By Craig Madsen
The Pacific Northwest Direct Seed Association hosted Soil Health Field Days on June 17 and 18 in Colton, Washington. Around 150 participants listened to Ray Archuleta, Dr. Christine Jones, and Alejandro Carrillo talk about the power of working with nature. Local farmers Douglas Poole, Brent Uhlorn, and Josh Riddle talked about their experience changing how they farm to build resilience and profitability.
So much great information was shared at the meeting; it will be covered in three articles. The first part will cover insights from Ray Archuleta. Ray said that he dislikes hearing that I am just a farmer. Farmers have a harder job than rocket scientists. Rocket science is complicated, but ecosystem management is complex. The ecosystem is a self-organizing living system that constantly changes during the year and from year to year. As land managers, we need to consider how our actions impact the whole system, not just a problem such as a weed or insect. The question becomes how is my management creating the conditions for the insect damage or weed issue versus what chemical do I need to use to kill the insect or the weed? Ray said we need a new agriculture model based on looking at the whole system.
Ray commented that most cropland soils are naked, hungry, thirsty and running a fever. Why is that? Because we are not allowing the plants to feed the soil biology. Ray brought up the critical functions of the four ecosystem processes, water cycle, nutrient cycle, sunlight capture and biodiversity.
How well are the four Ecosystem Processes functioning on your land? Do you see what nature is telling you?
To determine the effectiveness of the water cycle on your land the next time it rains, take a drive and answer these questions: Is the rain infiltrating your soils or running off? Is water ponding on the soil surface? Are you getting erosion? After the rain, does your soil crust? If the answer is yes, you have poor soil structure, causing an ineffective water cycle. You are losing critical moisture for your crops and creating your own drought. If you want to get scientific, conduct an infiltration test to see how long it takes an inch of water to infiltrate your soil. If it is over 12 minutes, your soil has poor soil structure.
What builds soil structure? Soil biology. What farming activities negatively impact soil biology? Tillage, herbicides, fungicides, synthetic fertilizers, monocultures. What farming activities encourage soil biology? No-till, diverse cover crops, crop rotation, natural fertilizers, biological stimulants, and livestock incorporation.
Nutrient Cycle: How well is the crop residue breaking down in your fields? How long has that manure been in pastures? What color is it? If your residue or manure is gray, it has been in your field for over a year, chemically breaking down through oxidation versus biologically. Your soils are constipated.
Energy Capture: How much of the year is your soil covered with growing vegetation to capture the free energy from sunlight? The more free energy you can capture from the sun, the higher the likelihood you will be profitable. Annual cropping system and a 3-year rotation – winter grain, spring grain, and summer fallow have a growing plan for 38% of the year. You are not capturing free sunlight energy for the rest of the year. The only way to feed the soil biology is through the plant root exudates. No growing plant with no root exudates results in starvation for the soil biology. The soil microbes turn to the carbon in the soil for food, eating the soil structure, which is critical for water and nutrient cycling. This is the reason Ray said that cropland soils are hungry and thirsty.
Christine Jones discussed how biological diversity is critical to healthy soils and plants. Remember, soils, like our bodies, are living systems that eat and breathe like us. Diversity above ground translates to diversity below ground. Different plant families feed different microbes with their root exudates. Different microbes access different nutrients and minerals, making them available to the plants. There are Nitrogen-fixing Bacteria, Phosphorous Solubilizing Bacteria, Actinomycetes that produce antibodies and digest cellulose and chitin, arbuscular mycorrhizal fungi (have a direct relationship with plant roots, help build soil aggregates, excrete acids to access minerals), and saprophytic fungi that digest the woody plant material. Chitin is the carbon compound forming fungi's cell walls and insects' exoskeleton. It is amazing, but fungi and bacteria can eat insects and fungi. The healthy soil is a dangerous place to live if you are a microbe.
Scientific research has focused on inputs rather than soil life. One costs you money, and the other works for you. If microbial diversity is the key, what is the impact of synthetic fertilizers on soil microbes? Applying synthetic fertilizers reduces the percentage of growth-promoting bacteria living on plant roots from 91% of total bacteria to 19%. Growth Promoting Bacteria produce growth hormones and antibiotics and provide nutrients to the plant. Due to this interrelationship between the plant and the soil biology, if you are planting cover crops, do not fertilize them. Synthetic fertilizer breaks the relationship between the cover crops and soil biology, which is counterproductive to the role of building soil structure.
Only 20 to 40% of the synthetic nitrogen applied is used by the plants. The rest is lost to leaching or into the air. The percentage of applied phosphorous utilized by the plant in the year it is applied is even worse, only 15%. Phosphorus is highly reactive and is rapidly tied up in the soil. Microbes create phosphatase, an enzyme that breaks the bonds holding phosphorous and releases it into the soil.
If you have been applying phosphorous for the last 10 years, you have adequate phosphorus for the next 90 years as long as you have the biology to access it. Microbes do not function well in simplified systems such as monocultures or single-species pastures. Phosphorous Solubilizing Bacteria stimulate Nitrogen-fixing bacteria. When you add water-soluble phosphorous to soils, plants do not feed Phosphorous Solubilizing Bacteria to get phosphorous. If the plant is not feeding the soil biology, it is starving, so the soil structure is degrading versus being built. Fertilizers are not poison to plants, but placing nitrogen, phosphorus, fungicides, or insecticide near the root stops the formation of the rhizosphere around the root, which provides protection for the plant and water and nutrients. The market for the exchange of goods and services is broken.
Healthy rhizosheath
Poorly developed rhizosheath
Remember that 78% of the air we breathe is nitrogen. Nitrogen fixation occurs inside plant leaves, stems, roots, and the rhizosheath surrounding the root system. Dig up some roots. Are they bare or covered with active biology? Are your plants and soil biology working for you, or are the inputs coming from your pocketbook?
Next month, we will cover more insights Christine Jones provides at the Soil Health Event.
See these related videos:
Rain simulation presentation by Ray Archuleta.
Secrets of the Soil Biome by Dr. Christine Jones.
The Nitrogen Solution by Dr. Christine Jones.
The Phosphorus Patradox by Dr. Christine Jones.
Cover crops for orchards and vineyards by Dr. Christine Jones.