Integrating Forages into Multi-Functional Landscapes: Enhanced Soil Health and Ecosystem Service Opportunities Douglas L. Karlen USDA-ARS Presented at the 5 th Annual Canadian Forage and Grassland Conference – Bromont, Québec November 19, 2014

 Why is a Soil Scientist interested in forages?  How do forage- or grassland-based crop rotations affect ecosystem services?  How does incorporating forage or grassland into crop rotations affect soil quality/health?  What innovative opportunities can forage and grassland help support?  Hint – Bioenergy and/or bio-products Presentation Overview

Why Is a Soil Scientist Interested in Grassland? It’s not necessarily for the buffalo From H.F. Reetz

Rather -- It’s Because of the Roots!

Selected Plant Root Functions  Input source for soil carbon  Cycling of essential plant nutrients  Source of exudates (food) for microbes  Ability to penetrate compacted zones  Enhance soil structure

Forage & Grassland Ecosystem Services  Food production  Erosion control  Water quality maintenance & improvement  Wildlife habitat  Improved soil quality/health

Water Quality Impact  Incorporating forages and grassland into agricultural landscapes can significantly reduce NO 3 -N losses and help mitigate soil erosion

Raccoon River Watershed This watershed is a major source of drinking water for Des Moines, Iowa A significant correlation (r = -0.76) was found between the land area cropped to small grain and hay and the NO 3 -N concentration in the water Hatfield et al., 2009

Forage & Grassland Effects on Soils  Rotations with three years of forage had:  Lower bulk density  Increased % of water stable aggregates  Higher microbial biomass carbon  Greater average corn yields Karlen et al., 2006

The Soil Management Assessment Framework (SMAF) Minimum Data Set Soil Function Indicator score Soil Function Indicator score Index Value Management Goals

Interpreting Dynamic Soil Quality Soil Quality Time Aggrading Sustaining Degrading Baseline

Crop Rotation– Soil Quality Index Values Karlen et al., 2006 RotationNashuaKanawhaLancaster Continuous Corn Corn – Soybean Corn-Corn- Oat/Alfalfa- Alfalfa- Alfalfa

Opportunities for Integrating Forages into Multi-Functional Landscapes

Windbreak Riparian Herbaceous Buffer Buffer

Switchgrass as a Biofuel Feedstock

Enhanced Alfalfa Production Use genetic strategies to improve alfalfa and its uses to increase farm and ranch sustainability and profitability Develop harvest and storage technologies to enhance alfalfa feed quality and develop new products Develop and evaluate farming systems that strategically incorporate alfalfa on the landscape to reduce the negative environmental impact of row crop and livestock agriculture.

Overall Research Goal

. Environmental Benefits of Alfalfa (compared to row crops such as corn and soybean) Captures more sunlight/more photosynthesis/more carbon. Captures C for a longer time period during the growing season. Provides N & improves nutrient cycling. Breaks pest life cycles when rotated with other crops. Less surface runoff. Less phosphorus lost to surface water. Less soil erosion. More soil carbon sequestration. Less nitrogen leached to ground water

Approach – An Alfalfa Paradigm Shift REAP goal – diversify landscape, provide feedstock, improve soil health, & protect water quality

Leaf Stripping and Protein Extraction

Summary & Conclusions  Forages and grassland are essential for long- term sustainable agricultural production  With regard to water quality, changes in cropping patterns were more important than changes in N fertilizer rate  Soil quality was improved by having extended crop rotations with at least three years of forage  New and innovative harvest strategies and uses for alfalfa protein and other components need to be developed.

Any Questions?