Go through the links, I have attached. Hope, the links will be helpful and guide you.

Chapter IoT-Based System to Measure Soil Moisture Using Soil Moistur...

https://www.youtube.com/watch?v=nh5x_H_lIko

Dear Sudip Ghimire,

the idea of Digital Twins (DTs) is very suitable for collecting real-time data on soil moisture, temperature and other environmental factors and using them in an intelligent way in agriculture.

The general idea of DTs can be found at the address:

https://www.researchgate.net/publication/366167747_Digital_Twins_in_IoT

Some options for using DTs for Smart Agriculture can be found in the added literature.

Best regards and much success

Anatol Badach

Christos Pylianidis, Sjoukje Osinga, Ioannis N. Athanasiadis: Introducing digital twins to agriculture; Computers and Electronics in Agriculture, Vol. 184, Mar 2021; DOI: 10.1016/j.compag.2020.105942

Mandana Moshrefzadeh, Thomas Machl, David Gackstetter, et al.: Towards a Distributed Digital Twin of the Agricultural Landscape; Journal of Digital Landscape Architecture, 2020, Issue 5; DOI:10.14627/537690019

Pelin Angin, Mohammad Hossein Anisi, Furkan Göksel, Ceren Gürsoy, Asaf Büyükgülcü: „AgriLoRa: A Digital Twin Framework for Smart Agriculture“; Journal of Wireless Mobile Networks, Ubiquitous Computing, and Dependable Applications; Vol. 11(4), Dec 2020, DOI:10.22667/JOWUA.2020.12.31.077

There are several ways to use sensors and other IoT devices to collect real-time data on soil moisture, temperature, and other environmental factors. Here are a few examples:

Soil moisture sensors: These sensors can be placed in the soil to measure the amount of moisture present in the soil. There are different types of soil moisture sensors, including capacitance sensors, tensiometers, and time domain reflectometry (TDR) sensors. These sensors can be connected to an IoT device that collects and transmits the data to a cloud-based platform for analysis and visualization.

Temperature sensors: These sensors can be used to measure the temperature of the soil, air, or water. Temperature sensors can be placed in the soil or in the air to monitor changes in temperature over time. They can be connected to an IoT device that collects and transmits the data to a cloud-based platform for analysis and visualization

Environmental sensors: Environmental sensors can be used to measure a range of environmental factors, including air quality, humidity, wind speed and direction, and sunlight. These sensors can be connected to an IoT device that collects and transmits the data to a cloud-based platform for analysis and visualization.

Smart irrigation systems: Smart irrigation systems use sensors to monitor soil moisture levels and weather conditions to determine when and how much water to apply to plants. These systems can be connected to an IoT device that collects and transmits the data to a cloud-based platform for analysis and visualization.

Farmers use manual intervention to control the greenhouse environment. The use of IoT sensors enables them to get accurate real-time information on greenhouse conditions such as lighting, temperature, soil condition, and humidity. Thermistors are really popular IoT temperature sensors due to their small size and low power consumption. They are also highly accurate and reliable. Other types of temperature sensors are thermocouples, resistance temperature detectors (RTDs), and infrared temperature sensors. The soil moisture sensor is a simple device for measuring the moisture level in soil and similar materials. The soil moisture sensor is straight forward to use. The two large exposed pads function as probes for the sensor, together acting as a variable resistor. Volumetric moisture sensors for soil determine the water-to-soil volume percentage. Two common varieties of volumetric sensors are neutron probes and electromagnetic sensors. Agriculture sensors such as air temperature and humidity, soil moisture, soil pH, light intensity, and carbon dioxide are often used to collect data in all aspects of crop growth such as nursery, growth, and harvest. Agricultural conductivity and agricultural pH sensors are used to monitor water and fertilizer. The Dragino N95S31is a NB-IoT Temperature and Humidity Sensor for Internet of Things solution. It is used to measure the surrounding environment temperature and relative air humidity precisely, and then upload to IoT server via NB-IoT network. An IoT ecosystem consists of web-enabled smart devices that use embedded systems, such as processors, sensors and communication hardware, to collect, send and act on data they acquire from their environments. The applications of IoT in environmental monitoring are broad − environmental protection, extreme weather monitoring, water safety, endangered species protection, commercial farming, and more. In these applications, sensors detect and measure every type of environmental change.