Cropping sequences integrating perennial forages and annual crops can generate multidimensional agroeconomic and environmental benefits. A 4-yr cropping sequence study was conducted from 2013 to 2016 to evaluate the relative merits of various cropping sequences. Three forage seed crops (creeping red fescue [Festuca rubra L.], alsike clover [Trifolium hybridum L.], and red clover [Trifolium pratense L.]) and four annual food crops (wheat [Triticum aestivum L.], canola [Brassica napus L.], barley [Hordeum vulgare L.], and pea [Pisum sativum L.]) were used to generate eight different cropping sequence treatments, which were split into three levels of nitrogen (N): 0, 45, and 90 kg ha⁻¹. The seed yields of different crops were expressed as canola equivalent yield (CEY) and summed for 4-yr cropping sequences. Economic benefits for 4-yr cropping sequences were calculated using the input–output price scenarios of individual years. The highest CEY, gross return, and gross margin over partial variable costs were obtained from creeping red fescue-based cropping sequences, irrespective of N application rates. Based on CEY and gross margins, the merit order is ranked as creeping red fescue-based sequences > high diversity annual crop sequences ≈ alsike clover-based sequence ≈ wheat–canola alternating sequence > continuous canola sequence. The clover-based sequences had positive effects on the performance of succeeding crops of wheat and canola. Among the annual crop-based sequences, economic profitability increased with the diversification from continuous canola through wheat–canola alternation to pea–barley–wheat–canola in the sequence. Further study investigating soil health and greenhouse gas emissions parameters is warranted to elucidate multidimensional agroecosystem services of diversified perennial forage seed crop-based cropping sequences compared with annual crops-based sequences.

中文翻译：

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将多年生牧草种子作物纳入一年生作物序列的价值

将多年生牧草和一年生作物相结合的种植序列可以产生多方面的农业经济和环境效益。2013 年至 2016 年进行了一项为期 4 年的种植序列研究，以评估各种种植序列的相对优点。三种饲料种子作物（匍匐红羊茅 [ Festuca rubra L.]、三叶草 [ Trifolium hybridum L.] 和红三叶草 [ Trifolium pratense L.]）和四种一年生粮食作物（小麦 [ Triticum aestivum L.]、油菜 [ Brassica napus L.]、大麦 [ Hordeum vulgare L. ] 和豌豆 [ Pisum sativumL.]) 用于产生八种不同的种植顺序处理，将其分为三个水平的氮 (N)：0、45 和 90 kg ha ^-1. 不同作物的种子产量以双低油菜籽当量产量 (CEY) 表示，并按 4 年种植顺序求和。使用各个年份的投入产出价格情景计算 4 年种植序列的经济效益。最高的 CEY、总回报和部分可变成本的毛利率是从基于红羊茅的匍匐种植序列中获得的，而与施氮量无关。基于CEY和毛利率，优等顺序排列为基于匍匐红羊茅的序列>高多样性一年生作物序列≈基于三叶草的序列≈小麦-油菜交替序列>连续油菜籽序列。基于三叶草的序列对小麦和油菜籽的后继作物的性能产生了积极的影响。在一年生作物序列中，随着从连续双低油菜籽到小麦-双低油菜籽交替到豌豆-大麦-小麦-双低油菜籽序列的多样化，经济盈利能力增加。需要进一步研究土壤健康和温室气体排放参数，以阐明与基于一年生作物的序列相比，基于多年生牧草种子作物的多样化种植序列的多维农业生态系统服务。