The quality of crop fractions of a degraded Panicum maximum pasture under different cutting intervals and nitrogen fertilizer rates

摘要

The effects of cutting frequency and levels of nitrogen application on quality of crop fractions of a degradedPanicum maximum?pasture was investigated in 2001 at Nsukka, Nigeria. Cutting intervals consisted of 3, 6, 9 and 12 weeks, while N rates were 0, 150, 300 and 450 kg-N ha-1. The percentage of P in the leaf, Na in all the fractions, Fe in the leaf and stem fractions, ash in the leaf and Zn in the leaf decreased significantly (P < 0.05) with increased interval between cuts. Nitrogen application increased significantly (P < 0.05) the percentage of P in all the fractions, and the percentage of Fe, K and Zn in the leaf compared with the control. Cutting every 3 weeks produced significantly (P < 0.05) higher concentrations of iron in the leaf and stem fractions than the other cutting intervals with application of 300 kg-N ha-1. The percentage of crude fibre in the stem increased significantly (P < 0.05) from 46 to 60% when the interval between cuts was increased from 6 to 9 weeks, while there was a 6% reduction in the crude fibre content of stem when nitrogen fertilizer was increased from 150 to 300 kg ha-1.