Zeolites Regulate Nitrogen Release From Manure-Amended Soil.

Manure-zeolite amendment of soil has recently been evolved as a novel approach to minimize reactive nitrogen formation and loss from agricultural fields. Zeolites are nanoporous secondary minerals having a high selectivity for cations especially ammonium ion which could be used for slow release of nutrients through organo-zeolite mixture concept. To study the effects of zeolite on regulating nitrogen release, a lab incubation study using dairy manure mixed with naturally mined zeolite (such as Clinoptilolite) was conducted at the Ohio State University South Centers at Piketon, USA during August and September of 2011. Zeolite and manure treatments were: Manure at 50-g oven-dried equivalent (M50); Zeolite + Manure at 1:5 ratio (ZM_1:5), ZM_1:10, ZM_1:15, ZM_1:20 and ZM_1:30, respectively mixed with soil and replicated 6 times. The zeolite-manure amended soil in different treatment combinations were incubated at room temperature (~25 ⁰C) for 7 days. The replicated samples of zeolite-manure treatments were taken every day over a period of 7 days and ammonium and nitrate concentration was measured calorimetrically. Results showed that the ZM1:15 had steadily and consistently release ammonium with a non-linear (parabolic) dynamics over time.