Celery Response to Type, Amount, and Method of N‐Fertilizer Application under Drip Irrigation1

Abstract

AbstractOptimizing N‐fertilization is important from both economical and environmental quality points of view. An experiment was conducted to evaluate celery (Apium graveolens L.) response to type, amount, and method of N‐fertilizer application under drip irrigation. The study was conducted on San Emigdio sandy loam (coarse‐loamy, mixed, thermic Typic Xerofluvent). Fertilizer types included ammonium sulphate (AS) and a slow release (SR) fertilizer applied to the soil before planting and urea ammonium nitrate (UAN) applied with the irrigation water during the growing season. Ammonium sulphate and SR were applied at 314 kg N/ha and UAN was applied at 168, 336, and 504 kg N/ha. Two irrigation variables were 400 and 500 mm of water application. Celery production tended to be higher under higher water application when fertilized with UAN but lower under high water application for AS and SR fertilizers. There was little difference between 336‐ and 504‐kg N/ha UAN treatments on most plant parameters throughout the growth period, but the 168‐kg N/ha UAN treatment was significantly lower than the higher application rates. Higher yields were obtained with 336 kg N/ha UAN than comparable AS and SR treatments. During early stages of growth the AS treatment tended to give the highest yield and N content but by harvest gave the lowest response. Results are explained on the basis of N availability and leaching over time.