Install soil sensors or neutron moisture probe to give you real time observations. Or else , take soil samples manually and go for gravimetric soil mositure analysis periodically , depending upon the kind of facilities, under which you carry the aforesaid experiemnt .

Thanks Anoop I used probes already to measure moisture but the question is how do i commpute soil evaporation from the treatments of Mulch 2cm, 4cm and 6 cm bases on soil moisture collected from these treatments or any other way if any?@Anoop

The user need to specifies in the Field management menu: - the degree of soil cover (mulching in percentage) and based on the type of surface mulches, which determines the magnitude of evaporation reduction. IN general , if Plastic mulches are used, it will efficiently reduce evaporation of water from the soil surface and taken as 100 %. Organic mulches may consist of unincorporated plant residues or foreign material imported to the field such as a straw, and reduce soil evaporation by 50% (by default). As a result of the reduction of soil evaporation, the ET water productivity (WPET) will increase when the soil surface is covered with mulches

Soil evaporation is the main process in the consumption of soil moisture, changes of which directly affect the management of soil water, and the improvement of the agricultural crop yield. You can have a look to the links:

Article Soil evaporation under different straw mulch fractions

http://www.fao.org/3/X0490E/x0490e0g.htm

https://link.springer.com/article/10.1007%2Fs12040-018-0933-4