Soil Health and Fertility Management
There are many things in farming that can’t be controlled. Farmers are all too familiar with some or all of these factors, like weather patterns, fertility and seed costs, fuel prices, land rent, market conditions, and so on. One thing that is within our control, however, is investing in practices and products this year that will benefit next year’s crop. Dustin Adcock, an agronomist with Southern States, advocates for considering the long-term impacts of management decisions being made this year. Dustin joined the NC Soil Health Coalition for our May Soil Health Hour and shared numerous insights about fertility management, soil biology, and considering the long-term impacts our actions are having on soil health.
It is sometimes difficult to understand the indirect or delayed consequences of our day-to-day management decisions. Many farmers and landowners are aware that quail populations have been declining in North Carolina for decades, particularly in the Piedmont and western part of the state where they are nearly extirpated. Habitat destruction is a major culprit for the population decline. A singular factor is not causing the habitat disapearance, though, and it has occurred over many decades, making it harder to address. One landowner may not see the removal of brushy and grassy field edges as an issue because it is only occurring on their property. When this is multiplied over thousands of acres, however, it leads to the significant population declines that have occurred.
It is difficult to understand the complete consequences of our actions on complex ecosystems. Habitat removal affects the ability for quail to reproduce, avoid predators, and feed on insects and plants. When you consider that quail are an indicator species and their decline marks the decline of songbirds, pollinators, and many other species, it becomes apparent that the destruction of what may seem like an insignificant area of habitat actually has compounding impacts.
Our management of the soil is very similar to this. The soil is a complex ecosystem that depends on diverse species of bacteria, protozoa, fungi, fauna, and plants to function properly. Management decisions made today, such as over-application of a salt-based nitrogen fertilizer, can cause the decline of certain species, although the damage may not be immediately obvious. Continued stress on the soil ecosystem and the decline of key species can lead to significant soil degradation, such as loss of soil aggregation, over time. Conversely, certain products and soil amendments, such as humic substances, lead to short- and long-term benefits. It is important to consider our management decisions and invest in actions that provide long-term returns instead of simply addressing an immediate need.
During our May Soil Health Hour, Dustin also covered some fertility basics and considerations that apply to all farms. He shared the well-known pH / nutrient availability chart and explained cost-effective options for managing pH so it is within the optimal range for nutrient availability.
In addition to pH, nutrient availability can be affected by the levels of other nutrients in the soil. This is due to antagonistic and synergistic relationships between nutrients, meaning that certain nutrients can reduce the availability of other nutrients and vice versa. For example, magnesium and nitrogen have a synergistic relationship and balanced levels of nitrogen can increase the availability of magnesium. Nitrogen also impacts the availability of potassium and an unbalanced amount of nitrogen can reduce potassium uptake. These relationships are important to consider when applying nutrients. It is possible to over apply one nutrient and reduce the availability of another, which may become the limiting factor for plant growth. Balancing the soil to maintain optimal levels of all nutrients is complex and potentially costly, however, building a healthy soil will employ soil microorganisms to do much of this work for you. This is one of the many reasons that healthy soil promotes healthy plants.
Dustin shared the benefits of humic substances, like humic and fulvic acids, which can improve soil structure, improve nutrient availability, and stimulate biological activity. Like any soil amendment, humics must be used in the correct conditions to be most effective. In some cases, faster acting fulvic acids may be desirable or longer lasting humic acids may be more appropriate. Sugars can also be used to stimulate biological activity and provide even longer lasting benefits. Humics are available in liquid and dry forms with the dry forms providing the longest lasting benefits. These products are available from a variety of companies, such as Monty’s Plant Food Company, which is distributed by Southern States. As with any soil amendments, humics should be used for a purpose, such as supporting soil microorganisms initially when rebuilding a degraded soil.
Lastly, Dustin covered a variety of biological products that inoculate the soil and plants with beneficial microbes to promote root growth, nutrient availability, and overall plant health. It’s important to remember that, like plants and livestock, microbes require the correct conditions to thrive. Using any biological products in the wrong conditions will lead to poor results. Remember, microbes require an ecosystem around them to survive, so adding microbes without addressing soil health to provide the proper environment for them to live could be wasted effort.
There are many pathways to building healthy soil, and we can all invest in practices and products today that will leave the soil healthier tomorrow!
