Inhibitory Effect of Neem Seed Extract on Soil Nitrogen Mineralization under Chemical and Organic Amendments

Background: Improvement of nitrogen use efficiency (NUE) chemical fertilizers and N-rich-organic amendments using natural mineralization inhibitors, like neem extract, was recommended to minimize (N) loss. This study hence aimed evaluate the effects combined uses seed extract with cricket feces on soil N plant NUE. Methods: The treatment combinations included i) amending materials involving unamended (Un), fertilizer at a rate 312.5 kg ha-1, 100 P ha-1 K (CF) three rates (CrF) [3.125 (CrFlow), 6.25 (CrFmedium) 12.5 (CrFhigh) Mg ha-1], ii) in combination without (-Nm) (+Nm) extract. Amaranth (Amaranthus tricolor) employed assay plant’s Result: Neem inhibited under Un (74%) CF (84%) treatments, but not any CrF treatments (-102%, -99% -2% for CrFlow, CrFmedium CrFhigh, respectively. In addition, significantly decreased NUE parameters, including recovery agronomy NUE, only treatment. could function as an inhibitor chemically fertilized soils.