Since 1979 commercial farming has replaced subsistence farming as the dominant mode of agricultural production. Some northern and western areas support rain-fed agriculture, while other areas require irrigation for successful crop production. The 1979 Revolution sought self-sufficiency in foodstuffs as part of its overall goal of decreased economic dependence on the West. Higher government subsidies for grain and other staples and expanded short-term credit and tax exemptions for farmers complying with government quotas were intended by the new regime to promote self-sufficiency. But by early 1987, Iran was actually more dependent on agricultural imports than in the 1970s.