As if breaking a spell cast on the land, rain came and the farm breathed a sigh of welcome. The driest January on record for the region is now past and the sobering reality of three consecutive years of warm temperatures and little to no rain and low Sierra snowpack should be reason for the farm community to consider the practices they employ and develop comprehensive strategies for the long term.
The impacts of the last few years touch many parts of our farm. Our fruit trees are short on the chilling hours that they require for healthy bloom and fruit set. Things are blooming early – by more than 2 weeks – which may mean more susceptibility to frost later in the spring. Winter rains are needed to replenish our wells. When the small side creeks that border the farm flow even for a few short days, we can measure a rise in well water levels as the ground acts as a reservoir for the beneficial winter rains. Last year, the uncertainty of a stressed irrigation system, both wells and creek water, challenged us to think not only about how to more efficiently apply water, but also about the long-term impacts of tillage on soil carbon, soil micro-life and the ability of the soil itself to more efficiently hold water and make that water available to plants. Often the efficiencies that farmers invest in to apply less water are built upon the assumption of clean tillage (no weeds) and bare soil. There are many opportunities for farms to do much more, but it may require a fundamental re-thinking about how we farm and the tools that are employed to farm.
Our land use practices – how we manipulate soil, our perception of its character and its life – are based on a history of immigrants to this land finding abundant, deep, rich soils that had millennia of fertility layered and accumulated. An incredible abundant resource: mineral rich, alive with the funk and vitality of time. It was a wealth to be turned, plowed ripped and planted, and the abundance that came from that land was nothing short of phenomenal: surpluses and affordable food to feed growing cities and support all of the innovations and industry found there.
With that soil resource, and as wildly exploitable, was water. The abundance of both shaped our land use and the expectations about food and resource use. For the greater good, dams were built, lakes drained, rivers diverted and wells drilled deep. The miracle of California Agriculture was built on the investments, concrete and knowledge to harvest more from the abundant and seemingly limitless resources that we inherited. We now understand that the patterns of use of these foundational resources have limits. Jay Lund, a U.C. Davis engineer, called our water use in the state a ‘slow moving train wreck.’
So what principles do we need to re-assess? Is there some more elegant way of agricultural thinking that solves for pattern? Can we enrich soil and sequester more carbon so that rainwater runs in rather than off? Do we need to build more dams and pour more concrete to store water or can we be far more effective in using soil as a living reservoir? Can we reduce CO2 levels in the atmosphere by storing more carbon in the soil so that agricultural land use patterns play a critical role in mitigating climate change? The answer is increasingly clear to researchers: A revolution in farm practices could play a critical role in water use efficiency, carbon sequestration, enhancing soil micro-life, and building a far more sustainable and resilient food system.
The fundamentals of this change are being explored in many places and are now being practiced worldwide. The changes involve tilling soil less, harvesting more sunlight with carbon-accumulating cover crops, minimizing bare soil, managing soil organic matter in the top few inches of the soil, harvesting more atmospheric nitrogen with legumes, reducing herbicide use, and rethinking the tools that we use in order to practice high-yield farming.
In terms of water, the more that can go into the soil from a rain event (aided by plant root pathways that allow infiltration) the greater the ‘harvest’ of that resource. The work of Jeff Mitchell of UC Davis’ conservation tillage group is demonstrating that conservation tillage practices may help farmers save an added 20% to 30% of crop water needs.
For farmers, sunlight is the driver for carbon accumulation through photosynthesis in growing plants. Bare soil – herbicided or tilled – harvests nothing and leads to poor water penetration. Bare soil makes it easier in so many ways to grow and harvest a crop, but it may be one of the greatest hurdles to overcome. We have developed our farming tools not needing to think about limits in a land so abundant and generous. We have not asked the questions about how we would design a productive farming system that regenerates itself and that mitigates climate change. We must recognize the biological components of soil – going beyond the mineral only – and employ billions of soil microbes as an essential workforce. (They love to dine and reside in and on carbon!) We need to fall in love again with the incredible beauty of a land green with life, fed with rain and manifesting diversity and a multifaceted harvest.
When water is scarce it is hard to think about using it to irrigate cover crops, yet the long-term pattern, integrating soil, water, carbon and new thinking about farming practices, will create the water savings and potential for farms to be the mega reservoir for excess carbon in the atmosphere. Solve for pattern, employ systems that have a timeless intelligence and enhance the potential of the whole yielding a far more bountiful harvest. This change requires a public acknowledgement of shared responsibility to make this investment in living vital patterns. Now is the time.
— Paul Muller
