This study investigated main effects of recycled residual paper pulp (RRPP) used as soil amending material, on the yield and other agronomic characteristics of lettuce, cabbage and sweet corn as well as in major soil properties affecting crop growth and yield. It was conducted for two years and in two soil types (clay loam and sandy loam) representing also variable climate and was applied in four application rates (0-1-2-and 4% by volume) in the top soil surface (0 - 15 cm). The plants were managed using minimum inputs under the LISA (Low Input Sustainable Agriculture) system. The material is a waste product from a major cardboard manufacturing company in Greece. Main application of this is for incineration, landfilling and recently the soil application of it has been evaluated. The results indicated that the RRPP increased soil organic carbon in some cases significantly, it did not affect pH and EC, and increased yield of all plant species in both years. The material has not contributed additional heavy metals in both soils, a major requirement for using it for soil applications. Due to encouraging results, the study will be continued for two more years and include other plant species and properties of crops and soils in the investigation.
The effect of recycled residual paper pulp application on the yield of three plant species under variable soil and climate conditions