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Two dimensional modelling of nitrate flux in a commercial apple orchard
Citation
Hardie, M, Two dimensional modelling of nitrate flux in a commercial apple orchard, Soil Science Society of America Journal, 81, (5) pp. 1235-1246. ISSN 0361-5995 (2017) [Refereed Article]
Copyright Statement
© Soil Science Society of America
DOI: doi:10.2136/sssaj2017.01.0029
Abstract
Extensive in situ monitoring in a young commercial apple orchard demonstrated that current management practices resulted in leaching of 56 to 84 kg ha1 yr1 of nitrate below the topsoil. The Hydrus 2D/3D suite of models was used to determine the effect of current management practices on nitrate leaching and explore options for reducing irrigation and nitrate loss. The models were parameterized using measured soil water retention data and calibrated using field data collected over a 596-d period. The orchard was found to be profoundly leaky with between 15 and 33% of the average annual rainfall being lost via runoff and deep drainage under rainfed conditions. Simulations estimated that the current management of the young trees resulted in loss of 38.1 kg N ha1 yr1 or 46% of the applied nitrate, and 34.6 cm yr1 of rainfall and irrigation as drainage below 2.0 m depth. For mature trees, our model scenarios predicted that converting from sprayers to drippers, would reduce the required irrigation by 44%, reduce nitrate requirement by 21%, and reduce deep drainage and nitrate leaching by 37%. Deficit-based irrigation and fertigation scheduling had minimal effect on the amount of deep drainage and nitrate leaching. In mature trees, excluding green fowl manure from the fertilizer regime was predicted to reduce the amount of nitrate leached below the soil profile by 12.9 kg N ha1 yr1 or by 73%. However rates of NPK and fertigation needed to be increased to meet tree nitrogen demand.
Item Details
Item Type: | Refereed Article |
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Keywords: | Hydrus, nitrate, apple modelling, leaf area index, one dimensional, two dimensional, 1D, 2D, LAI |
Research Division: | Environmental Sciences |
Research Group: | Soil sciences |
Research Field: | Soil physics |
Objective Division: | Environmental Management |
Objective Group: | Terrestrial systems and management |
Objective Field: | Evaluation, allocation, and impacts of land use |
UTAS Author: | Hardie, M (Mr Marcus Hardie) |
ID Code: | 121750 |
Year Published: | 2017 |
Web of Science® Times Cited: | 7 |
Deposited By: | Tasmanian Institute of Agriculture |
Deposited On: | 2017-10-13 |
Last Modified: | 2018-05-24 |
Downloads: | 0 |
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