ASSOCIATION OF WOODY SPECIES IN FODDER BANKS: INFLUENCE ON LITTER PRODUCTION, DECOMPOSITION AND NITROGEN RELEASE

Abstract

The litter production, decomposition and N release from leaves of three woody species, Leucaena leucocephala, Guazuma ulmifolia and Moringa oleifera, in pure fodder banks and the association of L. leucocephala + G. ulmifolia and L. leucocephala + M. oleifera, as mixed fodder banks, were evaluated. Twenty plots (200 m2) in a completely randomized block design with four replicates were used. Litter production was estimated using traps installed in the middle row of each plot. For decomposition, were used fresh leaves of L. leucocephala, G. ulmifolia y M. oleifera and their mixtures. 120 litter bags of 30 × 30 cm each were used and were randomly distributed within the plots (6 bags per plot). Two bags were removed from each plot at 4, 8 and 16 weeks. The remained material was weighed, dried, ground and N content was determined. To determine decay constant (k), we used the model Y=a•e^(-k•t). The litter accumulation was different among treatments (P < 0.05). The fodder banks of L. leucocephala + G. ulmifolia had the higher production, while that the M. oleifera bank had the minor. L. leucocephala, associate with G. ulmifolia presented a lower litter production (385 kg DM ha-1), which when associated with M. oleifera or was alone (623.3 and 653.2 kg DM ha-1, respectively). Litter production of M. oleifera associated with L. leucocephala, was superior, compared to monoculture (124.1 vs. 58.0 kg DM ha-1). At 4 weeks, litter from the banks of M. oleifera, L. leucocephala y G. ulmifolia registered a decomposition of 88, 76 and 73%, respectively; while L. leucocephala + G. ulmifolia y L. leucocephala + M. oleífera showed a decomposition of 76 and 83%, respectively. Fodder banks of M. oleifera, L. leucocephala y G. ulmifolia at 4 weeks, release the 90, 86 and 74% of the N content in their foliages, respectively. The accumulate litter production was higher in the mixed fodder banks. Most decomposition occurred in the banks that included M. oleífera. The N release from the foliage was faster in pure fodder banks.