Farming was revolutionised by vehicles powered by internal combustion engines, because of their speed and flexibility.
Some farmers were reluctant to replace their horses with tractors because early tractors were notoriously difficult to start. The engine oil often needed warming before hand cranking the tractor. Some farmers resorted to lighting a fire under the sump or using a blowtorch to warm the engine before starting it up.
The first tractors – an Ivel and a Kinnard Haines – were imported in 1904. These early tractors were large, heavy machines. By 1919 there were only 136 tractors on New Zealand farms. Lighter, more manoeuvrable machines were introduced from the 1920s, and became more widely used for towing machines to cultivate land, plant seeds, mow and reap. Some drove small stationary threshing machines, known as tin mills. By 1931 there were 5,023 tractors, mostly on arable (crop-growing) farms.
Crawler tractors were used on pastoral farms from the 1920s. They had tracks rather than wheels, and so could be used on wet ground and hill country, to clear scrub and make drains. The first tractors ran on kerosene and petrol, but in the early 1930s diesel engines came into use.
Wheeled tractors became common in pastoral farming after faster models with rubber tyres became available in the late 1930s. They allowed farmers to transport loads like stock fodder around the farm more quickly, and began to replace horses.
From 1948 large numbers of tractors that used the Ferguson system – a hydraulic three-point connection that enabled machinery to be towed more easily – were imported.
By 1960, 78,415 tractors were in use on New Zealand farms. Numbers reached a peak of 96,666 in 1971, and have since declined. However, tractors remained an important piece of farm equipment in the early 2000s. The latest models are high-powered, and take comfort into consideration, with features such as air-conditioned cabs and compact disc players.
Header harvesters, which appeared in 1927, made it possible to harvest and thresh grain in one pass. In 1932 self-propelled combine harvesters appeared, doing away with the need for a tractor. Combine harvesters became increasingly dominant in grain-growing areas after the Second World War.
Tractor-towed hay balers were first imported during the Second World War. In 1950 the International Harvester Company brought in balers operated by the tractor’s power take-off (a shaft protruding from the back of the tractor that was powered by the tractor engine). From the 1980s bale wrappers – machines that make large round bales and cover them with plastic – reduced the need for hay sheds. By the early 2000s there were also bale feeders, towed behind a tractor to unwrap and distribute bales of stock feed.
Silage making was made easier after the Second World War by the introduction of the buckrake – a hydraulically operated sweep mounted behind the tractor, which collected hay as the tractor reversed. The weight of the tractor was used to compress silage in the pit or stack. Forage harvesters, which cut, chopped and blew pasture into a trailer, were also used in making silage.
In the 1920s and 1930s, improved roads and the introduction of milk trucks made the collection of milk and cream faster and easier, widening the catchment area of dairy factories. The number of factories declined, but the production of those remaining increased rapidly. From 1950 milk tankers took over from can collection, again bringing the closure of many small local dairy factories.
After stock trucks were introduced, there was no longer a need to drove animals over longer distances, or through settled areas. Trucks and tractors were widely used for spreading lime and other fertiliser on farms.
Before the 1940s fertiliser could only be spread on hill country using human or horse power. There were experiments in aerial topdressing after the Second World War, and it became common on hill country from around 1950.
The use of aircraft – initially fixed-wing planes and then helicopters – sped up a variety of tasks, including sowing seed, spraying herbicide, dropping poisoned bait and lifting in fencing materials. As vineyards developed, helicopters were used to force warmer air down onto the vines on frosty nights.
Getting around the farm
Four-wheel-drive vehicles – notably the Land Rover, but also war-surplus jeeps, and even bren gun carriers – were used to access steep country. In the 1970s farm motorbikes made travel on the farm faster, and four-wheel ‘quad bikes’ became another way to transport material and workers.