The development and assessment of a direct energy calculator for use in sugarcane production.
The rising cost of energy coupled with an increasing awareness of Greenhouse Gas (GHG) emissions has led to a concerted effort to reduce fossil fuel Energy Use (EU) in all sectors. Sugarcane production in South Africa is dependent on fossil fuel to provide a source of energy for production. To remain commercially and environmentally sustainable, measures need to be taken to reduce EU and increase EU efficiencies of on-farm operations. The first step toward realising this is to identify and quantify energy inputs. Following on from this, total GHG emissions, also known as carbon footprint, can be estimated. The primary objective of this research is to develop an energy calculator to estimate EU in sugarcane production in South Africa. The results generated by the calculator highlight areas of high energy intensity and low energy efficiencies at three different levels of detail. Based on these results, changes in management practices and technological improvements can be made to reduce EU and carbon footprint. Case studies were used to test the functionality of the calculator. Results from the case studies show that, in irrigated sugarcane production, the harvest and transport process together with irrigation account for a majority of the total on-farm EU. For one of the case studies, an estimated 20 % saving in the total on-farm EU was identified and can be achieved if appropriate technology is adopted in irrigation practices. Less significant energy savings were realised when in-field tractor operations were optimised for best tractor-implement matching. It is envisaged that the energy calculator will help farmers minimise on-farm EU and subsequently reduce input costs and carbon footprint. It will also provide a valuable tool for researchers to benchmark and profile EU in sugarcane production in South Africa. Research focussed on the sustainable production of sugar, from the agricultural to milling phase is of high priority at present. The quantification of on-farm EU in sugarcane production will form a critical component of such research.