Abstract
The viability of a ‘urea-rubber matrix’ (URM) as a slow-release nitrogen fertilizer was assessed by field trials and incubation studies. Encapsulation of urea in the rubber matrix apparently prevented the inhibition of seed germination experienced at high temperatures (> 20°C) following high urea applications. The release of urea from URM increased with temperature and was well described by a diffusion model which allowed for the temperature-dependence of both the diffusion coefficient in water and the saturated concentration of urea. Initial results suggest that the effect of varying the size of URM cuboids on both their release characteristics in moist soil and N-supply to plants is also reasonably well predicted by the diffusion model. In a ryegrass field trial over 24 weeks, the URM gave higher dry matter yields than either prilled urea or (NH4)2SO4 (following a single application at sowing) through efficient matching of nitrogen supply and crop demand.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
