For such a small area, I would be amazed if point to point lora would not work and would probably be a lot easier to setup and keep within legal duty cycle requirements.
At what point of number of sensors would you want to move to a mesh vs. point to point ?for a 10 Acre/4 hectare farm the area is not that large and some of the answer lies in how it is laid out.But you are correct that starting point to point would be the easy way. If there were problems, the mesh would available.
Well for a TTN style setup, needing a single 8 channel gateway, hundreads of sensors a km or more from the gateway are not unusual, however air time is often kept low, so collisions are low.With a mesh setup in such a very small area (for LoRa) you would likely have a situation where every sensor is seeing every other sensor.
Another suggestion.Setup a RPi4 as an MQTT Broker. Use Python or Node-Red or your choice on the RPi to serve as central control. Use a micro controller with built in WiFi, ESP32, to connect to the RPi, MQTT Broker to publish individual site data units.
that i could do for the transmission but how to connect all the sensors together on a large area, or you suppose it is wireless ?
Is point to point LoRa usable where you are?
Is point to point LoRa usable where you are? XBee mesh is another possibility. How far do the sensors need to communicate? Depending on your topology, you might even get wifi to work. How will you power each node?
Depending on the shape of the farm, you might be able to get away with 4 high powered WiFi access points, and use ESP8266/ESP32/ATWINC500/W600 modules.Sample drawing for a square 4 hectare.The added benefit is you get to provide Internet access to users in the field and it's probably also cheaper to implement that commercial LoRa solutions