Jon Howcroft looks at how GPS and GIS technology are helping to boost farm productivity, while minimizing damage to the environment in eastern Sudan
Golder Associates Africa has introduced the first auto-steer tractor on the continent, to Agadi farm, an 80,000 ha rain-fed farm in Blue Nile state in eastern Sudan. The tractor is fitted with a GPS satellite guidance system that takes control of tractor steering and can maintain a preset course accurate to within 10 cm. The auto-steer unit has already helped reduce the average planting time on the Agadi farm by 60% compared with the previous two seasons.
During the past four seasons, Golder has been working with ASBNACO, a Sudan-based company that manages the Agadi farm, and the Arab Authority for Agricultural Investment and Development (AAAID), which has provided finance for testing the autosteer unit as well as technical support.
The Agadi project
The Agadi project is coordinated by the Precision Farming Unit (PFU), whose aim is to introduce site-specific farming, using GPS and GIS-based technology, for the commercial mechanized farming sector in Sudan.
The PFU has set up a GPS farm survey section that produces accurate base maps for use in GIS systems. It has also undertaken spatial yield monitoring using GPS field monitors installed in combine harvesters. These monitors record yield variations within each field and produce yield maps for each section of land harvested. Yield maps are produced annually so that farmers can identify areas of high and low productivity on their farms. The yield maps can also be processed and used to guide applications of fertilizer, seed and agro-chemicals.
Moreover, the unit has successfully introduced ‘controlled traffic farming’ (CTF) using GPS-based self-steering tractors. CTF restricts the movements of tractors to deliberately chosen ‘lanes’ within the field so that operations occur sequentially in the same wheel tracks, thus reducing soil compaction and erosion and improving efficiency by eliminating overlaps when sowing seed and applying chemical sprays.
The unit is currently developing a GIS-based farming information and management system. Future plans include the introduction of infrared photography and variable rate application (VRA) technology, both of which will have environmental and efficiency benefits. Infrared photography will be used to identify weed infestations, and areas suffering from water stress or crop pest outbreaks. In the latter case, chemical applications can be specifi cally targeted, thus reducing the wastage incurred with conventional blanket spraying. Using VRA, fertilizers, chemicals and seed are applied at rates derived from the previous seasons’ production figures and chemical analyses of the soil. For example, a variable-rate monitor installed on a tractor can use fertilizer maps to increase or reduce fertilizer dosages. This helps to even out yield variations, reduce fertilizer wastage and prevent unnecessary groundwater contamination.
Other techniques such as conservation and zero tillage have also been introduced to boost productivity. Zero tillage, where seed is sown directly into the ground without ploughing, harrowing or chemical weed control, has proved to be an ideal way of managing Agadi’s soil and weed problems. The farm’s soils have a high clay content - they are slippery and almost unworkable when wet, but become hard and crack when they dry out. As a result, they require special management skills to obtain profitable yields. By using a sophisticated zero tillage method for planting seed and for distributing fertilizers, soil disturbance has been kept to a minimum, tractor power requirements and fuel consumption have been cut significantly, and weed pressure has also been reduced as fewer weed seeds are buried or exposed. For three seasons, zero tillage has resulted in crop yields significantly higher than those achieved locally using conventional techniques. Golder has now started a farmer support project to introduce these new methods to other farmers in the region.
The innovative precision agriculture technology introduced at Agadi farm has generally helped to make farming practices more efficient. Planting times have been reduced by 60%, the area of plant cover has improved by 3.5%, and the cost of spraying herbicides has been cut substantially. However, precision farming in Agadi still faces a number of challenges. Special care is needed, for example, to ensure the reliable operation and maintenance of highly specialized equipment in the harsh conditions of this remote region. Greater efforts are also required to provide training for local technicians in the use of GPS equipment and the operation of GIS soft ware. Attention is also being given to assessing the way precision farming systems can be effectively integrated into current practices, or even replace them.
Plans have been made to expand this project significantly. However, precision farming must become more widely accepted before its potential can be fully exploited in other large-scale projects in the area, such as the Gezira irrigation scheme (800,000 ha) and the Kenana sugar estates (170,000 ha). For now, precision farming will continue to play a vital role in establishing an integrated management information system for Agadi farm, particularly if sufficient funding becomes available for such high-tech farming applications.
Jon Howcroft ( firstname.lastname@example.org ) is head of the Agribusiness and Rural Development Unit, Durban Offi ce, Golder Associates Africa (Pty) Ltd. For more information about the Agadi farm project, visit http://www.golder.com or http://www.aaaid.org.