Impact of Rice Straw and Biochar Compost Treated with Olive Mill Wastewater on some Sandy Soil Properties, Nutritional Status and Yield Productivity

Create highly nutritious compost. Four compost piles were constructed from farmyard manure (FY) with either biochar (Bc) in piles B and D or rice straw (RS) in piles C and E. All piles received urea, rock phosphate and feldspar, while their humidity's were maintained at 60% using either tap water (TW) B and C or olive mill waste water (OMWW) D and E. Compost piles were enriched with Trichoderma harzianum, Pleurotus eryngii, Bacillus polymyxa and Bacillus megatherium. During composting process piles containing RS reached maturity parameters sooner than those containing Bc. Themature compost from pile (E) FY+RS+ OMWW was superior in nutrients content (N, P, K) and humification parameters, includes humic acid content (HA%), humification ratio (HR) and humification index (HI), as compared to other compost piles. The mature composts were applied as organic fertilizer in sesame and soybean field experiments carried out in sandy soil. Composts application of RS (C and E) or Bc (B and D) using two application rates increased soil moisture content compared to control treatment (without compost application A). Soil pH values nearly decreased while salinity (EC) values increased by applying the composts at the higher rate of 10. 0 Ton ha-1 in descending order E > C > D > B >A. Soil organic matter (OM) content increased with the high rates of compost application as compared to control. Among both crops, rice straw compost was significantly superior in N, P and K availability and crop yield component (straw and seeds).