Publication Date

1993

Description

Coastal bermudagrass (Cynodon dactylon L. Pers.) is an important warm-season perennial grass in the Southern Piedmont of the USA. It has a high production potential, a consequent high N fertiliser requirement and is often recommended as cover for waste management systems. Forage NO3-N was correlated with dry matter yield, and drainage water with NO3-N concentration. Log forage NO3-N was significantly correlated with yield (R2=0,83) and with log soil water NO3-N (R2 .. 0.76) (P<0.01). Yields of bermudagrass associated with accumulation of IO mg NO3-N/I in shallow ground water were less than 75% of maximum, Bermudagrass growth modelling studies suggest that about 50% of maximum yield is the point of greatest N­use efficiency. This may approximate the upper limit of N application for the long term if excessive NO3-N concentration in shallow ground water Is to be prevented. Forage tissue testing for NO3-N may be useful for indicating when N-use efficiency is declining and when excess NO3-N accumulation in the soil may be expected.

Share

COinS
 

Use of Forage Nitrate-Nitrogen to Improve Nitrogen-Use Efficiency in Coastal Bermudagrass

Coastal bermudagrass (Cynodon dactylon L. Pers.) is an important warm-season perennial grass in the Southern Piedmont of the USA. It has a high production potential, a consequent high N fertiliser requirement and is often recommended as cover for waste management systems. Forage NO3-N was correlated with dry matter yield, and drainage water with NO3-N concentration. Log forage NO3-N was significantly correlated with yield (R2=0,83) and with log soil water NO3-N (R2 .. 0.76) (P<0.01). Yields of bermudagrass associated with accumulation of IO mg NO3-N/I in shallow ground water were less than 75% of maximum, Bermudagrass growth modelling studies suggest that about 50% of maximum yield is the point of greatest N­use efficiency. This may approximate the upper limit of N application for the long term if excessive NO3-N concentration in shallow ground water Is to be prevented. Forage tissue testing for NO3-N may be useful for indicating when N-use efficiency is declining and when excess NO3-N accumulation in the soil may be expected.