Optimizing Iowa land use: Past perspectives for current questions

Authors: OBRYCKI, JOHN - Orise Fellow; Karlen, Douglas

Submitted to: Journal of Soil and Water Conservation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/14/2018
Publication Date: 11/5/2018
Citation: Obrycki, J., Karlen, D.L. 2018. Optimizing Iowa land use: Past perspectives for current questions. Journal of Soil and Water Conservation. 73(6):693-704. https://doi.org/10.2489/jswc.73.6.693.
DOI: https://doi.org/10.2489/jswc.73.6.693

Interpretive Summary: Maintaining agricultural productivity and protecting soil resources requires matching crop management with landscape features. This is not a new concept as evidenced by an analysis of survey data collected during the 1930s from Iowa farmers. Although agricultural practices have changed since the 1930s, some of the rotations identified by those farmers are still suitable for maintaining agricultural productivity and protecting soil resources. This study will be of interest to producers, soil scientists, agricultural historians, and agronomists.

Technical Abstract: Agricultural landscape design (LD) is a land management strategy that links site-specific field attributes, farmer knowledge, market opportunities, and soil and water conservation and protection practices into robust, economically viable, and sustainable production systems. We hypothesized that insights from the past may offer forgotten perspectives for current and future LD research. An Iowa State University (ISU) library search revealed that during 1936 and 1937, county agricultural planning committees met with farmers throughout Iowa to learn which crop rotations were being grown by soil series and landscape position. Reports from 90 of Iowa’s 99 counties were located and used to identify traditional farmer-based crop rotation recommendations for five landscape positions. The average crop rotation included four crops, but ranged from one (monoculture) to eight. There were no identifiable differences in crop rotation length across landscape positions. The most common rotation (45%) consisted of two years of corn (Zea mays L.), followed by oat (Avena sativa L.), and most commonly one or more years of alfalfa (Medicago sativa L.). Farmer-suggested rotations did vary by landscape position with the most common for bottomland soils being vegetables and market gardens. Permanent vegetative cover was approximately 20% greater on bottomlands and upland slopes than on terrace or flat upland areas. Although production practices have changed since the 1930s, re-examining historical farmer knowledge within Iowa’s counties may provide some forgotten insights for building soil health and providing stable incomes for producers.