Doing so gives you plenty of time to plan a liming and fertilization program before the busy planting season. After harvest, the laboratory workload is lighter, and results can be returned more quickly. Sample whenever abnormal growth or plant discoloration occurs. Refer to Agronomic Division Sampling Folder No. 3, Diagnosing Plant Growth Problems , for more information. How often to sample For coastal plain soils, collect samples every two years or test one-half of your land every year.
Sandy soils lose nutrients quickly and become acidic when nitrogen is added.
For piedmont or mountain soils, collect samples every three years or test one-third of your land every year. Silt and clay-loam soils do not lose nutrients as quickly as sandy soils. How to collect soil cores Identify similar and unique field areas. Before you begin, make a detailed map of your land. Indicate the location of each field.