Internet of Things as an element of the frost protection system in orchards

Frosts cause serious damage to fruit and vegetable crops. In Poland, temperature decreases, and the occurrence of inflow (advective) frosts most often fall during the flowering period, i.e., in a phase extremely important for the development of the plant. For orchards, this causes the inflorescences of early flowering trees (cherries, plums and certain varieties of apple and pear trees) to freeze. A modern idea for reducing frost losses in orchards is to heat the air with mobile heaters. Protection by these machines consists of passing using an agricultural tractor in rows of trees or shrubs and heating and mixing the air. The problem that farmers may encounter during frosts is the awareness of when exactly such a weather condition occurs in their orchard. Weather forecasts are not detailed and usually apply to the entire region. Dangerous temperature declines below the critical minimum can occur locally and are also conditioned by geographical location and terrain diversity. The aim of the article is to present a measuring system that allows the construction of an individualised temperature model taking into account the unique shape of the orchard surface. The system is made in Internet of Things technology using long-range radio communication protocol LoRaWAN. Data from distributed measurement sensors are processed on a network server and displayed as a final application. The task of the system is to monitor the current situation in the orchard and to notify the farmer of the need to initiate a protective procedure. The operation of the system also supports the efficient use of mobile heating machines. The system facilitates the location of the areas in the orchard with the lowest temperature, as well as provides feedback on temperature changes inside the treetops caused by the passage of the mobile heater.