Fertilization network at Eastern Paraguay

CAPECO (Paraguayan Chamber of Cereals and Oils Exporters), with the support of IPNI and JICA (Japanese International Cooperation Agency), has started a network of fertilization experiments at three sites in eastern Paraguay (Itapua, Alto Parana, and San Pedro). This is the main region of soybean, corn, wheat, and sunflower production in the country. The main objectives are: 1) to study and verify current fertilization recommendations under no-tillage for soybean, corn, wheat, and sunflower crops, 2) to evaluate the effects of fertilization management and crop rotations on soil properties. and 3) to determine N, P, K, and S responses of the main field crops of eastern Paraguay.

Six experiments were established in 2008: two at the Itapúa Department, two at the Alto Paraná Department, and two at San Pedro Department. At each region, one experiment evaluates grain (wheat, and soybean, or corn) yield responses to N, P, K, S, and micronutrients; and a second one evaluates the interactions of cover crops and nutrient management on grain yield production and soil properties. Wheat yields averaged 4,177, 4,019, and 689 kg/ha at Itapua, Alto Parana, and San Pedro, respectively, across all fertilization treatments. Grain yields at San Pedro were sharply reduced because of intense drought. The average yield response to balanced fertilization at the three sites was +25%. Most of this response was due to N (+12%), while P+K+S contributed to an equivalent response (+13%). Paraguay-01