Water use is another critical indicator in terms of environmental sustainability. Sugarcane is an irrigated crop in several countries and it is known for being a water-intensive product when compared to other agricultural products. Sugarcane requires between 1400 and 2500 mm of water during the crop season from planting/previous harvest to harvest.
Furthermore, the milling process also involves a considerable amount of water use for washing cane, milling, and centrifugation as well as for the production of vapour, an essential element in the various stages of the processing of sugarcane, which requires high temperatures (concentration, crystallisation). Some mills are discharging waste water into the environment after a phase of treatment.
The Bonsucro Production Standard sets maximum levels of water consumption per tonne of cane produced (agriculture) and per tonne of cane crushed at the mill (industrial). In agriculture, the maximum use of water is 130kg of water per kg of sugarcane produced. In the industrial side, the calculations consider a maximum of 20 kg of water per kg of sugar, and 30 kg of water per kg of ethanol (results presented below are combined averages), the same observation is true for industrial water use: the limits of the Bonsucro Standard are high when compared to the levels achieved by certified mills.
Water use in agriculture has improved in 2015/16 with a 48% reduction from 2014/15 levels in Australia and 34% in India, where irrigated cane is mostly present. Several factors contribute to the level of water usage, including weather conditions, or use of better irrigation techniques like drip irrigation.
The data shows that farms are over performing compared to the objective set in the Bonsucro Production Standard. The lack of operators growing fully irrigated cane reduce the ability to contextualise these data and check the evolution of farms that have run under the Bonsucro objectives for a longer time compared to the newly certified entities.
The second graph below represents the level of water efficiency achieved by Bonsucro certified farms over the past years. It shows a continuous improvement in performance levels expressed by the larger quantity of sugarcane produced by each mm of water added. It is likely due to new technologies and practices that support increase of output for each amount of irrigation water added to the cane. Irrigation efficiency has improved by 70% over the 2014-2015 period, for all farms.
The results are even better on the industrial side. Mills have consistently reduced their water usage since Bonsucro certification started and reached their lowest water consumption level in 2015 at an average 0.5 kg of water per kg of sugar or ethanol produced.
Mills have improved their results in 25% from 2014 levels, in the whole period analyse the results are impressive with a total 88% reduction since 2011.
The country analysis reveals important information on the environmental impact and shows that Brazil and Australia are the countries responsible for the overall trend of lower consumption. We observe that Australian mills are net exporters of water whereas the Brazilian mills are net importers, impacting differently the water resources of their water sheds (the first having to implement contamination prevention measures and the second one adapting their intake to water replenishment). It is nonetheless encouraging to see both countries’ certified operators reducing their pressure on water resources, with a reduction of 80% of their water consumption over their certification period.
We observe that new mills are starting to consume more water that then average of certified mills. The mills that have achieved certification more recently have however a lower level of water usage than mills that have been certified for longer.
Outcome Report 2017
This text is taken from the Bonsucro Outcome Report 2017.