Soil salinity and sodicity after application of fresh and composted manure with straw or wood-chips

Abstract

Limited information exists on the effect of fresh versus composted beef cattle manure containing straw or wood chips on salinity (EC), soluble salts (Ca, Mg, Na, K, Cl, SO4), sodicity (sodium adsorption ratio, SAR), and potassium adsorption ratio (PAR) status of soil in the Great Plains region of North America. A site on a clay loam soil under irrigated barley (Hordeum vulgare) in southern Alberta was used for this study. The treatments were three rates (13, 39, 77 Mg ha-1 dry material) of fresh manure (FM) or composted manure (CM) containing either straw (ST) or wood-chip (WD) bedding, one inorganic (IN) fertilizer treatment, and a control (CON) treatment. All treatments were applied in the fall of 1998, 1999, and 2000. Soil sampling was conducted in the fall of 1998, 1999, 2000, and 2001 prior to manure and fertilizer application. Our results indicated that applying CM to irrigated barley for 3 yr at rates up to 77 Mg ha-1 should not cause an increase in any of the salinity variables compared with FM. Calcium, Mg, K, Cl, EC, and PAR were significantly higher for ST than WD bedding at certain rates and years. Year of sampling had a significant effect on Ca, K, Cl, SO4, EC, SAR and PAR. Salt distribution profiles indicated no accumulation of Ca, Mg, and SO4 in the soil profile relative to the control, increases in K and PAR at the 0- to 15-cm depth, increases in Na, Cl, EC, and SAR at the 0- to 30-cm depth, and accumulation of Cl at all depths. Overall, CM should not increase soil salinity and sodicity compared with FM, and bedding material may be a potential tool to manage certain salinity variables in the soil. Key words: Soluble salts, electrical conductivity, sodium adsorption ratio, fresh manure, compost, bedding