How do we reach our goal? My video and document search, along with our limited experience, shows that it is imperative that soil organic matter be increased. I list several points, not necessarily prioritized, that I have found to be important. 1--manage our cropping system with an eye on ways to reduce herbicide, insecticide, and fungicide applications. These all have components that negatively influence the development of soil organic matter. 2--we need to do minimal ground disturbance. This minimizes soil structure damage, keeps roots intact to help hold soil in place and leave root and worm channels exposed at the soil surface. This also minimizes loss of surface cover. This also maximizes any mycorrhizal network we may be able to develop for a nutrient/moisture transport, and communication pathway between plants. 3--develop and maintain surface residue. Residue protects the soil surface, reduces compaction from equipment, feeds the soil macrofauna along with some microfauna, and helps moderate the soil temperature. 4--minimize compaction. This will help improve soil structure. Compacted areas have poor soil structure and promote anaerobic soil conditions that increase the types of fungi and bacteria that cause plant diseases and insect predation. Aerobic soil conditions, on the other hand, increase fungi and bacteria types that promote healthy soil organisms, and reduce pathogenic organisms that negatively impact plants 5--we need to change our fertilizer practices, to minimize the lowering of soil pH, minimize harm to microbes, and reduce nutrient antagonism. 6--develop techniques to extend the time living roots are in the ground, --preferably all year long. 7--increase microbes and fungi, in our soil. With our history of a monoculture wheat system, our soils are extremely bacterial. Soils would perform better if the Bacteria to Fungi ratio was closer to 1/1. Fungi are important to soil and plant health. They convert nutrients into more plant available forms. When available, mycorrhizea fungal networks are an important transporter of moisture and nutrients to plant roots. Fungal mycellium serve as a line of defense for plant diseases. Fungi can be promoted by doing all of the (1-6) points discussed above which boils down to, --providing fungi food for as much of the year as possible and stopping the destruction of their hyphae and mycelium. The chart below shows the relationship between plant types and the bacteria to fungi ratio. The chart shows there is not much on the "left" of our wheat monoculture other than weeds and rocks.
For the past 2-3 years, I have participated with a group looking into soil and plant testing, organic forms of fertilizers, and ways to manipulate soil biology to increase soil health. This has been a valuable experience, and there is more to learn.
During this time I have come to the conclusion that we can build healthy soils by proper crop management without amendments. This requires absolute minimal tillage, keeping the soil surface covered, replacing chemical fallow with green fallow, diversifying our crop cultivars, extending the time we keep a living root in the ground, and paying attention to the synthetic inputs we apply to our crops so as to not destroy the positive gains we make from other practices employed. The use of animals is not mandatory, but it has been shown that grazing animals speed up the positive soil health processes when properly managed.
I feel our operation has the equipment and basic knowledge to begin the process of building soil health. We now need to develop management skills to make it all happen.
As a final note to this post: Absolute minimal tillage by itself works well too stop erosion and establish a base from which to develop practices that will improve our soils natural productivity. However, actual improvement of our soils natural productivity comes by managing soil biology through growing diverse plant cultivars. The intensity, meaning the time with living roots in the ground, and the time taken to mitigate negative components to soil biology, such as synthetic amendments, sets the pace for improving our soils natural productive capacity.
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