Arbuscular Mycorrhizal Fungi Colonization Response to Fertilization of Kernza ®
Kernza® is a wheat alternative harvested from the perennial intermediate wheatgrass (Thinopyrum intermedium). It’s notable as a perennial grain for upholding and in some cases improving key soil health metrics including preventing nutrient runoff and erosion through its extensive root system and year-round soil coverage. Arbuscular Mycorrhizal Fungi (AMF) are known contributors to soil health improving soil aggregate structure through the secretion of a glycoprotein called glomalin. Plants use AMF to access nutrients such as nitrogen and phosphorus from beyond the zone of depletion supplying them with carbon in return. However, AMF are known to be limited by nitrogen and phosphorus in cropping systems. This works presents fungal response to five different combinations of nitrogen, phosphorus, and potassium fertilizer in year two of Kernza® growth to determine what treatments are optimal for AMF colonization. The treatments included fertilizers of N-P-K (lbs/acre) values of 0-50-150, 80-50-150, 160-50-0, 80-0-150, and and organic fertilization of 160-0-0. By analyzing permanganate oxidizable carbon pools, labile carbon concentrations from first year to second year growth were determined. Glomalin and glomalin-like proteins from year two were quantified using the autoclave extractable protein method, and AMF colonies were observed from second year growth by using a root staining technique. The results found statistically insignificant data between treatment methods for all analysis. Labile carbon was determined to increase overall treatments from 2021 to 2022 samples. This project will serve as a reference for future fertilizer-based AMF colonization experiments, and the widespread commercialization of Kernza®.