Abstract

The objective of this study is to examine the effect of Sphagnum peat (SP) and three composts as a source of organic phosphorus (P), on the dry biomass yield of ryegrass grown, under greenhouse conditions, in a limed sulphide mine tailing (MT). Treatments consist of two rates of SP (0 and 33.8 g/kg MT) and five rates of P (0, 114, 229, 343 and 458 mg P2O5/kg MT). The P sources are: peat-moss and shrimp wastes compost, sheep manure compost, peat moss and chicken manure compost, and superphosphate (inorganic P source). The treatments are arranged in a randomized complete block design with three replications. Dry matter yield of plant biomass is positively and significantly affected by peat and P treatments. In all P treatments, the higher yields are obtained with mine tailing receiving peat. In conclusion, sulphide mine-tailing amended with lime and organic fertilizer could be transformed into substrate or soil capable of producing high ryegrass biomass yield.