Perennial Plant Establishment and Productivity Can Be Influenced by Previous Annual Crops

Abstract

Core Ideas Perennial treatments established into soybean residue had the highest stand frequency measured. Warm‐season mixtures tended to have higher biomass production following soybean. Previous annual crops affected biomass yields for switchgrass, intermediate wheatgrass–alfalfa, and a cool‐season mixture. Developing efficient, economical methods of perennial mixture establishment is needed for grazing and conservation purposes. Study objectives were to evaluate different perennial monocultures and mixtures planted into spring wheat (Triticum aestivum L.), corn (Zea mays L.), soybean (Glycine max L. Merr.), dry pea (Pisum sativum L.), and spring canola (Brassica napus subsp. Rapifera) residue to determine establishment and subsequent production variation near Mandan, ND. Perennial treatments were two monocultures, binary mixtures (grass + legume), a warm‐season moderate‐input moderate diversity (MIMD) grass mixture, a cool‐season MIMD grass mixture, and a low‐input high diversity (LIHD) mixture consisting of 16 native species. Seeding rate was 450 pure live seed (PLS) m−2 for all perennial treatments and were managed according to best management practices. Stand establishment, measured using the frequency grid method, indicated perennial treatments established into soybean residue had the highest stand frequency (59%). Cool‐season grass treatments tended to have higher stand frequencies than warm‐season grass treatments and LIHD. Biomass yields were highest for intermediate wheatgrass [Thinopyrum intermedium (Host) Barkworth & D.R. Dewey] (8.2 ± 1.2 Mg ha−1). Switchgrass (Panicum virgatum L.) produced the highest average biomass yield of the warm‐season grass treatments with 6.7 ± 1.2 Mg ha−1. The LIHD mixture was primarily cool‐season grasses followed by weeds, warm‐season grasses, and forb/legumes. This study highlights how transitioning from an annual cropping system to perennials can be influenced by the previous annual crop in a semiarid environment. Further research on establishing diverse, pollinator‐friendly perennial mixtures following annual crops is warranted.