Grain Elevator--Eastern Washington
This article from WSU Green Times is worth consdidering as an introduction to the complexities involved with turning away from our current agricultural practicice toward a sustainable organic method for producing staple commodities like wheat. The topic here is the wheat growing area in Eastern Washington State, the Palouse Plateau (after the river of the same name) which is a major part of State grain production and subject to massive amounts of erosion (higher than the average) caused by wind and runoff. From 1939 to 1979 cropland erosion on the Palouse averaged more than nine tons per acre per year and more than 100 tons per acre per year on steep slopes. Erosion on unplowed rangeland and forested land averaged one ton per acre per year. Plowing the loess increased erosion rates by a factor of ten to one hundred–most of it caused by runoff from newly plowed ground. One hopes that the “transition” efforts documented below will include conservation measures, i.e. regular crop rotation with green manure on fallow feilds.
Green Times – April 5, 2012
Failing for Success: Transitioning to Organic Grain on the Palouse
What choices do Palouse farmers have when they want to convert conventional agricultural land into organic grain production in order to earn the premium price on organic grain? Many, as it turns out, and the choices will have a significant effect on a farmer’s success, Washington State University researchers have found. Grain is notoriously difficult to raise as an organic crop, as weeds and pests can easily get out of hand without pesticides, and grain protein content and yields can be low without synthetic fertilizers. But even without artificial inputs, choices made during transition will significantly influence weed prevalence, grain yield, and grain protein content when the land enters certified organic grain production.
Farmers wishing to convert land to grow organic crops need to go through a three-year transitional period where they must avoid non-organic inputs, and yet cannot market their crop as organic. How can they best manage their land during this economically challenging transitional period and during subsequent organic production?
WSU Masters student Misha Manuchehri and Ph.D. student Kristy Ott-Borrelli, working with Ian Burke, an associate professor, and Pat Fuerst, an assistant research professor in the WSU Department of Crop and Soil Sciences, set out to answer this question, continuing a study initiated in 2002 by Robert Gallagher. To make the study relevant to the Palouse, they chose constraints likely to be faced by local farmers. Because the Palouse has very little animal husbandry, animal manures were avoided. “As a weed management issue, it would be very nice to plow,” said Fuerst, but they also avoided this practice due to concerns with fuel costs and erosion on the steep Palouse slopes. They decided to test different crop rotations at the Boyd Farm, a site leased by WSU for organic farming research, outside Pullman.
How successful were they? Many of their rotations were not at all successful. “We fail, so you don’t have to,” Ian Burke told farmers at a recent Tilth Producers Conference. Since researchers determined that granular organic fertilizers can cost ten times as much as synthetic fertilizer for the same amount of nitrogen, they tried legume green manures, a category of cover crop grown mainly to add organic matter and nitrogen to the soil. They also tried different spring crops in rotation with winter wheat. Spring green manures, including spring peas, did not fare well, due to pressures from insects and weeds. Bell beans (fava beans) didn’t work as green manure, either, since they weren’t suited to regional conditions. Winter peas, however, added nitrogen while competing better with weeds. But farmers looking for profitability during transition might choose three straight years of alfalfa. “Forage was a great crop for the transition,” Ott-Borrelli said.
When testing the competitiveness of six spring crops that can be rotated with winter wheat, broadleaves such as lentils, garbanzos, and canola fared poorly. “Barley does a pretty good job, from what I’ve seen,” said Manuchehri. Since barley emerges relatively early, it has a head start against weeds. Researchers planted the barley about two inches deep, rather than the typical one to 1.5 inches. When it emerged, it was better established, and more able to stand up against the next weapon in weed control: the rotary hoe. This tillage instrument uses an array of spikes to puncture the soil without turning it. Delicate, sprouting weeds are vulnerable to these rolling daggers, but the barley is well enough established that it is not harmed, according to field technician Dennis Pittmann, who drove the tractor that pulled the rotary hoe. Wet spring weather, however, can be an impediment to using heavy tractors and tillage instruments. “The earlier we can get in the field to control weeds,” said Manuchehri, “the better off we are.”
Another technique involved using higher seeding rates. To improve competition against weeds, organic grain growers might seed with 1.5 times as much grain as conventional growers. Manuchehri found that barley competed well with weeds when seeded at twice the normal rate, but this still wasn’t a magic bullet in particularly weedy areas. Her recommendation to organic farmers? “Go off local grower planting rates and adjust from there.”
Ott-Borrelli focused on nitrogen dynamics during transition. Both legume green manures and alfalfa boost soil nitrogen levels, so how did transitional rotations affect subsequent organic grain yield? Since nitrogen from alfalfa is more quickly available, forage systems gave the highest grain yield the first year of organic certification. But the second year, yields fell somewhat. Wheat crops that followed a green manure rotation, however, showed the opposite effect. Yields lagged the alfalfa rotation during the first year of organic production, but as nitrogen from the green manure became more available in the second year, yields surpassed that of the post-alfalfa wheat.
Yield obviously translates to profitability, but so does the protein content of the wheat, as hard wheat needs to reach sufficient protein levels to be suitable for bread. Conventional agriculture frequently adds synthetic fertilizer to boost soil nitrogen and therefore protein levels in wheat. Without the use of expensive organic fertilizers or the availability of animal manure, careful crop rotation was the only option for boosting protein content. The three-year alfalfa transition did well with boosting protein in subsequent wheat crops, but green manure showed a slight advantage.
Through careful crop rotation, farmers wanting to transition their land in order to grow organic grain can have an impact on weed control and soil nitrogen levels, although economic challenges may persist. One of the most important tools, according to Fuerst, is flexibility. Farmers need to start small and be ready to abandon unproductive practices and alter seeding dates and varieties to improve results.
Following their own advice, WSU scientists are changing parameters and exploring new techniques to advance the science of organic grain production. Ian Burke is developing an inter-row cultivator with precision guidance, allowing it to control weeds between rows while sparing the wheat. Researchers have also started finding local sources of animal manure for fertilizer. “Livestock integration with organic grain production makes a lot of sense,” noted Pat Fuerst.
Learn more about CSANR’s efforts in organic agriculture at http://csanr.wsu.edu/Organic/.