Availability of good quality irrigation water in sufficient quantities is becoming serious threat to world crop production.Several soil, plant and climatic factors influence B availability and uptake by crops.Farmers generally apply ground water of different SAR. Therefore it is a strong need to assess the changing B requirement with changing SAR. The objective of this research was to determine the internal and external requirements of B for maize cultivar grown on an alkaline calcareous soil when irrigated with different SAR levels to check its sufficiency range.