Introduction

Optimum growth of turf, flowers, fruits, and vegetables depends on many management factors, one of which is ensuring a sufficient supply of plant nutrients. There are at least 17 essential elements required for plant growth: carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, iron, manganese, zinc, copper, boron, molybdenum, chlorine, and nickel. Plants obtain carbon, hydrogen, and oxygen from air and water. The remaining elements are derived from the soil. When the soil cannot supply the amount of these nutrients required for adequate growth, supplemental fertilizer applications become necessary. Many urban soils are disturbed during the construction process. Top soil is often scraped off and removed and, as a result, nutrient and organic matter levels are often lower in these disturbed sites than in native soils. Adding organic matter as well as fertilizer may be necessary to improve the growth of plants on these sites.