Sus­tain­able agri­cul­tural inten­si­fi­ca­tion in sub-Saharan Africa

Sus­tain­able agri­cul­tural inten­si­fi­ca­tion in sub-Saharan Africa is needed for poverty alle­vi­a­tion, cli­mate change adap­ta­tion and mit­i­ga­tion, and in order to meet other grow­ing 21st cen­tury pres­sures.  Yet dis­sem­i­na­tion of agri­cul­tural tech­nolo­gies remains a chal­lenge in the region.  I report the results of a ran­dom­ized con­trolled trial in rural West­ern Kenya on adop­tion and impact of biochar, a novel input that can durably improve fer­til­ity in poor soils while seques­ter­ing car­bon.  To induce uptake, I ran­domly assigned sub­si­dies, demon­stra­tion plots (aimed at stim­u­lat­ing learn­ing), and deferred pay­ment offers whereby farm­ers could choose to pay after har­vest (aimed at reduc­ing risk and liq­uid­ity con­straints).  In spite of large yield increases on demon­stra­tion plots, uptake was rather low.  Hav­ing a demon­stra­tion plot increased odds of adop­tion by a fac­tor of 3.5, and increas­ing the share of ones neigh­bors with demon­stra­tion plots from 5% to 10% increased odds of adop­tion by a fac­tor of 8.5 – an effect equiv­a­lent to 53% sub­sidy.  How­ever, given very low uptake at no sub­sidy, the expected prob­a­bil­ity of biochar adop­tion only reaches 50% - at the opti­mally treated share of the social net­work - when biochar is offered at 35% of its cost.  While social learn­ing can be a tool for tech­nol­ogy dis­sem­i­na­tion, its effects here are con­di­tional on base­line adop­tion propen­sity, which is con­di­tional on sub­si­dies.  Given uptake well below the social opti­mum by the end of the project, heavy sub­si­dies appear jus­ti­fied from a social cost/benefit stand­point.  Given sub­stan­tial com­ple­men­tar­ity with inor­ganic fer­til­izer, biochar may be a use­ful tool for stim­u­lat­ing sus­tain­able agri­cul­tural inten­si­fi­ca­tion in the region.

Speaker: Andrew Crane-Droesch, UC Berkeley