Sustainable Agriculture: How to Conserve the Soil

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A sustainable resource is one that continues supplying the commodity or service indefinitely, without causing negative externalities.

Although many agricultural practices including mineral nitrogen fertilization and heavy tillage produce high yielding crops, over the long-term, these standard farming methods can contribute to soil degradation and compromise sustainability. Conventional ag management practices often extract carbon and other nutrients from soil faster than they are added, slowly draining the ground’s inherent fertility. With abundant mineral fertilizer, soil microbial growth is no longer limited by insufficient nitrogen. Like humans and other animals, most soil microorganisms are aerobic heterotrophs, meaning they “eat” carbon-based foods, such as plant or animal remains, “inhale” oxygen, and “exhale” carbon dioxide. Given plenty of nitrogen fertilizer, microbes consume soil carbon faster than it can be supplied by decaying roots and crop residue. Without an adequate food source, microbial populations decline and soil organic matter decreases, damaging soil structure and lowering cation exchange and water holding capacity. Low soil organic matter increases the risk of topsoil erosion, decreases water infiltration, and causes fertilizer runoff, polluting nearby surface waters.

As Franklin D. Roosevelt stated, “ The nation that destroys its soil destroys itself.”

Soil microorganisms and other decomposers are necessary to cycle nutrients and create humus, the organic material essential to maintaining soil quality. But, if the microbes are given too much nitrogen and not enough carbon, they consume the organic matter that makes soil fertile. We can help prevent humus loss by applying organic matter pre-plant and throughout the season. The extra carbon input will help support beneficial microbial activity without depleting the organic matter required to preserve soil health.

At Tri-Tech we try to make agriculture more sustainable by recommending conventional fertilizer at the right rate, the right time, the right place, and in the right amount. We supply organic matter products that will increase the soil’s carbon content to support microbial population growth without depleting soil humus. With more microbes and organic matter, the soil can hold and distribute water and plant nutrients more efficiently and prevent fertilizer from leaching below the root zone. By applying less N and more C, growers can improve soil health, ensuring high quality crop production far into the future.