Field comparison of traditional and slow releasing nitrogen fertilizers
Slow release fertilizers are a possible alternative to traditional fertilizers. With growing environmental concerns slow release fertilizers are a potentially more efficient method of delivering nitrogen (N) fertilization. Slow release fertilizers have been used for high-value crops, but, only recently, new formulations have been produced and are being re-introduced into row crop production. A two-year field trial was conducted to assess the effect of a urea-formaldehyde (Nitamin) slow release fertilizer on grain and biomass yields, and the corresponding amounts of N uptake, in corn in 2004 and 2005. To accomplish this, fertilizer rates of 0, 56, 112, 168, and 224 kg N ha−1 were used of both Nitamin and urea ammonium nitrate (UAN) fertilizer materials. The results obtained showed great variation between the two years of the study. In 2005 there was a significant increase in grain production when Nitamin was used as an N source. There was also a statistically significant increase in N uptake in Nitamin treated plots and a trend toward higher biomass production and N uptake in biomass in urea-formaldehyde treatments. In 2004 grain production was affected by N rate with trends favoring UAN fertilization. When all experimental data were analyzed there was a significant increase in grain production in plots receiving Nitamin fertilizer treatment.