Phosphorus plants interactions

All chemical fertilisers operate well below 100% efficiency and a proportion of the N, P and K is always lost and does not appear in the crop. The required concentration of available nitrogen is more easily lost from the soil than that of the other two elements, which can to some extent be stored. Phosphorus is usually considered to be the least mobile of the three fertiliser elements. The chemistry of fertiliser-soil-plant interactions is generally very complex and remains far from being completely understood. 

BARBER S.A. 1980. Soil-plant interactions in the phosphorus nutrition of plants. Chapter 21 in The Role of Phosphorus in "Agriculture. Eds. Khasawneh F.E., Sample E.C. and... 

A. Jungk, Soil-root interactions in the rhizosphere affecting plant availability of phosphorus. J. Plant Nutr. 70 1197 (1987). 

Miiller R, Morant M, Jarmer H, Nilsson L, Nielsen TH (2007) Genome-wide analysis of the ara-bidopsis leaf transcriptome reveals interaction of phosphate and sugar metabolism. Plant Physiol 143 156-171. doi http //www.plantphysiol.org/cgi/content/abstract/143/l/156 Neumann G, Romheld V (1999) Root exudation of carboxylic acids and protons in phosphorus-deficient plants. Plant Soil 211 121-130... 

Several phenolic acids and many nonspecific allelopathic conditions have been shown to alter the mineral content of plants, and certainly phenolic allelochemicals may perturb cellular functions in a number of ways that are of importance to plant nutrition (34,35). However, raising fertility does not always suppress allelopathic inhibition, and the interrelationships between these two factors are still not clear. Bhowmik and Doll (36) showed that allelopathic inhibition of corn and soybeans by residues of five annual weeds was not alleviated by supplemental nitrogen or phosphorus. Similarly, an increase in fertilizer did not overcome inhibition of corn by quackgrass or circumvent the autotoxicity of berseem clover Trifolivm alexandrium L.) (37,38). Even when raising nutrient levels releases Inhibition, it does not mean that allelopathy was inoperative under the original conditions. These instances simply illustrate the importance of the Interaction of the two stress conditions. 

Tan K, Keltjens WG. 1990a. Interaction between aluminum and phosphorus in sorghum plants. 2. Studies with the aluminum tolerant sorghum genotype SC0283. Plant Soil 124 25-32. 

Few data are available on the PolyP function in higher plants. PolyPs were first observed in maize roots (Vagabov and Kulaev, 1964), while Niemeyer studied PolyPs and their interactions with the inositol phosphate pools in plants (Niemeyer, 1975, 1976, 1999 Niemeyer and Selle, 1989). Some data on the dynamics of PolyPs during the development of cotton plants were obtained (Valikhanov et al., 1980). It is probable that some plants can use extracellular PolyP as a phosphorus source (Igamnazarov and Valikhanov, 1980). 

Leyval, C. Berthelin, J. (1989). Interactions between Laccaria laccata-Agrobacterium radiobacter and beech roots influence on phosphorus, potassium, magnesium and iron mobilisation from minerals and plant growth. Plant and Soil, 117, 103-10. 

Mutualistic species interactions contribute directly to many essential ecosystem processes, such as nutrient inputs through nitrogen fixation and mycorrhizal associations that govern phosphorus and organic nitrogen uptake by plants (Read, 1991). Other mutualisms, such as pollination and seed dispersal, have indirect effects, influencing the presence or absence of species that may have strong ecosystem effects. 

The reservoir representing the land (2) is defined as the amount of P contained in the upper 60 cm of the soil. This rather narrow definition of the land reservoir is made because it is through the upper portions of the soil system that the major interactions with the other P reservoirs occur. Specifically, most plants receive their nutritive P needs from the upper soil horizons and the return of P to the soil system by the decomposition of plant matter is also concentrated in this upper soil zone. Similarly, the major interactions with the atmosphere, ground-waters, and rivers occur near the soil surface. And, finally, phosphate in the form of fertilizer is applied directly to the soil surface. Thus, in attempting to represent the land and its interaction with other reservoirs, the surface soil horizon most directly interacts with all components and best represents the d)mamical nature of this reservoir. Phosphorus in soils deeper than 60 cm and in crusted rocks is included in the sediment reservoir (1). This reservoir accounts for all of the particulate P that exchanges with the other reservoirs only on very long time-scales. 

An additional phenomenon may also be important in the tropical forest C/P interaction. Humic molecules and organic acids actively compete with phosphorus for soil fixation sites. This means that increases in soil carbon density at higher [CO2] may serve to displace phosphate ions from sorption sites and into the soil solution, where they can then be utilized by plants. It is not inconceivable that this effect could give rise to a runaway positive feedback CO,-induced increases in tropical forest plant growth... 

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