It was once said that soil is only a medium used to hold the plants upright. With the event of the green revolution people discovered that with the aid of artificial fertilisers and chemicals, crops could be grown in all sorts of soils no matter how poor they were. This is true to a point.
As we implemented IPM and started looking at sustainable farming we learnt that the soil is playing a far more important role than we thought. Basically you need a living soil to produce living crops in a sustainable way.
One of the key things that is needed in soil is organic matter, something that is lacking in most Australian soils. Organic matter helps soil to retain moisture and at the same time improves drainage allowing more air into the soil, this then provides a habitat in which an enormous amount of insects and micro-organisms can live. These living creatures feed off the organic matter, converting it into food for plants, therefore producing a healthier plant. Healthy plants, that are growing free of stress, are able to then defend themselves better against pest and disease pressures. Getting the basics right first helps to make the job much easier all the way down the line.
Soil such as this, that is full of life also then supports other life in the surrounding environment, such as birds feeding on worms, hawks feeding on birds etc. adding to a richer environment all round.
With the richness of organic matter in the soil we are also able to better control erosion as it is less likely to blow away in the wind or erode by too much water run-off. Whenever we have a paddock empty for a considerable period of time we will always grow a cover crop on the soil so as to protect against erosion and this also keeps the soil environment alive. So with all this in place our soil actually improves over time becoming more and more productive.
Minimum tillage is also something that we are looking into. Minimum tillage is basically a method of growing crops without excessive soil tillage (ploughing). This can assist in moisture preservation and allow the natural organic layering of the soil to stay in tact. We are experimenting with ways in which we can apply this into our vegetable production.