Agronomic Services

Crop Fertilization Based on North Carolina Soil Tests

Part IV:  Resource Information
This section contains nineteen tables that provide quick reference for making fertilizer substitutions, determining equivalent fertilizer rates and converting English units to metric equivalents. Fertilizer Substitutions Fertilizers recommended on NCDA&CS reports are often commercial agricultural grades, such as those given in Table 4.1. Agricultural dealers that cater to farmers are most likely to have these fertilizers in stock. These grades may not be available at local discount stores or garden centers. Therefore, growers may need to substitute equivalent fertilizers. Table 4.2 provides some substitutions for commonly recommended fertilizer materials. North Carolina Limestone Specifications All limestone sold, offered for sale or distributed in North Carolina must show on the label a guarantee of % calcium, a guarantee of % magnesium, the % calcium carbonate equivalent and the number of pounds of material that equal 1 ton of standard lime. Standard lime has a calcium carbonate equivalent of 90%. Each type of lime must meet the screen requirements outlined in Table 4.3. This information must be displayed on the label. For example, with dolomitic lime, 90% must pass through a 20-mesh screen and 35% must pass through a 100-mesh screen. Reference Tables Table 4.1 Amounts of fertilizer that provide 1 lb of nitrogen per 1000 ft² Table 4.2 Nitrogen fertilizer substitutions Table 4.3 North Carolina limestone specifications Table 4.4 Equivalent fertilizer rates Table 4.5 Properties of fertilizer materials Table 4.6 Fertilizer dilutions necessary to deliver parts-per-million rates Table 4.7 Commonly available sources of nitrogen Table 4.8 Commonly available sources of phosphorus Table 4.9 Commonly available sources of potassium Table 4.10 Commonly available sources of magnesium Table 4.11 Commonly available sources of sulfur Table 4.12 Commonly available sources of boron Table 4.13 Commonly available sources of copper Table 4.14 Commonly available sources of manganese Table 4.15 Commonly available sources of zinc Table 4.16 Commonly available sources of molybdenum Table 4.17 Commonly available sources of iron Table 4.18 Equivalent measurements Table 4.19 Conversion factors for English and metric units
	Hardy DH, Tucker MR, Stokes CE. 2012. Crop fertilization based on North Carolina soil tests. Raleigh (NC): North Carolina Department of Agriculture and Consumer Services, Agronomic Division. Circular No. 1.