Farming the future
This study compares strategies for nutrient retention in agricultural fields in the Central United States. We propose the adoption of nitrogen management to minimize eutrophication-causing pollutants entering US waterways. The extent studied was regions drained by the Mississippi River. An abundance of corn monoculture in the study area provided suitable control for current soil loss and potential application areas for nitrogen management strategy. Total nitrogen loss was measured by suspended sediment load and dissolved nitrogen that was collected with numerical modeling or experimental field drainage in the literature. Three perennial planting management strategies are proposed (grassland conservation, alternating perennials, and multi-year rotation) and are hypothesized to reduce nitrogen loss and promote permaculture. We used a meta-analysis to compile literature estimates of nitrogen loss rates, mapped implementation areas with remote sensing, and calculated environmental impact. Algebraic models were then created to evaluate the alternating and multi-year strategies (Equations 1-9) and extrapolated by potential area. Ten-year conservation potential differed whether perennials of oat and alfalfa were planted half-time for alternating plots (8.15x108 kg N), one-third of the time for multi-year plots (up to (7.5x108 kg N), and continuously for grassland conservation (9.1x108 kg N). Data suggests multiple years between corn monoculture is most beneficial, identifies alfalfa as an effective nitrogen retention crop, and has widespread application potential. Implications for this research include support for diverse crop rotations and policy implementation to expand incentivized conservation programs.