Soil chemical properties under no-tillage as affected by agricultural complexity

Authors: DIESS, LEONARDO - The Ohio State University; KLEINA, GEORGIA - Universidade Federal Do Parana; MORAES, ANIBAL - Universidade Federal Do Parana; Franzluebbers, Alan; MOTTA, ANTONIO - Universidade Federal Do Parana; DIECKOW, JEFERSON - Universidade Federal Do Parana; SANDINI, I - University Of Rio Grande Do Sul; ANGHINONI, IBANOR - University Of Rio Grande Do Sul; CARVALHO, PAULO - University Of Rio Grande Do Sul

Submitted to: European Journal of Soil Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/31/2019
Publication Date: 8/20/2019
Citation: Diess, L., Kleina, G.B., Moraes, A., Franzluebbers, A.J., Motta, A.C., Dieckow, J., Sandini, I., Anghinoni, I., Carvalho, P.C. 2019. Soil chemical properties under no-tillage as affected by agricultural complexity. European Journal of Soil Science. https://doi.org/10.1111/ejss.12869.
DOI: https://doi.org/10.1111/ejss.12869

Interpretive Summary: Changes in soil fertility with the introduction of livestock grazing of cover crops remains an important area of emerging research. A scientist with the USDA Agricultural Research Service in Raleigh NC collaborated with investigators from the Federal University of Parana and Federal University of Rio Grande do Sul in Brazil to determine changes in soil chemical properties from three long-term experiments in southern Brazil as affected by grazing of cover crops. Greater agricultural complexity with grazing of cover crops led to greater soil pH and base saturation and reduced aluminum concentration, at the expense of reduced potassium concentration and copper availability. The integrated crop-livestock system was considered more sustainable because of stabilized crop yields, additional animal weight gain from grazing of cover crops, and greater productivity returns per land area and per nutrient input. This information will be valuable for scientists and farmers interested in designing more productive and sustainable agricultural systems.

Technical Abstract: Soil fertility under no-tillage farming may be affected by agricultural complexity. By transforming most of the ingested pasture into urine and feces, ruminants catalyze nutrient cycling by breaking down complex plant molecules, which can help to maintain or even improve soil fertility. We evaluated how integrating annual crops and ruminant grazing of cover crops in the same land area and at overlapping times affect soil fertility in no-tillage systems. Soil chemical properties were evaluated at 0-5 cm and 5-25 cm depths, in three long-term cropping experiments (7, 10 and 12 years) with and without ruminant grazing of cover crops. All sites were managed under no-tillage, and treatments with livestock were managed with moderate grazing intensity. Ruminant grazing increased soil Na and P concentrations at 0-5 cm depth, and increased Ca and Mg availability, basis saturation, and pH in deeper layers (5-25 cm depth) or across the soil profile (0-25 cm). Land-use complexity changed the soil exchangeable complex resulting in soil acidity amelioration, and consequently reduced Al toxicity, but it also had a negative impact on K saturation and cationic micronutrient availability (Zn, Mn, Cu and Fe). In general, grazing improved or did not change most soil chemical properties, and any negative effects of animal presence did not limit agro-ecosystem productivity. Therefore, with appropriate nutrient management, no-tillage farming with integrated crop-livestock systems can contribute to agriculture’s sustainable intensification.