The Best Fertilizer for Alkaline Soil

Alkaline Soil

• A variety of plants tolerate alkaline soil. Soil pH levels higher than 7.5 occur in desert areas and regions high in limestone and chalk. Alkalinity levels above 8.0 deprive plants of the necessary nutrients iron, zinc and manganese. Extreme alkalinity indicates the possibility of high salts, which kills plants. Correct extreme alkalinity in your soil.

Fertilizers

• Alkalinity is usually lowered adequately with fertilizers containing ammonium sulfate and sulfur-coated urea. The acidifying agents elemental sulfur or aluminum sulfate are applied in extreme cases. These fertilizers are successful in soils low in free lime. Elemental sulfur converts to sulfuric acid in the soil with the aid of bacteria and must be mixed with moist, warm soil and allowed to work for several weeks.

Amendments

• Soil amendments are worked into the soil to improve texture, water-retentiveness and drainage. Organic amendments increase nutrient levels and modify pH. Avoid wood ashes, which are high in salts. Organic matter including composted manure, peat and garden compost worked into the soil improve texture and contribute to acidifying alkaline soil.