Comparison of alternative tillage systems

Abstract

The aim of the project was to compare the performance and the costs of alternative tillage systems and machinery, in both energy and economic terms. To determine the energy requirements of tillage implements, experimentation in field conditions and controlled laboratory was conducted. Costs of alternative implements and complete systems were analysed. The field experiment was undertaken to determine the performance of tillage implements in real conditions. Draught force and area of disturbance of the implements were measured and specific resistance calculated. The implements involved in the experiment were 4 furrow mouldboard plough, 3 furrow disc plough, disc harrow and 7 winged tines. The mouldboard plough was operating at two different depths. Two tractors were used for execution of the implement and the wheel slip was measured. The soil bin studies were conducted in additional evaluation of the implements. The laboratory conditions ensure the uniformity of each test. The experiment was carried out to determine draught force, area of disturbance and specific resistance. The experiment involved single furrow mouldboard plough, disc plough, disc harrow and winged tines. Winged tines were made up of four different wing widths. Finally, an economic cost calculator was developed to compare the costs of different implements and tillage systems. Technical parameters and current prices of the implements were obtained from the manufacturers. The results from the field experiment show that there is a similar draught force per unit implement for mouldboard and disc ploughs, while draught force of mouldboard plough is significantly higher. The tillage efficiency of all implements is similar, with a mean of specific resistance of 58 kN/m2 and a range of 15 kN/m2. In the soil bin the vertical force preventing penetration occurred for disc plough and disc harrow. The specific resistance of the mouldboard plough had the lowest value, while the specific resistance of disc plough was higher by a factor of 1.65. By increasing the wing width of the tines the draught force was increased but the specific resistance decreased. Comparing the costs of complete tillage systems it was observed that minimum tillage decreases the operational cost per hectare by 30% compared to a conventional system based on ploughing. Direct drilling is the cheapest way to establish a crop, but if herbicide has to be applied the cost per hectare is similar to that of minimum tillage. The costs of different sizes (102, 162, 224 kW tractors) of alternative tillage systems are similar. Namely the cost of mouldboard plough is £ 80.33/ha with a range of £ +2.48/-1.93/ha, the cost of shallow mouldboard plough is £ 68.85/ha with a range of £ +2.02/-1.64/ha, the cost of stubble cultivator is £ 42.05/ha with a range of £ +2.02/-1.27/ha, the cost of direct drill is £ 20.76/ha with a range of £ +0.89/-0.75/ha and the cost of direct drill with herbicide application is £ 43.15/ha with a range of £ +0.41/-0.53/ha.