Evaluation of the CROPGRO/DSSAT model performance for simulating plant growth and grain yield of soybeans, subjected to no-tillage and conventional systems in the subtropical Southern Brazil.

During crop cycle, growth and phenological development are influenced by different factors such as weather conditions, genetic potential, soil fertility, and system management. Management practices influences soil water retention properties and consequently crop growth an yield. In Brazil, a paradigm chance in soil management has lead conventional tillage system to give room to no-tillage cropping system, due to impacts such as erosin processes and soil organic carbon losses. No-tillage is considered a conservationist system because it includes crop rotation, mulching and only minimum soil mobilization on the seeding line. Those practices promote higher soil water storage, which are attributed o improvement of mesoporosity and non-saturated soil hydraulic conductivity. Knowledge on soil-water-atmosphere system dynamics is required on modeling crop growth and yield for supporting decision systems. Among several options, the Decision Support System for Agrotecnology Transfer (DSSAT) seem to be the most suitable for practical application since it includes more than 18 different crops models tested worldwide. After model calibration against field data, it is possible to simulate realistic scenarios for decision-makers (farmers, managers, agricultural technicians and government), as well as to identify crop constraint for scientists defining research priorities. This study aimed to evaluate CROPGRO/DSSAT model performance to simulate soybean growth, development and crop yield under no-tillage and conventional tillage systems in subtropical climate conditions, in order to support decision making in soybean cropping of Brazil