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Uptake of 15N labeled nitrate by root systems of sweet corn, carrot and white cabbage from 0.2-2.5 meters depth

Kristensen, Hanne L. and Thorup-Kristensen, Kristian (2004) Uptake of 15N labeled nitrate by root systems of sweet corn, carrot and white cabbage from 0.2-2.5 meters depth. Plant and Soil, 265, pp. 93-100.

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Online at: https://link.springer.com/article/10.1007/s11104-005-0696-y

Summary

Leaching of NO3− from vegetable cropping systems can be very high compared to arable systems. This is a problem for vegetable growers in general as it decreases groundwater quality, and for organic growers in particular as the organic production is often limited by N. In a field experiment, we investigated the N uptake and root growth of three vegetables using minirhizotrons reaching 2.4 m with the purpose to study the relationship between vegetable root distribution and uptake of NO3− from deep soil layers. NO3− uptake was studied over a 6 d period at the end of September by injection of 15 NO3− at four depths in the ranges: 0.2–0.8, 0.6–1.8, and 1–2.5 m under late sweet corn (Zea mays L. convar. Saccharata Koern.), carrot (Daucus carota L.), and autumn white cabbage (Brassica oleracea L. convar. capitata (L.) Alef. var. alba DC), respectively. The root depths of the three crops were 0.6, 1.3, and more than 2.4 m, respectively. Uptake of15N was close to zero from placements below root depth, and linear relationships were found between root density and15N uptake from different depths. N inflow rates (uptake per unit root length) were in the same range for all species and depths. This indicates that the very different N use efficiencies often found for vegetable crops depend on species specific differences in root development over time and space, more than on differences in N uptake ability of the single root. Thus deep rooting is important for deep N uptake. Knowledge about deep root growth enables design of crop rotations with improved N use efficiency based on re-cycling of deep soil NO3− by vegetables.


EPrint Type:Journal paper
Subjects: Crop husbandry > Crop combinations and interactions
Soil
Crop husbandry > Production systems > Vegetables
Environmental aspects
Research affiliation: Denmark > DARCOF III (2005-2010) > VEGQURE - Organic cropping Systems for Vegetable production
Denmark > AU - Aarhus University > Faculty of Science and Technology
ISSN:0032-079X
Deposited By: Kristensen, Ph.D. Hanne Lakkenborg
ID Code:32023
Deposited On:14 Aug 2017 12:36
Last Modified:14 Aug 2017 12:36
Document Language:English
Status:Published
Refereed:Peer-reviewed and accepted

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