Personal income rose in 44 states during the first three months of 1987, with corn subsidy payments making Iowa the leader with a 9.7 percent increase, the Commerce Department said yesterday.

Excluding farm income, Delaware led the nation in income growth, with a rise of 2.9 percent. Only one state saw its nonfarm income drop: Alaska, whose income dropped 2 percent mainly because payments under a special state fund were reduced.

Total income growth averaged 1.7 percent in all 50 states and the District of Columbia in the first quarter of 1987 compared with October through December 1986. Nonfarm income rose an average 1.5 percent.

The government looks at both total and nonfarm income because farm subsidy payments swing wildly. For example, Iowa led the nation at 9.7 percent and Nebraska followed with a 4.5 percent increase in this quarter because farmers in those states got advance subsidy payments for their 1987 corn crops.

In contrast, income dropped in North Dakota, Montana, Idaho, Kansas and Oklahoma because most of their farm subsidy payments were for wheat and were made in the fourth quarter of 1986.

The Commerce Department attributed Delaware's nation-leading 2.9 percent rise in nonfarm income to increased production of small- and midsized autos. Nevada and Vermont tied for second at 2.5 percent, while Tennessee followed with a 2.4 percent increase and Maine's nonfarm income grew 2.3 percent.

Iowa also showed up well in this category, increasing 2.2 percent to reach sixth place among all states. The government credited that increase to the ending of a strike against a "major farm-equipment manufacturer" -- the 183-day strike against John Deere, which affected 8,000 workers in Iowa.

The Commerce Department attributed gains in Vermont, Tennessee and Maine to construction payrolls. Nevada grew because of payroll increases by service industries, while New Hampshire's gains stemmed from retail trade.

Most of the states that did poorest were oil dependent: Alaska, down 2 percent; Wyoming, up just 0.3 percent; Oklahoma, up 0.5 percent; and Louisiana and Utah, up 0.6 percent.

In Nebraska, the difference between total and nonfarm payrolls was particularly acute. While it was second overall in total growth, at 4.5 percent, it ranked 45th in nonfarm increases at 0.9 percent, primarily because of a strike by food processing workers