Ameliorating soils with recycled residual paper pulp to improve soil physical and chemical properties

Disposal of recycled residual paper pulp (RRPP) is a serious environmental challenge. In this study, the effects of RRPP were evaluated over two years on a clay loam and a sandy loam amended with 0, 1, 2, and 4% volume/volume (v/v) rates incorporated into the upper 0.15 m of soil. Soil properties measured included bulk density, organic carbon (SOC), pH, electrical conductivity, volumetric water content, total nitrogen and heavy metals. Furthermore, effects of RRPP on leaf chlorophyll and fresh yield of Brassica oleracea, Lactuca sativa, and Zea mays var. saccharata were examined. Results indicate a statistically significant increase in SOC for the 4% v/v pulp application rate in sandy loam during both years and in clay loam during the second year. Application rate affected pH significantly only in the sandy loam on both years. All RRPP application rates resulted in proportional yield increases for most crops in both soils.