Applications Of Integrative Soil Quality Assessment In Research, Extension, And Education

Abstract

Declining soil quality is an emerging issue of global concern because degraded soils are becoming more prevalent due to intensive use and poor management. The degradation of agronomically essential soil functions significantly impacts agricultural viability, environmental sustainability, and food security. The Cornell Soil Health Test (CSHT) measures and interprets an integrative set of physical, biological, and chemical indicators. It was developed as a tool to be used in applied research, extension, and education to assess and monitor soil quality, aid in making management decisions, and to increase public awareness of the importance of maintaining soil quality. In this dissertation, I explore applications of integrative soil quality assessment in three projects. 1) An open inquiry unit on runoff and infiltration was designed for use in high school earth science classrooms. The unit successfully stimulated student engagement and learning about the importance of soils in their lives and the process of authentic scientific inquiry. 2) In an assessment of the effects of stover harvest and tillage, overall soil quality was found to be much lower in plowthan no-till systems, irrespective of stover treatment. Stover harvest appeared to be sustainable when practiced under no-tillage management. 3) The CSHT Framework was further developed to be easily modified by users, and applied as an assessment tool to a chronosequence experiment on smallholder farms in western Kenya. The framework showed soils degraded most in low-input maize fields, but much less so in kitchen gardens. Indicator values and interpretive scores derived from scoring functions successfully discerned effects of long-term as well as residual short-term agricultural management differences, and were predictive of yield on smallholder farms studied. The CSHT was shown to be useful for monitoring, assessment, and in guiding on-farm management decisions. Its low infrastructure needs makes it a feasible approach to standardized soil quality testing for a variety of users internationally. In conclusion, the CSHT is potentially useful not only for applied researchers, but also for extension, non-profit, and governmental professionals to monitor soils and develop solution-oriented programs and policies that further sustainable use of soil and water management practices, locally, regionally, and potentially globally