In his years of inquiry, he discovered that our fertile farmlands at that time were literally being destroyed by chemical fertilizers and pesticides. Essential minerals were being leached from the soil with no effort being made to return nutrients to their source, Mother Earth. He searched the globe to find an area where farming methods had not left a depleted land as a result of over production and chemical destruction. To his amazement he found the answer in ancient Palestine!

The ancient knowledge of the Arabs in this area included wonderful secrets of soil renewal. Following this important discovery, Paul joined a group of outstanding agriculturists in England, who under the guidance of Lady Evelyn Balfour, were known as the Soil Association. At the time it was Britain's leading organic food and farming organization. Paul continued to blaze the way for organic farming on a commercial scale and began sharing the ancient Semitic secrets of the Arabs with Japanese farmers in the Escondido area.               

Paul was a true pioneer in the emerging organic movement and continued to share his vision of "good ground to grow good food." He knew that if the ancient agriculturists could renew their lands and keep the thin soil of the desert like areas productive for thousands of years, it could be done with the rich and fertile lands of southern California. Paul organized an Organic Gardening and Nutrition Club in Los Angeles, which was the first of its kind in America. He established a second club in Pasadena and a third in Escondido and then continued to set up the Natural Method Grower's Program to guide and certify the authenticity of true organically grown products.

In 1957, Paul DeSouza moved to Orange County and established DeSouza's Chlorophyll manufacturing and distributorship. After Paul's death in 1988, his wife Rosalie DeSouza carried on the company with a market that grew to International recognition. After Rosalie's passing in 2015, the company was sold and suspended production.