3 Effects of Pearl millet (<i>Pennisetum glaucum</i>) forage cropping pattern on biomass yield and in vitro NDF digestibility

Abstract

The study was conducted to evaluate four Pearl millet forage cropping pattern within the Guinea Savannah Agro-ecological zone of Ghana. Four cropping patterns (sole grass as control, grass cultivated on the borders of Pigeon pea crop, Grass cultivated as intercrop with Pigeon pea and Grass cultivated as spot in Pigeon pea) in RCBD were imposed on pearl millet forage. Agronomic data which included plant height, number of tillers, and total biomass yield was taken in both the initial establishment and regrowth. The biomass was separated into leaf, stem, and whole botanical fractions for chemical composition and in vitro NDF digestibility analysis. Cropping patterns significantly (p< 0.05) influenced all agronomic parameters except for plant height at first cut. The grass in spot cropping pattern had the highest plant height (1.48 m) at the first harvest. Meanwhile, intercropping in the second harvest produced the highest (23) number of tillers whilst spot planting in the third harvest gave the least number of tillers (8). Sole grass (control) produced the highest (1352.6 kg DM/ ha) biomass yield in the second harvest whereas spot planting gave the lowest biomass (45.6 kg DM/ha) in the third harvest. A total biomass yield of 2,755.3 kg DM/ha/annum, 1,695.7 kg DM/ ha/annum, 1,199.5 kg DM/ ha/annum and 594.2 kg DM/ ha/annum were produced for sole grass, border, intercrop, and spot respectively. In the first cut, the two-way interaction effect of cropping pattern and botanical fraction significantly (p<0.05) affected all chemical parameters except DM. The highest NDF and ADF were reported in the Whole fraction of the Spot cropping pattern and stem fraction respectively. Botanical fraction significantly (p<0.05) influenced digestibility parameters with the leaf fraction of spot planting recording the highest IVDMTD (870.4 g/kg DM) and NDFD (773.9g/kgDM) and the highest ME obtained in the leaf fraction of sole grass. The two-way interaction effect of cropping pattern and botanical fraction significantly (p<0.05) influenced all chemical parameters and ME with the highest NDF and ME recorded in the stem and leaf fractions of sole grass in the second cut. In the third cut however, botanical fraction significantly influenced all chemical parameters except DM and the two-way interaction effect of cropping pattern and botanical fraction affected all digestibility parameters analysed. The study concluded that pearl millet forage can be introduced as a border crop in a crop/livestock farming system in the savannah agro-ecological zone of Ghana.