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| Submitter's Name |
Andre Luiz Biscaia Ribeiro Da Silva |
| Session Name |
Poster Session - Agricultural/Silvicultural Water |
| Poster Number |
2 |
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| Author(s) |
Andre Luiz Biscaia Ribeiro da Silva, Horticultural Sciences Department, University of Florida (Presenting Author) |
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Lincoln Zotarelli,
Horticultural Sciences Department, University of Florida |
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Michael Dukes, Agricultural and Biological Engineering Department, University of Florida |
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Kati Migliaccio, Agricultural and Biological Engineering Department, University of Florida |
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Edzard van Santen, Agronomy Department, University of Florida |
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Spatial and temporal distribution of soil N under four irrigation systems as function of N fertilizer rate and timing of application in potatoes |
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Agricultural areas with coarse-texture soils and shallow water table may require greater nitrogen (N) fertilizer supplementation than plant N requirements, which leads to N losses irrigation are not properly managed. The study objective was to evaluate the spatial and temporal distribution of soil N in coarse texture soils under seepage, tile drainage, subsurface drip (SDI) and sprinkler irrigation under a combination of different N fertilizer rates and timings of application. A factorial randomized complete block design with three N rates (0, 56, 112 kg.ha-1) applied at planting (Npl) and two N rates (56 and 112 kg.ha-1) at emergence (Neme) and at tuber initiation (Nti) was setup within each irrigation system for two seasons in Hastings, FL. Soil mineral N was determined in the 0-15, 15-30 and 30-60 cm soil depth layers at five-potato growth stages. Under seepage, tile drainage and SDI the water table was raised to irrigated the crop and the upward soil water flux held soil N longer in the root zone compared to sprinkler. A combined management of water table level and sprinkler irrigation can potentially reduce the downward movement of soil N. The application of 112 kg.ha-1 of N at planting resulted in higher soil residual N at the harvest compared to 56 kg.ha-1 in 2015 due to lower precipitation compared to 2016. Nti above 56 kg.ha-1 of N increased soil N at tuber maturation stage but there was no increase in tuber yield. In 2016 regardless of irrigation system and N rates, soil N concentration was lower than 5.8 mg.kg-1 at the potato harvest. The application of 56, 112 and 56 kg.ha-1 of N fertilizer at Npl, Neme and Nti, respectively, provided enough N to supply the potato crop with lowest soil N residual. |
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