INVESTIGATION INTO YIELD REDUCTION OF SUGARCANE PLANTATION OF THE SAVANNAH SUGAR COMPANY
1.1 Background of the Study
Brady and Weil (2015) defined soil quality as the capacity of a specific soil to function, within natural or managed ecosystem boundaries, to sustain plant and animal productivity, maintain or enhance water and air quality, and support human health and habitation. Thus, soil quality assessment reflects biological, chemical, physical properties, and engineering processes, and their interactions within each resource unit (Karlen et al., 2011).
Sugarcane grown under irrigation in arid and semi-arid region is frequently adversely affected by soil salinity. The crop is moderately sensitive to salinity, with threshold for yield reduction at 1.7 dS/m (Golabi et. al, 2015). The Salinity in the root zone of sugarcane decreases sucrose yield, through its effect on both, biomass and juice quality (Lingle and Wiegand, 2016). The salinity of soil or irrigation water reduces sugar stalk yield by reducing both the stalk population and weight. Wiegand et. al (2016) found that each dS/m increase in the root zone salinity decreases stalk population by 0.6 stalk/m2 and individual stalk weight by 0.15 kg, resulting in a stalk yield decrease of 13.7 t/ha. It has been estimated that globally, approximately 40% of land under irrigation is salt-affected (Moore, 2014; Shannon, 2014). This problem is prevalent in soils under irrigated sugarcane (Saccharum sp.), especially in areas of low rainfall and high evaporative demand (Haynes and Hamilton, 2015).