%0 Journal Article
%T Field Scale Studies on the Spatial Variability of Soil Quality Indicators in Washington State, USA
%A Jeffrey L. Smith
%A Jonathan J. Halvorson
%J Applied and Environmental Soil Science
%D 2011
%I Hindawi Publishing Corporation
%R 10.1155/2011/198737
%X Arable lands are needed for sustainable agricultural systems to support an ever-growing human population. Soil quality needs to be defined to assure that new land brought into crop production is sustainable. To evaluate soil quality, a number of soil attributes will need to be measured, evaluated, and integrated into a soil-quality index using the multivariable indicator kriging (MVIK) procedure. This study was conducted to determine the spatial variability and correlation of indicator parameters on a field scale with respect to soil quality and suitability for use with MVIK. The variability of the biological parameters decreased in the order of respiration > enzyme assays and qCO2 > microbial biomass C. The distribution frequency of all parameters except respiration were normal although the spatial distribution across the landscape was highly variable. The biological parameters showed little correlation with each other when all data points were considered; however, when grouped in smaller sections, the correlations were more consistent with observed patterns across the field. To accurately assess soil quality, and arable land use, consideration of spatial and temporal variability, soil conditions, and other controlling factors must be taken into account. 1. Introduction The challenge of feeding 9 billion people by the year 2050 is intimidating. Multiple strategies are needed to meet this challenge. Strategies include reducing human population growth, decreasing protein consumption, increasing crop and animal production, and increasing the agricultural land base for production. While some food staples (crops and livestock) are increasing, others are static or decreasing [1]. Currently food production for 6 billion people occurs on 13% of the global land surface [2]. The current strategical focus has been on increasing yields and increasing the agricultural land base [3, 4]. The challenge to moving these strategies forward is to evaluate (1) new land for the ability to produce crops and (2) the soil¡¯s resilience and resistance to degrade over time from agriculture management. Thus, the concept of soil quality needs to be developed to evaluate and manage land developed for increased crop production [5, 6]. In a global context, soil quality affects not only soil productivity but is also a significant factor governing environmental quality, human and animal health, and food safety and quality [7]. Soil quality of current and future agricultural land is of similar importance to humankind as air and water quality; thus, it is apparent that simply protecting
%U http://www.hindawi.com/journals/aess/2011/198737/