Ploughing in sugar beet tops and the effect on the content of mineral nitrogen in the soil during spring barley cultivation
2000
Provaznik, K. | Richter, R. | Zimolka, J. (Mendelova Zemedelska a Lesnicka Univ., Brno (Czech Republic))
Changes in the soil content of nitrogen were studied in field experiments conducted in 1997 to 1999 in a maize-growing region, 184 m altitude, average annual temperature 9.2 degr C and sum of precipitation 484 mm. The beet tops were incorporated in mid-October (variant A) and mid-November (variant B). Variant C was grown without beet tops. Early incorporation of the beet tops into the soil significantly increased the content of nitrate nitrogen in the soil compared with the variant where the tops were incorporated late. The nitrogen doses in the mineral fertiliser increased the content of nitrate nitrogen in the soil. Small changes were observed in the content of ammonia nitrogen which was influenced more by weather of the respective year and by mineral fertilisation than by the beet tops. The value of the index of nitrification (IN), which characterises the nitrites /ammonia nitrogen ratio, showed that after early incorporation of the beet tops the major part of nitrogen was transformed to nitrate, while after late incorporation of the beet tops the IN value was not balanced until one month later when the demands of barley for nitrogen were lower.
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