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Changes in Soil Quality from 25 Years of ZeroTillage in North Dakota
By Mark Krebsbach
Upon completing a course of study at North Dakota State University in 1974, I began teaching in the Agricultural Department at what is now University of North Dakota Lake Region. It was there I first heard about planting a crop directly into the previous year's stubble without cultivation. That seemed to me to be a good practice to help keep the soil from blowing in the sandy region I was from. I also started farming when I started teaching so I began experimenting with this no-tillage planting. At the beginning of my farming career I didn't give much thought about improving soil quality. Most of my efforts were exerted towards maintaining soil quality. Primarily keeping the soil on the field, by stopping wind and water erosion.
The soils in the area I was farming were under the normal farming method of producing crops. Either summer fallow every other year or every third year. Wind and water erosion were a problem. The organic matter was generally low, earthworms were very few if any to be found, soil fertility was low, and soil structure was something I didn't understand. I would take a handful of soil from a cultivated field and let the dirt run through my fingers to the ground. I couldn't see any soil structure because there was none there to be seen. Somewhere out in the field I not only decided soil quality could be stabilized and improved but it also needed to be improved if I was going to remain farming.
What is soil quality? They tell me soil quality is the capacity of a soil to function for specific land uses or within ecosystem boundaries. I'm not so sure that this Norwegian farmer understands that with one quick look. I translate that into soil quality is the ability of the soil to do what you want it to do.
To me that means the ability to:
Soils of good quality are healthy soils. A spoon full of healthy soil may contain more micro-organisms than there are people on earth. The greater the biological activity of a soil the more productive it is. Earthworms have a great effect on the soil. They are a good indicator of soil quality. Many earthworms in the soil indicate a high quality soil.
After zero-tilling for sometime, I noticed my soils developing more structure. The soil was becoming porous, less compacted, much more mellow. Then earthworms started showing up, in great numbers over the years of no-till. I once counted over 30 earthworms in one square foot. The low spots I previously had to go around started to dry up. I noticed less water run off after rains. The soil was taking water in faster and it seemed the soil was holding more water. That would explain the wet spots drying up. Now some of these spots have been planted every year for several years-even in the past 5 wet seasons. Also, I've noticed that the ground doesn't seem to crack open during dry spells as much as cultivated fields nearby. Herbicide and commercial fertilizers certainly have been reduced without reducing yields. I'm sure the organic matter has increased over the years of zero-till and the soil tests seem to indicate higher fertility levels.
Nature can make soil good or poor quality and quality can and does change. Man can make soil quality change also from good to poor. But, also we can improve soil quality, but at a much slower rate than we can destroy soil quality. Soil quality on my farm has definitely increased through years of zero-tillage.
We didn't inherit this land from our parents, we are borrowing it from our children. It must be returned to them with interest!
From every heart, one prayer…
That all men live as one with nature,
and peace reign everywhere.