In a recent article, I stressed the importance of soil organic matter (SOM). I stressed how through solar energy, green growing plants, water and photosynthesis, SOM (58% carbon) can be increased in soils resulting in a rich aggregate. That organic sponge becomes housing for a multitude of gifts and not only makes for healthy plants rich in nutrients but provides a healthy hydrological cycle.
Over the last 60 years or so 50% of soil carbon has been lost from this once green planet. SOM has been lost through burning, clearing, tillage, over-fertilizing, biocides, and fallowing; this according to Walter Jehne, Acres USA, “Supporting the Soil Carbon Sponge”. These agricultural practices result in respiration through bacterial activity or oxidation from exposure. In both cases carbon is released as CO2 into the atmosphere. Agriculture could easily be a sink for CO2, but isn’t. 5/8 of the earth’s forests have been cut. They too could easily be a sink for CO2, but not if they are cut. We are destroying our soil capital and with that the ability of the soil to hold on to water within that soil profile.
Regenerating the carbon sponge is essential for a healthy water cycle. For every 1% increase in SOM – 16,500 gallons can be held within a one acre soil matrix. Using Carbon Sequestration farming practices, Gabe Brown, an advocate for regenerative agriculture, incearsed the SOM on his farm from 1.7% to 7.5%. In 2009 – a rain storm hit his farm – his soil absorbed 13.8 inches of rain in 22 hours, no puddles – no runoff. Why is this so important? With climate change creating weather events, we more often get rain events followed by long stretches without rain. With the carbon sponge, water can be held for longer periods of time within the soil, infiltration is slower and water purification happens. Several other things happen here: with the continued presence of water within the organic sponge, photosynthesis is increased drawing more carbon out of the atmosphere, more oxygen is released, more carbon is sequestered, more transpiration in the form of water vapour from the plant leaf is also released – creating a powerful feedback loop.
Transpiration has other important impacts. The water vapour has a cooling effect – 1 gram of vapourized water absorbs 590 calories of heat energy. This is good news for a warming planet. But without holding on to all accessible water and the continued feeding of the carbon sponge, this cycle cannot self-perpetuate. We no longer regenerate our soil capital.
For the water vapour micro-droplets to coalesce to form raindrops, precipitation nuclei are needed. The most active nuclei ( Aerobacter) are released with the transpiration through the leaf stomata to bring together the micro-droplets so that moisture can come back to the soil as rain. A deciduous tree in its life time will transpire 250,000 gallons of water. A corn plant on healthy soils can transpire 250 gallons of water in one season.
It is clear that to maintain a healthy water cycle, clean air, clean water, healthy soils, plants and people we need to promote all these natural cycles – and to do so we need to observe and learn what nature has been doing for millions of years.