Effects of Carbon Amendments, Tillage and Cover Cropping on Arbuscular Mycorrhizal Fungi Association and Root Architecture in Corn and Cotton Crop Sequence

Abstract

A field experiment was conducted to study the effects of carbon amendments, tillage, and cover cropping on arbuscular mycorrhizal fungi (AMF) association and root architecture at Farm Services at Texas A&M University. Three levels of carbon amendments at the rate of 500 kg C ha−1 (biochar, composted biosolid, and control (no carbon amendment)), two levels of tillage (conventional disking (CT) and no tillage (NT)), and two levels of cover crop (a mixture of oat, mustard, and pea (CC) and no cover crop (NCC)) were arranged in a split-split plot design with four replications. Over a two-year crop sequence of corn followed by cotton, AMF colonization of roots was 4.43% greater in biochar-treated soil than in the control treatment. Colonization in cotton was 5.17% and 6.09% greater under NT and CC treatments, respectively, compared to CT and NCC. Carbon amendments did not alter corn root length but did alter root angle at 20–30 cm. Carbon amendments did not affect root angle under CC. However, tillage did affect CC root length and angle. Root length and root angle were found to differ among the cover crop species. The results imply that farmers may combine certain practices to optimize and harness the benefits of AMF.