烟地土壤氮素的氨化作用与硝化作用的强度变化

Changes of Ammonification and Nitrification Intensity of Soil Nitrogen in Tobacco Field

通过大田试验,探讨了不同施肥量下烟地土壤氮素氨化作用与硝化作用强度随烤烟生育期的变化规律,并在盆栽条件下,测定了不同土壤类型对土壤氮素氨化与硝化作用强度变化的影响。结果表明,烟地土壤氮素氨化作用与硝化作用强度的变化趋势与施肥量的多少、烟地土壤类型的不同无关。在烟草的伸根期,烟地土壤硝化作用强度最大,大田试验中高、中、低肥力下各表现为0.43 mg/kg、0.42 mg/kg0、.38 mg/kg。伸根期后硝化作用强度逐渐降低,至现蕾期时降至最低点,三种肥力下各表现为0.12 mg/kg、0.064 mg/kg0、.054 mg/kg,随后又大幅度回升。烟地的氨化作用强度则表现为在烤烟生长初期较低,大田试验中高、中、低肥力下各表现为0.23 mg/kg、0.16 mg/kg0、.047 mg/kg。随着烤烟生育期的变化,氨化作用强度逐渐增大,至使其成熟中期出现最高峰,三种肥力下各表现为7.87 mg/kg6、.46 mg/kg6、.02 mg/kg,随后呈下降趋势。

The field and pot experiments were conducted to investigate the change law of ammonification and nitrification intensity of the soil nitrogen in tobacco field at different growth stages under different application amounts and effects of different soil types on change of ammonification and nitrification intensity of the soil nitrogen. The results show that there is no correlation between the change of ammonification and nitrification intensity and the application amount or soil types. The nitrification intensity of tobacco soil is up to maximum at the elongation stage of tobacco roots, decreases step by step after the elongation stage of tobacco roots, is the lowest at the squaring stage of tobacco plants and goes up again greatly after the squaring stage of tobacco plants. The ammonification intensity of tobacco soil is lower at the early growth stage of tobacco plants, increases step by step after the early growth stage of tobacco plants, is up to maximum at the middle ripening stage and declines after the middle ripening stage.