Effects of cutting frequency and nitrogen fertilizer application on yield, proportion of crop fractions and leaf to stem ratio in guinea grass (Panicum maximum) pasture

In a sandy loam soil at Nsukka, the effects of fertilizer-N application and cutting management on the yield and proportions of crop fractions of Panicum maximum sown pasture were investigated in 2001 through 2004. The experiment was a 4 x 4 factorial laid out in a randomized complete block design with three replications. Treatments comprised four levels of nitrogen of 0, 150, 300 and 450 kg N ha-1 and four harvesting frequencies of 3-, 6-, 9- and 12-weekly intervals, resulting in sixteen treatment combinations per block. Increase in cutting interval and incremental application of N reduced the proportion of leaf to stem in the total grass dry matter yield. The proportion of inflorescence increased significantly (P < 0.05) with increase in interval between cuts in all the years. Nitrogen treatment increased significantly (P < 0.05) the proportion of inflorescence in 2002 and 2004 compared with the control. Leaf blade yield was significantly (P < 0.05) higher where N application at the 300 kg N ha-1 was combined with cutting at 6- and 12-weekly intervals in 2003 and 2004, respectively compared with when the 3-weekly interval of cut was combined with 0 kg N ha-1. Inflorescence dry matter was significantly (P < 0.05) higher where 12-weekly cutting interval was combined with 300 kg N ha-1 in 2004, compared with the 3-weekly interval of cuts at any N rate. On the whole, herbage dry matter yield was highest with 12-weekly cutting interval and with the higher N rates. [PUBLICATION ABSTRACT]