Probing deep to express root‐zone enrichment of soil‐test biological activity on southeastern U.S. farms

Abstract

Abstract Soil organic carbon (C) and nitrogen (N) accumulation contributes to improved soil health condition, particularly after a history of tillage‐intensive land use. Soil‐test biological activity (STBA) is an active fraction of organic matter that is responsive to conservation management. This essay summarizes the need, concept, and method of calculating root‐zone enrichment of STBA and other organic C and N fractions on private farms. Calculation of root‐zone enrichment separates the pedogenic influence on organic matter content from that of contemporary management. This separation is particularly important when attempting to determine STBA or soil organic C stock change in response to management across variable landscapes. Reasonable farm‐level estimates of STBA and stocks of soil organic C and N can be obtained from one to two dozen sampling sites on farms with differences in land use, a process that could help propel in‐depth assessments of soil health condition and C stock change.