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Addition Of Gel-Forming Hydrophilic Polymers To Nitrogen Fertilizer Solutions, Robert Mikkelsen, A David Behel
Addition Of Gel-Forming Hydrophilic Polymers To Nitrogen Fertilizer Solutions, Robert Mikkelsen, A David Behel
Robert Mikkelsen
Environmental and economic concerns are causing a search for more effective fe rtilizer products and improved methods for managing existing fertilizers. This laboratory and greenhouse study was conducted to determine if the addition of gel-forming hydrophilic polymers to N fertilizer solutions could reduce N leaching loss and increase plant uptake of N. In the first experiment, a solution of urea ammonium nitrate (UAN, 32% N) was mixed with a variety of polymers at three concentrations, band applied to a sandy soil, and leached weekly for six weeks. Nitrogen leaching losses were reduced from 0 to 45% during the first four …
Controlled-Release Fertilizers To Increase Efficiency Of Nutrient Use And Minimize Environmental Degradation - A Review, Avi Shaviv, Robert Mikkelsen
Controlled-Release Fertilizers To Increase Efficiency Of Nutrient Use And Minimize Environmental Degradation - A Review, Avi Shaviv, Robert Mikkelsen
Robert Mikkelsen
Total world consumption of fertilizer N, P2 O5, and K2O in 1990 / 1991 was 78. 37. and 26 million tons per annum respectively, with a projected yearly increase of demand of about 2 to 3% . Trends in crop production (maize and wh eat) in the last four decades s how that N application rates increased about 15 times whereas its accumulation in grain increased only 3 to 4 times. At the same time nutrient recovery by crops remained relatively low (e .g. a bout 50% for N). This represents a potentially alarming situation from environmental, economic and resource …