Poultry Litter Biochar: sustainably boosting crop yields and soil health

What if agricultural waste could be transformed into a resource that boosts crop yields and improves soil health? A team of UF/IFAS researchers believes poultry litter biochar (PLB) has the potential to do just that. Dr. Andressa Freitas and Dr. Vimala Nair in the UF/IFAS department of soil, water, and ecosystem sciences led the study. Their most recent work indicates PLB is a potential replacement for inorganic phosphorus (P) fertilizers. Conducted over two years across different soil types in Florida, the findings provide evidence for the benefits of PLB in sustainable agriculture.

A woman walks down a corn field row holding a bucket of poultry litter biochar. She is broadcasting the amendment to the soil.
Applying the poultry litter biochar to the corn. (Photo from Dr. Nair)
Testing Biochar in Florida’s Diverse Soils

The research took place at two locations: the sandy, well-drained Entisols of the UF/IFAS Plant Science Research and Education Unit in Citra and the nutrient-challenged Spodosols of the UF/IFAS Beef Research Unit in Gainesville. The cropping system included rye, corn, and sorghum, grown sequentially across two years. They tested three treatments: poultry litter biochar, inorganic phosphorus fertilizer, and a no-phosphorus control. In the second year, the researchers examined the effects of the first year’s treatments, highlighting PLB’s long-term potential.

“The study is designed to capture the immediate and residual effects of PLB application, especially in soils where nutrient leaching is a common issue,” Dr. Freitas explained. “This dual focus helps to evaluate PLB’s real-world viability.”

The results were promising. In both locations, poultry litter biochar either matched or outperformed inorganic P in cumulative crop yields. At the Entisols site, PLB led to higher total biomass compared to inorganic P. At the Spodosols site, however, both treatments showed similar results.

Corn, a nutrient-demanding crop, responded particularly well to PLB (added at ~0.3% on a weight basis in relation to the soil weight) compared with inorganic fertilizer applications applied at the same total phosphorus rate, especially in the second year. This is likely due to PLB’s ability to release P gradually, delivering nutrients at critical stages of crop growth. Rye and sorghum yield also benefited, demonstrating the versatility of this biochar amendment.

“The gradual nutrient release from PLB aligns well with the nutrient uptake patterns of crops like corn,” Dr. Nair noted. “This characteristic also reduces the risk of nutrient loss through leaching, which is a significant concern in sandy soils.”

A corn field divided into test plots for an experiment.
Corn field test plots with signs identifying application types and rates. (Photo by Barbra Larson)
Impact on Soils

One of the study’s more significant findings was the residual impact of PLB. Plots that received PLB in the first year continued to support strong yields in the second year, even without additional P applications. This long-lasting effect could help reduce both input costs for growers and environmental impacts. By contrast, the residual effect of inorganic P was less pronounced, requiring reapplication to maintain yields.

“The residual benefits of PLB can significantly contribute to the sustainability of farming systems,” Dr. Freitas emphasized, “especially when input costs are high, or resources are limited.”

Beyond crop yields, PLB also contributed to soil health by supplying additional macronutrients. This multi-nutrient contribution may explain its superior performance in certain conditions, as well as its ability to support robust yields over time.

The biochar’s slow-release properties also align with environmental goals, minimizing the risk of P runoff and leaching. These features make PLB particularly valuable for Florida’s sandy soils, which often struggle to retain nutrients.

A Step Toward Resilient Agriculture
A corn field test plot with poultry litter biochar added to the soil.
The mature corn showing height differences between the different test plots. (Photo from Dr. Freitas)

This study shows poultry litter biochar is a practical and sustainable alternative to traditional P fertilizers in Florida’s sandy soils. By providing a consistent nutrient supply, improving soil health, and offering residual benefits, PLB addresses multiple challenges that modern agriculture faces.

“This research demonstrates the potential of PLB to not only enhance crop production but also address environmental concerns associated with nutrient management,” Dr. Nair said. “It’s a promising development for agriculture and sustainability.”

The team cautions that more research is needed to refine application rates and understand long-term effects across different environments. With the potential to reduce costs and recycle agricultural waste, PLB could play a significant role in the future of sustainable farming.

The research is in Agronomy Journal. You can find the article here: https://acsess.onlinelibrary.wiley.com/doi/10.1002/agj2.21745


Featured image from Adobe Stock Images #340208664.

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Posted: January 12, 2025


Category: Agriculture, UF/IFAS Research
Tags: Andressa Freitas, Biochar, Fertilizer, Phosphorus, Poultry Litter, Soil Health, Soil Nutrient Management, Soil Water And Ecosystem Sciences, Vimala Nair


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