Soil moisture modulates biological nitrification inhibitors release in sorghum plants

Abstract Background and aims Sorghum ( bicolor ) is able to exude allelochemicals with biological nitrification inhibition (BNI) capacity. Therefore, sorghum might be an option as cover crop since its BNI ability may reduce N pollution in the following due a decreased nitrification. However, exudation related physiological state development of plant, so abiotic stresses such drought modify rate exudation. Hence, objective was determine effect stress on plants’ release. Methods The residual effects crops over ammonia-oxidizing bacteria (AOB) were monitored 3-year field experiment. In controlled-conditions experiment, plants grown under Watered (60% WFPS) or Moderate (30% conditions, fertilized ammonium sulphate (A), + DMPP (A+D), potassium nitrate (KNO 3 − ). Soil mineral determined, AOB populations quantified. Additionally, plant biomass, isotopic discrimination C, photosynthetic parameters measured plants. Results driest year, relative abundance by 50% at conditions. plant-soil microcosm, reduced leaf parameters, which had impact biomass. Under these exposed A treatment 25% compared treatment. Conclusion release limited water conditions ensure high soil NH 4 -N pool for uptake reduction nitrifying microorganisms.