EXTRACCI 3N DE NITR 3GENO EN SEIS ESPECIES OLER\ucdCOLAS DURANTE SU CICLO DE CRECIMIENTO

El objetivo de la presente investigaci\uf3n fue determinar la concentraci\uf3n y acumulaci\uf3n de nitr\uf3geno en funci\uf3n del tiempo en seis especies oler\uedcolas cultivadas en sistemas sin suelo: col china (Brassica campestris), lechuga crespa (Lactuca sativa), r\ue1bano (Raphanus sativus), tomate (Solanum lycopersicum), pimiento (Capsicum annuum) y pepinillo (Cucumis sativus). Durante el ciclo de cultivo se realizaron muestreos destructivos cuantificando la materia seca acumulada y la concentraci\uf3n porcentual de N. La concentraci\uf3n de N en la biomasa total de tomate, pimiento, pepinillo y r\ue1bano disminuy\uf3 durante su ciclo de crecimiento, mientras que en las hortalizas de hoja (col china y lechuga crespa), la concentraci\uf3n se mantuvo en constante incremento, alcanzando m\ue1ximos de 4,0 a 4,7 % de N en la cosecha, valores mayores a los encontrados en el resto de las especies estudiadas. La acumulaci\uf3n de N al momento de la cosecha estuvo influenciada de manera determinante por la biomasa total producida en las diferentes especies. Las tasas m\ue1ximas de absorci\uf3n nutrimental difirieron entre las especies estudiadas y ocurrieron cuando la materia seca acumulada oscil\uf3 entre 43,3 y 64,5 % del total. ABSTRACT Nitrogen extraction in six vegetable species during their growth cycle The objective of this research was to determine the concentration and accumulation of nitrogen of six horticultural species grown in soilless systems: chinese cabbage (Brassica campestris), crisp lettuce (Lactuca sativa), radish (Raphanus sativus), tomato (Solanum lycopersicum), pepper (Capsicum annuum) and cucumber (Cucumis sativus). During the crop cycle, destructive samples were taken to measure the accumulated dry matter and the concentrations of N. The N content in the total biomass of tomato, pepper, cucumber and radish decreased during the growth season, while in foliar vegetables (chinese cabbage and crisp lettuce), the concentration continually increased reaching a maximum of 4.0 to 4.7 % of N at harvest, values higher than those found in the rest of the studied species. The nitrogen accumulation at harvest time was definitely influenced by the total biomass produced by the plants. The maximum rates of nutrient absorption were different among the species and occurred when the accumulated dry matter ranged between 43.3 and 64.5 % from the total