Chapter 10

Soil Nutrient Managment

(book excerpts)

Soil nutrient management is an essential part of sustainable agriculture. Nutrient management is the process of managing the amount, source, timing, and method of nutrient application with the goal of optimizing farm productivity while minimizing potential impact on the environment. The key principle behind nutrient management is balancing soil nutrient inputs with crop requirements. Nutrient management includes developing nutrient budgets (i.e., records) that consist of knowing the amounts of nutrients present in the soil, determining the amount of nutrients needed by the crop, and then applying manures, composts, or inorganic fertilizers and growing cover crops to meet the nutrient needs of the crop. When inputs are applied in proper quantities and at the right times, added nutrients help achieve optimum crop yields; applying too little will limit yield and applying too much doesn't make economic sense and can harm the environment. Environmental concerns have resulted in more emphasis on better management of nitrogen and phosphorus over the past few decades. While these nutrients are critical to soil fertility management, their mismanagement causes widespread environmental problems. In many regions of the United States and other countries, surface and groundwater pollution has been caused by poor soil management, overuse of fertilizers, and mishandling of livestock manures.

Topics Within This Chapter:

  • Essential Plant Nutrients
  • Movement of Nutrients from Soil to Plants
  • Root Interception
  • Mass Flow
  • Diffusion
  • The Concept of the Limiting Factor
  • Conditions Affecting Nutrient Availability
  • Antagonistic and Synergistic Effects of Soil Nutrients
  • Nutrient Management for Organic Crops
  • Crops Preferences for Soil pH
  • Climate Change and What it Means to for Plant Nutrition
  • Nitrogen
  • Forms of Nitrogen Taken up by Plants
  • Nitrogen Deficiency in Plants
  • Nitrogen Toxicity in Plants
  • Mobility of Soil Nitrogen
  • Management of Soil Nitrogen
  • Timing of Nitrogen Applications
  • Nitrogen Application Rates
  • Minimizing Nitrogen Leaching
  • Minimizing Volatilization Losses
  • Organic Nitrogen Sources
  • Legume Cover Crops
  • Phosphorus
  • Forms of Phosphorus Taken up by Plants
  • Phosphorus Deficiency in Plants
  • Phosphorus Toxicity in Plants
  • Mobility of Soil Phosphorus
  • Management of Soil Phosphorus
  • Potassium
  • Forms of Potassium Taken up by Plants
  • Potassium Deficiency in Plants
  • Potassium Toxicity in Plants
  • Mobility of Soil Potassium
  • Management of Soil Potassium
  • Calcium and Magnesium
  • Forms of Calcium and Magnesium Taken up by Plants
  • Calcium and Magnesium Deficiency in Plants
  • Calcium and Magnesium Toxicity in Plants
  • Management of Soil Potassium
  • Sulfur
  • Forms of Sulfur Taken up by Plants
  • Sulfur Deficiency in Plants
  • Sulfur Toxicity in Plants
  • Management of Soil Potassium
  • Micronutrients
  • Boron
  • Copper
  • Iron
  • Manganese
  • Molybdenum
  • Zinc