During the conference in Mauritius, I managed to snick out for some hours with a scientist from the sugar research institute from Mauritius and two professors from the Netherlands who have worked on sugar. Sweet like sugar, the landscape more beautiful than in any dreams, it was a fantastic field trip. I could learn so much that I felt 10 years older after it. Let me try to share this amazing experience with you.
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A mountain shaped by a volcano, with a water harvesting pond next to a sugar field |
Mauritius is a little island in the Indian ocean. Its is shaped by volcano and therefore has fantastic mountains and beaches. Next to tourism, the sugar industry is the main user of land.
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Sugar used to be the major income of the island, and used to sell its sugar mainly to Europe. There were about 23 sugar mills around the island. At that time the sugar was produced by smallholders. With time and the increase of labor price, the mechanization process started. Mechanization implied that the fields need to be cleared from the big stones, a process that was implement over many years and partly funded by EU development projects. Also these stones could then be sold on market for construction. Sugar productivity could be increased dramatically, but this mechanization resulted in more compacted soils, and therefore run-off increased. Since ever, organic waste from sugar cane is returned to the soil, and therefore soil fertility is not such an important issue in the area.
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a modern sugar mill |
In more recent years, the sugar price fell dramatically due to trade liberalization. Nowadays there are 6 mills left and soon two others will close. One third of the area under sugar cane cultivation disappeared. Some of the fields owned by commercial farms were replaced by horticulture (mainly carrots, potatoes, onions) in order to reduce the dependency of the country in terms of food. But most of the land was simply urbanized. A tiny part has been converted to grass production for golf courts.
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left overs from an old sugar mill |
Nowadays, the sugar production is very efficient, fully mechanized and processed in modern sugar mills. 60% of the land under sugar production are commercial and big farms, and 40% is owned and managed by smallholders. Because sugar needs to be processed directly after harvesting, and there are only 6 mills left, the country is divided in sections, and contracts are made with the mills in terms of delivery date and quotas. There are 9 major types of sugar cane : for each agro-ecology, namely dry, wet and very wet there is an early maturing sort, a mid maturing sort and a late maturing sort. The commercial farms hire contractors to harvest the fields, whereas smallholders are organized in groups that also hire additional labor if needed.
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a carrot field |
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a field growing grass for golf courts |
Though in the very wet area, sugar could in principle be rain-fed and is drought resistant, most of the fields are irrigated in order to guarantee the sugar content of the cane is maintained. Indeed, the sugar mills pay not per kilo of sugar cane but in terms of sugar content. The most common irrigation method is the pivot irrigation, a sort of arms up to 1 km fixed in the center of the field turning slowly, resulting in circular fields. Usually the center where the pivot is fixed, there is a pump that pumps water. Source of this water is, the water pipes coming from sources and bigger reservoirs (crater lakes) managed by the government, there are also smaller private water harvesting ponds, and near to cities, also cleaned waste water is mixed into the irrigation system. As water is becoming more and more scarce on the island, many water management methods are investigated such as drip irrigation, desalination of sea water (very expensive), increase the storage capacity (more water harvesting ponds) or depression irrigation. Depression irrigation is a method that consists to only irrigate up to 80% of the water need of the plants to allow the eventual rainwater falling in the upcoming days to be absorbed by the soil. (if the plant would be irrigated at 100%, then the rainwater could not be absorbed by the soil and would be just run-off).
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pivot irrigation |
Mauritius certainly has to adapt its agriculture to be more climate smart, to use water more efficiently, and oblige the tourists to pay for the water use (and therefore making water desalination more profitable). The conference in Mauritius has shown that the dialog between scientists, practitioners and policy-makers has started and that the solution is likely going to be a combination of different approaches.
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center of the pivot irrigation with the pump on the right |
I would like to thank Dr. Roland NG Chong, research manager at the Mauritius sugar industry research institute for having shown us his island and shared his expertise. I also would like to thank the manager of the sugar farm we visited for answering our millions of questions and showing us his irrigation schemes. Finally a thanks go to Professor Meine van Dijk and Professor John Cameron for sharing this fantastic afternoon!