Sward structure, light interception and herbage accumulation in forage peanut cv. Belmonte subjected to strategies of intermittent grazing management

Estrutura do dossel, interceptação de luz e acúmulo de forragem em amendoim-forrageiro cv. Belmonte submetido a estratégias de pastejo rotativo

ABSTRACT.

Nitrogen fertilization ensures productivity and persistency of pastures, but may be expensive. Perennial forage peanut, becomes an interesting alternative for N supply. Little is known about its use under grazing. The objective of this study was to evaluate regrowth process of forage peanut using an experimental protocol analogous to tropical forage grasses under rotational grazing. Treatments corresponded to two pre- (95% and maximum canopy light interception - LI_95% and LI_Max) and two post-grazing (post-grazing heights of 40 and 60% of pre-grazing height) conditions, in a 2x2 factorial arrangement in a randomized complete block design (n = 4). Targets of LI pre-grazing affected pre-grazing height and LI post-grazing. The residual sward LAI did not vary, resulting in similar grazing interval. Greater rates and total herbage accumulation were recorded for LI_Max target, consequence of the greater accumulation of stolons at the lower strata of the swards. Greater percentage of leaflets was recorded for the LI_95% target. Given the stoloniferous growth habit of forage peanut, stolon accumulation in the lower strata of the sward do not represent a limitation to leaf accumulation and morphological composition. The greater pre-grazing sward height associated with the LI_Max target facilitate herbage prehension and intake, further investigation is needed.

Keywords:
intermittent stocking; sward structure; pre-grazing height; botanical/morphological composition; grazing management