Historical perspective of soil balancing theory and identifying knowledge gaps: A review

The common philosophies that contextualize soil test results and fertilizer recommendations are sufficiency level of available nutrients, buildup and maintenance, and basic cation saturation ratio (BCSR). The BCSR approach postulates maintaining an ideal ratio of basic cation saturations on the soil exchange sites to maximize crop yields. The practice of adding amendments to alter the ratios of basic cation saturations in soils is called “soil balancing.” While the scientific community disregards this theory, some farmers, crop consultants, and commercial soil‐testing laboratories still use BCSR to guide their fertilizer recommendations. Earn 1 CEU in Soil & Water Management by reading this article and taking the quiz at www.certifiedcropadviser.org/education/classroom/classes/537 .