ABSTRACT
Based on the fertilizer experiments conducted in different regions with improved varieties, fertilizer dose is recommended for each environment. Increasing nutrient efficiency is the key to the management of soil fertility. The proportion of the added fertilizer actually used by plants is a measure of fertilizer efficiency. Soil characteristics, crop characteristics and fertilizer management techniques are the major factors that determine fertilizer efficiency. In dry land agriculture, limited water availability is usually the factor that ultimately limits crop production. Fertilizer practices greatly affect nutrient cycling and availability in rainfed conditions. Recent advances in technology have combined the Global Positioning System (GPS) of earth-obtaining satellites, computer programs capable of making detailed maps that integrate information about many soil properties, and technologies that allow farm equipment to alter the rate of fertilizer, seed or chemical delivery on the go.
