Provide the ideal pH of 5.8 to 6.0 through the application of dolomitic limestone. This is a key step in a cost-effective and responsible nutrient management plan. Low pH causes greater solubility of soil aluminum (and manganese in piedmont soils), which reduces root growth and development. Therefore, liming to promote healthy root systems improves drought tolerance and nutrient absorption, sometimes resulting in better yields.
In previous research trials, limed plots produced higher yields than unlimed plots regardless of the nitrogen rate (Table 5-3). Also, note that the yield of unlimed plots that received 15 pounds per acre of extra nitrogen was no higher than that of limed plots that received 15 pounds per acre less than suggested nitrogen. These data indicate the following:
- Extra nitrogen cannot overcome the adverse effects of low soil pH.
- Lower nitrogen rates are possible when acid soils are limed according to soil test suggestions.