The field variability of soil moisture can have a direct impact on yield. Computer models have been used to estimate the change in crop yield based on the total amount of applied water and the variability of the available water in a field. Generally, an increase in total water applied will result in greater yields but greater field variability will result in reduced crop yields. The potential change in yield is ultimately realized as profit (or loss) and the amount of profit is dependent on the cost of all inputs. In this example, water is the only input that will be considered when calculating profits.