Factors that influence grain and pulse production
Yield is a measure of the amount of grain or pulse produced per hectare of
land cultivated. It can vary substantially from year to year. For instance,
barley yield ranges between 1.12 and 1.95 tonnes per hectare and can be as high
as 4 tonnes per hectare. It differs from grain to grain where average rice yields
in Australia are
9 tonnes per hectare compared to average wheat yields of around 1.7 tonnes
per hectare.
The following factors determine grain yield and protein content:
i. Climatic factors
Rainfall and temperature can affect grain yield. Drought in 1994 reduced
wheat yield to 1.13 tonnes per hectare in 1994-5. Too much rain increases the
yield, but the protein content of the grain is often low. At higher temperatures,
the development of protein is more rapid.
ii. Soil quality and fertility
In the 1980s, concern about the sustainability of Australian farming systems
grew and resulted in the establishment of the Landcare movement which encourages
conservation farming practices.
In 1990-91, the Australian Wheat Board began to pay growers according to the protein content of their wheat. This resulted in an increased use of nitrogen fertiliser. Grains grown in rich soils are higher in protein than those grown in light sandy soil or land exhausted by continuous cropping. In Australia, farmers increase soil fertility by rotating the type of crops grown on the same area of soil. Legumes, such as lupins and field peas, are used because of their ability to add nitrogen to the soil. Field peas can raise soil nitrogen content and have a major role in improving yield and protein content of the next wheat crop, as well as reducing the need for nitrogen fertiliser.
Organic farming differs from conventional farming in that fertilisers and herbicides are not used. Organic farmers rely on biological pest control and natural fertilisers such as rock phosphate and animal manure. This difference does not make a significant impact on the nutritional value of grains and pulses produced.
iii. Grain variety or cultivar
Grain variety determines hardness of the grain, milling quality and dough
properties.
iv. Location of crop
Wheat yields vary from 6 tonnes per hectare in Tasmania to 1.68 tonnes
per hectare in Victoria.
v. Economic factors
World grain prices are determined by production, consumption and stocks.
For example, the price of wheat rises with reduced production (due to unfavourable
weather), higher consumption and a decline in stocks. When wheat prices are
high, more wheat is used for human consumption than for animal feed. Grain production
is also affected by the price of other commodities that may be substitutes for
land use. For instance, in 1989-90, as the price of wool decreased, the number
of specialist grain farms increased by 104% while the number of specialist sheep
farms fell by 51%.