نتایج جستجو برای: nitrate leaching

تعداد نتایج: 42222  

2000
Birgitte Hansen Erik Steen Kristensen Ruth Grant Henning Høgh-Jensen Svend Erik Simmelsgaard Jørgen E. Olesen

The level of nitrogen leaching from organic compared to conventional farming was evaluated by using a systems modelling approach. Two different methods were used for estimating and evaluating nitrate leaching. A simple function was used in which nitrate leaching is dependent on percolation, soil clay content, average nitrogen input and crop sequence. A nitrogen balance model was used to estimat...

2007
R. W. Malone L. Ma D. L. Karlen T. Meade R. S. Kanwar

An accurate and management sensitive simulation model for tile-drained Midwestern soils is needed to optimize the use of agricultural management practices (e.g., winter cover crops) to reduce nitrate leaching without adversely affecting corn yield. Our objectives were to enhance the Agricultural Production Systems Simulator (APSIM) for tile drainage, test the modified model for several manageme...

2000
MengBo Li

Increasing nitrate levels in groundwater have been attributed to inappropriate nitrogen (N) management. The application rates, timing, and methods of both N fertilization and irrigation are important management tools that determine and control the fate and behavior of N in soilÿplant systems. For example, multiple applications with small amounts of fertilizer (e.g. split application) usually en...

2012
C. Colin Hollister James J. Bisogni Johannes Lehmann

137 Biochar (BC) was evaluated for nitrogen (N) and phosphorus (P) removal from aqueous solution to quantify its nutrient pollution mitigation potential in agroecosystems. Sorption isotherms were prepared for solutions of ammonium (NH4 +), nitrate (NO3 -), and phosphate (PO4–P) using BC of corn (Zea mays L.) and oak (Quercus spp.) feedstock, each pyrolyzed at 350 and 550°C highest treatment tem...

2017
N. L. Klocke Darrell G. Watts J. P. Schneekloth Don R. Davison R. W. Todd Anne M. Parkhurst

Nitrate-nitrogen leached from the root zone of land in intensive corn production is a major groundwater contaminant in some of the intensively irrigated regions of the western Cornbelt, including central and western Nebraska. To obtain a clearer understanding of the amount and timing of nitrate leaching losses from irrigated crops, 14 monolithic percolation lysimeters were installed in 1989-199...

Journal: :Proceedings of the New Zealand Grassland Association 1985

ژورنال: علوم آب و خاک 2018

The growth of world population and the demand for agricultural products can be regarded as one of the important issues that humanity has ever faced. There are serious concerns regarding surface and ground water pollution by nitrates because of using nitrogen fertilizers in the agriculture. Improving agricultural water management systems can reduce nitrate in drainage outflow and therefore, redu...

Journal: :اقتصاد و توسعه کشاورزی 0
آذر شیخ زین الدین عبدالکریم اسماعیلی منصور زیبایی

introduction: agricultural activities increasingly use water, fertilizers and pesticides, which may generate negative impacts on environment. nowadays, nitrogen leaching from agricultural lands is a widespread global problem. therefore, alternative land management practices such as nutrient management (rate, method and time of application), tillage operations (conservation and no-tillage), and ...

Journal: :Environmental pollution 2017
Jin Fu Rainer Gasche Na Wang Haiyan Lu Klaus Butterbach-Bahl Ralf Kiese

In this study water balance components as well as nitrogen and dissolved organic carbon leaching were quantified by means of large weighable grassland lysimeters at three sites (860, 770 and 600 m a.s.l.) for both intensive and extensive management. Our results show that at E600, the site with highest air temperature (8.6 °C) and lowest precipitation (981.9 mm), evapotranspiration losses were 1...

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