Spatial Variation of Soil Health Indices in a Commercial Potato Field in Eastern Canada

Abstract

There is increasing interest in using various indices to assess soil health; however, the nature of the within‐field variation in such indices, and their relationship with soil properties, are generally unknown. This study examined the spatial variation of 15 soil health indices in a 21‐ha commercial potato field in New Brunswick, Canada. Soil samples (0–15 cm depth) were collected in spring of 2016 at 154 geo‐referenced locations within the field. With the exception of CaCl2 extractable NH4–N, all soil parameters demonstrated strong or moderate spatial dependence. Several soil properties were significantly correlated, for example, soil organic carbon was strongly positively correlated with indices of soil C availability, soil N availability and soil physical properties. Principal Component Analysis suggested that the parameters fell into three major groups: PC1 (39.9% of total variance) was associated primarily with parameters related to the quantity of soil organic matter; PC2 (15.3% of total variance) with parameters related to soil organic matter quality; and PC3 (10.3% of total variance) with parameters related to soil structure. In comparison, the spatial pattern of total tuber yield was related to soil texture and soil drainage and was most strongly correlated with indices of soil organic matter quality (PC2). Soil management zones and mapped soil series were both generally effective in capturing the spatial variation in soil health indices and can be used to stratify the sampling of soil health indices in spatially variable fields.