By Gary Zimmer with Leilani Zimmer-Durand
Editor’s Note: This is an excerpt from Acres U.S.A. original book, The Biological Farmer, written by Gary Zimmer. Copyright 2017, softcover, 518 pages. $30.00 Regularly Priced.
What’s Wrong with the N-P-K Approach to Farming?
Does it make sense to use high levels of only highly concentrated water-soluble nutrients? The N-P-K-pH chemical approach to farming is both incomplete and wasteful.
Nitrogen — Managing nitrogen should not be just mathematical. Crop rotation, the nitrogen source used, and when and where the nitrogen is applied all have a bearing on how much nitrogen we need, as does soil air, soil life, organic matter, and
the presence and balance of other elements (such as sulfur and calcium). Biological farmers do not want to use any more nitrogen than absolutely necessary, not only because of cost and possible environmental pollution, but also because excess nitrogen suppresses long-term stable biological processes in the soil.
Research from the University of Minnesota has found that corn yields are highest when legumes are added to the rotation (O’Leary, Rehm, and Schmitt, 2008). By including soybeans, alfalfa, or other nitrogen-fixing plants, it is possible to grow your own plant-available nitrogen and reduce fertilizer requirements. Now consider how conventional thinking advocates applying more nitrogen to increase yield. Is yield always increasing as much as the nitrogen applied? Are your added fertilizer dollars getting you results? If not, what happens to the extra nitrogen you apply? Does it benefit the soil, the environment — or your water? What are the overall costs? Continue Reading →