Pangola Digitgrass Yield and Nutrient Uptake with Liquid and Solid N‐P‐K Fertilizers1

Abstract

Abstract‘Pangola’ digitgrass (Digitaria decumbens Stent.) is an important tropical and subtropical forage species which responds dramatically to N fertilization. Responses to the application of P and K, however, or the combinations of N, P, and K are not as clearly defined. Its response to N, P, and K applied in solution has not been established. A 2‐year study to compare the effect of the application of liquid and solid N‐P‐K (9:1:4) fertilizers on digitgrass production and nutrient uptake was conducted on a Wabasso sand (siliceous, hyperthermic, Alfic Haplaquod) on the Deseret Ranches in Central Florida. There was a positive linear relationship between the amount of N‐P‐K fertilizer applied and the amount of forage produced. The concentrations of N and K were positively affected by increased N‐P‐K levels while P concentration was negatively affected. A positive linear relationship was also observed between the uptake of N, P, and K and the rate of application. The liquid fertilizer produced an average of 20.9 and 21.4% less forage than the solid for 1980 and 1981, respectively. Solid fertilizer maintained a higher N concentration in the forage than the liquid, but no differences in P and K concentrations were observed with the two forms of fertilizer. The forage treated with solid fertilizer averaged 24, 35, and 59% higher relative uptake of N, P, and K than the forage treated with liquid fertilizer, respectively. Under the conditions of the study, ammonia volatilization was probably the major reason for lower yields, N concentrations, and N uptake from the use of liquid fertilizer. The lower uptake of P and K with liquid fertilizer was associated with the lower yields obtained with this source.