EVALUATION OF IRON CONTENT IN A POTENTIAL FODDER CROP OAT (AVENA SATIVA L.) GROWN ON SOIL TREATED WITH SUGARCANE FILTER CAKE

The effects of different doses of sugarcane filter cake (SFC) on iron concentrations in the leaves of varying age of a potential fodder crop oat (Avena sativa L.) are reported in this study. Nine different treatments of SFC used were: 0 (control), 600, 900, 1200 and 1500 kg/ha applied to soil as full doses before sowing, and 600, 900, 1200, and 1500 applied as two equal splits, Ist before sowing and the 2 nd before flower initiation. Samples of soil were taken just after mixing the appropriate dose of SFC, whereas those of leaves were taken at the vegetative stage (45 days after sowing; hereafter they are referred as early leaves) and at the grain filling stage (hereafter referred to as late leaves). Iron (Fe) concentrations in soil and leaf samples (early and late) were determined unconnectedly. Soil Fe content increased significantly due to soil amendment with filter cake and it was well above the known critical level (2.5 mg/kg). In contrast, although soil amended with SFC improved the Fe content of both early and late leaves, their Fe content was well below the normal requirement of grazing animals. Thus, the ruminants feeding on this fodder species growing on soils amended with SFC are prone to experience Fe deficiency. Mineral supplementations containing reasonable amount of Fe sources are recommended to prevent complications caused by Fe deficiency as well as to achieve an optimal animal production of ruminants being reared on the pasture.