| The new radio telescope of the LOFAR (Low Frequency Array) project is based on tens of thousands of antennas that are connected to each other with a large ICT infrastructure. LOFAR_Agro will make use of this infrastructure and has chosen as its first application the measurement of the micro-climate in potato crops. This information will be used to improve the advice on how to combat Phytophtora within a crop, based on the circumstances within each individual field. Phytophthora is a fungal disease in potatoes, which can enter a field through a variety of sources. The development and associated attack of the crop depends strongly on the climatological conditions within the field. The factors that are most important indicators for the development of Phytophtora are: temperature, humidity and whether or not the leaves are wet. Sensors with wireless communication capabilities are being developed right now and are generally expected to be as small as a fertilizer pellet by 2010. Further miniaturization is likely and these sensors may ultimately resemble dust. Prices are expected to decrease to about one dollar each. The Phytophtora project will make use of Motes, which consist of a radio transmitter and a sensor board. The radio works at a frequency of 433 MHz and can cover distances of up to 15-30 meters. The sensor part of the Mote, measures air pressure, temperature, relative humidity and illumination. Because the humidity of the soil is also a major factor in the development of the microclimate, a number of sensors that measure soil humidity will also be included in each field. About a hundred motes will form a network within a field. These motes will pass information to each other which will ultimately be gathered together at a collection point known as a Field-Gateway at the edge of a field. The information from a local meteorological station will be added to the data stream. The wireless sensors are capable of determining their relative positions within the field, so that it is automatically known for which part of the area under study the microclimate applies. The Agro Server collects the data streams from the Field Gateways on the different parcels of land. The information is checked and stored in a database, together with any other relevant data that is available. Users may be granted (restricted) access to the data on the Agro Server, which may also be pre-processed on the server before it is made available. The decision support system (DSS) which helps the farmer to combat Phytophtora in his crop, gathers the information from the meteorological station and the wireless sensors from the Agro Server. Based on this information maps will be made of the temperature distribution within the fields, as well as other quantities. Together with the weather forecast this information will be used by the DSS to develop a strategy on how the disease can best be prevented or controlled. It will alert the farmer of patches within his fields which are most susceptible and can be used to gauge the steps that need to be taken. |
