Soil acidity damages and impedes cultivation. A piece of land at Ban Prik Sub District, where the soil was so highly acidic that rice could not be cultivated, was another problem overcome by His Majesty’s initiative. His methods were granted to improve the soil conditions, eventually making the land fertile again for cultivation. This led to the establishment of the Royally-Initiated Project of Experimental Stud for Acidic Soil Solutions in Ban Na District of Nakhon Nayok Province. The key experiment had been conducted by using 3 methods to solve the acid soil problem. These include using rainwater, developing a plot of land to adopt the New Theory and experiment on the use of marl and water to dilute the acidity, and using lignite ashes. The outcome of this experiment serves as a useful model to be adopted by all farmers.