Soil Test

• Soil tests measure the soil pH to determine how acid or alkaline soil is and what nutrients will balance the pH. Unless major amendments were recently added to the soil, soil only needs a test every five years.
  
  Test results range from 4.5 to 8.5. A soil pH of 7.0 is neutral; a soil pH above 7.0 is alkaline and below 7.0 is acidic. Oregon State University recommends a soil pH between 6.0 and 7.0 for vegetables, indicating that this allows plants to absorb nutrients effectively. A pH below 5.5 or above 7.0 requires modification. The soil pH is essential for preventing nutrient deficiencies and toxicities in vegetables, compromising growth and harvest.
  
  

Raising Soil pH

• Rototillers distribute soil amendments evenly.Creatas/Creatas/Getty Images
  
  Lime is added to soil to raise the pH. Lime is available in many forms, including limestone, dolomite, burned lime, quick lime, hydrated lime and slake lime. Dolomitic limestone is most widely available, and it contains calcium and magnesium carbonate. Ground lime is effective because smaller particles enter the soil faster. The most effective form of agricultural limestone is pulverized limestone.
  
  Limestone eliminates some acid in soil and allows nutrients to be more available to plants. Unlike other fertilizers or soil amendments, lime should be rototilled 6 inches deep into the soil for even and equal distribution throughout the soil area.
  
  

Commercial Vegetable Fertilizers

• Fertilizer is distributed to vegetable plants through soil.Ablestock.com/AbleStock.com/Getty Images
  
  Commercial vegetable fertilizers come in packages that are labeled according to grade. The numbers refer to the amount of specific minerals in the fertilizer. N indicates nitrogen, P indicates phosphorus and K stands for potassium. Fertilizers always list minerals in that order. Nitrogen enters soil quickly, but phosphorus and potassium enter soil slowly.
  
  Vegetable fertilizers are either chemical or organic. Organic fertilizers consist of compost, manure, grass clippings, wood ashes, and bone or blood meal. Plants get the same minerals from both types of fertilizers, but chemical fertilizers are used when applied and organic fertilizers are broken down by soil bacteria and fungi before use.
  
  

Applying Vegetable Fertilizer

• Wait to apply vegetable fertilizer, including lime, until after a soil test. Spread it evenly over the entire garden before you rototill it 6 inches into the soil. Banding is a method of applying fertilizer in a 3-inch deep trench that is dug at least 2 inches away from where seeds are planted. As your plants grow, their roots will reach toward the fertilizer, absorbing nutrients as needed.