Effect of three types of composts of olive oil by-products on growth and yield of hard wheat "Triticum durum Desf.”

The extraction of olive oil generates colossal by-products quantities; generally unexploited and causes serious environmental problems in Algeria. In tackling this problem, we performed three types of composts (C1: 50% cows manure, 50% olive husks and olive mill wastewaters; C2: 50% olive husks treated by the lime, 50% cows manure with fresh urea and olive mill wastewaters; C3: 50% olive husks, 50% cows manure and water) for five months to use them as biofertilizers for hard wheat "Triticum durum Desf." ‘Waha’ cultivar. Results obtained showed that at the end of composting, the pH stabilized at 7.29 to 7.45; however saltiness was variable. For the three composts, the organic matter was degraded and the polyphenols content decreased significantly; C2 was the compost that contains more mineral elements (N, P, K, Ca and Na). Indeed, the use of this compost as biofertilizer allowed an increase of the yield to 30.61% and an improvement of wheat growth, spikes’ number (5.25±0.3 per plant in comparison with 1±0.09 for control) and seeds (57.12±0.99 per plant in comparison with 14.87±1.88 for control).Keywords: Compost, Olive husks, olive mill wastewaters, Triticum durum Desf., Algeria.African Journal of Biotechnology, Vol 13(52) 4685-469