Value of integrating perennial forage seed crops in annual cropping sequences

Abstract

Cropping sequences integrating perennial forages and annual crops can generate mul-tidimensional agroeconomic and environmental benefits. A 4-yr cropping sequencestudy was conducted from 2013 to 2016 to evaluate the relative merits of variouscropping sequences. Three forage seed crops (creeping red fescue [Festuca rubraL.], alsike clover [Trifolium hybridumL.], and red clover [Trifolium pratenseL.])and four annual food crops (wheat [Triticum aestivumL.], canola [Brassica napusL.], barley [Hordeum vulgareL.], and pea [Pisum sativumL.]) were used to gener-ate eight different cropping sequence treatments, which were split into three levels ofnitrogen (N): 0, 45, and 90 kg ha−1. The seed yields of different crops were expressedas canola equivalent yield (CEY) and summed for 4-yr cropping sequences. Eco-nomic benefits for 4-yr cropping sequences were calculated using the input–outputprice scenarios of individual years. The highest CEY, gross return, and gross marginover partial variable costs were obtained from creeping red fescue-based croppingsequences, irrespective of N application rates. Based on CEY and gross margins,the merit order is ranked as creeping red fescue-based sequences>high diversityannual crop sequences≈alsike clover-based sequence≈wheat–canola alternatingsequence>continuous canola sequence. The clover-based sequences had positiveeffects on the performance of succeeding crops of wheat and canola. Among theannual crop-based sequences, economic profitability increased with the diversifica-tion from continuous canola through wheat–canola alternation to pea–barley–wheat–canola in the sequence. Further study investigating soil health and greenhouse gasemissions parameters is warranted to elucidate multidimensional agroecosystem ser-vices of diversified perennial forage seed crop-based cropping sequences comparedwith annual crops-based sequences.