August 2019
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Objective: to provide a practical demonstration of how olive oil mill wastewater and pomace can be used for agricultural purposes on land growing woody or annual crops, thus providing a rational answer to the problem of wastewater and preventing its discharge into urban infrastructures and/or surface water courses.

Project executing agency: L. Di Giovacchino from the Experimental Olive Oil Technology Institute of Pescara.

Countries involved: Algeria; Morocco, Syria and Tunisia.

Sources of financing: CFC/IOC

Duration: 3 years

Project starting date: July 2002


The purpose of this project is to provide a practical demonstration of the utility of recycling olive oil mill vegetable water (wastewater) and pomace on agricultural land growing tree crops or annual crops. It will be carried out in four southern/eastern Mediterranean olive-growing countries where olive production is high, or will be so in the near future, and where the soil has a relatively poor content of organic matter.


  • A rational solution will have been found to the problem of the disposal of the wastewater produced by olive oil mills.
  • The disposal of wastewater into urban sewerage or into surface watercourses, which aggravates environmental pollution, will be avoided. Vegetable water and composted olive pomace will be used as conditioners and fertilisers for agricultural land in order to raise crop productivity.
  • Consumption of chemical fertilisers will have been reduced, with the ensuing benefits for the agricultural economy and the environment.


In many olive-growing countries, even in some of the most advanced ones, the solution found to vegetable water disposal is irrational and environmentally damaging. Specifically, the waste is run through channels or collected in artificial ponds that give off a bad smell with time and that are dangerous because of the possibility of polluting any water-bearing strata in the subsoil owing to soil infiltration.

The best way to protect the environment and to take advantage of the soil conditioning and fertilising properties of vegetable water and olive pomace is through controlled spreading on cultivated agricultural land. This practice is permitted in some olive-growing countries where it is regulated through appropriate legislation that specifies the maximum quantity of vegetable water or pomace that may be spread on the land and the ways in which it may be spread.

The proposal is to identify two areas in each country where plots can be established to demonstrate the uses of vegetable water and olive pomace on agricultural land growing olives, vines, and if possible, annual cereal or oilseed crops, with the goal of heightening the awareness of olive oil millers and olive growers to this question.

These plots will be monitored and inspected for at least three years by technical personnel specialised in the tree crops grown who will be entrusted with carrying out periodic surveys to determine how the treatment affects plant and fruit growth.


  • Positive effects on the vegetative development of the plant, or of the herbaceous crop, following controlled spreading of different quantities of vegetable water or olive pomace compost on cultivated land.
  • Positive effects on crop productivity.
  • Reduction, or elimination, of the use of synthetic chemical fertilisers for fertilising the cultivated land, which are replaced efficiently by the organic and mineral matter supplied by the vegetable water or olive pomace compost.
  • Improvement of the structure and chemical composition of the soil by increasing the organic matter and achieving a more balanced C/N ratio.
  • Conservation, or enhancement, of the species and number of soil microflora and microfauna.


This project has been approved for funding by the Common Fund for Commodities