# Precision Agriculture: A Remote Sensing Monitoring System Architecture +
## 6 The Application Layer  
Based on the proposed precision agriculture monitoring system architecture, the farmer can interact with the IoT applications of the system to remotely manage the cultivation process. Such applications may concern any aspect of the agricultural field ranging from planting and irrigation processes to plant protection and harvesting methods [45]. The applications that can be adopted may involve the fertilizer application, the weed mapping, the spraying process, the irrigation of the field and the alert system. The Variable Rate Fertilizer (VRF) application has as a target to optimize the usage of nutrients by defining the amount of fertilizer applied based on the health of the plant. Variable rate fertilizer in precision agriculture is an area of technology that focuses on the automated application of fertilizer to a given landscape. The way in which the materials are applied is based on data that is collected by sensors, maps, and GPS. VRF applications bring several benefits related to savings on fertilizers and chemicals, potential yield increase and environmental protection. In the same context is the Variable Spraying application. These types of applications implement controllers that turn the herbicide sprayers on and off. Usually variable spraying applications take into consideration information coming from the weed mapping tools such as the weed locations. In that case the appropriate volume of herbicide is estimated and applied in the field based on the weed intensity. The Weed Mapping application focuses on the visualization of the weed occurrences within a certain crop field with the help of mappings. The GPS receiver with an aerial vehicle generates maps which show the weed occurrences. These weed maps can be combined with fertilizer maps and yield maps. The IoT-based irrigation system use a micro-controller that serves as information gateway receiving real-time information from soil moisture and temperature sensors placed on the fields. Generally, a moisture/temperature threshold is specified based on which the micro-controller automatically switches on the water pump. The micro-controller also has servo motors to ensure that the area is uniformly irrigated. The entire system can be managed remotely by the end-user through the dedicated application. Alert/ notification applications are also very popular in IoT-based precision agriculture. Producers and agriculture companies implement IoT solutions for instantly tracking their crop fields. In this case, the data coming from IoT devices is processed and transformed into knowledge properly visualized for offering information regarding the health of the vegetation and the soil, the behavior patterns of the plants, detect signs of disease on time, identify insects and harmful animals and instantly alert producers about potential difficulties. This type of applications serves for storing and analyzing data, providing producers with relevant recommendations. The aforementioned applications aim at the efficient field and crop management to:  
* increase production efficiency
* improve product quality
* provide more efficient use of chemicals in cultivation
* manage pesticide amounts
* reduce energy consumption
* protect the soil
* control water consumption and underground water amounts  
The IoT-based agriculture applications can be implemented for an Android or Windows smart-phone, a tablet or as a web application. The applications of IoT-based smart farming apart from conventional, large farming operations, targets also other growing or common trends in agricultural such as organic farming, family farming (complex or small spaces, particular cattle and/or cultures, preservation of particular or high quality varieties etc. ), and enhance highly transparent farming. Our precision agriculture monitoring system can also benefit the dry farming technique that encompass specific agricultural techniques for the non-irrigated cultivation of crops.