Authors: Daniel Nessly*, University of Idaho, Gigi Berardi*, Huxley College, Western Washington University
Topics: Agricultural Geography, Land Use and Land Cover Change, Environment
Keywords: Soil quality, organic, agriculture, agricultural, sustainability, soil, soil fertility, organic matter, organic farm
Session Type: Paper
Start / End Time: 3:05 PM / 4:45 PM
Room: Jackson, Marriott, Mezzanine Level
Presentation File: No File Uploaded
An important indicator of agricultural sustainability is soil quality, the soil’s ability to function as a living system in sustaining biological productivity and promoting soil organismal health. The objective of this research was to investigate whether differences in soil quality between organically and conventionally farmed fields could be determined in matched pair comparisons. The soil parameters studied were soil moisture, soil compaction, pH, electrical conductivity, soil organic matter, and annelids. Research sites were vegetable fields in Skagit County, Washington, a county characterized by climate, soil, and water resources highly favorable for vegetable and bulb production. In spring 2013, farm fields were matched on farming and crop history, soil type, aspect, hydrology, climate, parent material, and relief. Data averaged for all matched pairs showed statistically significant differences for pH (conventional fields), soil organic matter (organic fields), and annelids (organic fields). Low pH in organic fields could be due to the use of shallow tillage resulting in stratification with a more acidic pH in the top 30 cm of topsoil. Higher values in organic fields for soil organic matter are indicative of several factors, including the systematic use of organic matter (green manures, some compost) as part of a soil fertility management regimen. The statistically significant higher levels of SOM and annelids, although qualified, suggest a greater biological soil quality in organic farms in relation to their conventional counterparts. The results indicate a role that organic farm systems may play in improving biological properties of soil quality.