Nebraska Irrigated and Rainfed Soybean Yield and Acreage Trends

• In 2017, Nebraska irrigated and rainfed soybean yields averaged 67.5 bu/ac and 55.1 bu/ac, respectively. The US average soybean yield was 49.1 bu/ac.
• Nebraska irrigated soybean yields are increasing at a rate of 0.678 bu/ac per year, which is about two-thirds of a bushel per acre per year.
• Nebraska rainfed soybean yields are also increasing, but at a slower rate of 0.467 bu/ac per year.
• US soybean yields (mostly rainfed) are rising at a rate of 0.470 bu/ac per year, which is only slightly higher than the rate in Nebraska.
• Large season-to-season fluctuations occur in rainfed soybean yields because of annual variance in seasonal rainfall event amounts and distribution.
• Irrigated soybean yields are predictably high each year so investing in yield-improving technological inputs is less risky and potentially more profitable.
• Such investments are likely why the yield difference between irrigated and rainfed production is widening on average by 0.21 (about 2/10) bu/ac per year.

Nebraska Irrigated and Rainfed Acreage Trends

• In 2017 2.805 million irrigated acres (48%) and 2.895 million rainfed acres (52%) of soybeans were grown in Nebraska.
• Irrigated acreage, which in 1976 accounted for just 7% of total acreage, increased to 29% by 1990 and in 1998-2001 increased to about 45%.
• Rainfed acreage followed a similar trend, but after a spurt upward in 1995-2000, it has remained mostly level since then.
• The 2007 dip in irrigated and rainfed soybean acreage was due to a temporary shift of soybean acreage to corn acreage in anticipation of ethanol-driven higher corn prices.