Abstract

HAHN VILLALBA1,2*, Enrique Oswin; SAMANIEGO MONTIEL1,2, Luís Ramiro  and  ARNOLD PEREZ¹, Adriana Carolina. Evolution of the spatial variability of chemical attributes of an Oxisol with variable-rate input application. Investig. Agrar. [online]. 2014, vol.16, n.1, pp.36-42. ISSN 2305-0683.

The correction of soil at variable rate is a technique to lower the spatial variability of soil properties that need further investigation. The aim of this work was to study the evolution of the spatial variability of the soil with applications of fertilizer and lime at variable rate. The experimental area is located in Alto Verá, Itapúa, Paraguay, in an area of 20.26 hectares. In 2010 the first soil sampling was realized. Maps were made for Phosphorus (P), Potassium (K), Aluminium (Al), Calcium (Ca) and Magnesium (Mg). Then, recommendations were generated for application of triple superphosphate with dose of 0, 60 and 130 kg ha^-1, Potassium Chloride with dose of 0, 100 and 180 kg ha^-1 and for agricultural lime dose of 600, 1100 and 1600 kg ha^-1. At the end of 2011, after three crops in succession, in the same points a new soil sampling and a diagnosis by maps to measure the evolution of the fertility was realized. An important aspect of the applications of P at variable rate was that the coefficient of variation decreased from 20.7% to 14.6%. The K concentration rose up to a "high" level in much of the plot and Al concentration in the soil decreased while the average concentration of Ca and Mg increased. It was concluded that the application of fertilizer and lime at variable rate reduced the spatial variability of P, K, Ca and Mg.

Keywords : Precision Agriculture,; soil fertility,; spatial variability..

        · abstract in Spanish     · text in Spanish     · Spanish ( pdf )