减氮配施有机肥对滴灌春小麦花后同化物转运和籽粒灌浆特性的影响

【目的】研究减氮条件下新疆滴灌小麦高产高效的调控途径,分析滴灌春小麦花后同化物转运和籽粒灌浆特性的调控效应,为新疆滴灌春小麦的高产优质栽培提供科学依据。【方法】设置不同减氮配施有机肥处理,采用裂区设计,氮素为主区,品种为副区;于2019年在田间滴灌条件下设置7种减氮配施有机肥水平(N_CK、N₅、N₁₀、N₁₅、N₂₀、N₂₅、N₀),比较分析不同减氮配施有机肥处理条件下,强筋小麦新春38号和中筋小麦新春49号的花后同化物转运及籽粒灌浆特性的变化。【结果】在灌浆期内,花后干物质(茎、叶)随灌浆期推进呈先升后降趋势,峰值出现在花后14 d,而穗干物质则呈逐渐增大的变化。随减氮配施有机肥程度增加,2个品种的花后干物质积累、花后干物质转移率、花后贡献率、粒重及灌浆各参数均呈现先增后减的趋势,在N₁₅处理下各指标均达到最优值,N₁₅>N₂₀>N₂₅>N₁₀>N₅>N_CK>N₀。2个品种的快速累积持续时间(t₂~t₁)、平均灌浆速率(V_mean)、最大灌浆速率(V_max)与粒重间均存在显著关系,且平均灌浆速率与粒重间的直接效应最大,2个品种的直接通径系数为1.034 7和0.957 3。在N₁₅处理下, V_mean相比其它处理分别增长了1.92%～30.58%(新春38号),1.02%～27.93%(新春49号)。【结论】在减氮配施有机肥处理下,以N₁₅处理(85%N+15%有机肥)的花后干物质积累量、花后转运率及贡献率最高,籽粒粒重最高,与之相关的灌浆各参数表现最优,即N₁₅处理为最优配比组合。

Effects of Nitrogen Reduction and Organic Fertilizer Application on the Assimilation Transport and Grain Filling Characteristics after Anthesis of Drip Irrigation Spring Wheat in Xinjiang

【Objective】 Drip irrigation wheat is a cultivation model of efficient use of water and fertilizer for densely planted crops, and is the main cultivation technology of wheat in Xinjiang. This project aims to investigate the regulation methods of high efficiency and high yield of nitrogen in drip irrigation wheat in Xinjiang under nitrogen reduction conditions by setting different nitrogen reduction and organic fertilizer treatments, research the regulation effects on the post-flowering assimilates transport and grain filling characteristics of spring wheat under drip irrigation in the hope of providing scientific basis for the high yield and quality cultivation for drip irrigation spring wheat in Xinjiang.【Method】 The split-plot designs were adopted, nitrogen was taken as the main plot, and the variety as the subplot; in 2019, seven levels of nitrogen reduction combined with organic fertilizer application (N_CK, N₅, N₁₀, N₁₅, N₂₀, N₂₅ and N₀) were set to compare and analyze the changes of the post-flowering assimilate transport and grain filling characteristics of strong gluten wheat Xinchun 38 and medium gluten wheat Xinchun 49 under different nitrogen reduction and organic fertilizer treatment conditions.【Result】 During the filling period, the dry matter (stems and leaves) after anthesis showed an upward trend and then a downward trend with the advance of the filling period, the peak appeared at 14 days after anthesis, and the dry matter of ear showed gradually increasing trend. With the increase of nitrogen reduction and organic fertilizer application, the post-flowering dry matter accumulation, post-flowering dry matter transfer rate, post-flowering contribution rate, grain weight and grain filling parameters of the two varieties showed a trend of first increasing and then decreasing. The indicators reached the optimal value at N₁₅ treatment, specifically expressed as N₁₅>N₂₀>N₂₅>N₁₀>N₅>N_CK>N₀, and the difference between different treatments was significant (P<0.05). The filling parameters were closely related to the grain weight. The correlation analysis showed that there was a significant relationship between the rapid accumulation duration (t₂-t₁), average filling rate (V_mean), maximum filling rate (V_max) and grain weight of the two varieties. Path analysis showed that the direct effect between the average filling rate and grain weight was the largest. The direct path coefficients of the two varieties were 1.034,7 and 0.957,3.Under N₁₅ treatment, Vmean increased by 1.92%-30.58% (Xinchun38) and 1.02%-27.93% (Xinchun 49) compared those with other treatments.【Conclusion】 Under the treatment of nitrogen reduction and organic fertilizer application, the dry matter accumulation, post-flower transport rate and contribution rate of N₁₅ treatment (85% N 15% organic fertilizer) are the highest, and the grain weight is the highest under this treatment, and the related grouting parameters are the best, that is, N₁₅ treatment is the optimal proportion combination in this experiment.