This article was originally published on PotashCorp eKonomics. Identifying the cause — or in some cases, multiple causes — of lower-than-expected yields is a complicated task many farmers face after they finish harvest. While there are a number of diagnostic options available, some methods are much more effective than others. Soil testing is usually an adequate and reliable means of measuring soil fertility, and is generally used as a predictor of potential issues in future crops. In recent years, grain testing has emerged as a helpful trend for growers looking to determine if nutrient deficiencies — specifically potassium — were [...]