The Internet of Things has found its usage in a large number of different application areas such as smart industry, smart city and smart vehicle, but also smart agriculture, all for the purpose of interconnecting the physical and virtual world into a single whole via the Internet as a medium of communication. The Internet of Things has proved to be a very important potential in the already mentioned smart agriculture sector, as a reaction to the food demand increase due to the population growth, as a reaction to the reduce of natural resources and arable land and as a reaction to the weather conditions becoming increasingly unpredictable. In order to improve the daily work of farmers through better monitoring of crop development, control of food production and processing, better understanding of specific growing conditions, such as weather/environmental conditions, more sophisticated remote management of farms, processing and logistics operations, etc., all for the purpose of better productivity, quality and profit of crops, the Internet of Things in the field of smart agriculture together with data analytics/data visualization is a conceptual solution for maintaining and meeting the world's food needs in the coming years. This paper deals with the topic of data visualization for monitoring various parameters within smart agriculture on the example of a web application prototype. A review of the Internet of Things paradigm was given, its application in the smart agriculture sector was presented, data analytics, more precisely data visualization was explained, and finally the implementation of the above application for displaying stored data from IoT devices in the field was described.