What lessons have we learned from Mother Nature about soil?
Upon entering, walking through, and collecting a soil sample from any given geographical area under native vegetation, one will invariably encounter three basic scenarios: a) a soil surface permanently covered with organic material in the form of various residue types, b) a high diversity of plant and animal life, as well as microbial activity, meso and macrofauna, and c) a dark, soft, carbon-rich soil filled with roots, indicating optimal health. Are we following these lessons?
The Earth’s surface is approximately 13 billion hectares (Bha), and current annual crops occupy approximately 1.6 (FAO Stat, 2024) to 1.87 Bha (U.S. Geological Survey-Global Map, 2024). However, only 0.205 Bha (Kassam et al., 2022) of the world’s agricultural land is used for conservation agriculture, which is equivalent to 12.8 to 10.9%, i.e. almost 90% of the cropland is ploughed and, in several situations, leads to high levels of degradation. Is it possible to modify and ultimately reverse this situation? The answer is yes! The scientific and practical knowledge that has been accumulated over the last two decades, combined with the lessons that Mother Nature has taught us, provides us with the necessary tools to change this scenario. The goal of soil management is to simultaneously provide three essential components within the soil’s pores that are necessary to sustain life and promote plant growth: air flow, water and nutrients. When we consider the essential message of Mother Nature, it can be boiled down to a single, overarching concept: agriculture-based carbon (ABC) or maximizing the accumulation of C into the soil fixed by crops during photosynthesis. A systemic approach is required to integrate environmental variables, soil management strategies, and crop knowledge for the sole purpose of producing food, fiber, and energy. It is of utmost importance that farmers re-examine their self-perception as mere commodity producers. From a contextual perspective, they are soybean, corn, and cotton producers. However, they need to develop production systems that are resilient, profitable, and low-carbon emitters, it is essential to integrate lessons from Mother Nature. The interaction of all the tools leads to the conclusion that the optimal strategy is to produce more with less. This conclusion is supported by the evidence that following this single piece of advice means developing no-till production systems based on more biomass-C input and more diversification in the mix of species that feed the soil. We can state that crop residue is the food of the soil, and feeding the soil, we feed the human beings and agriculture can contribute to minimizing the climate crisis. What are we waiting for to do our part?
Sincerely,
João Carlos De Moraes Sá (Juca Sá)
Senior Associate Researcher
CFAES Rattan Lal Center for Carbon Management and Sequestration
College of Food, Agriculture, and Environmental Sciences, The Ohio State University