Potato requires high levels of nitrogen fertilizer. Up to now in Quebec, no nitrogen fertilizer recommendation has been based on nitrogen availability in the soil, even those soil nitrogen testing is available. The objectives of this study were: (1) to determine the relation between soil nitrate-N content, nitrogen fertilization and potato yield; and (2) to determine the time and the sampling depth of soil most appropriate to predict potato yields and response to nitrogen fertilizer under Quebec conditions. Soil samples were taken at two depths at planting and at hilling time in 28 sites fertilized at four levels of nitrogen. Laboratory measures of nitrate-N were carried out on those samples. A combination of nitrate-N and nitrogen fertilisation gave the best explanation of the variation potato yields. A maximum of 46% of yield variation was attributed to the combination of those two factors in general. Best coefficients of determination were obtained when the sampling of nitrate-N was done at planting time compared to time. Regression models predicted nitrogen fertilizer needs of 89 to 200 kg ha$ sp{-1}.$ The same conclusions were found in the case of the variety Superior alone. The variation of yield explained was up to 62%. Regression models predicted nitrogen fertilizer needs of 77 to 224 kg ha$ sp{-1}$ for Superior. It was concluded that the analysis of soil nitrate-N can improve the prediction of nitrogen fertilizer needs for an optimum potato production.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.27896 |
| Date | January 1997 |
| Creators | Painchaud, Jacques. |
| Contributors | Mackenzie, A. E. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | French |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Natural Resource Sciences.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001619877, proquestno: MQ37155, Theses scanned by UMI/ProQuest. |
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