Ayub Khan imposed the martial law in 1958 and was in power till 1969. Zia remained in power from 1977 will 1988. During Ayub's period, Pakistan consisted of two provinces i.e. West Pakistan and East Pakistan. But during Zia period East Pakistan had already been separated and the Pakistan consisted of four provinces of Punjab, Balochistan, Sindh and NWFP. Ayub abrogated the 1956 constitution and gave a new constitution in 1962 which introduced Presidential form of Government. Zia suspended the 1973 constitution and reinforced it in 1985 with some amendments. Ayub gave great attention to agriculture and industry. He introduced land, reforms of 1959 and his policies gave much protest to agriculture. The Indus Water Treaty, 1960 was signed which solved the irrigation water problem. As a result, agricultural production nearly doubled during 1960 to 1965 period. It was called 'Green Revolution". Ayub policies also gave a boost to industries and industrial production during 1960-65 periods. Zia took the step of de-nationalization of industries. Industrial development, which was halted during the previous years, started picking up slowly.