dc.contributor.author |
Tesfamariam, Eyob Habte
|
|
dc.contributor.author |
Annandale, John George
|
|
dc.contributor.author |
Steyn, J.M. (Joachim Marthinus), 1963-
|
|
dc.contributor.author |
Stirzaker, Richard John
|
|
dc.contributor.author |
Mbakwe, Ikenna
|
|
dc.date.accessioned |
2016-11-07T06:56:59Z |
|
dc.date.available |
2016-11-07T06:56:59Z |
|
dc.date.issued |
2015-04 |
|
dc.description.abstract |
Process-based computer simulation models are often used as reasoning support tools to integrate the
complex processes involved in the soil-plant-atmosphere system. The objectives of this study were to
evaluate the performance of the SWB-Sci model as a reasoning support tool for sludge management in
agricultural lands, and use the validated model to assess the long-term agronomic and environmental
implications of water availability and crop intensity on sludge-amended land. The model was calibrated
for the test crops, maize (Zea mays Pan6966) and oats (Avena sativa L.), using data collected during the
2004/2005 growing season from irrigated plots at the East Rand Water Care Works, Gauteng, South
Africa. Model validation was performed using independent data sets collected during the 2004/2005 to
2007/2008 growing seasons. The model was successfully calibrated for maize and oats as allthe statistical
parameters were within the prescribed ranges [index of agreement (d) >0.8; relative mean absolute
error (MAE%) <20%; coefficient of determination (R2) >0.8]. The results indicate that SWB-Sci simulated
aboveground biomass (TDM) and grain yield (GY) of maize and oats with high accuracy (d > 0.85, MAE%
≤20%, and R2 > 0.91) but with a slight overestimation by 0.2–4 Mg ha−1. The model predicted nitrate
leaching and crop N uptake reasonably well(d > 0.85,MAE% ≤14%, and R2 > 0.8), withslight overestimation
of TDM and GY N uptake by 11–57 and 4–48 kg ha−1, respectively. Long-term model simulations indicate
that fixed sludge application rate recommendations generated from laboratory incubation studies may
in the long-term result in spontaneous excessive nitrate leaching below the active root zone during high
rainfall events, if recommendations do not consider N contribution from soil organic matter. Modelling
also showed that leaving room for rain during each irrigation event may minimize the risk of nitrate
leaching |
en_ZA |
dc.description.department |
Plant Production and Soil Science |
en_ZA |
dc.description.librarian |
hb2016 |
en_ZA |
dc.description.sponsorship |
The Water Research Commission of South Africa (WRC), East Rand Water Care Works (ERWAT), and Technology and Human Resources for Industry Programme (THRIP). |
en_ZA |
dc.description.uri |
http://www.elsevier.com/locate/agwat |
en_ZA |
dc.identifier.citation |
Tesfamariam, EH, Annandale, JG, Steyn, JM, Stirzaker, RJ & Mbakwe, I 2015, 'Use of the SWB-Sci model for nitrogen management in sludge-amended land', Agricultural Water Management, vol. 152, pp. 262-276. |
en_ZA |
dc.identifier.issn |
0378-3774 |
|
dc.identifier.other |
10.1016/j.agwat.2015.01.023 |
|
dc.identifier.uri |
http://hdl.handle.net/2263/57676 |
|
dc.language.iso |
en |
en_ZA |
dc.publisher |
Elsevier |
en_ZA |
dc.rights |
© 2015 Elsevier B.V. All rights reserved. Notice : this is the author’s version of a work that was accepted for publication in Agricultural Water Management. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. A definitive version was subsequently published in Agricultural Water Management, vol. 152, pp. 262-276, 2015. doi : 10.1016/j.agwat.2015.01.023. |
en_ZA |
dc.subject |
Nitrogen |
en_ZA |
dc.subject |
Modelling |
en_ZA |
dc.subject |
Irrigation |
en_ZA |
dc.subject |
Nitrate leaching |
en_ZA |
dc.subject |
Maize |
en_ZA |
dc.subject |
Oats |
en_ZA |
dc.title |
Use of the SWB-Sci model for nitrogen management in sludge-amended land |
en_ZA |
dc.type |
Postprint Article |
en_ZA |