Abstract
Diffusion of ions in the soil depends on soil moisture content. In a dry soil, transport of nutrients towards the root and the concomitant uptake could be reduced. However, pot and field experiments showed that this is not always the case. The objective of this paper was to investigate possible mechanisms of plants to counteract reduced nutrient supply due to water shortage. A split root system was used to investigate P and K inflow of oat and sugar beet at different soil moisture contents (Θ) without water shortage for the plant. The measured average P and K inflows were compared to model calculations considering diffusion, mass-flow, sorption and uptake processes. In the calculations, soil dryness impeded diffusion and decreased nutrient inflow as expected. Measured K inflow was decreased in a similar way indicating that Θ influences K diffusion. In contrast to this, measured P inflow was not influenced by Θ and under-estimated by the model. Low and high molecular exudates were collected at different water supply levels showing that exudation rate of both compounds was increased at water shortage. Especially the high molecular exudates (i.e. mainly mucilage) from water-stressed plants increased P concentration in soil solution under dry conditions in an incubation experiment. Calculated inflow considering this increased P concentration agreed well with measured P inflow indicating that exudation of mucilage could be a mechanism to overcome nutrient transport problems due to soil dryness.
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References
Adams F, Burmester C, Hue N V and Long F L 1980 A comparison of column-displacement and centrifuge methods for obtaining soil solutions. Soil Sci. Soc. Am. J. 44, 733–735.
Beißner L 1997 Mobilisierung von Phosphor aus organischen und anorganischen P-Verbindungen durch Zuckerrübenwurzeln. Cu-villier Verlag, Göttingen, Germany. 214 pp.
Bhadoria P B S, Kaselowski J, Claassen N and Jungk A 1991 Im-pedance factor for chloride diffusion in soil as affected by bulk density and water content. Z. Pflanzenernaehr. Bodenkd. 154, 69–72.
Bhadoria P B S, Steingrobe B, Claassen N and Liebersbach H 2002 Phosphorus efficiency of wheat and sugar beet seedlings grown in soils with mainly calcium, or iron and aluminium phosphate. Plant Soil 246, 41–52.
Brewster J L, Bhat K K S and Nye P H 1976 The possibility of predicting solute uptake and plant growth response from inde-pendently measured soil and plant characteristics. V. The growth and phosphorus uptake of rape in soil at a range of phosphorus concentrations and a comparison of results with the predictions of a simulation model. Plant Soil 44, 295–328.
Campbell R and Greaves M P 1990 Anatomy and community struc-ture of the rhizosphere. In The rhizosphere. Ed. J M Lynch. John Wiley & Sons Ltd., England.
Claassen N. and Steingrobe B 1999 Mechanistic simulation models for a better understanding of nutrient uptake from soil. In Mineral nutrition of crops. Fundamental mechanisms and implications. Ed. Z Rengel. pp. 327–367. Food Products Press, Haworth Press Inc., New York.
Claassen N, Syring K M and Jungk A 1986 Verification of a math-ematical model by simulating potassium uptake from soil. Plant Soil 95, 209–220.
Czarnes S, Dexter A R and Bartoli F 2000 Wetting and drying cycles in the maize rhizosphere under controlled conditions. Mechanics of the root-adhering soil. Plant Soil 211, 253–271.
Dunham R J and Nye P H 1976 The influence of soil water content on the uptake of ions by roots. III. Phosphate, potassium, cal-cium and magnesium uptakeand concentration gradients in soil. J. Appl. Ecol. 13, 967–984.
Edwards O W and Huffman E O 1959 Diffusion of aqueous solu-tions of phosphoric acid at 25 C. J. Phys. Chem. 63, 1830–1833.
El Dessougi H. and Claassen N 2003 Potassium efficiency of crop species grown in the field on a low potassium supplying soil. In Potassium and water management in West Asia and North Afrika. Ed. A E Johnston. Proceedings of the regional work-shop of the international potash institute held at Amman, Jordan. pp. 26–37. International Potash Institute, Basel, Switzerland.
Föhse D and Jungk A 1983 Influence of phosphate and nitrate sup-ply on root hair formation of rape, spinach and tomato plants. Plant Soil 74, 359–368.
Gardner W K, Barber D A and Parbery D G 1983 The acquisition of phosphorus by Lupinus albus L.. III. The probable mechan-ism by which phophorus movement in the soil/root interface is enhanced. Plant Soil 70, 107–124.
Gerke J 1992 Phosphate, aluminium and iron in the soil solution of three different soils in relation to varying concentrations of citric acid. Z. Pflanzenernaehr. Bodenk. 155, 339–343.
Gerke J, Römer W and Beißner L 2000 The quantitative effect of chemical phosphate mobilization by carboxylate anions on P uptake by a single root. II. The importance of soil and plant parameters for uptake of mobilized P. J. Plant Nutr. Soil Sci. 163, 213–219.
Grimal J Y, Frossard E and Morel J L 2001 Maize root mucilage decreases adsorption of phosphate on goethite. Biol. Fert. Soils 33, 226–230.
Hinsinger P 2001 Bioavailability of soil inorganic P in the rhizo-sphere as affected by root-induced chemical changes: A review. Plant Soil 237, 173–195.
Jones D L 1998 Organic acids in the rhizosphere – a critical review. Plant Soil 205, 24–44.
Jungk A, Asher C J, Edwards D G and Meyer D 1990 Influence of phosphate status on phosphate uptake kinetics of maize (Zea mays) and soybean (Glycine max). Plant Soil 124, 175–182.
Kitson R E and Mellon M G 1944 Colorimetric determination of phosphorus as molybdovanadophosphoric acid. Indian Eng. Chem. Anal. Ed. 16, 379–383.
Kuchenbuch R Claassen N and Jungk A 1986 Potassium availability in relation to soil moisture. Plant Soil 95, 221–231.
Mackay A D and Barber S A 1985a Soil moisture effects on root growth and phosphorus uptake by corn. Agron. J. 77, 519–523.
Mackay A D and Barber S A 1985b Soil moisture effects on potassium uptake by corn. Agron. J. 77, 524–527.
Meyer D and Jungk A 1993 A new approach to quantify the util-ization of non-exchangeable soil potassium by plants. Plant Soil 149, 235–243.
Morel J L, Habib L, Plantureux S and Guckert A 1991 Influence of maize mucilage on soil aggregate stability. Plant Soil 136, 111–119.
Murphy J and Riley J P 1962 A modified single solution method for determination of phosphate in natural waters. Anal. Chem. Acta 27, 31–36.
Nagarajah S, Posner A M and Quirk J P 1970 Competitive ad-sorption of phosphate with polygalacturonate and other organic anions on Kaolinite and oxide surfaces. Nature 228, 83–85.
Nye P H 1983 The diffusion of two interacting solutes in soil. J. Soil Sci. 34, 677–691.
Parsons R 1959 Handbook of electrochemical constants. Academic Press, New York.
Schmid H and Claassen N 1994 Wirkung des Bodenwasserge-haltes auf die P-Aufnahme von Zuckerrüben im Feld. Mitt. Ges. Pflanzenbauwiss. 7, 245–248.
Schüller H 1969 Die CAL-Methode, eine neue Methode zur Bestimmung des pflanzenverfügbaren Phosphates im Boden. Z. Pflanzenernaehr. Bodenk. 123, 48–63.
Seiffert S, Kaselowski J, Jungk A and Claassen N 1995 Observed and calculated potassium uptake by maize as affected by soil water content and bulk density. Agron. J. 87, 1070–1077.
Steingrobe B, Claassen N and Syring K M 2000 The effect of the function type for describing the soil buffer power on calculated ion transport to roots and nutrient uptake from the soil. J. Plant Nutr. Soil Sci. 163, 459–465.
Tennant D 1975 A test of a modified line intersect method of estimating root length. J. Ecol. 63, 995–1001.
Williams R F 1948 The effects of phosphorus supply on the rates of intake of phosphorus and nitrogen and upon certain aspects of phosphorus metabolism in gramineous plants. Aust. J. Sci. Res., Ser. B. 1, 333–361.
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Liebersbach, H., Steingrobe, B. & Claassen, N. Roots regulate ion transport in the rhizosphere to counteract reduced mobility in dry soil. Plant and Soil 260, 79–88 (2004). https://doi.org/10.1023/B:PLSO.0000030191.92338.6a
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DOI: https://doi.org/10.1023/B:PLSO.0000030191.92338.6a