Organic amendment effects on crop productivity and nutrient uptake on reclaimed natural gas wellsites

Abstract

Restoration of productivity on agricultural soils disturbed by industrial activity is important for agronomic and environmental reasons. Because of the role of organic matter in soil health and quality, organic amendments have been widely used in the reclamation of disturbed soils such as those on abandoned oil and natural gas wellsites. This study examined the effects of one-time applications of alfalfa (Medicago sativa L.) hay or beef cattle (Bos taurus) feedlot manure compost on wheat (Triticum aestivum L.) yield and nutrient uptake on two abandoned natural gas wellsites that had recently been reclaimed in southern Alberta, Canada. The base amendment rate (1x) [dry wt.] was 5.3 Mg ha-1 for compost and 3.1 Mg ha-1 for alfalfa. The five treatment amendment rates of 0, 1x, 2x, 4x, and 8x were soil-incorporated at the wellsites. Yields and plant nutrient uptake were generally higher at Hussar than at Turin, reflecting the higher inherent fertility of the soil at Hussar. Grain yields were similar for alfalfa and compost amendments, indicating that either amendment can be used depending on availability and/or transportation costs. Our results show that spring wheat yields on these reclaimed soils can be optimized at alfalfa and compost rates of no more than 6 and 10 Mg ha -1, respectively. Continued monitoring of crop productivity and soil properties may provide insight into the long-term benefits of alfalfa and compost amendments in wellsite reclamation schemes. © 2007 Springer Science+Business Media B.V.