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Retention of Maize on Farms

SiQ was appointed by the Maize Trust to conduct a survey to obtain accurate figures and trends regarding the storage capacity and retention of maize on farms. The time frame of the project was 3 years which started in March 2008. The reason for obtaining an accurate figure for the retentions of maize on farms was to assist in verifying the accuracy of the crop estimate figure as published by the Crop Estimates Committee (CEC).

The aims of the project were:

  • To determine the spatial location of all the South African Grain Information Service's (SAGIS) registered premises.
  • To develop a list frame of all the producers with storage capacity (non-commercial) and to determine the spatial location of the farms.

The first and one of the most important steps in ensuring the success of the project was to have discussions with all the relevant stakeholders to obtain their commitment and support towards the project. The development of a communication strategy was also vital to ensure the collaboration of the producers.

Satellite (SPOT 5) and aerial imagery were utilized to determine the spatial location of SAGIS's registered premises. Agricultural businesses and SAGIS also assisted with these physical addresses and locations.

The main focus of the project was to develop a comprehensive list frame of all the producers with storage capacity (non-commercial) on their farms.
Software was developed to assist with the capturing of the data of the producers. A questionnaire template was designed in MS Access that was linked to the GIS software with a hyperlink. When a new point of a producer with storage facilities was created in the GIS software, it was possible to link to the MS Access questionnaire to capture all the relevant details. Agricultural and farmers unions were contacted through Grain SA’s structures and meetings arranged with them. Large hardcopy maps of the areas were taken to the meetings and the producers asked to locate their farms if they had storage capacity and to verify their data. This data was then captured later on the GIS software.

Once a list of producers was compiled the quality assurance process was extremely important to remove any possible duplications or inaccurate data.

The list of producers with storage capacity was then used to contact the producers to determine the actual amount of maize that was retained on their farms at a given time and to obtain their total storage capacity. The telephonic survey was conducted once a year by trained personnel with knowledge of the agricultural industry.

The total storage capacity (excluding silo bags) of the November 2011 telephonic survey was 1 657 773 tons, representing on-farm storage facilities (non-commercial) of approximately 2 000 producers.

"When a new point of a producer with storage facilities was created in the GIS software, it was possible to link to the MS Access questionnaire to capture all the relevant details."