Development of precision agriculture and ICT application thereof to manage spatial variability of crop growth

Precision agriculture has been developed in order to achieve more productive, more profitable and environmentally sound agriculture by adjusting the input level in the site-specific manner. Therefore, the delineation of management zone in spatially variable farmland was thought to be crucial for a site-specific management of crops. Recent introduction of ICT (Information and Communication Technology) to precision agriculture however, changed the concept of management zone. Advancement in ICT enable to produce prescriptions tailored to each field by integrating soil fertility map, quasi real-time crop growth data, and weather data. In this review, at first, history of development in the assessment of the spatial variability of soil, crop growth, and yield will be mentioned. Then, the problem of inter year variability of crop yield is considered, which was caused by the interaction between soil properties and fluctuating weather. To overcome this temporal variability, integration of soil data, crop data, and weather data are indispensable, and crop models play a pivotal role in the solution. ICT includes global navigation satellite systems (GNSS), various sensors including machine vision, robotic technology, artificial intelligence, internet of things, and cloud computer which could realize the big data analysis by using data base supplied from public and private domains and raw field data from farms. High performance of cloud computer enables to derive an appropriate management zone and prescriptions. Agricultural machineries equipped with ICT devices such as GNSS, on-the-go machine visions, and sensors such as ECa, are already in market. Automatic material application equipment and automatic steering or guidance system have contributed the widespread of precision agriculture considerably. The recent advancement of precision agriculture research in Japan for paddy and upland field is reviewed as well.