When it comes to feeding the world — nearly 10 billion people by 2050 — access to water via the ground or through precipitation is going to be absolutely key.
This not only means helping small-holder farmers in places like sub-Saharan Africa find more efficient, effective ways to farm without wasting water, but also finding solutions to water-endangered regions of the U.S. such as the western Grain Plains, where the Ogallala aquifer’s viability is in danger.
Often, when I read studies about irrigation practices there’s a plethora of information about newfangled technology that can improve water-use efficiency — and I’m sure the tools do just what they say. But reducing or eliminating tillage seems to get little or no mention as a strategy to employ.
It seems like that may be changing a bit with some of the global stakeholders in farm production. In a 168-page report from the Chicago Council on Global Affairs entitled “From Scarcity to Security: Managing Water for a Nutritious Food Future,” authors state, “increasing soil fertility, addition of organic matter, conservation tillage and soil mulching” can contribute to improved water productivity.
But the Daugherty Global Institute at the University of Nebraska seems to get this wrong in its 20-page report about increasing farmer-led investments in sustainable ag water management in sub-Saharan Africa. Center pivot irrigation is seen as an answer to more profitable and successful farming in that area, with makes sense. But tillage is described as a “modern” farming method, alongside irrigation, seeds, fertilizer and pest control.
Sounds like the old farming tale, “We’ve got to till that field up so it can take a rain.” Tillage releases more moisture into the atmosphere than would occur if the soil was just left alone. Every tillage pass causes the loss of about 0.25 inches of plant available water, whereas crop residue moderates soil temperature, leading to a reduction in soil moisture evaporation — especially at the top 1-2 inches, experts note.
Soil disturbance also brings dormant weed seeds to the surface to germinate that otherwise wouldn’t be an issue, and tillage also disturbs the habitats of natural predators that could help provide a free boost for crop protection.
So how is clean-tilled soil with no cover, baking to 120 F or more during the summer, helping small-holder farmers with a lack of resources succeed?
I think the answer to solving food and fiber production challenges in water-challenged areas — whether it’s here in the U.S. or globally — lies in the soil and what we choose to do or DON’T do to it. Let’s start with no-till as an important first step.
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