Effect of N, P, and K Fertilization and Stages of Maturity on Chemical Composition of Fiber in Kleingrass (Punicum coloratum L.)1
- F. M. Rouquette,
- E. C. Holt and
- W. C. Ellis2
Studies were conducted to determine the influence of N, P, and K fertilization and different stages of growth on the nutritional quality of kleingrass (Panicum coloratum L.) forage. Nitrogen rates ranged from 28 to 560 kg/ha with additions of 24 and 73 kg/ha P, and O, 46, and 139 kg/ha K. Leaf-stem separations were made at each harvest date and cellular (neutral detergent extract; NDE) and cell wall constituents (neutral detergent fiber; NDF) were determined on the plant parts. The NDF fraction was then sequentially partitioned into hemicellulose, cellulose, lignin, and ash. Levels of N or P were significantly negatively correlated with percent NDF of leaf laminae. Chemical components of stem fiber were not altered by fertility levels. On a whole-plant basis percent NDF was reduced about 5 percentage units by additions of N. Percent NDF in leaves and stems increased with chronological and morphological age. The holocellulose content of leaves remained relatively constant throughout the study period; with advancing maaturity, however, the hemicellulose fraction accounted for a greater portion of the NDF than did cellulose. The hemicellulose:cellulose ratio increased to approximately 1.7:1 in leaves, but remained at 1:1 in stems with increasing maturity. The leaves apparently had more influence on decreasing NDF of the whole plant under fertilization, whereas, stems were the dominant factors involved in increasing NDF of the whole plant with advancing maturity.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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