General Commission for Scientific Agricultural Research-
GCSAR/ Horticulture Research Administration
Mediterranean Agronomic Institute “CIHEAM” Bari- Italy,
The synchronization between nutrients release and plant demands even in organic agriculture is a major challenge to provide the plant with necessary nutrients at critical stages. Compost has aslow release-over a longer period, compared to the immediate availability of chemical fertilizers. Since organic farmers do not use synthetic nutrients to restore degraded soil, they must concentrate on building and maintaining soil fertility primarily through their basic farming practices. They depend on multicropping systems and crop rotations, cover crops, organic fertilizers and minimum tillage to maintain and improve soil quality. The natural fertilizers they use, such as green manure, farmyard manure, compost and plant residues, build organic content and increase the soils capacity to circulate nutrients, air and water The experiment tried to develop a procedure to extract more organic matter from compost by alkaline solutions instead of water in compost tea to get compost extract richer in nutrients. Two extraents KOH, KHCO3 were applied in three concentration: 0.25, 0.50, 1.00 N on composts from different raw materials N2PLUS, PULA, at three ratios 1:10, 1:20, 1:40 for two periods 24h, 48h. The comparison among the treatments depended on organic carbon and total nitrogen content. The best results was obtained by using KOH with the highest concentration (1N) with N2PLUS compost ,when the solution was more concentrated (1:10 ratio), for a longer time (48 hours).