Montana State
University
Weed Science
Cropping Systems
by Perry Miller, Cropping Systems Specialist, MSU
Mike Greytak (grain producer - Billings) escorted Keith Schott (grain and livestock producer - Broadview) and myself to two stops in the Dakotas “to learn about warm-season crops”. I don’t think Keith or I felt we could take the time out of our busy schedules to take this trip. Though I can’t speak for Keith, I have but a single regret. I wish I had visited Dwayne Beck’s no-till research farm 6 years ago, when I first began my career in diversified cropping systems. Beck’s overbearing personality and hard-nosed public stances on the research required to build economically and environmentally sustainable agricultural systems has invited more darts and arrows than bouquets from researchers throughout the Great Plains. But the producers believe. That becomes overwhelmingly evident once you leave the gates of his research farm and travel the western half of South Dakota, and the SW corner of North Dakota. The incredible crop diversity cannot be ignored. Beck is a powerful observer of natural systems and has designed his principles accordingly.
Water
We arrived in Pierre Sunday night on the tail of a massive black T-storm. The Days Inn had a big yellow banner hanging out front that said “Boat Parking” in big red letters. Since the Interstate running past the Days Inn at the east end of Pierre was flooded well above the sidewalks, the sign seemed appropriate. As we guided the rental car through 18" of floodwater I was absolutely sick that I had committed 3 days of my time to this trip, of what would be a 1500-mile round trip, only to be “rained out”. Monday morning we visited Beck’s field office so we could at least have a chat. They had received 4.7" on Sunday on his clay-based soil. But we were hardly in the door when he hustled us out to his old 4WD Bronco, much to our astonishment. The first area of the farm we stopped at was irrigated .... which had just received 2" of water on Saturday, since the Sunday storm had not even been in the forecast. We were driving on dirt roads after 6.7" of water had been received over the past 48 hours. We walked the fields in our shoes and didn’t even get mud on our feet. How was this possible??? Incredible soil porosity. Between the narrow (15" spacing) rows of his 7' tall corn, night crawler mounds were visible everywhere. Beck hired a local fishing bait dealer to raise night-crawlers for him, and then ‘seeded’ them throughout the farm several years earlier. It was obvious that these ravenous critters played a key role in consuming the massive quantities of crop residue that are produced from 240+ bu corn and 100+ bu winter wheat. This was important for rapid building of soil organic matter and internal drainage. Beck’s philosophy on crop water use is that you have to be an opportunist when designing a cropping system. By managing incredibly high crop residue loads, and creating the right soil structural conditions, he captures every drop of water he receives. This is especially key during the occasional intense rainfall events which characterize weather systems in the Great Plains and which are normally lost as runoff, with the nasty side-consequence of soil erosion.
Crop Health -- Productivity
In their book, Wheat Health Management, Cook and Veseth discuss the 4 A’s of wheat yields: Absolute, Attainable, Affordable, and Actual. Beck’s farm puts some meaning behind this theory, representing a substantive paradigm shift for most of us. Beck is focused on the Absolute genetic yield potential, while strategizing to modify the field microclimate to narrow the difference between Attainable and Absolute yield. Most producers and researchers aim for what we think is Affordable, and settle for the Actual yield after diseases, insects, and weeds have taken their share. There is a fundamental difference in the underlying philosophy. Beck is worried about how ‘healthy’ his crops are, while we’re trying to make ours less ‘sick’. How does he maximize crop health? Crop rotation, together with cultural practices and chemical input management, assure that his crops have every competitive edge and literally ‘race’ toward their yield goal with maximal water use efficiency. He manages crop rotations by stacking various winter, cool, and warm-season crops together to maintain temporal distance between successive field occupation by the same crop type, usually staying out of production at least 4 years for any given crop.
Corn and winter wheat are the backbone of his rotations, providing high yields and high amounts of crop residues. Relative to area recommendations, Beck normally uses corn, soybean and wheat cultivars with longer maturity and winter wheat with lower winter hardiness to push the yield envelope. His record irrigated corn yield is 270 bu/ac. Dryland winter wheat ... 107 bu/ac. He considers 100 bu/ac corn in dryland a crop failure. Quality is also key .... protein is always protected with flex decisions based on cumulative rainfall, and near-term rain probabilities to top dress with N. One of his high intensity crop rotations under irrigation was “corn-corn-chickpea-winter wheat-spring wheat-soybean”. 2/3 warm, 1/3 cool. In a dryland situation he lines up less water-use-intensive crops, by using fewer warm-season crops, and more shallow-rooted crops. “Corn-field pea-winter wheat-spring wheat-sunflower-millet” might be an example: 50% warm-50% cool with shallow rooting for pea (cool) and millet (warm). Intervals between high residue producing cereal crops are kept short to ensure the water-saving soil ‘duff’ layer is maintained at all times. How can these principles be applied to Montana?
The plant diversity of the farm is stunning, with the great variety of crops growing in close proximity to each other. Canola, flax, chickpea, field pea, soybean, spring wheat, winter wheat, millet, sunflower, corn, and I’m sure I missed some. Weeds are occasionally present but only at very low densities. He is mildly concerned about the growing presence of healthy prickly pear cactus in many dryland fields. More stunning is the tactile web of animal and insect diversity. During the tour of his fields we saw leopard frogs, pheasant, hawks, blackbirds, and deer. Other animals such as mice, rabbits, raccoons, gophers, badgers, coyotes and foxes also use his farm. He promotes inhabitation by rattlesnakes for gopher control so that badgers will go bother someone else’s farm. Earthworms are omnipresent. I saw crickets, grasshoppers, beetles, mayflies, dragonflies, bumblebees, mosquitoes. Beck often speaks about the microbial life in his soil and how valuable it is for detoxifying residual herbicides, and supplying soil nutrients. However it remains undefined and uncharacterized in any scientific way. He has observed fewer insects in the residues of BT-corn, has commented publicly on it, and beaten up accordingly. To hear him tell it, verbal and written beatings from various chemical, crop genetic and seeding equipment companies have been common over the years. He has survived for 17 years and the beatings are now less frequent.
Weed Angle
At one point I asked a question about some disease showing symptoms on only a few of his sunflower plants. Beck didn’t know what it was and stated, “My goal is to know nothing about disease and insect pests.” If he designs his rotations properly, he’s certain he won’t need this knowledge, because these crop pests won’t be present at economic levels. But he has focused heavily on understanding all cultural and chemical aspects of weed management. Beck routinely characterizes weeds as cool or warm-season, grass or broadleaf, and sets out a rotation intended to run constant interference with those life cycles. Herbicides are used with precision, but not in the variable-rate sense of the word. Timing and rates (typically reduced) are carefully considered, and strategies developed, often with a ‘Plan A’ and a ‘Plan B’, depending on what weeds emerge. Residual chemistry is crafted into his ‘stacked’ 6-year rotations. He might use a residual chemical during the first year of a 2-year ‘stack’ of corn. Corn or another tolerant crop follows, without re-application of that chemical, the 2nd year. After visiting his rotations, one gets the feeling that he is bullet-proof from weeds. It is obvious that Leon Wrege (sp?) and Beck have shared a mutually productive career, learning how to manage weed populations in diversified crop rotations. Key to all strategies is low disturbance seeding, accomplished with a disc-type no-till drill. He minimizes soil disturbance to keep weed seeds stranded in the duff layer. In that layer they can’t germinate and are likely to be fed on by predators such as birds and beetles. No post-harvest harrowing to stimulate weed germination. For the same reason, he will not allow livestock in his fields. Not only do they introduce weed seeds to the field, but the hoof traffic serves as an effective weed-seeder. In fact, his unique prototype no-till drill, which is drawing quizzical ag engineers from all over the globe, is based on the “Buffalo 1 - Buffalo 2" concept. The first buffalo presses the seed firmly into the ground; the 2nd kicks a loose layer of trash over top. His highly unorthodox, but also highly efficient and effective seeder is based on this concept. Asked to explain it, he went to a nearby chalkboard and diagramed the operation of a primitive hand-held hoe planter. Centuries-old principles. Weeds are well managed and scarcely present. Beck facilitates a lot of main campus research as sub-areas within his rotational fields .... there was a striking example where a higher disturbance seeder was used ineffectively and the plots were over-run with weeds. So the weeds are there, they’re just not allowed to play.
Engineering
One of many things that clearly sets
Beck apart from most other cropping system researchers is his obvious
appreciation and understanding of farm machinery. He combines his deep
knowledge
of crop physiology and soil physics with engineering like nobody else
I’ve
met. Beck operates the seeder and the combine ..... on every acre of
his farm.
Because he drives the machinery himself he sees first-hand the
practical
pitfalls associated with using a machine in a certain situation. He has
been
working on a seeder prototype for 5 years and the final changes were
being made
while we were there. It is very likely that private companies will
pirate many
design attributes. Beck’s design is not patented, and he displays it
publicly
to make it difficult for outright theft of his design to occur
(apparently,
after sufficient public display, the concept becomes public knowledge
or
something like that). He says he wishes he didn’t have to do this work
but
until he can get design engineers on the right track, he feels
compelled to show
them what he wants available in a commercial unit to accomplish the job
of seed
and fertilizer placement that he demands in his high residue
conditions. Hooked
on a 150 h.p. tractor, the 15' unit was able to turn on a 55' diameter
and could
be backed quickly into any position. He created a large hydraulic
capacity tank
so that he can run up to 3 drill-fills simultaneously, rather than
plodding one
by one. All seeding units can be quickly unclogged and removed
altogether by
undoing a single bolt. With the flick of a lever, seeding patterns can
be
changed between a paired row configuration more suitable for
small-seeded crops,
to a wider row pattern suitable for large seeded crops. Maximizing
acres/hour.
Every design feature keys on that aspect of efficiency. Optimizing seed
and
fertilizer placement. He harvests with a stripper-header to speed up
harvesting
and maximize standing residue for snow catch, and ease of seeding.
Loose trash
is a devil to get through; anchored trash is relatively simple. Long,
dense
strands of standing wheat stubble provide a surprising amount of
floatation for
loaded tractor tires, permitting seeding in wetter soil conditions than
would
otherwise be possible. 6 lb is the maximum tire pressure allowed on any
machine
that travels his farm. He uses the stripper header in all manner of
crops,
including some for which it was not designed. For weed competition and
efficient
water use, his corn production has gone to relatively narrow 15" row
spacing. Corn rows narrower than 20" exceed the adjustment capabilities
of
conventional corn headers. A farmer friend and he invented a way of
rejigging
the header to permit harvesting of narrower rows, requiring only a
single
non-standard part. His farmer friend now has a fairly brisk commercial
business
making these conversions. I’m sure there’s much more my non-mechanical
mind
failed to appreciate.
Economics/ Efficiency
Beck has an arrangement with his employer, SDSU, whereby 80% of his annual operating budget comes from the sale of grain from his plots. This seems more than challenging, given the added complexities of having to produce grain on random, replicated plots, stopping to record results in a weigh-wagon and often managing around other SDSU research projects in the middle of the plot. Time is money. He seeds ~1200 acres/year with a 15' seeder. He buys all his inputs and markets and delivers all his own crops. If he makes a good marketing move, his research farm benefits. If he doesn’t, improvements on the Buffalo prototype must wait. He’s farming on a realistic scale. Because he doesn’t depend absolutely on the success of the farm to take care of his family (he is a full-time SDSU employee), he operates like a producer with a high-risk preference. But he uses the rotation principles in a way that permits strong flexibility between crop enterprises with much different risk/profit portfolios while allowing a similar rotational effect. In this way principles apply to producers with lower risk preferences. He knows the cost of inputs. He knows the challenge of marketing many different crops. Producers quickly sense that he’s talking from real experience. He is an aggressive N manager. He is not willing to take a chance on N being the limiting factor for yield, and with cheap N, shoots for high yield targets. In wheat, he protects grain protein via flex N application, according to current weather probabilities. Any N the crop doesn’t use can be picked up by next year’s crop.
Plan a Visit
If you’re interested in diversified cropping systems, go see Beck’s research farm. Like me, you don’t have time. Do it anyway. No amount of description is a substitute for what you will experience first-hand. You have to be immersed in it; see it, hear it, touch it, smell it, feel it, simultaneously. His crew calls it “getting a brain transplant”. It feels much like that. Their website is www.abs.sdstate.edu/aes/dakotalakes/ . Hit the information button, then ‘publications’. The Power Behind Crop Rotations will provide a glimpse of the philosophy driving their highly profitable and sustainable vision of where agriculture must go.