Sir Howard's work and writing inspired many of the early pioneers of organic agriculture. He communicated the importance of soil fertility and the inherent weakness of chemical fertilizers.
Sir Howard noted the relationship between the rise and fall of civilisations and their agricultural practices, such as the Romans, who abandoned sustainable methods.
In 1905, he began work in India, with his wife Gabrielle, as an economic botanist, where he observed the methods of cultivation adopted by the local farmers and peasants. It was here that he promoted the 'Indore Method' of composting that focused on returning nutrients to the soil and creating quality 'humus'.
Howard's book, An Agricultural Testament (1940), explains the relationship between the health of the soil, the health of plants and the health of animals.
Howard acknowledges Darwin as the founder of reformed agriculture in the West and in his introduction to the 1945 edition of Charles Darwin's The Formation of Vegetable Mould, Howard states:
"Nature is the supreme farmer and gardener, and that the study of her ways will provide us with the one thing we need - sound and reliable direction."