Fall Plowing

Posted in Farming on Tuesday, November 11, 2014

Fall Plowing

It felt really good to finish fall field work this year.  I think in part it was because I finished up with the plow. Maybe it is because plowing takes so long, slowly changing the land from white stubble to black earth, and then suddenly, with one more turn of the tractor, all the stubble is gone.  Standing straw marked by combine tracks, has been thoroughly replaced by regular waves of broken soil.

“Broken” is the exact word.  A moldboard  plow consists of a sixteen or eighteen inch long, flat blade with a hardened point on one end that is drawn on a diagonal to the direction of travel.  It slices  horizontally through the soil at a depth of four to eight inches below the surface.  As the blade or shear (the “plow shear” – though probably not made from beaten swords) is drawn forward, the soil is lifted and rolls up and to the side along the compound curve of a steel moldboard.  Two hundred years ago, when the curved steel was an actual wooden board, the term ‘mouldboard’ made more sense.  The end result is that top half foot of soil is uplifted and rolled upside down and moved sixteen or eighteen inches to the side, a brutal, and ninety plus percent fatal, ride for any young plants trying to grow.

When the moldboard and attached plow shear have gone by, a four to six inch deep trough about a foot wide is left.  The next pass of the plow will break and invert the soil beside the trough to evenly fill it – IF (a big IF) you drive just right.  Plowing is hard! I think to be good at it, you have to have started practicing by age 12.  I did not, and I don’t think I will ever be as good at it as the farmers a generation before me.  You have to drive precisely to keep the plow within about 2 inches of your previous mark.  If you don’t, you get unfilled troughs or humps or ridges – all features that are not conducive to even, productive crops next spring.  Those old farmers could do it in their sleep, and they instinctively knew where the plow was without ever looking back, even on the ever changing slopes, curves, and hills of the Palouse.

Though GPS guided, “self- driving,” tractors are available now, I’m not aware of a plow equipped for sub inch accuracy to go with them.  A plow like that would require multiple position sensors on the plow to constantly adjust for not just position, but, depth, pitch, roll, and yaw.  In addition to presenting unique challenges, the demand for plows continues to decline.

Many feel strongly that moldboard plowing is a thing of the past that should be left with the horse-drawn binder and wagon, and there are sound arguments for that sentiment.  Eliminating tillage, especially heavy, soil inverting tillage from farming essentially stops erosion.  I think there are few if any who still plow like grandfather did: plow everything possible, and always down hill. There has been a tremendous amount of erosion over the last 100 years simply from rolling that furrow slice down the hill every time.  Most people who still plow, are plowing uphill, moving that furrow slice upward instead of down. Depending on the steepness of the slope, it is actually possible to reverse erosion by plowing. 

Weed and disease control are the primary reasons to still perform some level of tillage.  Plowing, with its ability to bury weed seeds deep enough to prevent germination, is one of the most effective non-chemical weed control methods available.  In fact, though some tillage may be done primarily to prepare a seedbed to accommodate older planting equipment, all tillage has a weed control component to it.  Without tillage, that physical weed control must be replaced by chemistry. 

In addition, there are some diseases of wheat that are carried from one season to the next by surviving on wheat residue.  There are several others that are favored by high levels of crop residue on the soil surface.  Do you leave the residue on the surface to stop soil erosion, or bury it to stop the disease?  If next year is going to present me with great weather for disease development, I better burry it all.  If not, I don’t want to take a chance on weather that brings me great erosion potential. 

I did some of both.  I don’t  think anyone plows as much as was done even 20 years ago.  It takes time.  You can spray a field with weed killers four or five times in the time it takes to plow it. Plowing buries as much residue as possible and takes more fuel/acre than other implements. Chisels, discs, disc rippers and other implements are used that leave more erosion stopping residue on the surface.  I plowed only the fields that produced a lot of straw residue, and chiseled everything else.  The ground that grew peas this year, was fertilized and seeded to next year’s winter wheat crop without any other tillage.

More and more acres are farmed without tillage every year, which is great for conserving soil and stopping erosion, but it is hard to imagine a successful no till system without greater reliance on chemicals for weed control.  Winter annual grasses, plants that have the same life cycle as winter wheat, are a severe and increasing problem.  Farming outside the greenhouse or laboratory is one giant balancing act, constantly weighing offsetting factors.  Each farmer has their own personal weighting system for considering all the factors that go into producing every crop.

The one thing I am certain of, is that having every individual farmer, farm their own way is the best solution for all. Many individuals weighing the factors that can impact their crops, erosion control, disease control, chemical use, (the list is very long) results in multiple approaches and solutions.  We all gravitate to systems that consistently make us money, but within that broad parameter, there are still varying ideas.  It is that variation that helps stabilize regional production from year to year.  Adverse weather this year hurts my wheat but because of different production decisions, my neighbors no-till does a little better.  Next year, with different weather, the effect may be reversed and mine may be better.  If we all farmed exactly the same way, we would all be stricken by the same exact disasters in the same way, and that isn’t good for anyone.