不同密度下氮肥运筹对半干旱区青贮玉米碳氮积累与转运特征的影响OA
Effects of nitrogen application at different densities on carbon and nitrogen ac-cumulation and translocation characteristics in forage maize in semi-arid regions
明确不同密度下氮肥运筹对半干旱区青贮玉米碳氮积累、转运及粗蛋白合成的影响,可为半干旱区青贮玉米高产优质栽培提供理论依据.本研究以"陇青贮 1 号"为研究对象,设计 2 种密度(6.0 万株 hm-2 和 7.5 万株 hm-2),3种施肥方式(氮肥全部基施、40%和 60%氮肥大喇叭口期追施),测定了青贮玉米花前和花后干物质、非结构性碳水化合物(NSC)和氮素累积量、转运量和贡献率,并分析了上述指标与青贮玉米产量、粗蛋白含量和产量之间的相关关系.结果表明,氮肥追施可显著降低花前干物质和NSC积累与转运,但提高花后干物质和NSC积累量.其中,与CK1(6.0万株 hm-2,氮肥全部基施)相比,T1(6.0 万株 hm-2,40%氮肥大喇叭口期追施)和T2(6.0 万株 hm-2,60%氮肥大喇叭口期追施)花前干物质和NSC的转运量、转运率及其对干物质贡献率均显著降低,但花后干物质积累量分别平均提高46.29%和 22.63%,花后NSC积累量分别平均提高 29.53%和 17.54%,均差异显著;与CK2(7.5万株 hm-2,氮肥全部基施)相比,T3(7.5 万株 hm-2,40%氮肥大喇叭口期追施)和T4(7.5 万株 hm-2,60%氮肥大喇叭口期追施)花前干物质和 NSC 的转运量、转运率及其对干物质贡献率均显著降低,但花后干物质积累量分别平均提高 5.88%和 5.90%,花后 NSC积累量分别平均提高 19.53%和 65.57%,均差异显著.氮肥追施可显著提高花前氮素转运量、转运率和花后氮素积累量,其中,与 CK1 相比,T1 花前氮素转运量、转运率和花后氮素积累量分别平均提高 64.48%、7.77%和74.86%,T2 分别平均提高 43.21%、7.52%和 32.27%;与CK2 相比,T3 分别平均提高 12.51%、8.92%和 74.94%,T4 分别平均提高 47.37%、8.75%和 73.41%.青贮玉米产量与花后干物质积累量(R2=0.1547*)、花后氮素积累量(R2=0.1582*)呈显著正相关,粗蛋白含量与花前氮素转运量(R2=0.1263*)、花后氮素积累量(R2=0.1764**)、花后NSC积累量(R2=0.2155**)呈正相关,粗蛋白产量与花后干物质积累量(R2=0.1723*)、花后氮素积累量(R2=0.1682*)呈显著正相关.氮肥追施在提高花前氮素转运和花后碳氮积累量的前提下,显著促进了青贮玉米粗蛋白合成,其中,T1 粗蛋白含量9.42%,T2 粗蛋白含量 8.40%,分别较CK1 提高 62.18%、44.80%;T3 粗蛋白含量 7.06%,T4 粗蛋白含量 8.12%,分别较CK2 提高 39.25%、60.15%.因此,T1 和T4 是该区适宜推广应用的青贮玉米品质提升种植方式.
To provide a theoretical basis for high-yield and high-quality cultivation of silage maize in semi-arid regions,this study investigated the effects of nitrogen application on carbon and nitrogen accumulation,translocation,and crude protein synthesis in silage maize under different planting densities.Using'Longqingzhu 1'as the experimental material,two planting densities(60,000 and 75,000 plants hm–2)and three nitrogen application regimes(all nitrogen as basal fertilizer,40%and 60%of nitrogen applied as topdressing at the bell stage)were examined.Measurements included dry matter,non-structural carbohydrate(NSC),and nitrogen accumulation and translocation before and after flowering,as well as their contribution to total plant biomass.Cor-relations between these physiological parameters and forage yield,crude protein content,and crude protein yield were also ana-lyzed.Compared with CK1(60,000 plants hm–2 with all nitrogen applied basally),treatments T1 and T2(same density with 40%and 60%nitrogen topdressing,respectively)showed significantly reduced dry matter and NSC translocation and contribution rates at the pre-flowering stage,but significantly increased post-flowering dry matter accumulation by 46.29%and 22.63%,and NSC accumulation by 29.53%and 17.54%,respectively.Compared with CK2(75,000 plants hm–2 with all nitrogen applied basally),T3 and T4(same density with 40%and 60%nitrogen topdressing,respectively)also showed reduced translocation and contribu-tion rates at the pre-flowering stage,while post-flowering dry matter increased by 5.88%and 5.90%,and NSC accumulation in-creased by 19.53%and 65.57%,respectively.Nitrogen topdressing significantly increased nitrogen translocation and translocation rate at the pre-flowering stage,as well as nitrogen accumulation at the post-flowering stage.Compared with CK1,T1 showed increases of 64.48%,7.77%,and 74.86%,while T2 increased by 43.21%,7.52%,and 32.27%,respectively.Compared with CK2,T3 increased by 12.51%,8.92%,and 74.94%,and T4 by 47.37%,8.75%,and 73.41%,respectively.Forage yield was significantly positively correlated with post-flowering dry matter accumulation(R2=0.1547*)and nitrogen accumulation(R2=0.1582*).Crude protein content was positively correlated with pre-flowering nitrogen translocation(R2=0.1263*),post-flowering nitrogen accu-mulation(R2=0.1764**),and NSC accumulation(R2=0.2155**).The crude protein yield of the whole plant was significantly positively correlated with post-flowering dry matter(R2=0.1723*)and nitrogen accumulation(R2=0.1682*).These results indi-cate that nitrogen topdressing significantly promotes crude protein synthesis in silage maize by enhancing nitrogen translocation at the pre-flowering stage and carbon and nitrogen accumulation at the post-flowering stage.The crude protein content of T1 and T2 was 9.42%and 8.40%,which was 62.18%and 44.80%higher than that of CK1,respectively.The crude protein content of T3 and T4 was 7.06%and 8.12%,39.25%and 60.15%higher than that of CK2,respectively.Therefore,T1 and T4 are recommended for improving silage maize quality in semi-arid regions.
马海会;张国平;杨思存;王红丽
甘肃省农业科学院旱地农业研究所,甘肃 兰州 730070||农业农村部西北旱地农业绿色低碳重点实验室,甘肃 兰州 730070||甘肃省旱作区水资源高效利用重点实验室,甘肃 兰州 730070甘肃省农业科学院旱地农业研究所,甘肃 兰州 730070||农业农村部西北旱地农业绿色低碳重点实验室,甘肃 兰州 730070||甘肃省旱作区水资源高效利用重点实验室,甘肃 兰州 730070甘肃省农业科学院旱地农业研究所,甘肃 兰州 730070||农业农村部西北旱地农业绿色低碳重点实验室,甘肃 兰州 730070||甘肃省旱作区水资源高效利用重点实验室,甘肃 兰州 730070甘肃省农业科学院旱地农业研究所,甘肃 兰州 730070||农业农村部西北旱地农业绿色低碳重点实验室,甘肃 兰州 730070||甘肃省旱作区水资源高效利用重点实验室,甘肃 兰州 730070
密度施肥调控碳氮积累粗蛋白合成
planting densitynitrogen fertilizationregulationcarbon and nitrogen accumulationcrude protein synthesis
《作物学报》 2026 (4)
1193-1207,15
本研究由国家自然科学基金项目(32360532),甘肃省自然科学基金重点项目(23JRRA1335),农业农村部西北旱地农业绿色低碳重点实验室和甘肃省旱作区水资源高效利用重点实验室开放基金(2024HNS12)资助.This study was supported by the National Natural Science Foundation of China(32360532),the Key Project of the Gansu Provincial Natural Science Foundation(23JRRA1335),the Open Fund of the Key Laboratory of Northwest Dryland Agriculture Green and Low-Carbon,Minis-try of Agriculture and Rural Affairs,and the Open Fund of the Key Laboratory of Water Resources Efficient Utilization in Arid Areas of Gansu Province(2024HNS12).
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