Soils Provide the Foundation

 In Providing Insight

The Maximum Farming System® is built on key insights about crops and soils that have been revealed through basic science research. Farmers who appreciate this foundation can achieve better outcomes for their operations. At it simplest, this foundation of basic science starts with the recognition that all life on the farm is dependent on the sun’s energy and the air-water balance of the soil. Beyond that, what insights from basic science lead farmers to increased crop yields?

Pay Attention to Light and Heat Cycles to Fix More Carbon

First, one needs to understand the roles of both light and heat in crop production. In the field, photosynthesis can only lead to crop biomass accumulation during daylight hours when plant cells are active and water can flow freely through the plant. This only happens when both soil and air temperatures are well above freezing, averaging between 55 and 85 degrees Fahrenheit.

Daylight hours each year peak in late June and the sun’s light begins to slowly heat the planet’s surface. This leads to average daily air and soil temperatures typically peaking in early August, then cooling again in the fall. As the season progresses and these temperatures rise, both soil and plant processes increase in rate by two- to four-fold. This occurs up to about 85 to 95 degrees Fahrenheit at which point the heat becomes too much for terrestrial life to complete biological functions.

These fundamental processes are predictable, and, while they vary dynamically by geography, farmers rely on these facts and the annual solar cycle to predict good planting and harvest windows.

Understand the Importance of Balancing Air and Water
Second, enough air and water must be present to support crop growth, especially where roots grow. This is trickier to manage because precipitation patterns are much less predictable on a weekly and monthly basis. However, basic science has revealed that both root growth and soil microbial activities are maximized when air and water fill roughly an equal share of open pore space in soils. This then becomes a target for managers who need to recognize that weather, soil composition, and management can impact that balance over time.

The actual balance of air and water will fluctuate daily based on many factors, most notably the rate and volume of precipitation. However, the amount and distribution of crop residues, organic matter, clay content, and cationic balance (e.g. %Ca and %Mg) all play significant roles in determining how quickly water enters and exits soils.

To maximize yield potential, farmers need to understand how to adjust the balance of air and water in their soils via the amount and type of inputs they apply, as well as the timing of their field operations relative to soil conditions. In this regard, lime, gypsum, cover crops, and animal manures might all have a role to play in optimizing yield potential.

Farmers’ Management Choices are the Deciding Factor
Farmers can’t control the availability of light and heat, but they can plan for it. Experience is essential, but direct measurements and good record-keeping will supplement that experience to optimally plan the timing of key operations. Start by analyzing multi-year averages of air and soil temperatures as well as seasonal precipitation patterns to establish optimal planting, side-dressing, spraying, and harvesting windows. Just as importantly, farmers must be disciplined and observant to know when to conduct field operations. By operating only when soils are warm and dry enough to support both equipment and plant growth, soil compaction can be avoided.

Careful observation of soil and crop conditions over the course of multiple growing seasons can also reveal soil issues that can be effectively addressed by management. Regular soil testing is essential for determining which features that affect air and water balance need to be adjusted to increase yield potential (e.g., increasing SOM through reduced tillage or adjusting %Ca and %Mg levels through addition of gypsum or lime). Additionally, observations of wet spots and/or erosion can point towards where significant soil engineering (e.g., adding drainage or terracing) might be needed to significantly improve air-water balance.

Besides attending to soil conditions, farm managers must focus on providing optimal nutritional support for their growing crop. Because mineral nutrients are largely supplied through the actions of soil and root-inhabiting microorganisms, fertilizers should be viewed as supplemental inputs to provide support only when and to the extent that soils are unable to provide them. Because of this, Ag Spectrum offers crop-specific fertilizer recommendations along with high-quality, well-formulated products whose combination and timely application provide support to maximize yield potential. Read more on Ag Spectrum’s system-based approach to optimizing crop nutrition.

-submitted by Dr. Brian Gardener, Technical Director

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