Intercropping Maize and Faba Bean for Silage Under Swedish Climate Conditions

Abstract

Cultivation of forage maize is increasing in Sweden. Sole maize is low in protein and supplementation of protein feed is needed. This study investigated whether forage maize and legumes can be intercropped in a system suitable for farmers (simultaneous sowing and harvest) under Swedish climate conditions, and whether intercropping maize and faba bean improves the forage quality compared with sole maize. Two field experiments were performed in which maize intercropped with faba bean (Vicia faba L.) in alternate rows with 0 or 60 kg N/ha was compared with sole maize crop with 120 kg N/ha. Maize dry matter (DM) yield decreased by intercropping (from mean 14,171 kg DM/ha for sole maize to 8,888–10,791 kg DM/ha for intercropped maize). Mean yield of faba bean ranged from 2,907 to 2,966 kg DM/ha. Compared with sole maize, intercropped treatments slightly increased forage protein content (mean increase 10–15 g/kg DM). Furthermore, intercropping increased forage in vitro organic matter digestibility by 4 % units (from 80.8 to 84.7 %), while the starch concentration slightly decreased from 316 to 236–254 g/kg DM. Intercropping increased neutral detergent fibre concentration from 435 to 478–497 g/kg DM and the sugar concentration from 57.3 to 61.5–72.3 g/kg DM. The results showed that intercropping silage maize and faba beans is possible under Swedish climate conditions.