Purines discharge capacity of a liquid manure spreading tank

Abstract

Introduction. Liquid manure can improve soil structure and crop productivity, but calibrated equipment is needed to achieve uniform distribution. Objective. The objective of this work was to determine at the field level, the appropriate combinations of operation of a liquid manure distribution tank and a tractor that commands it to achieve a uniform distribution of slurry and diluted manure. Materials and methods. The experiment was carried out during July 2016 at the Experimental Station “Alfredo Volio Mata” of the Universidad de Costa Rica, in Ochomogo of Cartago, Costa Rica. A plowed and harrowed plot of 5000 m2 was used where twenty plastic containers were placed, arranged in two rows separated, 4 m between and within rows. A manure tank coupled to a tractor was used and the treatments were four travel speeds (four low gears of the tractor) and a fixed degree of acceleration (442 rpm). The measured variables were the capacity and volume of discharge per unit area, and the covered area. Results. The discharge and dispersion of liquid manure in the different gears was highly significant (p<0.01), being the discharge per unit of area greater in the low gears. The relative discharge between the different working speeds was quantified, and the highest discharge gear (Gear I) equivalent to 52 m3 ha-1, was set as 100 %, in gear II the relative discharge was 65 % compared to the first. In gears III and IV, the volumes were 24 and 17 m3 ha-1 respectively. Conclusion. The low gears distributed more material per m2 favorable in more demanding crops, while with higher marches more area can be covered with less material.