Abstract

BOUZO, Carlos Alberto  and  ASTEGIANO, Eugenio Domingo. Effects of different agro-ecosystems in the dynamic of nitrogen, phosphorous, and potassium in the tomato crop. Rev. Mex. Cienc. Agríc [online]. 2012, vol.3, n.5, pp.907-924. ISSN 2007-0934.

The objective ofthis research was to evaluate the dynamics of nitrogen, phosphorous, and potassium in tomato crops and in different soils of agro-ecosystems. The research consisted of studying the effect of three agro-ecosystems: 1) agricultural (T₁), natural (T₂) and horticultural (T₃). These agro-ecosystems are characterized by the sequence of the maize and wheat crops during 8 years (T₁), natural vegetation of grasses (T₂), and rotation of horticultural crops during 20 years (T₃). The study was done in Santa Fe, Argentina (31° 15' S, 60° 50' W) between 2009 and 2010, having used a hybrid tomato crop, round with indeterminate growth. The concentration of N-NO₃^- in the soils had a high value (< 65 ppm) at the beginning of the crop in the three agro-ecosystems. The concentration of P was also very high (< 250 ppm) in the horticultural agro-ecosystem (T₃) and less than the rest, with approximately 50 ppm for T1 and 150 ppm for T2. The same occurred in this agro-ecosystem with K. The natural agro-ecosystem (T₂) was the one that had the lowest concentration of P in the soil. The concentrations of N, P, and K resulted with highly significant differences (p≤ 0.01) in the concentrations of the stalks of the plants coming from the three agro-ecosystems. However, the concentrations of N and K were deficient towards the end of the study in the agricultural (T₁) and natural (T₂) agro-ecosystems.

Keywords : Solanum lycopersicum L.; nutrient concentrations; mineral nutrition; agricultural rotation.