Influence of irrigation intervals on dry matter yield, concentration of crude protein, calcium and phosphorus in Lablab purpureus and Sorghum almum fodder in the sudan savanna zone of Nigeria

Résumé

Irrigation trials were conducted in the late dry season (March to June) with Lublab (Lablab purpureus) and Columbus grass (Sorghum almum) in the Sudan savanna of Nigeria. The objective of this study was to determine the dry matter yield (IDM/ha), crude protein (CP), calcium (Ca) and phosphorus(P) in dual-purpose lablab bean and Sorghum almum at 3 irrigation schedules (5, 7 and 10 days irrigation interval). The results obtained showed dry matter yield in lablab increased (P<0.05) and varied from 1.7 to 11.7 IDM/ha. Calcium and P concentrations differed significantly (P<0.05). Mean CP for the lablab was 15.57%. Dry matter yield obtained for Sorghum almum varied (P<0.05) from 11.07 to 19.6 tDM/ha. Concentration of CP and Ca rose and declined thereafter with a mean concentration of 9.86% for CP und 0.08% for Ca while P declined consistently (P<0.05). Intervals of irrigation days had a relationship (P<0.05) with DM/ha, Ca and P in lablab. The increasing trend in foruye yield with increased irrigation interval showed optimum irrigation interval was not attained. It is therefore recommended that longer irrigation intervals be tried to determine the optimum irrigation interval after which forage yield would be depressed due to moisture stress. From the results of the present study Sorghum almum and lablab would be grown successfully at a 10-day irrigation interval.