Urban Waste Compost: Effects on Physical, Chemical, and Biochemical Soil Properties

TLDR

The study aimed to assess how urban waste compost affects the physical, chemical, and enzymatic properties of a calcareous soil. A long‑term field experiment measured soil porosity, organic carbon, heavy metal content, and enzyme activities after compost application to Fluventic Xerochrept soil. Compost increased porosity, organic carbon, Pb, Cu, and Zn, and enhanced enzymatic activities, with several enzymes positively correlated with porosity and negatively with bulk density, demonstrating improved soil health without heavy‑metal inhibition.

Abstract

Abstract A long‐term field experiment was conducted to determine the effect of the additions of urban waste compost on the physical and chemical properties and enzymatic activities in a calcareous soil (Fluventic Xerochrept). Total porosity (pores >50 µm measured on thin soil sections from undisturbed samples by image analysis) was greater in the plots treated with compost than the control plots due to a larger amount of elongated pores. In the amended plots total and humified organic C, Pb, Cu, and Zn showed a significant increase compared with nonamended plots. Enzymatic activities (L‐asparaginase, arylsulphatase, dehydrogenase, phosphodiesterase, and alkaline phosphomonoesterase) were significantly enhanced by the compost addition thus indicating no inhibiting influence of the heavy metals present. The increased levels of the arylsulphatase, dehydrogenase, phosphodiesterase, and phosphomonoesterase activities were significantly correlated with total porosity: the first three with pores ranging from 50 to 1000 µm, mainly with pores 50 to 200 µm in size, and phosphomonoesterase only with pores whose size was <500 µm. L‐asparaginase activity was not correlated with porosity. Only arylsulphatase, dehydrogenase, and phosphodiesterase were negatively correlated with bulk density.