Decomposition and Nutrient Release of Tree Legumes in an Agroforest System

  •  Larissa Portela    
  •  Anagila Silva    
  •  Gustavo Santos    
  •  Joab Pedrosa    
  •  Conceição Oliveira    
  •  Alana Aguiar    


The research compared biomass production and nutrient release in an alley cropping system in two collection methods, the litterbag method and the direct collection method (Morley, Bennett, & Clark, 1964). The system was implemented in 2015 at 2017, at the Maranhão Federal University, Maranhão, Brazil. The experiment was a randomized block design with four treatments, consisting of leucaena+sombreiro (Leucaena leucocephala and Clitoria fairchildiana), leucena+acacia (Leucaena leucocephala and Acacia mangium), gliricidia+sombreiro (Gliricidia sepium and Clitoria fairchildiana) and gliricidia+acacia (Gliricidia sepium and Acacia mangium). In order to determine the remaining dry matter, nutrient release (N, P, K, Ca, Mg and Mn), the decomposition constants and the half-lives times of plant residues, 100 g of fresh material were conditioned in litterbags (50 g of each species), arranged on the soil surface. The second method was done by randomly throwing a collector on each plot in the same dimensions of the litterbags (0.40 x 0.40 m) and collecting the litter. For the two methods samples were collected at 0, 30, 60, 90 and 120 days after the start of the experiment. The litterbags method showed a higher C/N ratio at day 30 up to 120 days, which implies that this method is providing a different environment from the litter, where it would be overestimating the C/N ratio and retarding the decomposition. The G+S and G+A combinations were more rapidly decomposed than the combinations of L+S and L+A. The following order of release was established for the litterbags method: P > N > K > Ca > Mn > Mg, and for the method of collecting the litter: N > P > Ca > Mg > K > Mn.

This work is licensed under a Creative Commons Attribution 4.0 License.