Results of the experimental study of the combined Shirvan Harrow

Abstract

The Shirvan Plain of the Republic of Azerbaijan is predominantly characterized by sierozem soils, which are widely used for cotton and grain cultivation. Pre-sowing tillage of these soils and the destruction of surface crusts remain major agronomic challenges, as conventional implements such as cultivators, needle harrows, and spring harrows do not provide sufficient soil loosening and clod crushing.
The aim of this study was to develop and experimentally evaluate a combined harrow, named “Shirvan”, for improving pre-sowing tillage quality of sierozem soils. The implement was designed and manufactured under laboratory conditions at the Agromechanika Scientific Research Institute of the Republic of Azerbaijan, and field experiments were conducted during 2017–2020 on the institute’s experimental fields located in the Samukh district.
Field trials were carried out with four replications. Soil samples collected after tillage were analyzed using a sieve set with mesh sizes of 10, 25, 50, and 100 mm to determine soil aggregate distribution and clod crushing efficiency. During testing, the operating speed of the implement ranged from 7.6 to 8.9 km/h with a working width of 3.0 m. The roller tooth penetration depth was 6 cm for the roller, while the tillage depths were 17.5 cm for the heavy-toothed section and 7 cm for the zigzag harrow. Clod crushing efficiency reached 71–75% at soil moisture contents of 17–21% and 38–45% at 9–12% moisture.
Practical recommendations for agricultural use include: to achieve optimal soil fragmentation (70%+) and energy efficiency, the “Shirvan” harrow should be deployed when soil moisture is within the 17–21% range at an operating speed not exceeding 9 km.h-1. This aggregate represents a robust solution for enhancing seedbed quality in arid sierozem zones, meeting rigorous agrotechnical requirements for sustainable crop production.