The study was carried out to determine the contributions of agricultural extension workers in promoting sustainable agricultural development among farmers in Kaduna State, Nigeria. Six specific objectives were raised. Descriptive survey research design was adopted. The population of farmers in the three senatorial districts were 4,056 and sample size of 333, were randomly selected. Structured questionnaire were used to collect data. Analysis of Variance (ANOVA) was used to determine the responses of farmers. The result reveals that 59.5 percent of the respondents are between the ages of 20 to 34 years, about 58% of farmers are male, and less than 70% are married. Majority of the farmers are educated (75%). Agricultural Extension Workers contributed through the control of erosion in the farm land, that farmers were influenced by Agricultural Extension Workers by disinfecting their store houses against pest and diseases before storage with 67% of the respondents agreed to the statement. There was significant difference in the opinions of farmers on the contribution of Agricultural Extension Workers on soil and water management practices among farmers in promoting sustainable agricultural development in Kaduna State having 51% disagreed to the stated statement. But the differences were traced to Northern and Central districts for five items and one to Northern and southern districts. In view of the findings, it was concluded that agricultural extension workers have influenced farmers positively (67%), which led to better management of soil, water, animal production practices and others. It was recommended that Agricultural Extension Workers should organize public enlightenment campaign on soil and water management to create more awareness among rural farmers.

Agricultural extension is an applied behavioural science, which is applied to bring about desirable changes in the behavioural complex of farming community, usually through various strategies and programmes of change, by applying latest scientific and technological innovation (Bokor, 2008). According to Iwena (2008), agricultural extension is a process whereby modern farming techniques and research findings are taking to the farmers through extension and problems of the farmers are taken to research institutions for solution. Iwena, (2008) added that, agricultural extension is an informal, out of school voluntary agricultural education involving the spread or dissemination of information, recent improved development in agriculture from researchers to the farmers through extension agents.

Agricultural extension workers teach farmers about marketing and help farm groups organize both buying and selling cooperative. Extension workers help farmers grow crops, home owners plan and maintain their homes, and children learn skills to become tomorrow‟s leaders.

Extension teaching is the process through which the extension workers stimulate interest in the learning more by using various teaching methods, tools and techniques to improve the situation. The essential role of agricultural extension workers is to create an effective learning situation. Other roles played by extension workers according to Iwena, (2008) include the following:

Providing agricultural consultancy services, planning and executing programmes, organizing and supervising farmers groups, conducts and organizing training for farmers, liaising with other agencies, assisting in improving famers outlook, acting as intermediary between researchers and farmers, teaching farming practices, evaluating extension programmers and locating marketing channels.