Corn (Zea mays L.) silage and alfalfa (Medicago sativa L.) rotations dominate dairy forage production in temperate regions, but low yields during establishment of spring seeded alfalfa limits productivity and profitability. Interseeding alfalfa with corn silage is a novel establishment method that could enhance environmental quality, alfalfa production, and farm income, but it also incurs additional costs. Forage yields derived from long‐term field studies in Wisconsin along with feed values and input costs from 2012 to 2017 were used to predict net returns of corn silage–alfalfa rotation sequences that utilized conventional spring seeding or interseeding for alfalfa establishment and cereal rye (Secale cereal L.) as a winter cover crop following corn silage. Interseeded rotations yielded annual net return of $303 to $367 ha⁻¹, with a 3‐yr corn and 3‐yr alfalfa sequence identified as the most profitable. Conventional rotations provided lower annual net returns of $260 to $320 ha⁻¹ and the most profitable was a 4‐yr corn and 4‐yr alfalfa sequence. Sensitivity analyses demonstrated that interseeded alfalfa had a robust economic benefit, with increased net returns obtained when the corn yield penalty was limited to less than 20% or the success rate of alfalfa establishment exceeded 49% of attempts for the most profitable interseeded rotation sequence. A plant protective chemical application to interseeded alfalfa provided a net economic benefit if it increased the success rate of alfalfa establishment by at least 16%. Interseeding alfalfa into corn silage is predicted to enhance profitability of corn–alfalfa based cropping systems.

中文翻译：

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通过与青贮玉米交配来建立苜蓿，预计将提高玉米青贮-苜蓿轮作的利润

在温带地区，玉米（Zea mays L.）青贮饲料和苜蓿（Medicago sativa L.）轮作占主导地位，但春季播种苜蓿的低产量限制了生产力和盈利能力。将苜蓿与青贮玉米混合播种是一种新颖的建立方法，可以提高环境质量，苜蓿产量和农场收入，但同时也会产生额外的成本。从长期的实地研究在威斯康星州衍生饲料值和投入成本沿着饲料产率2012年至2017年被用来预测玉米青贮苜蓿旋转序列，其利用传统的弹簧播种或interseeding苜蓿建立和谷类黑麦的净回报（黑麦属谷类L.）作为玉米青贮后的冬季作物。轮作的轮作产生的年度净回报为303美元至367公顷^-1美元，其中3年玉米和3年苜蓿序列被认为是最有利可图的。常规轮换将较低的年净收益从260美元降低到320公顷^-1最赚钱的是4年玉米和4年苜蓿序列。敏感性分析表明，当玉米产量损失限制在20％以下或苜蓿建立成功率超过49％尝试最有利的种子轮作顺序时，杂交苜蓿具有很强的经济效益。如果将紫花苜蓿播种到植物上，则该植物的化学保护剂如果将紫花苜蓿的建立成功率提高至少16％，则可带来净经济利益。预计将苜蓿与玉米青贮饲料混种可提高基于玉米-苜蓿的种植系统的获利能力。