This is the current buzz word that can mean very little.
At Great Wollaston it means producing as much as we can whilst using the least finite resources per unit of production while protecting the environment.
This usually means not producing as much as we can. But then the idea is not to chase yield but profit.
Can profit and the environment be bedfellows?
True sustainability is balancing financial sustainability, environmental sustainability and social sustainability. Like a three legged stool; without one, it all falls over.
As has been said in How we do it, clover is used in the grassland to reduce the amount of inorganic fertilizer, ammonium nitrate* or urea, that is used.
We use the animal manures as plant nutrient and only use inorganic fertilizers to make up any shortfall.
We select high yielding grass seed with high soluble sugars as this increases animal production. We do something similar for the cereal crops, selecting varieties that have good disease resistance even if they are not the highest yielding because that extra yield is paid for by more chemical sprays.
With the cows we select bulls whose daughters are healthier and produce more butterfat and protein because we are paid for how the milk is made up as well as how much we sell.
Lots of biology and business studies here for school visits.
That ethos of using less finite resources is why this is still a traditional mixed farm growing most of what is needed to feed the animals on the farm. There are reduced food miles by not selling the cereals and buying in processed animal feed.
One area where there is still work being done to increase sustainability is sourcing protein feed. Soya is a common source of high grade protein feed but it is imported and can have a high environmental impact: Felling rain forest to get land to grow it.
We try and grow sources of protein on the farm. Clover is one and as an arable silage crop we grow spring barley (starch source) and peas (protein). We have tried lupins but without much success.
To work the ground to plant crops we use a mixture of plough and minimum tillage (min-till). Ploughing involves turning the soil over to a depth of 150mm (6”) and then slowly power harrowing, which is a machine that uses vertically rotating steel tynes powered by the tractor to create a seedbed 100mm deep.
With min-till we use a fixed tyne machine to break up the top 50mm of soil and then quickly power harrow that depth of soil. There are advantages and disadvantages to both systems but we try to use min-till as much as possible as it is quicker, uses less fuel, destroys less soil invertebrate and soil structure, and leaves more organic material near the surface to be easily broken down to humus.
Ploughing is slower and uses more fuel and the soil needs more cultivation to create a seedbed but if there is too much organic material on the surface which can block up the seed drill then this can be buried, also if the ground is uneven because the ground has been wet and tractor wheels have cut channels then ploughing will level the soil. Some weed seeds die if they are buried and so this can reduce certain weed populations but other weeds are not affected.
On the energy side of the farm we are using LEDs to replace failed lights. We start to cool the milk, as it must be stored at 4oC, with water via a heat exchanger. The warm water is then used for drinking water for the cows.
There is a constant need for improvement as new ideas and practices come along and we hope that we never think we have done all we can do. The way we live has to change; as a society we cannot keep consuming limited resources at the rate we are.
It is not sustainable
*It takes 6 tonnes of natural gas to produce 1 ton of ammonium nitrate fertilizer.
When inorganic fertilizers are used they release small quantities of nitrous oxides (NOx) which are 230 times more effective as greenhouse gases as CO2.
Unfortunately animal manures also produce NOx when used as fertilizers so cannot be seen as the prefect answer.