Further reductions in pollution will require new management approaches based on ecosystem concepts. In this paper we examine three case studies that analyze flows of nutrients in urban ecosystems to identify new approaches for pollution management. An analysis of the food chain for the Twin Cities (Minneapolis-St. Paul, Minnesota, USA) is used to examine generation of nutrient pollution in the ...

to evaluate the effects of phosphate solubilizing bacteria and chemical phosphorous fertilizer on turnip (brassica rapa) forage yield under limited irrigation regimes, a field experiment was conducted in research farm of college of agriculture and natural resources, university of tehran, in karaj/iran during 2009 growing season. the experimental treatments were arranged as split plots. five lev...

Commonly N release from legume residues is rapid in the tropics. Legume mixtures with grasses can result in slower nutrient release from residues, better matching the N requirements of the following crop. The objectives of this study were to evaluate the effects of the green manures sunnhemp (Crotalaria juncea) and millet (Pennisetum glaucum), alone or mixed, on the performance of a subsequent ...

Excessive use of animal manure on agricultural lands can impact the quality of surface and groundwater resources. A three–year study (1998–2000) was conducted on nine 0.4–ha plots and on six 2.1–m 2 lysimeters to investigate the effect of two nitrogen (N) application rates from laying hen manure and one N application rate from urea ammonium nitrate (UAN) fertilizer on surface and groundwater qu...

introduction: an appropriate water resources management and planning is necessary due to the scarcity of water resources and rapidly growing world population. in this regard, selecting appropriate methods for irrigation is one of the most important issues. drip irrigation is a recent advanced irrigation method in which fertilizers can be efficiently applied along with irrigation water. drip fer...

BACKGROUND: Fertilizer management plays an important role for obtaining satisfactory yields and to increase crop productivity. Improve saving water in irrigated agriculture and thereby improving water use efficiency is of paramount importance in water-scarce regions. OBJECTIVES: This study was conducted to assessment effect of different levels of irrigation re...

in order to study the effects of integrative applications of chemical fertilizers and biofertilizers on grain yield and oil of borago officinalis under water deficit stress, a field experiment was conducted at kermanshah, iran, in 2011. experiment was arranged as split plot under a randomized complete block design with 3 replications. water deficit stress with four levels was applied as the mai...

water scarcity in arid and semi-arid climate of iran has made deficit irrigation as a strategy for optimal water use and conservation in agricultural sector. this study aimed at evaluating the effects of water-deficit stress and n fertilizer levels on sugar beet performance. the study was conducted in split block design based on randomized complete block design arrangement. the row factor consi...

A study on monitoring of nitrogen (N) leaching was conducted in acidsulfate clayey soil in the central region of Thailand. The objective was to measure the N leaching to shallow groundwater from a tropical paddy field to assess the consequences of agricultural management practices. Mass balance approach was used to estimate the contribution of nitrogen fertilizer to the water environment. The N...