Integration of pelleted biosolids with cover crops for improving soil properties

Abstract

Measuring and assessing soil properties is critical for understanding how changes in agronomic practices affect the capability of soil to support cropping systems. A field study was conducted on a Marietta silt loam soil at the Plant Science Center at Mississippi State University to determine the effects of pelleted biosolids (PBS) relative to poultry litter (PL) and inorganic N fertilizer applied to corn (Zea mays L.) and cotton (Gossypium hirsutum L.) in the presence of winter wheat (Triticum aestivum L.) cover crop (WCC) and winter fallow (WF) on soil properties. Experimental design was a split-plot randomized complete block with three replications. The whole plots were WCC and WF and the subplots were fertilization. Fertilization treatments included PBS and PL at 11.2 Mg ha -1 and 6.7 Mg ha -1 applied to corn and cotton, a one-time single application at 37 Mg PBS ha -1 to corn in 2016, inorganic N fertilizer at the recommended rate, and an unfertilized control. Soil cores were collected after harvest and analyzed for nutrient concentrations, water stable aggregate (WSA), and enzyme activities. The WCC reduced bulk density (ρ b ) and penetration resistance (PR) and increased soil total C (TC), WSA, and infiltration rate, as compared with winter fallow (WF). Relative to inorganic N fertilizer, application of PBS decreased soil ρ b and PR by 3 and 20%, respectively, and increased soil TC, WSA, and infiltration by 19, 23, and 45%, respectively. A combination of PBS and WCC improved soil physical and chemical properties under southeast agroecosystems.