Phosphorus availability from rock phosphate: Combined effect of green waste composting and sulfur addition

J Environ Manage. 2016 Nov 1;182:557-563. doi: 10.1016/j.jenvman.2016.08.016. Epub 2016 Aug 17.


Rock phosphate constitutes a natural phosphorus (P) source for organic farming systems, but with a limiting direct agricultural use due to its poor inherent reactivity. Thus, this work studies the effect of the co-composting of rock phosphate with green wastes and elemental sulfur on phosphorus availability. Six composts were prepared combining different green wastes and rock phosphate in three different proportions (0%, 0.27% and 0.54% P fresh mass basis) and elemental sulfur in two proportions (0% and 0.5% S fresh mass basis). During composting, the temperature of the mixtures was monitored, as were physico-chemical and chemical parameters, especially those related to phosphorus. The co-composting of green wastes with rock phosphate improved phosphorus mobilization and also constituted a viable method to manage green wastes, obtaining P-enriched compost for organic farming systems. Sulfur addition favored the composting process and also phosphorus solubilization, especially in the mixture with the lowest proportion of rock phosphate.

Keywords: Compost; Elemental sulfur; Organic agriculture; Organic phosphorus; Phosphorus solubility.

MeSH terms

  • Agriculture / methods*
  • Carbon / chemistry
  • Electric Conductivity
  • Hydrogen-Ion Concentration
  • Nitrogen / chemistry
  • Organic Chemicals / chemistry
  • Phosphates / analysis*
  • Phosphates / chemistry
  • Phosphorus / analysis*
  • Phosphorus / chemistry
  • Principal Component Analysis
  • Soil*
  • Sulfur / analysis*
  • Sulfur / chemistry
  • Temperature


  • Organic Chemicals
  • Phosphates
  • Soil
  • Phosphorus
  • Sulfur
  • Carbon
  • Nitrogen