Agronomic characteristics and yield of organic maize straw intercropped with perennial green manures

Abstract

Maize intercropped with perennial green manure is an option to promote soil coverage, control weeds and recycle soil nutrients, in an organic system. This study aimed at evaluating the agronomic characteristics and yield of grains and organic maize straw intercropped with perennial green manures sown at different maize growth stages. A 3 x 2 + 1 factorial design was used, with three perennial species of green manure - calopogonium (Calopogonium mucunoides Desv.), tropical kudzu [Pueraria phaseoloides (Roxb.) Benth] and perennial soy [Neonotonia wightii (Wight & Arn) Lackey] - and two green manure sowing times - at the maize V4 (four expanded leaves) and VT (bolting) stages - plus a control treatment (maize monoculture). A randomized blocks design, with four replications, was used. Soil coverage, production of green manures dry matter and weeds, and maize growth and production variables were evaluated. The sowing of green manures at the V4 stage had a higher percentage of soil coverage, in relation to the VT stage. Calopogonium, when compared to the other green manure species, had the highest percentage of soil coverage (35.63 %) and dry matter (1.0 Mg ha^-1). Perennial green manures grown intercropped with maize did not affect growth, grain yield and maize straw. However, they were not effective in suppressing weeds.