Resumen

LOPEZ, Marisol et al. Effect of the inorganic fertilization on the availability of nutrimentos in the ground, level nutricional of the plant and fungi micorricicos arburculares in plantations de theobroma cacao. Agronomía Trop. [online]. 2007, vol.57, n.1, pp.31-43. ISSN 0002-192X.

Agronomic practices used in cocoa, Theobroma cacao L., plantations to increase crop production include inorganic fertilization to cover the nutritional requirements of the plant and to increase only the chemical soil fertility (macronutrients available), underestimating the biological component. The objectives of this study were to evaluate the effect of inorganic fertilization on: the availability of soil nutrients, the nutritional level of cocoa crop and the presence of arbuscular mycorrhiza (AM) spores. A field experiment was carried out in the farm "Los Torres", in Choroni, Aragua state, (10º 20’ 58" N and 67º 37’ 36" O). The doses of nutrients (g tree^-1) were: 45 of nitrogen (N), and 0, 45, 90 and 135 of phosphorus (P) and potassium (K), for a total of 16 treatments, repeated three times. During the second year of evaluation, highly significant differences between P treatments were found (α = 1%), increasing availability. Interactions between levels of P and K were observed. The potassium doses of 45, 90 and 135 g plant^-1 favored P availability in the soil. After the first year of evaluation, the levels of P, Ca and Mg in plant increased significantly. While potassium increased in the 2^nd year of evaluation. The available phosphorus affects the number of spores of AM in the systems of production of cocoa, the number of spores decreased when the doses of P increased.

Palabras clave : Theobroma cacao L; inorganic fertilization; doses; mycorrhizal; soil of fertility; plant nutritional analysis; field experiment; Aragua; Venezuela.