December 5^th is World Soil Day. Recommended by the International Union of Soil Sciences in 2002, the establishment of World Soil Day was led by the Kingdom of Thailand as part of the Global Soil Partnership—it was formally adopted by the UN General Assembly after endorsement by the FAO in December 2013. December 5^th was chosen for World Soil Day as it corresponds with the official birthday of H.M. King Bhumibol Adulyadej, the King of Thailand, who sanctioned the original event.

2024 marks the 10^th annual World Soil Day with the theme “Caring for Soils: Measure, Monitor, Manage.” This emphasizes the importance of accurate data and information systems for understanding soil characteristics and supporting informed decision making for sustainable soil management and food security.

Events and resources for the 2024 World Soil Day are available on FAO’s website at https://www.fao.org/world-soil-day/en/ and include a World Soil Day Event Map, Children’s Book Contest, Farmer Contest, and Podcast Contest.

To recognize World Soil Day, Renewable Agriculture and Food Systems, published by Cambridge University Press, is featuring the following five articles selected by Editor-in-Chief Katherine Dentzman. These articles cover a wide range of issues including immigrant farmers’ knowledge and needs related to soil health; the impact of organic fertilizers, cover crops, and mulches on soil health properties; and how farmer belief systems impact soil management practices.

Below, we provide citations and a brief description of each article. We encourage you to pick at least one that interests you and read it in more depth in honor of World Soil Day.

Hoidal N, Fernandez A, Kubovcik K, et al. Emerging specialty crop farmer perspectives and educational needs related to soil health and nutrient management in the Upper Midwest. Renewable Agriculture and Food Systems. 2024;39:e25.

• This study focuses on gaining a better understanding Midwestern U.S. immigrant farmers’ wisdom and educational needs related to soils.
• They found that farmers already were highly skilled in assessing physical and biological aspects of soil health but often needed support in understanding properties of soil, how to test soil, and how to interpret soils tests and apply results to on-farm management practices.
• Of particular importance was educating the educators on farmers’ former experiences in agricultural systems outside of the U.S., including how to adapt this knowledge to their new Midwestern context.

Li B, Zhang C, Qian Y. The application of organic fertilizers and farmers’ income increase. Renewable Agriculture and Food Systems. 2024;39:e22.

• Li et al. recognize that organic fertilizers help improve soil quality and reduce non-point source pollution; however, they investigate whether this contributes to an increase in farmers’ income.
• Findings indicate that farmers’ income can be bolstered by organic fertilizer application only when supported by soil testing formulas (i.e. precision fertilizer application techniques) and extension outsourcing services.

Gantlett R, Bishop J, Jones HE, Lukac M. Modern arable and diverse ley farming systems can increase soil organic matter faster than global targets. Renewable Agriculture and Food Systems. 2024;39:e17.

• This study investigates the soil organic matter accumulation potential of a 2-year diverse ley (23 species of legumes, herbs, and grasses) compared to permanent pasture and bare soil controls.
• The ley system increased soil organic matter accumulation in plots with lower baseline levels, but ultimately hit an upper limit. In contrast, permanent pasture showed a consistent increase in organic matter accumulation regardless of baseline levels. Still, ley systems can contribute to carbon sequestration and soil organic carbon, particularly in poor quality pastures.

Bloom EH, Atallah SS, Casteel CL. Motivating organic farmers to adopt practices that support the pest-suppressive microbiome relies on understanding their beliefs. Renewable Agriculture and Food Systems. 2024;39:e8.

• Bloom et al. investigate how a range of organic farmer beliefs predict management practices related to pest management in the soil microbiome in New York State.
• Farmers who believed on-farm management practices were important for promoting soil microbiomes tended to use fewer pesticides and synthetic mulches while also expressing motivation to adopt new practices supporting the microbiome. Farmer demographics and farm characteristics did not correlate with farmer motivations, suggesting that beliefs are the most important driving factor.

Maher RM, Rangarajan A, Caldwell BA, Ho S-T, Hutton MG, Ginakes P. Tarping and mulching effects on crop yields, profitability, and soil nutrients in a continuous no-till organic vegetable production system. Renewable Agriculture and Food Systems. 2024;39:e1.

• Four contrasting tillage systems were compared for impacts on crop yields, labor, profitability, and soil nutrients in New York State cabbage and winter squash production. Specifically, the authors tested conventional rototilling, shallow rototilling, no-till, and no-till with polyethylene tarping between crops. Within each tillage treatment, they compared three mulching treatments: rye mulch, compost mulch, and no mulch.
• Findings indicate that mulch treatments had a dramatic impact on soil properties after four years. Compost mulch led to a 49% increase in total soil carbon, a 31% increase in total soil nitrogen, and a 497% increase in extractable phosphorous. These additionally varied by soil depth and tillage treatment.