Author
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Alva, Ashok |
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Submitted to: Journal of Vegetable Crop Production
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 11/1/2003 Publication Date: 10/1/2004 Citation: Alva, A.K. 2004. Potato nitrogen management. Journal of Vegetable Crop Production. 10:97-130. Interpretive Summary: Technical Abstract: Management of nitrogen (N) fertilization, in terms of rate, timing, and method of application, influence the yield and quality of potatoes. Optimal management of N and irrigation is important to improve N uptake efficiency, and minimize N losses while maintaining high yields and quality. Management of these inputs become quite a challenge in sandy soils, which are vulnerable for leaching of water and soluble nutrients. Real-time continuous monitoring of soil water within and below the rootzone is important to improve scheduling of irrigation to ensure adequate supply of water for plant growth and tuber production, without the risk of excessive leaching of water below the rootzone, which can contribute to leaching of soluble nutrients. The field studies conducted at various production regions show that a combination of pre-plant and in-season N application program is necessary to increase N uptake efficiency, and produce high yields of high quality potatoes. The rates and timing of application of pre-plant and in-season N appeared to vary to some extent in different production regions. Excessive N applications contribute to excess vine growth at the expense of the tuber production. The production conditions must be favorable for translocation of N from vines to the tubers. Maintaining adequate supply of N availability in the soil is particularly important through the tuber bulking stage. Potato is generally grown in rotation with grain crops. In the Pacific Northwest of the United States, most common rotation sequence is: potato-wheat-corn. The vegetative residue from the preceding crop provides a source of available N, following decomposition of the vegetative residue and transformation of organic N into inorganic N forms, i.e. 'N mineralization'. The contribution of available N from mineralization of the organic N forms in the soil, to N requirement of potato should be investigated under various potato production regions to avoid the risk of application of N in excess of the crop N requirement. Analysis of petiole for NO3-N provides a convenient, rapid, and non-destructive technique for evaluation of N status in the plants. Critical limits of petiole NO3-N are established for different growth stages for only a few current cultivars. Further research is needed to examine if these critical concentrations are applicable across the other cultivars. |
