August 28, 2024
A massive surge in fertiliser prices in 2021/22 had given rise to an award-winning study on the possible use of less nitrogen (N) on sugarcane without compromising profit.
SA Canegrowers’ Industry Affairs Manager, Dr Muhammad Kadwa, in collaboration with Economic Research Manager, Richard Nicholson and the South African Sugar Research Institute (SASRI) authored the paper titled: A simple economic sensitivity analysis of nitrogen application rates: a case study using ratoon trials under irrigated and rainfed conditions in South Africa.
Kadwa presented the paper at the latest International Sugar Cane Technologists (ISSCT) Agriculture Commission Workshop held in Chonburi, Thailand. The theme for the workshop – which was its first since the Covid-19 pandemic – was “Towards bio-circular-green (BCG) economy, smart farm to drive economic recovery and sustainable sugarcane industries”.
In the paper Kadwa, and his co-authors, used a simplistic economic analysis to examine the sensitivity of nitrogen fertiliser and costs, compared with income, using ratoon crop response data from research trials. Sugarcane and sucrose yield (unpublished) data from several nitrogen trials held over the past 15 years by the institute for irrigated and rainfed growing regions formed the basis for the study.
As the South African sugar industry uses the Recoverable Value (RV) system for cane payments, the sucrose and cane yields were converted to approximate RV yields with gross income estimated at three different RV price levels. The cost of the nitrogen application was zero for untreated control treatments and assumed the same for all other nitrogen rates. Income comparisons were made with low, median and high nitrogen prices over three recent years.
The results of the study suggest that growers should consider both the prevailing RV price and the nitrogen price when determining the rate of nitrogen applications in their fields together with the impact of reduced nitrogen applications on subsequent ratoons.
In the study abstract, Kadwa contends that the analysis provides a snapshot of nitrogen application rates at different RV Price and nitrogen price levels and that there would be value in carrying out commercial-scale tests on grower-operations to help guide and develop site-specific guidelines.
