ORGANIC FORAGE PRODUCTION : RESPONSES OF LOXODERA LEDERMANNII GROWN UNDER THE COMPOST APPLICATION IN SUBEQUATORIAL BENIN

Abstract

This study examines biological and agronomic responses of Loxodera ledermannii to the compost application. A complete random block of 3 treatments (0 t/ha, 5 t/ha and 10 t/ha of organic fertilizer in 3 replicates was designed. Each plot (1.5 m x 2 m) is seeded 24 tussocks acclimated in the Botanical Garden of the UAC from 2011 to 2013. Leaf morphometric, ecophysiological and agronomic measurements are subjected to ANOVA with STATISTICA 9.0. Results showed that organic fertilization significantly affects the tillers production, Specific Leaf Area (SLA) and aboveground biomass. SLA are the highest under compost (SLA >208.61±10.81 cm 2 .g -1 ) and the lowest with the controls (153.33 cm 2 .g -1 ≤ SLA ≤ 169.05 cm 2 .g -1 ). The leaves of L. ledermannii accumulate naturally more biomass per area unit and have a long lifespan. The compost application increases significantly SLA by 25% (P< 0.01). This increase implies a low accumulation of biomass per area unit, indicating that compost would impoverish the leaves of L. ledermannii in carbon reducing by the way its life expectancy. The controls produced 10.33 t DM.ha -1 , which was 46% other than production under 5 to 10 t per hectare of compost. SLA is positively correlated to the leaf dry matter content (R = 0.88; p< 0.01) and negatively to the leaf water content (R = -0.89; P< 0.01). These results suggest that L. ledermannii is a slow-growing species and the organic fertilization tends to disrupt its development. Its utilization in ecological farming requires knowledge on strategies and functional status of this species.