I-Corps: Digital soil and yield mapping with an optimized sampling design to provide accurate, rapid, and inexpensive maps for farm managers

Iowa State University, Ames IA

Investigators

Abstract

The broader impact/commercial potential of this I-Corps project is to understand the benefits of inexpensive and high-quality soil fertility and yield maps. Soil testing helps farmers to determine the amount of fertilizer needed for plants. In 2017, total agricultural land in Iowa was 30.5 million acres, and the average farm size was 351 acres. If all farm managers took samples based on the commonly used sampling design, they would spend over $291 million. With the new sampling design, farmers in Iowa may save close to $129 million (44%). During participation in the ISU I-Corps Site program, a key customer discovery finding was that farmers need these more accurate and less expensive maps compared to existing ones in order to fertilize their crops effectively, but without waste. This I-Corps project will help to determine if farmers are interested in an alternative sampling design, which can provide low cost analysis of field variations. The technology will have the ability to supply precise management zones from accurate soil maps. The technology will create soil maps with relatively fine resolution (9 sq. meters) compared to the existing maps (2.5 acres). Preliminary results show that kriging can produce a soil map with 9 sq. meters; however, the accuracy of kriging maps (R2 = 0.1) with small sample sizes is remarkably smaller than the proposed maps (R2 = 0.53-0.61). Thus, the nutrient recommendations will remain effective while the costs decrease compared to the current methods (block and kriging). This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.