Effectiveness of neem materials and biochar as nitrification inhibitors in reducing nitrate leaching in a compost-amended Ferric Luvisol

The nitrates produced after mineralization from compost may be prone to leaching, especially in tropical sandy soils, because of the increased rate nitrification and porous nature such soils. This result low nitrogen (N) use efficiency adverse environmental effects. Inorganic inhibitors are costly mostly unavailable Ghana. Research on simple but effective local materials for as is therefore a priority. Two neem biochar. Neem can suppress nitrifying bacteria due their antimicrobial properties. Biochar hold ammonium soil, making it temporarily bacteria. study aimed determine efficacy biochar influence nitrate leaching. In preliminary studies: 1) pot incubation was conducted 60 days estimate with manure, compost, NH 4 Cl N source (150 kg N/ha) one set seeds, bark, leaves (1.25 µg azadirachtin/g) another set, using concentrations; 2) sorption desorption capacities sawdust, rice husk, groundnut husk were determined. main study, treated milled seeds or bark sawdust (20 t/ha) days, which inhibition determined concentrations. A leaching experiment columns similar treatments maize sown then quantify leachates. high recorded compost-amended almost half that standard (NH Cl). biochar, showed highest capacity, resulted 40% lasted entire period. an azadirachtin concentration 3.92 mg/g inhibition, this only 40 days. Inhibition caused by both about 60% reduction leached. Thus, (498 kg/ha) mt/ha) could used control short-duration long-duration crops, respectively.