Journal article

Publication year: 2022

Pages: 2516-2529

Journal: Journal of Soils and Sediments

Volume number: 22

Issue number: 9

ISSN: 1439-0108

eISSN: 1614-7480

DOI Link: https://doi.org/10.1007/s11368-022-03246-4

Publisher: Springer

Abstract: 

Purpose: Knowledge of nitrogen (N) dynamics of organic fertilisers as partial substitutes for chemical fertilisers could improve the retention of mineral N and optimise fertilisation practices in paddy soils. Materials and methods: 15 N tracing was performed to quantify the effect of 36 years of partial substitution of chemical N by organic N on gross N transformation rates in soils, and its relationship to organic N fractions. Treatments were chemical fertilisation (NPK), substitution of chemical N with 30%, 50% and 70% organic N (70F + 30 M, 50F + 50 M and 30F + 70 M), and no fertilisation (control). Results and discussion: Partial substitution elevated N mineralisation, ammonium immobilisation, autotrophic nitrification and nitrate consumption rates by 58.4-609.3%, 36.0-304.2%, 0.5-320.0% and 51.4-112.6%, respectively, compared to NPK treatment. However, gross N transformation rates differed with varying organic N substitution proportions. Fifty percent substitution increased mineralisation and immobilisation of the labile organic N pool by increasing the level and distribution of amino acid N fractions in acid-hydrolysable N, resulting in the highest N supply and retention capacity and the lowest N loss potential. Thirty percent substitution also increased the supply and retention capacity of nitrogen, but its integrated effect was inferior to the 50% substitution treatment. However, 70% substitution increased the potential loss of nitrate by increasing the ratio of gross nitrification rate to gross ammonia immobilisation rate (N/I). Partial substitution also increased the yield by 4.26-6.91% (p < 0.05), but there were no significant differences between organic N substitution proportions. Conclusion: Thus, accumulating active fractions of the soil organic N pool enhanced soil N supply and mineral N retention in acidic rice fields. Given optimal sustainable agricultural practices, and considering yield, N retention and potential N losses, a 50% substitution of chemical N with organic N can be recommended for the study region.

Harvard Citation style: Hou, H., Liu, X., Zhou, W., Ji, J., Lan, X., Lv, Z., et al. (2022) N transformation mechanisms and N dynamics of organic fertilisers as partial substitutes for chemical fertilisers in paddy soils, Journal of Soils and Sediments, 22(9), pp. 2516-2529. https://doi.org/10.1007/s11368-022-03246-4

APA Citation style: Hou, H., Liu, X., Zhou, W., Ji, J., Lan, X., Lv, Z., Liu, Y., Zhang, J., & Müller, C. (2022). N transformation mechanisms and N dynamics of organic fertilisers as partial substitutes for chemical fertilisers in paddy soils. Journal of Soils and Sediments. 22(9), 2516-2529. https://doi.org/10.1007/s11368-022-03246-4