@article{marconi_nelson_1984, title={LEACHING OF APPLIED PHOSPHORUS IN CONTAINER MEDIA}, volume={22}, ISSN={["1879-1018"]}, DOI={10.1016/0304-4238(84)90061-X}, abstractNote={Pre-plant P as superphosphate (8.7% P) at the rate of 1.5 kg m−3 was added to two root media in 16.5-cm azalea-type pots. Saturated media were periodically leached to 15% excess. Media type had a definite influence on P leached. Over one third of the total applied P was leached from a peat moss:vermiculite (PV) (1:1, v:v) mix after 9 weeks compared to less than 5% leached from a sand:soil:peat moss (SSP) (1:1:1, v:v:v) mix in a simulated plant watering scheme. Approximately the same amount of P was leached at any given watering in the PV (4.2%), whereas 2.6% of that applied was lost after an initial watering at 1 h and only 0.04% after an initial watering at 9 weeks in the SSP mix. This difference was related to differences in P fixation by the various root media components. P adsorption isotherms were conducted on 7 root media components or mixtures of components, including the 2 above-mentioned mixes, to determine the quantity of P adsorbed to give 0.2 ppm in the soil solution. The resulting plot of P adsorbed versus P in solution confirmed that the greater leaching loss of P in the soil-less mix was due to a lower P adsorption capacity. Maximum P adsorption capacity in the soilless media was reached with the addition of 262 g P m−3. The adsorption capacities of soil, sand and SSP were not reached at the highest rate of P addition (524 g P m−3. The higher P buffering capacity of these materials necessitates greater P addition to achieve 0.2 ppm soluble P, considered optimum for most plants, but ensures that the level of soluble P will be maintained for a longer period.}, number={3}, journal={SCIENTIA HORTICULTURAE}, author={MARCONI, DJ and NELSON, PV}, year={1984}, pages={275–285} }