain filling stage was 2.1%-6.4%and 5.4%-10.2%lower than D15 and CK,respectively.The C/P values decreased by 3.8%-5.2%and 5.4%-6.0%,respectively.In 2021,the distribution of N/P values increased by 1.4%and 4.1%,and in 2022,the N/P values decreased by 1.6%and 0.2%,respectively.Compared with D15 and CK,the SPAD values of D30 flag leaves increased by 1.8%-6.5%and 15.5%-18.2%,respectively.Pn increased by 21.6%,27.0%,28.5%-36.6%,respectively.Compared with D15 and CK,the growth rate of D30 shoots increased by 22.1%-41.2%and 68.4%-80.8%,respectively.The dry matter accumulation of D30 at maturity stage increased by 10.6%-11.1%compared with D15 and CK,respectively.The output increased by 15.7%-15.9%and 46.5%-49.3%,respectively.The contribution rate of nitrogen fertilizer in D30 increased by 46.6%-52.4%compared with D15.The partial productivity of nitrogen fertilizer increased by 15.7%-16.0%.The agronomic effi-ciency of nitrogen fertilizer increased by 69.6%-76.7%.Correlation analysis showed that the contents of C,N,and P in flag leaves of spring wheat at grain filling stage were positively correlated with SPAD value,Pn,and dry matter accumulation in flag leaves.The ecological stoichiometric characteristics of flag leaf were negatively correlated with SPAD value,Pn and dry matter accumulation of flag leaf.Therefore,30 cm deep fertilization under drought conditions increased the contents of C,N and P in flag leaves from booting to filling stage,delayed the decrease of N and P contents in flag leaves after flowering,optimized the ecological stoichiometric characteristics of flag leaves,reduced the restriction of N and P on the photosynthesis of flag leaves of spring wheat,increased the growth rate of Pn and shoots of flag leaves of spring wheat,delayed the senescence of flag leaves,and promoted the increase of yield.
基金项目
国家重点研发计划项目(2021YFD1900700)
甘肃省科技计划项目(22JR5RA763)
甘肃省科技计划项目(23JRRA1340)
甘肃省科技计划项目(20JR10RA464)
农业农村部东北平原农业绿色低碳重点实验室 2022年度开放基金()
国家科技期刊平台
NSTL
万方数据