Nutrient dynamics from surface‐applied organic matter amendments on no‐till orchard soil

Advancing conservation agriculture depends on understanding nutrient dynamics of organic matter amendments (OMA) no-till soil. This field incubation study compared surface-applied composted dairy manure (CM), green waste compost (GWC) and an unamended control from March to September in 2015 2016 using a RCBD California almond (Prunus dulcis) orchard. Measurements included OMA release rates, changes soil carbon (SOC), total N (TN) inorganic N, P K availability in-season sampling collection ion exchange resin (IER) membranes 0 10 cm depth, cumulative IER cores 50 depth. We hypothesized sources with lower initial C:N increase availability, greater soluble phosphorus (P) potassium (K) concentrations all SOC the greatest recovery TN pool. No differences were observed C, while rate was greatest. In-season showed no effect but differed as evidenced by adsorption extractable K. Both significantly increased TN. Net mineralization ranged 0.7% 8.0% applied pools based C:N. These results advance our conserving due practice OMA.