It appears that along this coast of south east NSW we are in for a persistant dry period, and perhaps it is time to learn some lessons.
There are three conditions on wich yield in plant crops depend.
1. Water; 2. Sunlight; 3. Carbondioxide
We have plenty of sunlight and carbondioxide in Australia. So: it comes down to the supply of water.That dairy farmers are the most affected of the persistant dry period makes sense, if one calculates how much is lost in the conversion from grass to milk. And if that milk is made in to cheese then the losses are even greater.The future for the Bega valley, as far as farming is concerned,lies in a more productive conversion of rainwater to plants to food. Let us have a look what that means.
During any rainfall, whether that be during the winter or the summer month, there are certain losses. During the minimal rainfall in a drought these losses are serious indeed. The reports on the papers state the plain facts.
Losses of water/moisture from soils are from:
Run-off
evaporation
some observations during the last four years are,
A. Run-off is abnormally high in this valley for three reasons.
Reason 1. The soil is seriously compacted
Reason 2. The soil lacks oxygen and is practically dead.
Reason3. The natural vegetation of trees has been completely removed and been replaced by shallow rooted pastures for the production of dairy products.
B. Losses due to evaporation are higher than average due to the fact that there has been no practice of cultivation on the contour.
We have to adopt 3 important rules if we want to deal with the above mentioned loss of water, particularly during minimal rainfall periods.
Rule 1. Open up soils with a CHISEL PLOUGH, to aerate the soils.
Rule 2. Plough only on the contour, not up and down or in squares.
The effect of these first 2 rules will be that 100% of all rain will enter the soil, meaning runoff will be virtually eliminated
The other effect will be that water once in the soil can not evaporate again, because it cannot get back to the surface. (COMPACTED SOILS as well as preventing water entry, also provide a direct path for water to rise to the soil surface from as far as 2 meters down via capillary action.)
Rule 3. Supply a blanket to the soil for protection against cold, heat and wind.We use the word blanket on purpose, because a blanket has such relevance for us humans as protection; After all the soil is the earth skin. On a soil blanket can be made of dead material, such as loose soil, dead leaves, wood chips, mulch, stubble. In a garden we prefer compost.
In the papers frost has been mentioned as making a drought much worse. of course frost and dry weather go together. Frosts suck water out of soils.
A blanket can also be in the form of a wind break made out of shrubs or trees. Since a very large percentage of loss through evaporation is caused by wind, its not hard to understand why a windbreak has that label.It breaks the force of the wind. Windbreaks can be so designed as to protect land over a distance of 8-10 times their height
