Climate-smart agriculture (CSA) is increasingly being promoted among scientists, policy makers and donors as an approach towards sustainably increasing agricultural productivity, building and increasing resilience of farming systems to climate change, and reduction of greenhouse gases. Successful implementation of CSA, however, depends on the ability to identify and quantify the trade-offs involved in its adoption. This study investigates the trade-offs involved in the adoption of mulching among smallholder farmers in Rakai district of Uganda. It specifically examines the effect of mulching on the expenditure shares of herbicides, pesticides, fertilizer, and labour. A translog cost function is estimated jointly with expenditure shares on these inputs using seemingly unrelated regression analysis. Results indicate a negative relationship between mulching and expenditure share on herbicides on one hand, and a positive relationship between mulching and expenditure share on pesticides, fertilizer, and labour on the other hand. The paper discusses the policy implications.