Use of sensors and spatial variability to fertilization management in processing tomato

One of the main problems in fertilization management in commercial plots is the lack of technical knowledge in the adjustment of the crop fertilization requirements in relation to its production, phenological moment, and the spatial variability. In this sense, the objective must be to establish methodologies and sensors that can help to establish a more adjusted crop fertilization need in each area and during all crop cycles with the aim of more efficient crop production. However, technicians do not have sufficient knowledge of these techniques and these measures are strongly influenced by spatial variability. To reduce these problems, transfer of knowledge is a crucial factor. The aim of this study was to determine the influence of spatial variability to determine nitrogen status in processing tomato crop with different sensors (massive and punctual) to help the technician to design a more efficient fertilization management, locate the measure points and select the adequate sensor. For this study, in the FERTINNOWA project, a trial was conducted in 2017 in a commercial plot belonging to the CONESA group, with 'H-1311' tomato cultivar of medium cycle (125-135 days). The spatial variability was studied with a NDVI image from Sentinel 2 satellite obtained in the previous year and the measure of the ECa sensor. These data permitted to select different control points in relation with the crop grown and soil texture, to evaluate the crop nutritional status during the all processing tomato crop cycles. Different fertilization status sensors were evaluated with lab plant analysis in the different control points to determine variability and representability of the measure to determine nutritional plant status. The data showed that the variability between control points were high with different sensors and in different crop moments.