Chemical Composition of Cotton Plant Biomas.

Cotton is an important crop in the southern and southeastern parts of USA. Although lint is the most valuable part, other biomass materials of the cotton plant are also useful as soil amendment, animal feed, bioenergy source, and certain industrial raw materials. In this study, whole cotton plants were collected at mid-season and just before harvest. These plant samples were separated into six (mid-season) or eight (pre-harvest) biomass fractions: main stems, leaf blades, branches, petioles, roots, and the reproductive part (or bur, peduncles+bracts, and seeds). The contents of macro (P, Ca, K, Mg, Na, and S) and micro (Fe, Zn, Cu, and Mn) elements, crude protein, acid detergent fiber, neutral detergent fiber, and acid detergent lignin in these biomass fractions were determined using standard procedures. We found growth stage affected the relative contents of some, but not all, measured parameters. Regression analysis revealed that the contents of some parameters were well correlated with each other, but other parameters were quite independent of each other. The information reported in this work would be helpful in exploring and optimizing management practices and processing strategies in utilizing these cotton crop biomass materials as valuable and renewable natural resources.