engleski

Influence of nitrogen fertilization on NO3-N concentration in lysimeter water

With the aim of determining the sustainable mineral nitrogen rates for fertilization of major field crops according to the yield and nitrate concentration in lysimeter water, as well as establishing the optimal rate of this nutrient, a stationary field trial with 10 treatments was set up in Central Croatia. Water leached through the soil to a 80 cm depth was caught by the installed zero tension pan lysimeters. On experimental plots, crops were grown in the following crop sequence: 1996. - maize (Zea mays), 1996/97. - winter wheat (Triticum aestivum), 1997/98. - oil rape (Brassica napus var oleifera) and 1999. - maize (Zea mays). NO3- N concentration in lysimeter water varied in dependence on the application time of mineral nitrogen fertilizers, temperature, and especially on the quantity and intensity of precipitation. In treatments without mineral nitrogen application, the average NO3- N concentration was relatively low (3.7 - 5.6 mg L-1 NO3- N). Increased rates of applied mineral nitrogen (fertilization with 200, 250 and 300 kg N ha-1) led to higher average values of NO3- N concentration in water (14.3 - 28.7 mg L-1 NO3- N).

nitrate nitrogen; leaching; lysimeter

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