Crop rotations and poultry litter affect dynamic soil chemical properties and soil biota long-term

Authors: Ashworth, Amanda; ALLEN, FRED - University Of Tennessee; Owens, Phillip; DEBRUYN, JENNIFER - University Of Tennessee; SAMS, CARL - University Of Tennessee

Submitted to: Journal of Environmental Quality
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/30/2018
Publication Date: 5/17/2018
Citation: Ashworth, A.J., Allen, F.L., Owens, P.R., Debruyn, J.M., Sams, C. 2018. Crop rotations and poultry litter affect dynamic soil chemical properties and soil biota long-term. Journal of Environmental Quality. 47(6):1327-1338. https://doi.org/10.2134/jeq2017.12.0465.
DOI: https://doi.org/10.2134/jeq2017.12.0465

Interpretive Summary: Soil health is the ability of soils to function within their biosphere to sustain plant and animal health. Anthropogenic reductions in soil function and soil health are an ongoing and pressing ecological concern. Soil biodiversity is seen as indicators for both ecosystem services and to the sustainability of management practices, however, studies linking agroecosystem management to soil biota and plant production are limited. Researchers found that after 12-yrs of cropping systems management (various crop rotations, cover crops, and poultry litter applications), soil chemical properties and plant yield were greatest under poultry litter amended soils compared to cover crops. In general, soil chemistry after long-term cover crop implementation did not differ for the fallow control (winter weeds). Overall, soil biodiversity favored nutrient rich soil amendments (poultry litter) and high residue producing, less pesticide-intensive cropping rotations (soybean and corn rotations compared to cotton) as food sources, which has implications for sustainable soil dynamics under no-tillage for these crops. These results corroborate direct linkages between cropping systems management, soil biodiversity, and nutrient cycling with the systems’ plant and soil health continuum.

Technical Abstract: Dynamic soil physiochemical interactions with conservation agricultural practices and soil biota are largely unknown. Therefore, this study aims to quantify long-term (12-yr) impacts of cover crops, poultry litter, crop rotations, and conservation tillage and their interactions on soil physiochemical properties, and determine their relationships with nutrient cycling, crop yield, and soil biodiversity (soil microbial and earthworm communities). Main effects were 13 different cropping sequences of soybean (Glycine max), corn (Zea mays), and cotton (Gossypium hirsutum) at the Research and Education Center at Milan, TN, and 8 sequences of corn and soybean at the Middle Tennessee Research and Education Center, Spring Hill, TN. Sequences were repeated in 4-yr phases from 2002 to 2014. Split-block cover crop treatments consisted of winter wheat (Triticum aestivum), hairy vetch (Vicia villosa), poultry litter, and a fallow control. Soil carbon and nutrient fluxes were calculated at surface (0-5 cm) and sub-surface (5-15 cm) during years 0, 2, 4, 8 and 12. After 12 years of cropping systems, weighted means (0-15 cm) of soil pH, P, K, Ca, Mg, total N and C were greatest under poultry litter amended soils compared to cover crops (P<0.05). In addition, continuous corn sequences resulted in greatest soil K, N, and C concentrations, compared to soybean-soybean-corn-corn rotations (P<0.05). Poultry litter treatments were positively correlated to greater soil physiochemical levels, as well as higher crop yield and soil biodiversity These results underscore linkages between manure additions and cropping sequences, within the nutrient cycling, soil health, and crop health and production continuum.