Farm machinery, explained.

A plough cuts a slice of soil and turns it over, burying stubble, weeds and manure and leaving loose ground ready to be worked into a seedbed. Modern tractor ploughs carry several bodies in a row, so each pass turns several furrows at once.

A balance plough is a two-ended plough, built like a see-saw, that was pulled back and forth across a field on a steel cable by steam ploughing engines. One set of bodies works while the other is held up in the air, so the plough never needs turning round.

A round baler picks up a row of hay, straw or wilted grass and rolls it into a tight cylindrical bale, then wraps it in net or twine. The bales can be stacked, stored outside or wrapped in plastic film to make silage.

A square baler gathers hay or straw from a row and presses it into rectangular blocks tied with twine. Small (conventional) square balers make bales one person can lift, while big square balers make heavy, dense bales handled by loader or telehandler.

A seed drill sows seed in evenly spaced rows at a set depth and covers it over, instead of scattering it on the surface. It is the usual way to sow cereals, oilseed rape, grass and many other crops.

A precision planter, also called a precision drill or maize drill, places single seeds at an exact spacing along each row rather than a stream of seed. It is used for maize, sugar beet, sunflowers, soya and other crops where every plant needs its own space.

A crop sprayer applies liquid crop protection products, liquid fertiliser and similar products across a field through a row of nozzles on a wide boom. It can be mounted on the tractor's linkage, towed behind it or built as a self-propelled machine.

A power harrow is a PTO-driven cultivator with a row of rotors, each carrying a pair of vertical tines that spin across the ground. It breaks ploughed or cultivated soil down into a fine, level seedbed, and is often teamed with a seed drill to sow in the same pass.

A cultivator loosens and mixes soil without turning it right over as a plough does. Tine cultivators pull pointed legs through the ground and disc cultivators use rows of angled rolling discs; both are used for stubble work, weed control and seedbed preparation.

A tractor mower cuts standing grass or lucerne for hay, haylage or silage. A mower-conditioner also crushes or scuffs the cut stems in the same pass so the crop dries faster in the field.

A tedder spreads and fluffs freshly cut grass so it dries quickly and evenly. A rake then gathers the dry crop into neat rows, called windrows or swaths, ready for a baler, forage harvester or loader wagon.

A forage harvester, also called a forager or chopper, picks up or cuts a green crop, chops it into short pieces and blows it into a trailer running alongside. The chopped crop is packed into a clamp or bag and fermented to make silage for livestock.

A front loader is a pair of hydraulic lifting arms fitted to the front of a tractor, carrying a bucket, forks or other tool. It turns an ordinary tractor into a machine that can load, lift, stack and carry around the farm.

A manure spreader, or muck spreader, is a trailer that carries farmyard manure to the field and spreads it evenly over the land. It returns nutrients and organic matter to the soil in a controlled way rather than in heaps.

The three-point linkage is the set of two lower arms and one top link at the back of a tractor that carries and lifts implements. Developed by Harry Ferguson, it lets the tractor's hydraulics raise, lower and control the depth of ploughs and other tools.

The power take-off, or PTO, is a splined shaft on a tractor that passes engine power to an implement through a drive shaft. It runs balers, mowers, spreaders, pumps and many other machines that need rotating power rather than just pulling.

A farm trailer is a tractor-drawn trailer for moving grain, silage, bales, soil, machinery and other loads. Tipping trailers lift their body with a hydraulic ram to unload, while flat and bale trailers are loaded and unloaded from the side.

A telehandler, or telescopic handler, is a lifting machine with an extending boom that can reach forward and upward. On farms it loads trailers, stacks bales, handles feed and muck, and does many jobs once done by a tractor loader.

A subsoiler is a heavy tillage tool with a few strong legs that are pulled deep through the ground to crack compacted layers below normal cultivation depth. Loosening this layer lets roots grow deeper and water drain away.