Performance and possibilities of maize crop under no-tillage system in the state of Paraná

Abstract

On a long term trial, IAPAR is developing multidisciplinary research since 1976 in two major patterns of soil and climatic, in the State of Paraná, aiming to: a. Compare no-tillage and conventional tillage systems, among different crop rotations, in terms of production and profit return; b. Assess the effects of the tillage systems and rotations on the occurrence of weeds, insects and plant diseases; c. Find new crop alternatives for the no-tillage system. The effects on no-tillage, measured from 1976 to 1980 indicated the following: faster rate of seedling emergency; more uniform and vigorous initial plant growth and lower lodging rates; greater rate of broken stalks and reduction on the grain yield; this was probably related to nitrogen deficiency, which became less pronounced under soybean rotation; greater incidence of weed population and stalk rot: lesser consumption of fuel and more consumption of herbicides. The 4-year mean grain yield and the variable costs for maize (Zea mays L.) production did not differ significantly between the tillage systems. Alternating maize and soybean in rotation with wheat was more profitable than continuous soybean and wheat.