Four Long-Term Studies That Prove Poultry Litter Pays Off
Better margins, stronger soil, and resilience under stress. The data doesn’t lie.
Looking for a proven way to reduce fertilizer costs and improve soil health? Poultry litter has proven to be one of the most effective, affordable alternatives to synthetic, salt-based fertilizers. Peer-reviewed studies across the Midwest show that manure-based systems not only maintain yields and reduce dependance on synthetics, but also improve long-term soil fertility, and boost profit margins. Here's the research farmers should know.
What Decades of Research Say About Poultry Litter Fertilizer
12-Year South Dakota Trial
This poultry litter trial evaluated nutrient management across a corn-soybean rotation on Midwestern soils. Over a dozen years, plots fertilized with turkey manure consistently outperformed synthetic treatments in soil health and nutrient retention.
📈 +25% increase in soil organic matter vs. synthetics
💧 Improved soil structure and water infiltration capacity
⚖️ Stabilized soil pH without the need for additional lime
💡 Informed phosphorus management practices for the Upper Midwest
20-Year Iowa State Study
This landmark study tracked the performance of poultry litter on continuous corn and corn-soy rotations over two decades. It’s one of the most economically compelling head-to-head trials against synthetic nitrogen.
🌽 +25% higher yields in continuous corn vs. UAN
💵 $50–$80/acre more profit after application—even with transport
🄽 Higher nitrogen retention and slower-release nutrient availability
🌱 Significantly better particulate organic matter in manure-treated soils
🔗 Read Iowa State’s poultry litter study ›
Meta-Analysis of 116 Trials
Across 116 peer-reviewed trials globally, poultry and turkey litter proved to be an effective organic fertilizer, particularly in diversified and corn-based cropping systems.
🔋 Increased nutrient uptake efficiency vs. synthetic NPK blends
🌿 Improved soil microbial activity and structure over time
💰 Higher long-term ROI in manure systems, particularly in low-rainfall or marginal soils
🌍 Broad validation across climates, crop types, and soil types
🔗 Explore poultry litter fertilizer trials ›
Rodale’s 40-Year Farming Systems Trial
Rodale’s benchmark organic-vs-conventional trial included poultry litter in the organic fertility program. Over four decades, it’s proven that manure-fed systems perform best when it matters most.
🌾 30% better yields during drought years vs. synthetic systems
💸 Lower input costs with no reduction in long-term productivity
🧬 More resilient soil biology and carbon retention
🌦️ Maintained fertility through variable weather and stress
🔗 Rodale's organic vs synthetic comparison ›
You don’t have to overhaul your whole system. Most farmers in these studies started small—trialing poultry litter on a few fields. The results added up: stronger soil, lower input costs, and more resilient yields.
So if you're looking to reduce synthetic dependence, rebuild organic matter, or just stabilize your input costs, we can help.