Characterizing root nitrogen uptake of wheat to simulate soil nitrogen dynamics
- 931 Downloads
Background and aims
Michaelis-Menten (MM) kinetics and a physical–mathematical (PM) model are the popular approaches to describe root N uptake (RNU). This study aimed to examine RNU and compare the two model approaches.
A hydroponic experiment (Exp.1) investigated the effects of root length, root N mass, transpiration, plant age and solution N concentration on RNU of wheat (Triticum aestivum L. cv. Jingdong 8). The two models were applied to simulate the RNU and soil N dynamics in a soil–wheat system (Exp.2), and the results were compared to the measured data.
Under the hydroponic conditions, RNU was better correlated with root N mass and transpiration than root length. The influences of solution N concentration on RNU rate per root length (MM1) and RNU rate per root N mass (MM2) were described well with MM kinetics. The kinetic parameters for MM1 changed with plant age but the parameters for MM2 were not age dependant. The description of RNU with the PM model was also independent of plant age, and was more reliable when the RNU factor decreased as a power function with the solution N concentration (PM2) than an assumed constant (PM1). In Exp.2, the root mean squared errors between the simulated and measured soil solution N concentration and the relative errors between the simulated and measured N uptake mass for MM kinetics were much larger than those for the PM model.
Both the MM and PM models successfully described RNU under the hydroponic conditions, but the PM model (especially PM2) was more reliable than the MM model in the soil–wheat system.
KeywordsRoot water uptake Root N mass Root length Michaelis-Menten Uptake modeling
Days after planting
High water and high N supply
High water and low N supply
Low water and high N supply
Low water and low N supply
Root N mass
Root N uptake
Root water uptake
This research was supported partly by the Non-profit Industry Financial Program of MWR, China (200901083) and the National Natural Science Foundation of China (50809071). This study was partially completed while Jianchu Shi was visiting the Gilat Research Center of Israel’s Agricultural Research Organization. We thank the Agricultural Research Organization/China Scholarship Council Joint Scholarship Scheme for this opportunity.
- Barber SA (1995) Soil nutrient bioavailability: a mechanistic approach. 2nd ed. John Wiley, New York, pp 69–132Google Scholar
- Epstein E, Bloom AJ (2005) Mineral nutrition of plants: principles and perspectives, 2nd ed. Sinauer, SunderlandGoogle Scholar
- Feddes RA, Kowalik P, Zarandy H (1978) Simulation of field water use and crop yield. Pudoc Wageningen, pp189Google Scholar
- Hopmans JW, Bristow KL (2002) Current capabilities and future needs of root water and nutrient uptake modeling. Adv Agron 77:104–175Google Scholar
- Jones JB Jr (1998) Plant nutrition manual. CRC press, Boca Raton, pp 1–54Google Scholar
- Jungk AO (2002) Dynamics of nutrient movement at the soil–root interface. In: Waisel Y, Eshel A, Kafkafi U (eds) Plant roots, the hidden half. Marcel Dekker, Inc, New York, pp 587–616Google Scholar
- Liu Z, Zhu S, Yuan H (2004) Encyclopedia of water science in China, irrigation and drainage div (in Chinese). China Water Power Press, Beijing, p 87Google Scholar
- Marschner H (1995) Mineral nutrition of higher plants, 2nd ed. Academic, San DiegoGoogle Scholar
- Oscarson P, Ingemarsson B, Larsson CM (1989) Growth and nitrate uptake properties of plants grown at different relative rates of nitrogen supply. II. Activity and affinity of the nitrate uptake system in Pisum and Lemna in relation to nitrogen availability and nitrogen demand. Plant Cell Environ 12:787–794CrossRefGoogle Scholar
- Romano N, Santini A (2002) Water retention and storage: field–field water capacity. In: Dane JH, Topp GC (eds) Methods of soil analysis, Part 4. SSSA Book Ser No 5, SSSA, Madison, pp 723–729Google Scholar
- Schoups G, Hopmans JW (2002) Analytical model for vadose zone solute transport with root water and solute uptake. Vadose Zone J 1:158–171Google Scholar
- Silberbush M (2002) Simulation of ion uptake from the soil. In: Waisel Y, Eshel A, Kafkafi U (eds) Plant roots, the hidden half. Marcel Dekker, Inc, New York, pp 651–661Google Scholar
- Toride N, Leij FJ, van Genuchten MTh (1995) The CXTFIT code for estimating transport parameters from laboratory or field tracer experiments. Version 2.0 US Salinity Laboratory Res Rep 137, US Salinity, RiversideGoogle Scholar
- van Genuchten MTh (1987) A numerical model for water and solute movement in and below the root zone. Res Rep 121, USDAARS, US Salinity Laboratory, RiversideGoogle Scholar
- Waisel Y, Eshel E, Kafkafi U (2002) Plant roots, the hidden half, 3rd ed. Dekker, New YorkGoogle Scholar