ASOCIACIÓN DE ESPECIES LEÑOSAS EN BANCOS DE FORRAJE: INFLUENCIA SOBRE EL APORTE DE HOJARASCA, DESCOMPOSICIÓN Y LIBERACIÓN DE NITRÓGENO

Abstract

<p>The litter production, decomposition and N release from leaves of three woody species, <em>Leucaena leucocephala</em>, <em>Guazuma ulmifolia </em>and <em>Moringa oleifera</em>, in pure fodder banks and the association of <em>L. leucocephala</em> + <em>G. ulmifolia</em> and <em>L. leucocephala</em> + <em>M. oleifera</em>, 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 <em>L. leucocephala</em>, <em>G. ulmifolia </em>y <em>M. oleifera </em>and their mixtures. 120 litter bags of 30 × 30 cm each were used and 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 (<em>k</em>), we used the model . The litter accumulation was different among treatments (<em>P</em> &lt; 0.05). The fodder banks of <em>L. leucocephala</em> + <em>G. ulmifolia </em>had the higher production, while that the <em>M. oleifera </em>bank had the minor<em>. L. leucocephala</em>,<em> </em>associate with <em>G. ulmifolia </em>presented a lower litter production (385 kg DM ha^-1), which when associated with <em>M. oleifera</em> or was alone (623.3 and 653.2 kg DM ha^-1, respectively). Litter production of <em>M. oleifera </em>associated with <em>L. leucocephala</em>, was superior, compared to monoculture (124.1 vs. 58.0 kg DM ha^-1). At 4 weeks, litter from the banks of <em>M. oleifera</em>, <em>L. leucocephala</em> y <em>G. ulmifolia</em> registered a decomposition of 88, 76 and 73%, respectively; while <em>L. leucocephala</em> + <em>G. ulmifolia</em> y <em>L. leucocephala</em> + <em>M. oleífera </em>showed a decomposition of 76 and 83%, respectively. Fodder banks of <em>M. oleifera</em>, <em>L. leucocephala</em> y <em>G. ulmifolia </em>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 <em>M. oleífera</em>. The N release from the foliage was faster in pure fodder banks.</p>