Despite recent industrial development, Haryana is primarily an agricultural state. About 70% of residents are engaged in agriculture Wheat and rice are the major crops. Haryana is self-sufficient in food production and the second largest contributor to India's central pool of food grains. The main crops of Haryana are wheat, rice, sugarcane, cotton, oilseeds, gram, barley, corn, millet etc. There are two main types of crops in Haryana: Rabi and Kharif. The major Kharif crops of Haryana are rice, jowar, bajra, maize, cotton, jute, sugarcane, sesame and groundnut. For these crops the ground is prepared in April and May and the seeds are sown at the commencement of rains in June. The crops are ready for harvesting by the beginning of November. The major Rabi crops are wheat, tobacco, gram, linseed, rapeseed and mustard. The ground is prepared by the end of October or the beginning of November and the crops are harvested by March.

About 86% of the area is arable, and of that 96% is cultivated. About 75% of the area is irrigated, through tubewells and an extensive system of canals. Haryana contributed significantly to the Green Revolution in India in the 1970s that made the country self-sufficient in food production. The state has also significantly contributed to the field of agricultural education in the country. Asia's biggest agricultural University - Chaudhary Charan Singh Haryana Agricultural University is located at Hisar and it has made a significant contribution in ushering in the 'Green Revolution' in the state.

Dairy farming is also an essential part of the rural economy. Haryana has a livestock population of 98.97 lakh. Milk and milk products form an essential part of the local diet. There is the saying Desaan main des Haryana, jit doodh dahi ka khaana, which means "Best among all the countries in the world is Haryana, where the staple food is milk and yoghurt". Haryana, with 660 grams of availability of milk per capita per day, ranks at number two in the country as against the national average of 232 grams. There is a vast network of milk societies that support the dairy industry. The National Dairy Research Institute  at Karnal, and the Central Institute for Research on Buffaloes at Hisar are instrumental in development of new breeds of cattle and propagation of these breeds through embryo transfer technology. The Murrah breed of water buffalo from Haryana is world-famous for its milk production.