Journalartikel

Jahr der Veröffentlichung: 2022

Zeitschrift: Soil Biology and Biochemistry

Bandnummer: 174

ISSN: 0038-0717

eISSN: 1879-3428

Open Access Status: Bronze

DOI Link: https://doi.org/10.1016/j.soilbio.2022.108817

Verlag: Elsevier

Abstract: 

Long-term application of high doses of N fertilizer to achieve high yields has led to a significant accumulation of soil N (largely in the form of NO₃⁻) in greenhouse vegetable production (GVP). At present, it is not clear how efficiently vegetables can use the NO₃⁻ accumulated in soil and from which source the N taken up by vegetables in GVP originates. In this study, three greenhouse soils with various degrees of soil NO₃⁻ accumulation (N1 15N tracing pot experiments. The amount of N derived from soil (ANDFS), N use efficiency (NUE) of cucumbers, and gross N transformation rates were investigated to explore processes leading to the accumulation of NO₃⁻ in soil and how available this N is for N uptake by cucumbers. The results showed that the percentage of N derived from soil of cucumbers were 72–89% in greenhouse soils. ANDFS and NUE values of cucumbers decreased with NO₃⁻ accumulation. Plant NH₄⁺ uptake (U_NH4) was one of the main factors regulating NUE and ANDFS. Soil gross N mineralisation rates (M) were 2.5- and 3.0-fold higher in N1 than in N2 and N3, respectively, while autotrophic nitrification rates (O_NH4) were significantly lower in N1 and N2 (by 4.31 and 4.25 mg N kg⁻¹ day⁻¹) than N3 (9.44 mg N kg⁻¹ day⁻¹). This resulted in significantly higher O_NH4/M ratios in soils with relatively higher NO₃⁻ accumulation, which reduced the amount of NH₄⁺ available to cucumbers and inhibited U_NH4, in turn, reducing ANDFS and NUE. Higher O_NH4 in soils with relatively high NO₃⁻ accumulation could result in fertilizer-derived NH₄⁺ being rapidly oxidised to NO₃⁻, leading not only to lower NUE but also to greater NO₃⁻ accumulated in soil due to a lower plant NO₃⁻ uptake rate. High soil electrical conductivity (EC) in N2 and N3 caused salt stress in cucumber plants and inhibited plant N uptake, resulting in low ANDFS and NUE. These results demonstrate that NO₃⁻ that is accumulated and newly mineralized in soil is available for cucumbers, and should be considered together with the prevailing soil N transformations in N fertilizer recommendations for GVP. Combined application of NH₄⁺ fertilizer (e.g. in form of urea) with nitrification inhibitors is recommended to increase NH₄⁺ retention and enhance NUE and utilisation of soil accumulated and newly mineralized NO₃⁻ by cucumbers.

Harvard-Zitierstil: Dan, X., Meng, L., He, M., Chen, S., He, X., Zhao, C., et al. (2022) Gross N transformations and plant N use efficiency in intensive vegetable production soils, Soil Biology and Biochemistry, 174, Article 108817. https://doi.org/10.1016/j.soilbio.2022.108817

APA-Zitierstil: Dan, X., Meng, L., He, M., Chen, S., He, X., Zhao, C., Li, X., Cai, Z., Zhang, J., & Müller, C. (2022). Gross N transformations and plant N use efficiency in intensive vegetable production soils. Soil Biology and Biochemistry. 174, Article 108817. https://doi.org/10.1016/j.soilbio.2022.108817