ABSTRACT
High yield in maize is closely associated with nitrogen (N) application, but only where other inputs and management practices are optimal. N interacts positively with plant population, earliness of sowing, variety, weed control and moisture supply. N fertilizer application is best scheduled in accordance with this pattern of uptake in order to avoid serious losses by volatilization or leaching and to ensure that N levels are high in the soil when the crop demand is also high. Maize can suffer from a number of micronutrient deficiencies. However, zinc deficiency is perhaps the most widespread problem. Maize accumulates phosphorus throughout the growing season with maximum uptake occurring between 3 and 6 week of growth. Phosphorus uptake is generally paralled to dry matter accumulation, proceeding slightly ahead of dry matter accumulation early in the season and lagging behind somewhat later on.
