Long-term cropping systems management influences soil strength and nutrient cycling

Authors: Ashworth, Amanda; Owens, Phillip; ALLEN, FRED - University Of Tennessee

Submitted to: Geoderma
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/29/2019
Publication Date: 3/1/2020
Citation: Ashworth, A.J., Owens, P.R., Allen, F. 2020. Long-term cropping systems management influences soil strength and nutrient cycling. Geoderma. 361. Article 114062. https://doi.org/10.1016/j.geoderma.2019.114062.
DOI: https://doi.org/10.1016/j.geoderma.2019.114062

Interpretive Summary: Crop biomass from cover crops and animal inputs such as poultry litter can reportedly improve soil productivity. Soil compaction and soil strength are important considerations for soil structural stability, and is impacted by equipment use and other conservation management factors. Researchers conducted studies to identify fertility and compaction impacts under commonly implemented crop rotations, cover crops, and poultry litter under non-tillage. In this experiment, long-term poultry litter and subsequent winter weed growth resulted in the greatest soil fertility; therefore, poultry litter may be a viable alternative to cover crops, although economic and ecological analyses are needed to confirm viability. In addition, assessment of soil compaction indicates continuous cotton was the most compact, followed by continuous soybean, the corn-soybean rotation, continuous corn, and the corn-cotton rotation. Therefore, the planting and spraying traffic under no-tillage are likely the source of soil compaction. Study results help identify direct and indirect impacts of conservation agricultural management practices (crop rotation, animal manure inputs, cover crops, and no-tillage) on soil physiochemical properties under long-term no-tillage, such data are needed for identifying soil quality based on soil management.

Technical Abstract: Elucidating complex interactions of cover crops and crop residues on soil physiochemical properties is critical to sustaining soil productivity long-term. Our objective was to compare soil physiochemical traits, cover crop residue composition, and soil compaction following 15-years of cropping system implementation under non-tillage. Main effects were cropping sequences of soybean (Glycine max L.), corn (Zea mays L.), and cotton (Gossypium hirsutum L.], grown on a Loring silt loam, and sequences of corn and soybean on a Maury silt loam. Split-block treatments consisted of winter wheat (Triticum aestivum L.), Austrian winter pea (Pisum sativum L. sativum var. arvense) and hairy vetch (Vicia villosa Roth) cover crops, as well as poultry litter, and a fallow control. Soil physiochemical characteristics were evaluated at surface (0-15 cm) and sub-surface (15-30 cm) depths. Overall, soil physiochemical parameters were more affected by long-term cover crops and poultry litter in surface layers, whereas crop rotations impacted soil chemistry at sub-surface layers. High-nitrogen (N) containing cover crops had more desirable composition for soil biota (less recalcitrant), whereas corn had the highest soil carbon (C), N, and C:N ratio, likely owing to the greatest amount of residue being produced under this cropping sequence. Whole profile (0-1.2 m) assessment of soil compaction indicates: continuous cotton>continuous soybean>corn-soybean>continuous corn>corn-cotton, likely owing to greater planting and spraying traffic throughout the cotton production cycle. Study results help identify cropping system management effects on soil physiochemical properties under no-tillage and such data are needed for quantifying soil quality indices based on soil conservation management.