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2007 Soil and Water Conservation Society - Soil Quality Workshop

"Soil Quality: the Foundation for Natural Resource Quality"


John Idowu, HM van Es, GS Abawi, DW Wolfe, RR Schindelbeck, BK Gugino, BN Moebius, and JE Thies
Cornell University, Ithaca, NY

There is a pressing need for quantitative soil quality assessment to assist the sustainable management of land as it supports important ecosystem functions and services. The recently developed Cornell Soil Health Test (CSHT) integrates physical, biological and chemical soil measurements for the evaluation of quality of agricultural fields. Initially, thirty-nine potential soil quality indicators relevant to crop production function were assessed and streamlined for the development of the CHST. Fifteen indicators were selected for a routine soil health assessment based on their i. sensitivity to management, ii. ability to describe major soil processes, iii. ease and cost of sampling, iv. significance to agronomic and environmental soil functions, v. consistency and reproducibility and vi. cost of laboratory analysis. The physical indicators selected are aggregate stability, available water capacity, bulk density, field measured surface and subsurface penetration resistance. The biological indicators are organic matter, active carbon, potentially mineralizable nitrogen and root health potential. The chemical indicators include pH, phosphorus, potassium and a few minor elements. Scoring functions were developed for these various indicators rating them on a scale of 1 to 10. Some of the scoring functions relied on the probabilistic distribution of measurements in our database of soil health in the Northeast, while some others were based on already established guidelines and expert knowledge. A specific protocol was developed to sample for soil quality during the spring. Soil health results are presented in a visually enhanced format, indicating the ratings for individual indicator as well as the total soil quality rating for the sampled field. Whenever an indicator scores below the acceptable range, the report highlights the constraints, which may limit the field from agronomic and environmental perspectives. Suggested management options are also provided. This test is useful for targeting management practices to address specific field constrains and to assess directional changes in soil quality. Further work is planned to refine the CSHT and interpretations for different land use and management scenarios.

John Idowu - John Idowu received his MSc in Agronomy from the University of Gottingen, Germany, and his PhD in Land Management from Silsoe College, Cranfield University, United Kingdom. John worked for several years as a Research Fellow at the Institute of Agricultural Research and Training, Ibadan, Nigeria. His research focused on sustainable land use in tropical ecosystems with emphasis on managing soil physical properties, nutrient management, soil tillage, erosion control, and spatial variability. John joined Cornell University about 4 years ago and has been working on soil quality assessment and management in the Northeast. He is currently a Research Associate and Project Coordinator of the Soil Health Initiative at Cornell University.