The draft is calculated based on the soil resistance and the cross-sectional area of the furrow. If the unit draft is given as 70 kg/cm² and the furrow cross-section is 1 cm² (as implied by the context of unit draft calculations), the total draft equals 70 kg. This calculation assumes standard soil resistance parameters provided in the problem statement.

A spike tooth harrow is a secondary tillage implement primarily used for breaking clods, leveling the seedbed, and controlling small weeds. Because of its design, it is intended for shallow soil manipulation, typically operating at a depth of approximately 5 cm. It is not designed for deep primary tillage, but rather for final seedbed preparation to ensure a fine tilth suitable for germination.

V-shaped sweeps are designed to cut through the soil at a shallow depth while leaving crop residues on the surface. This makes them ideal for stubble mulch tillage, a conservation practice that helps prevent soil erosion and improves moisture retention by protecting the soil surface with organic matter.

A chisel plough is designed to break up compacted soil layers without inverting the soil surface. By maintaining surface residue and increasing soil porosity, it significantly enhances water infiltration and reduces runoff, thereby conserving soil moisture more effectively than conventional inversion ploughs.

All listed statements are correct. Flat fan nozzles provide uniform coverage for broadcast applications. Turbo floodjet nozzles are engineered for high-volume, low-pressure applications, reducing drift while ensuring effective soil incorporation. Cone nozzles are specialized for creating fine droplets or specific patterns required for targeted pesticide application, demonstrating the diversity of nozzle technology in modern precision agriculture.

In agricultural engineering, when an implement is pulled by a tractor, the total force can be resolved into different components. The horizontal force acting perpendicular to the line of motion is known as the side draft. This force is critical in implement design, as excessive side draft can cause the implement to pull to one side, affecting steering and operational efficiency.

Chisel ploughing is a form of deep tillage designed to break up compacted soil layers (hardpans) to improve aeration and water infiltration. Unlike shallow tillage, chiseling is performed at significant depths to reach subsoil layers. A depth of 50 to 60 cm is generally considered appropriate for deep subsoiling operations to effectively loosen the soil profile while maintaining surface residue.

A ridger is a versatile tillage implement used for creating ridges and furrows. It is effectively used for making irrigation channels to distribute water, creating furrows for planting crops, and performing 'earthing up' operations, which involve mounding soil around the base of plants to support growth, improve drainage, and control weeds.

Ridgers are primarily used for crops that require earthing up or furrow irrigation, such as potato, sugarcane, and maize. Peas are typically grown in flat beds or on raised beds without the specific need for ridging operations during their growth cycle.

A trailed type cultivator is an implement designed to be pulled by a tractor, where the weight of the implement is supported by its own wheels during operation and transport. Unlike mounted implements that rely on the tractor's three-point linkage for support and depth control, trailed implements are connected via a drawbar.