The comparison of nitrogen mineralisation assessment methods between aerobic incubation and greenhouse pot experiment
Oka Banaty1, Koen Wilekins2, Stefaan De Neve3
1Ghent University, Environment, Belgium
Laboratory incubation methods are frequently used to predict N mineralisation potential from the soil organic. However, the assessment of N mineralisation from the incubation methods has sometimes been overestimated or underestimated compared to the field measurements. These could be related to biotic factors, such as root exudates of the grown plant, which might affect N mineralisation. Meanwhile, the greenhouse pot experiment method with crops has also been used to determine potential N mineralisation, generating a more accurate prediction for fertiliser requirements. Notwithstanding, no studies broadly report the relationship between mineralised N from laboratory incubation and greenhouse pot experiment methods. Therefore, it is crucial to investigate laboratory incubation and pot experiments in the greenhouse that could involve the N uptake by plants. Thus, this study aimed to evaluate the correlation between N mineralisation from aerobic incubation with pot experiments in the greenhouse. Ten soil samples without adding fertiliser were set up for laboratory aerobic incubation using fresh soil and air-dried soil, and greenhouse pot experiments were unplanted and planted entire 98 days. The soils were collected from arable agricultural fields in Flanders, Belgium. Linear correlations analyses were performed to test the relationship between the measurement methods of N mineralised from laboratory incubation and greenhouse pot experiment. The results showed that the relationship between N mineralised from laboratory aerobic incubation using fresh soil or air-dried soil was significantly correlated with planted pot experiment in the greenhouse when expressed in relative, at days 42, 70 and 98 (P < 0.05). Nevertheless, the N mineralisation between the unplanted pot experiment and aerobic incubation was only significantly associated with using fresh soil on day 42. This study confirmed that the laboratory aerobic incubation using fresh and air-dried soil was reliable with the greenhouse pot experiment methods with plants to predict N mineralisation from soil organic matter.
Keywords: Aerobic incubation, greenhouse pot experiment, N mineralisation
Contact Address: Oka Banaty, Ghent University, Environment, Coupure links 653, 9000 Ghent, Belgium, e-mail: okaardia.okaardianabanatyugent.be