Corn plantability intercropped with Aruana grass in an integrated crop-livestock system

ABSTRACT: This study evaluated corn plantability in different agricultural/ crop-livestock systems. The experiment was conducted on a commercial farm in Candói. Paraná, Brazil. The soil was classed as Cambic Aluminic Oxysol. The area where the experiment took place was 24 hectares. The experimental design was of randomized blocks with three treatments: 1) Corn (Zea mays L.) that preceded the sowing of aruana grass (Megathyrsus maximus cv. Aruana) after winter grazing (ICLSaruana); 2) Corn sowed after winter grazing on a pasture composed by mixing rye (Secale cereale cv. Temprano), annual ryegrass (L. multiflorum cv. Ponteio), and prairie grass (Bromus catharticus) (ICLS); and 3) Corn sown after winter forages without animal grazing (CAS). The winter production cycle lasted 109 days for the levels ICLSaruana and ICLS, and 90 days for the level CAS. The occupation time length for the levels ICLSaruana and ICLS was 49 days with intermittent stocking rate. The average animal live body weight was 1,589 kg PV-1 ha (3.5 UA ha-1), and instantaneous stocking rate of 6,431 kg ha-1 (13.9 UA ha-1). Seventy three Aberdeen Angus cows (36 months old and 400 kg of initial bodyweight) were picked to graze the area. Sowing Aruana-Grass preceded corn sowing by a day, the seeder was equipped with double opener discs spaced 17 cm apart. Parameters evaluated related to corn plantability were: seeding depth, mobilized soil volume, furrow depth, plant distribution uniformity (acceptable spacing, failed or double), emergence rate and initial plant stand. No differences were observed (P > 0,05) amongst treatment levels for all varieties. The presence of grazing cattle, as well as anticipated aruana-grass sowing do not affect corn plantability.