Effect of Rose Wastes on Salinity and Heavy Metals Reduction in Compost and Soil

In recent years, salinity and pollution due to municipal solid waste compost, has caused many problems. The main purpose of this research is to investigate the effect of mixing rose greenhouse waste with urban waste on the quality of produced compost and the chemical and physical properties of the soil after using this fertilizer.

 An experiment in CRD design as factorial was conducted to investigate the effect of Rose greenhouse wastes on quality of compost with two factors consisted of 1) waste type with 2 rates: a) separated and b) unseparated waste) and 2) amendment ratio with 3 rates: a) 100% waste-0% amendment, b) 80% waste-20% amendment and c) 60% waste-40% amendment, with three replications. Then a field experiment based on CRD, with 7 treatment (consisted of soil mixed with six types of produced compost in previous stage and control) and 3 replications was conducted to investigate the effects of produced compost on some characteristics of soil.

Results showed that the separation of wastes at the source, increased compost nitrogen by 2.75 times, cation exchange capacity by 4.14 times, phosphorus by 2.14 times, water holding capacity by 2 times and organic carbon by 69% compared to the non-separation. But reduced available potassium, pH and sodium of the compost. In soil, it also reduced bulk density, salinity, and cadmium and lead concentrations, and increased soil MWD. Adding Rose greenhouse waste in rate of 40%, reduced compost EC by 58% campared to control. It also reduced available sodium and potassium and increased pH of the compost. In soil, reduced bulk density, salinity and concentration of lead and cadmium. Treatment of soil and separated compost with 40% of amendment, increased soil Si by 0.078 unit and soil organic carbon by 32% compared to the control.

Results showed that separation of wastes at the source and adding Rose greenhouse waste can improve physical and chemical properties of compost and soil.