The effect of long-term fertilization on the content of mineral nitrogen in soil
1995
Petr, J. (Statni Kontrolni a Zkusebni Ustav Zemedelsky, Lipa (Czech Republic)) | Vanek, V. | Prochazka, J. | Najmanova, J.
The content of soil mineral N in early spring and after the harvest of crops (beginning September) was studied in two sites at Lipa and Svitavy (in the Czech Republic) in 1991-1993 in long-term stationary trials. Trials were arranged in eight-plot crop rotation with 50 % cereals, 25 % forage and 25 % root crops. High content of mineral N was found in spring 1991 in the clover stand (20.7 to 40.1 ppm N), but also in autumn after incorporation of clover (20.7 to 30.1 ppm). Most of determined mineral N was in ammonium form. Marked increase in mineral N was found in autumn 1993 in treatments fertilized by gradated doses of NPK in combination with manure (applied in autumn 1992). Gradated fertilization of P and K did not affect more significantly the content of mineral N.
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