No abstract

for crop nutrient removal are an important component of nutrient management planning and crop production. Effective nutrient management requires an accurate accounting of Although state agronomy guides and other sources nutrients removed from soils in the harvested portion of a crop. Because the typical crop nutrient values that have historically been used often publish values for crop nutrient removal, the origimay be different under current production practices, a study was nal studies on which those values are based are seldom conducted to measure nutrient uptake in grain harvested in 1998 and cited. Also, the values that were established in the past 1999 from 23 site-years in the Mid-Atlantic region of the USA. There may not be correct for current agronomic technologies were 10 hybrids included in the study, but each site grew only one such as hybrid, higher plant population, yield potential, hybrid each year. Corn (Zea mays L.) production practices followed fertilizer practice, and soil conditions. Furthermore, local state extension recommendations. Minimum, maximum, and there is a need to re-evaluate crop nutrient removal mean corn grain yields were 4.9, 16.7, and 10.3 Mg ha Ϫ1. Nutrient values for corn as several states in the Mid-Atlantic concentrations were determined on grain samples oven-dried at 70؇C USA now mandate the development of comprehensive for 24 h. Minimum, maximum, and median nutrient concentration nutrient management plans (Simpson,

for crop nutrient removal are an important component of nutrient management planning and crop production. Effective nutrient management requires an accurate accounting of Although state agronomy guides and other sources nutrients removed from soils in the harvested portion of a crop. Because the typical crop nutrient values that have historically been used often publish values for crop nutrient removal, the origimay be different under current production practices, a study was nal studies on which those values are based are seldom conducted to measure nutrient uptake in grain harvested in 1998 and cited. Also, the values that were established in the past 1999 from 23 site-years in the Mid-Atlantic region of the USA. There may not be correct for current agronomic technologies were 10 hybrids included in the study, but each site grew only one such as hybrid, higher plant population, yield potential, hybrid each year. Corn (Zea mays L.) production practices followed fertilizer practice, and soil conditions. Furthermore, local state extension recommendations. Minimum, maximum, and there is a need to re-evaluate crop nutrient removal mean corn grain yields were 4.9, 16.7, and 10.3 Mg ha Ϫ1. Nutrient values for corn as several states in the Mid-Atlantic concentrations were determined on grain samples oven-dried at 70؇C USA now mandate the development of comprehensive for 24 h. Minimum, maximum, and median nutrient concentration nutrient management plans (Simpson,

No abstract

Tremendous changes have occurred during the past century in the sources and methods for supplying nutrients for horticultural crops. Reliance on animal manure, cover crops, and animal tankage was insufficient to meet the crop nutrient demand for a rapidly expanding population. The Haber-Bosch process for ammonia synthesis (1910s) revolutionized the availability and affordability of nitrogen (N) fertilizer. Discovery of large-scale deposits of rock phosphate in South Carolina (1860s) and Florida (1880s) alleviated widespread nutrient deficiencies. Acidification of rock phosphate and bone material significantly improved phosphorus (P) availability for plants. Discovery of potassium (K)-bearing minerals in New Mexico (1920s) and later in Canada (1960s) now provide a long-term nutrient source. Modern fertilizer technology allows nutrients to be applied in the correct ratio and amount to meet crop needs. Advances in understanding plant nutrition, coupled with slow-release fertilizers, foliar fertilization, soluble nutrients, and the development of soil and tissue testing have all improved the yield and quality of horticultural crops. Future developments will likely focus on fertilization in an increasingly competitive global economy, while requiring sophisticated management to minimize environmental impacts.