Location: Sustainable Agricultural Systems Laboratory
Project Number: 8042-21660-005-059-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 1, 2022
End Date: Aug 31, 2025
Objective:
The overall goal is to quantify links between carbon and nitrogen inputs into soil (quantity and quality) and plant available nitrogen and crop yields.
The objectives are to:
1) Quantify changes over time in soil particulate organic matter and mineral associated organic matter in response to the quantity and quality of inputs to soil in diverse cropping systems and develop quantitative relationships with changes in plant available nitrogen.
2) Quantify the contribution of poultry litter inputs to soil particulate organic matter, mineral associated organic matter, plant available nitrogen, and corn grain yield to refine and expand relationships defined under Obj. 1.
Approach:
Plant, soil, and manure samples archived from the long-term Farming Systems Project (FSP) in Beltsville, Maryland, will be used to address the objectives. Carbon and nitrogen contents will be measured (using dry combustion) and quality determined (lignin, polysaccharides, cellulose, amines, lipids will be measured using an Orbitrap IQ-X Tribrid mass spectrometer) of select archived plant samples and all archived poultry litter samples. Subsets of archived soils, collected from the plow layer of conventional and organic cropping systems at FSP plots annually will be selected from years when plant available nitrogen was deficient (years 1996 to ~2003), increasing (~2004 to ~2008), and sufficient/excess (~2009 to 2020) to quantify the trajectories of particulate and mineral associated organic matter in relation to plant available nitrogen. Particulate organic matter quality will also be analyzed using the Orbitrap IQ-X Tribrid mass spectrometer. This will allow: 1) quantifying relationships among carbon and nitrogen input quantity and quality and soil particulate and mineral associated organic matter, and 2) relating these changes to plant available nitrogen (Obj. 1). A similar approach will be followed using plant, soil and poultry litter samples archived from a poultry litter reduction experiment embedded within the larger FSP in which poultry litter was applied at four different rates during four years. This will allow quantifying the effects of poultry litter rate on soil particulate organic matter, mineral associated organic matter, plant available nitrogen, and corn grain yield (Obj. 2).
