Comparison of the technical and economic performances of two different shredders on pomegranate pruning residues

Abstract

Aim of study: The study aimed to examine the technical and economic performances of two different shredders for three windrow densities of pomegranate residues.Area of study: The study was conducted in the Serik District of Antalya Province, Turkey.Material and methods: Two different pruning residue shredders driven by tractor power take off (PTO) were used. Machine‑I has pick‑up, shredding, screen units. Machine‑II only has a shredding unit. The experiment was conducted at windrow densities of 1.49, 2.10, and 2.41 kg/m2 in a pomegranate orchard; the study used a completely randomized split‐plot design with two treatments and three replications.Main results: The power values for the increasing windrow densities were 8.00, 11.73, and 18.47 kW/m for Machine-I and 5.08, 5.68, and 6.48 kW/m for Machine-II. Moreover, the average particle length of 68.6 mm shredded by Machine‑I was approximately 20 mm smaller than that of Machine‑II. The minimum unit energy value of Machine-II was 2.53 kWh/t at the maximum windrow density of 2.41 kg/m2. This value for Machine-I was 5.58 kWh/t at the medium windrow density of 2.10 kg/m2. The lowest unit cost for Machine-I and Machine-II was calculated as 27.2-7.1 US$/t (at medium density) and 16.8-3.5 US$/t (at maximum density), respectively.Research highlights: The appropriate windrow densities for Machine-I and Machine-II were different in terms of energy requirements and total unit cost. Machine-I is more effective at consistently chopping the residues than Machine-II, but it requires more energy and a higher unit cost.