Managing soil, water and photosynthesis
Kumbartcho pasture into its second year of drought.
Top of our list when we went ‘shopping’ for a new farm, was water.
In times of drought it becomes really apparent that water is the single most limiting factor in our agricultural enterprises/gardens. Here we have a flowing creek, with water allocation, and a bore which is adequate for irrigation purposes (un-regulated).
Now it is well and good to have all this water, however the cost of pumping it has largely become prohibitive for many agricultural enterprises.
How then are we addressing this issue of water??
Our pasture and soil management is focused on having soils in best possible condition and pastures are managed for perenniality and diversity.
Soil in good condition has the capacity to hold more water, as well as an increased infiltration rate when rains come.
- One hundred kilograms of soil with 4 to 5 % organic matter will hold two hundred litres of water. With 1.5 to 2% organic matter it will hold only forty five litres!!!
- Trials in the Kimberly showed that on similar soil types, water infiltration rates on bare ground were 25 mm per hour, on litter cover 45 mm per hour, and on perennial grass 175 mm per hour. On applying “simulated rainfall” a second time on the same sites the bare ground infiltration rate went down to 12 mm per hour, litter cover down to 30 mm per hour, while the perennial grass site infiltration rate increased to a massive 300 mm per hour!!!
It is not rocket science then that if we manage our soils, and pastures we can make much more effective use of what rainfall we get.
An important fact then, that is emerging out of all this, is to do with PHOTOSYNTHESIS.
In this day of “global warming/climate change”, as farmers/gardeners, we have a huge FREE resource, which along with sunshine, air, and water, we can HARVEST.
That free resource is CARBON DIOXIDE, and the way to ‘capture’ it is through photosynthesis.
If our soils have high organic matter, and have healthy diverse pastures, then we can capture, and store more of the available rainfall. It is this stored moisture that keeps our plants growing when it is not raining. The longer we can keep plants green, and growing, then the more (through photosynthesis) we are able to capture carbon dioxide from the atmosphere.
To quote Alan Lauder from Carbon Grazing, “water, and fertility follow CARBON. Photosynthesis puts carbon into our soils!”
If we continue to keep grazing animals, while compromising our pastures need for rest, we are “giving up” the possibility of harvesting effectively the FREE RESOURCES. It is these free resources, which have the capacity to maintain our RESOURCE BASE - the farm.
By learning to effectively ‘harvest’ we can reduce the impact of drought, flood, and fire.
On Kumbartcho pastures are actively managed to retain green growth
even in drought conditions.