Soils determine early revegetation establishment with and without cover crops in northern mixed grass prairie after energy development

Authors: Espeland, Erin; Hendrickson, John; Toledo, David; West, Natalie; Rand, Tatyana

Submitted to: Ecological Restoration
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/8/2017
Publication Date: 12/1/2017
Publication URL: https://handle.nal.usda.gov/10113/6472297
Citation: Espeland, E.K., Hendrickson, J.R., Toledo, D.N., West, N.M., Rand, T.A. 2017. Soils determine early revegetation establishment with and without cover crops in northern mixed grass prairie after energy development. Ecological Restoration. 35(4):311-319.

Interpretive Summary: We measured rangeland health and perennial grass establishment in twelve interim oilfield reclamations. That were planted with and without cover crops. Sites at Ft. Berthold Indian Reservation in North Dakota were planted with two different perennial grass mixes, with and without an oat cover crop in late summer/fall of 2014 and with a single grass mix with and without a cover crop cocktail in spring of 2015. All sites were measured in August 2015. Sites planted in 2014 ranged from 20 (±10 stdev) to 38 (±0.5) perennial grass plants/m2. Sites planted in 2015 ranged from 6 (±1.8) to 29 (±11) plants/m2. Cover crop treatment and grass mix treatments did not determine perennial grass establishment. Instead, soil nutrients were key: sites with poor plant establishment had high levels of salts, sulfur, copper, and sodium. Rangeland health trended towards being greater when a cover crop was planted, but the effect was very small. We will eventually determine the long-term benefits of cover crops, but cover crops that establish at low densities due to stressful soil conditions may only have small effects in reclamations.

Technical Abstract: We measured rangeland health and perennial grass establishment in twelve interim reclamations as part of oil extraction activity. Sites at Ft. Berthold Indian Reservation in North Dakota were planted with two different perennial grass mixes, with and without an oat cover crop in late summer/fall of 2014 and with a single grass mix with and without a cover crop cocktail in spring of 2015. All sites were assessed for plant establishment and rangeland health in August 2015. Sites planted in 2014 ranged from 20 (±10 stdev) to 38 (±0.5) perennial grass plants/m2. Sites planted in 2015 ranged from 6 (±1.8) to 29 (±11) plants/m2. Cover crop treatment and grass mix treatments were not significant determinants of perennial grass establishment (p > 0.05). Soil nutrients appeared to drive revegetation success: sites with poor plant establishment had high levels of salts, sulfur, copper, and sodium. Rangeland health trended towards being greater when a cover crop was planted, but the effect was very small. We will eventually test if the long-term benefits of cover crops in agricultural systems transfer to restoration, but cover crops that establish at low densities due to stressful soil conditions may only have small effects in reclamations.