Effect of simulated wet spring conditions on the relative efficiency of three forms of nitrogen fertilizer on grassland

• Published in: The Journal of agricultural science 1986-08, Vol.107 (1), p.219-222
• Main Authors: Watson, Catherine J., Adams, S. N.
• Format: Article
• Language: English
• Subjects: ammonium nitrogen; dry matter; grasslands; nitrogen fertilizers; Short Note; spring; uptake
• ISSN: 0021-8596; 1469-5146
• DOI: 10.1017/S002185960006696X

There is evidence from solution culture studies that ammonium nitrogen is taken up by grass preferentially to NO3-N at low temperatures (Clarkson & Warner, 1979). In addition NH4 ions are less subject to leaching losses or denitrification (Ryden, 1982). It has been speculated therefore that ammonium N could be the best form of nitrogen for early grass, especially in wet springs. Field experiments have studied the efficiency of different nitrogen forms at the first application over a number of years (McAllister et al. 1965; Van Burg, Dilz & Prins, 1982). The yield response has tended to be variable and may have depended on climatic and soil conditions. Investigations of climatic effects on fertilizer efficiency have often necessitated long-term field studies, but it is proposed that the importance of rainfall in particular could be investigated by means of a short-term irrigation experiment. This paper reports such an experiment using irrigation to simulate a wet spring while keeping other conditions the same for all treatments.