EFFECT OF HARVESTING DAYS, CROPPING YEAR AND FERTILIZER LEVELS ON AGRONOMIC PERFORMANCES, NUTRITIONAL QUALITY AND ECONOMIC FEASIBILITY OF WASHO GRASS (Loudetia arundinacea)

Abstract

A field experiment was carried out to study the effect of fertilizer levels, cropping year, and harvesting days on the agronomic traits, forage yield and chemical composition of Loudetia arundinacea. Two crop years, three nitrogen fertilizer amounts (75 kg, 100 kg, and 120 kg urea/ha), and three harvesting days (60, 90, and 120 days) were employed in a 2×3×3 factorial randomized complete block design. Data on number of tillers per plant, number of leaves per plant, leaf length, plant height and dry matter yield were collected. Similarly the chemical composition and in vitro dry matter digestibility data were determined. Fertilizer levels and harvesting days had significant effect (P < 0.05) on the agronomic data and nutritional values of the grass. The DM, ash and fibre fractions (NDF, ADF and ADL) were significantly higher (P<0.01) at 120 kg/ha nitrogen fertilizer level and 120 days of harvest. The contents of CP (crude protein), IVDMD, DOMD and Metabolizable energy were significantly higher (P<0.01) at 75 kg/ha fertilizer level and 60 days of harvest. Plant height, crude protein yield, leaf to stem ratio, leaf length and herbage yield were significantly higher (P<0.05) at 120 kg/h fertilizer levels. Similarly plant height, number of branches, leaf number and Inter node length were higher (P<0.05) at 120 days of harvest. Combined analysis of data for fertilizer levels, harvesting days and cropping year resulted significantly different (P<0.001) results on grass DM, CP, Ash, NDF, ADF, ADL and IVDMD contents. Except DM and Crude protein contents, Ash, NDF, ADF, ADL and IVDMD are significantly (P<0.05) influenced by grass growing years. Results from this study revealed that fertilizer, harvesting days and cropping years have significant influences on agronomic performances and nutritional quality of washo grass. Similarly, year and harvesting days interaction had significant (P<0.01) effect on all chemical composition parameters. Moreover, the outcome showed that applying fertilizer at a rate of 120 kg per ha may generate more forage with a higher marginal rate of return with a value of 262.86 as compared to applying fertilizer at a rate of 75 to 100 kg per ha for forage production.