Dinamica del nitrogeno en el sistema suelo-planta con pasto guinea (Panicum maximum Jacq).
1995
Pirela M.F. | Fernandez L. | Clavero T. | Casanova A. | Sandoval L.
In order to study the dinamic of nitrogen in the soil-plant system with guinea-grass, a trial was carried out in the Laberinto area, Jesus Enrique Lossada County Zulia State area. Representing a dry tropical forest with an average yearly rainfall that varies between 780 and 1744 mm showing a bimodal regime with 2 rainy periods and 2 dry periods with average monthly temperature for the highest of 36,6 deg. C and lowest of 22.1 deg. C. An experimental design in random blocks was used with 5 replications and 3 treatments. TO=O kg N ha-1, T1=1OO kg N ha-1T2=200 kg N ha-1. The content of nitrogen was evaluated (N-Total) and the production of dry matter in the plant, the losses by percolation at the 2 different depths 0 to 20 cm and 0 to 40 cm and losses by runoff. N content was evaluated (N-Total, N-NH4+ and N-NO3-) in a soil-depth of 0 to 20 cm for each grass clipping, also the supply of nitrogen was analyzed (N-NH4+ and N-N03-) by effect of rainfall. The results showed a high linear positive correlation between the concentration of N-Total in the plant and the production of dry matter. When the relation was established between the nitrogen in the plant and present in the soil a significant correlation is showed with the N-NH4+ while with N-N03-were showed as the lowest and negative. The percent distribution of nitrogen in the plant became 55 percent in removed biomass, 35 percent in the residual biomass and 10 percent in the root biomass. The losses by percolation were presented by 80 percent like N-NH4+ while N-NO3- by 20 percent. The losses by runoff were low and did not exceed 1 kg N ha-1 year-1. The nitrogen in the rainfall water resulted low, however N-NH4+ became the highest with 8.4 kg N ha. year-1. while supplied 4.16 kg N. ha-1 showing 66,8 percentage and 33.2 percentage respectively.
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