The effect of the disc coulters forms and speed ratios on cutting of crop residues in no-tillage system

A. Jasinskas, K. Romaneckas, E. Sarauskis, K. Kriauciuniene, L. Masilionyte

Abstract: The introduction of sowing technologies into minimum- or no-tillage soil has a number of economical and environmental virtues, such as improving soil properties, decreasing soil erosion and degradation, and saving working time and fuel. However, the main disadvantage of these technologies is that plant residues on the soil surface reduce the quality of the germination of the crop seeds, thus requiring plant residues to be removed or cut. The theoretical investigations substantiate the dependence of the disc coulter diameter on the disc penetration depth, the depth of the plant residue layer and the compression angle. The active, constrained torsion coulters cut the straw by sliding cutting. The experimental investigations have established that of the four different forms of disc coulters with 380 mm diameters (smooth with number of notches n=0, depth of notches Δr=0 mm; notched n=12, Δr=15 mm; notched n=18, Δr=10 mm; notched n=18, Δr=20 mm), the disc coulters of 18 notches (Δr=20 mm) cut the best natural moisture (W=10.1 %) and humid (W=22.3 %) winter wheat straws. The experimental investigations have confirmed that the constrained rotation of active disc coulter at increased speeds (speed ratio λ>1.27 and λ=1.5) results in larger amount of cut straw compared to that in the case of inactive disc coulter rotation in contact with the soil (λ=1.0). The notched disc coulters cut more straw than the smooth disc coulters. The investigations have also confirmed the dependence of the straw cutting on the straw moisture content, where the amount of straw cut decreases as the moisture content increases.

Keywords: Crop residue; Disc coulter; No-till; Speed ratio; Straw moisture content

Date published: 2019-02-27