Today we will be touring a farm of the future that employs the state-of-the-art farming methods that have been developed over decades of effort by growers, academic researchers, extension agents, and technology companies. Actually most of what we will see is already possible in 2010 and only the things highlighted in red require some change to become fully available.
Our tour guide is Sarah – a 24 year-old intern who works on the Gordon family farm in North-Central Iowa. Sarah is part of a major USDA program to encourage young people to go into farming. None of her family has farmed for generations, but she was intrigued by the rural lifestyle and by the interesting technologies. She switched majors to graduate with a degree in Agronomy.
Who Is Driving!?
The first thing you notice is that as we progress across a large field in early May, is that Sarah is not actually driving the tractor – no one is! Seeing your alarm she laughs and explains that the tractor and the fertilizer/planter it is pulling are both being controlled by a sophisticated computer guidance system called Real-Time Kinetics (RTK) . It uses satellite GPS but also signal from a tower she points to in the distance. The path we are following is “auto-steered” to the inch so that it achieves “controlled wheel traffic.” This means that a large percentage of this field is NEVER driven over or compressed by the weight of equipment. The lack of overlap pays for the system, but the lack of soil compression dramatically lowers emissions of the potent, ozone destroying and greenhouse gas, nitrous oxide from this field. The Gordon’s qualify for “carbon offset” income because of this.
Sarah also points to the computer display in the cab showing how the rate of fertilizer being applied is adjusted foot-by-foot according to site-specific yield history and soil sampling maps. The fertilizer is being “knifed-in” just the right distance below the seed so that the developing crop roots will efficiently absorb it. This “precision, variable-rate fertilization” pays for itself in lower fertilizer rates overall, but it greatly reduces the amount of nitrogen that leaches into groundwater as nitrate. The Gordon’s appreciate this because they and their neighbors drink the well water in the aquifer beneath this field. This approach lowers nitrous oxide emissions even more.
Where’s the Dirt?
The second thing you notice as the tractor moves itself along is that you don’t see much is any actual soil. The entire surface of the field both ahead and behind the tractor is covered with brown plant residue. Sarah explains that this “trash cover” is a combination of last year’s wheat crop residue and the “winter cover crop.” “The idea is to keep plants growing on this land and feeding the soil every possible day of the year, not just while the cash crop is being grown,” she says. “All this trash also blocks any evaporation from the soil so we save more of the snow melt and rain we get.”
Farmers Without Plows
The reasons for leaving all this plant matter on the surface of the field go well beyond blocking soil evaporation. This is “continuous no-till farming,” a system where the soil is treated as a delicate, living system. Just as the “wheel traffic” has been minimized, the goal in this planting/fertilizing pass is to do the absolute minimum of disruption to the soil ecosystem of this field. That is why the weeds are controlled with what are actually quite benign chemical herbicides rather than by mechanically ripping them out of the ground. That is why the fertilizer is “knifed-in” and the seeds are “drilled” so that the vast majority of the soil retains a stable, vibrant, microbial community with very active populations of earthworms and other beneficial organisms like Mycorrhizae. No-till farming has been around for 50 years, but the combination with cover crops and controlled wheel traffic takes this environmentally beneficial practice to a whole new level. In addition to saving a good deal of fuel, this farm is sequestering about 1 metric ton of Carbon dioxide/acre/year in the soil, which is great for climate change management, but it is also very good for the long-term productive potential of this ground.
Drought-Proofing of Soils
Sarah describes a major rain event that occurred last week. The field we are planting was able to capture virtually all of that water with no erosion or runoff (because of the no-till, cover cropping, and wheel traffic practices and the excellent “hydrological” properties of this excellent soil). That means that this field didn’t contribute pollutants to local streams in terms of fertilizer or pesticide residues. The ever-increasing organic matter in this undisturbed soil also makes it like a sponge to store the water it gets. This means that if there are periods of drought, this field will do better – often dramatically better. The neighbors of the Gordon farm who have not yet adopted this sort of super sustainable farming were struck last year by the high yields the Gordon’s were getting in a dry year where they were having major drought-stress loss. One of the neighbors modified a great line by the character, Inigo Montoya in the movie, “The Princess Bride” to ask the question, “are you farming with the same rain we’re farming with?”
See Part 2 of this post which describes the challenges for moving to this kind of farming.
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Planting Image from the Minnesota Department of Agriculture.