Evaluation of field performance indicators of subterranean ploughs for breaking hard layers at different depths and speeds

ABSTRACT

The experiment was conducted in the spring season of the year 2023, at the beginning of May, in the Al-Rajaiba area, Al-Jadid Al-Gharbi district, Karbala Governorate, Iraq. The land area is 1/2 hectare, 44 m wide x 114 m long. To evaluate the performance of a subsoil plough for breaking the hard layer with different ploughing depths and speeds in some field performance indicators in the soil. The soil texture of the experimental field is clay. The research included a statement of the effect of different ploughing depths and speeds on some technical indicators of field performance under two levels of speed (3.71 and 5.21) km/h and three levels of depths of 40 cm, 50 cm and 60 cm, with three reparations. The least significant difference test under the confidence level of 0.05 was used to compare the averages of the parameters. The studied characteristics were cohesion strength, bulk density, theoretical productivity, actual productivity, and total porosity. The results showed that the speed of 5.21 km/h was significantly superior to that of 3.71 km/h in all the studied characteristics of the soil ploughed with a subsoil plough compared to the unploughed soil. Using a subsoil plough decreased the bulk density and cohesive strength by 1.31 g/cm³ at the speed of 3.71 km/h, at a depth of 40 cm and 48.65 kN/m², at the same depth and speed, respectively. The use of the plough also led to an increase in the total porosity, actual productivity, and theoretical productivity by a value of 50.322 g/cm³ at a speed of 3.71 km/h and a depth of 40 cm, 10.758 ha/h and 15.369 ha/h at a speed of 5.21 km/h and a depth of 40 cm, respectively. That led to improving field performance indicators and soil physical properties. The results also showed an increase in bulk density and soil cohesion with increasing ploughing depth and with increasing live service or use of the land. It is recommended to do this process frequently.

Keywords: Subsoil, speed, depth, plough, hard layer.