Optimizing Manure, Cover Crops for Water

Penetrometer measurement
Practice: 
Nutrient Management

Title:  Evaluating Manure Application and Cover Crop Planting Timing to Maximize Water Quality Benefits in Corn

Location:  Borlaug Learning Center Research and Demonstration Farms

Time Period:  2024 - 2026

Research Team:  Daniel Andersen, Raj Raman, Ken Moore, Phillip Rockson

Project Description: This project explores the integration of cover crops and perennial groundcover (PGC) systems with manure management to enhance water quality and crop performance. Building on prior research at Iowa State University’s Northeast Research and Demonstration Farm, it directly compares the water quality and yield impacts of winter annual cover crops (cereal rye) with perennial systems like Kentucky bluegrass and Poa bulbosa. The project also examines how the timing of cover crop establishment (interseeding vs. post-harvest drilling) and manure application (early fall, late fall, spring, and split applications) affects nitrate leaching and crop productivity. Early findings highlight the potential of cereal rye and PGC systems to reduce nitrate losses without sacrificing corn yields, even under challenging conditions. Supported by the Iowa Pork Producers Association and the Iowa Nutrient Research Center, this research addresses practical questions around manure application and cover crop timing, offering valuable insights for farmers and policymakers. Results are shared through Iowa State University’s Manure Applicators Training, Crop Advantage, and Integrated Crop Management programs, as well as regional and national conferences. Deliverables include annual farm reports, enterprise budgets, peer-reviewed publications, and extension materials to guide sustainable practices. By advancing adoption of cover crops and PGC systems, the project aims to improve nutrient management, reduce environmental impacts, and support Iowa’s nutrient reduction goals.

Publications:

Funders: Iowa Nutrient Research Center and Iowa Pork Producers Association