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ARS Home » Southeast Area » Fayetteville, Arkansas » Poultry Production and Product Safety Research » Research » Publications at this Location » Publication #390299

Research Project: Developing Best Management Practices for Poultry Litter to Improve Agronomic Value and Reduce Air, Soil and Water Pollution

Location: Poultry Production and Product Safety Research

Title: Multivariate evaluation of watershed health based on longitudinal pasture management

Author
item Ashworth, Amanda
item KATUWAL, SHEELA - University Of Arkansas
item Moore, Philip
item Owens, Phillip

Submitted to: Science of the Total Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/3/2022
Publication Date: 2/22/2022
Citation: Ashworth, A.J., Katuwal, S., Moore Jr, P.A., Owens, P.R. 2022. Multivariate evaluation of watershed health based on longitudinal pasture management. Science of the Total Environment. 824. Article 153725. https://doi.org/10.1016/j.scitotenv.2022.153725.
DOI: https://doi.org/10.1016/j.scitotenv.2022.153725

Interpretive Summary: Watershed health and water quality from grasslands is paramount for sustainable beef and forage production. Against the backdrop of 60% increases in food production demands and the need for sustainable intensification, more holistic evaluations are needed to identify best management strategies for restoring soil and watershed health on Earth's largest land-use, or grasslands. Researchers conducted a 14 year experiment where watersheds were consistently managed by either business as usual practices (such as continuously grazed or hay management), or aspirational or best management practices (including rotational grazing and riparian buffer strips at the edge of fields) and soil and water quality measurements collected following annual poultry litter applications. Researchers then evaluated watershed health through novel holistic systems-level evaluations. This study found that continuously, or over-grazed systems had lower water quality relative to hay and rotationally grazed systems with riparian buffer strips. Consequently, pasture management practices that maintained higher ground cover and reduced grazing intensity drove water quality. Water quality and overall watershed health was positively influenced by conservation pasture management and precipitation during the growing-season, with long-term pasture management driving runoff parameters and water quality. Overall, animal grazing days was not only related to grazing intensity, but to animal manure inputs and soil compaction, which was adversely linked to watershed health. Therefore, this investigation of long-term conservation pasture management practices identified factors that contribute most to watershed health and may be useful in optimizing grassland agroecosystems.

Technical Abstract: Watershed and pasture health is a transdisciplinary concern and crucial to promoting sustainable practices. The aim of this study is to identify effective systems-level conservation pasture management practices in a longitudinal study following 14-years of consistent management by i) teasing apart complex relationships between multivariate water and soil quality using principal component analysis (PCA); and ii) identifying interactions among variables that contribute most to watershed health within catchments using partial least squares-path modeling (PLS-PM) based on five treatments: hayed (H), continuously grazed (CG), rotationally grazed (R), rotationally grazed with an unfertilized buffer strip (RB), and rotationally grazed with an unfertilized fenced riparian buffer (RBR). Over 14-years, H and RBR systems had greater watershed health based on runoff water quality parameters. Therefore, management systems that keep forage heights >10-cm, have less frequent vegetative removal, and riparian filter strips promote enhanced watershed health. Of the over 20 runoff variables measured over 14 study years, only electrical conductivity and annual total suspended solid loads constructed a significant water quality PLS-PM model. Water quality was positively influenced by pasture management and precipitation, with long-term pasture management driving runoff parameters and water quality. Overall, animal grazing days was not only related to grazing intensity, but to animal manure inputs and soil compaction, and adversely related to watershed health. Study results denote that best management strategies such as rotational grazing and riparian buffer strips prevent pasture system degradation and maintain carrying capacity while reducing anthropogenic pressure on soil and water systems.