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| Format: | Artículo científico |
| Language: | en |
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Universidad de Costa Rica
2005
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| Online Access: | https://www.redalyc.org/articulo.oa?id=43629207 |
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Table of Contents:
- Soil P forms and P uptake P under intensive plant growth in the greenhouse Randy Killorn Carlos Henríquez Agrociencias The concentration of available soil (P) isa function of the equilibrium established amongdifferent soil P forms through numerous anddifferent reactions in soil. The objective of thisstudy was to examine the changes in P forms andP supply under exhaustive extraction conditionsin soils from 3 different land use areas. In order toestablish a greenhouse experiment, representativesoil samples (0-20 cm) were taken from threefields located adjacent to one another, in a TypicHapludands in Costa Rica. One field was acoffee plantation (Coffea arabica var Catuai),the second a sugar cane plantation (Saccharumspp. var 611721), and the third a secondaryforest. Sorghum (Sorghum bicolor var Glazer41) was planted in 1-liter pots and harvested4 times consecutively. Treatments were no Pand P application (100 mg kg-1) for each of thedifferent land-use soil samples. Shoot and rootdry matter and total P uptake were determined.Soil samples were taken before and after each ofthe 4 plant growth cycles and analyzed using amodified Hedley et al. (1982) soil P fractionationmethodology. Labile-Pi, NaOH-Pi, HCl-Pi,extractable-Po, and residual-P were determined.Applied P increased labile-Pi, NaOH-Pi andHCl-Pi. Statistical changes were not observedin extractable organic P and residual-P due to Papplication. The NaOH-Pi and HCl-Pi seemed to act as a temporary pool of applied P. The possibleparticipation of residual-P in replenishment oflabile-P and NaOH-Pi was observed. The amountof plant P uptake was closely related to the initialamount of labile-Pi and was higher in coffeethan in forest and sugar cane soils. The labile-Pwas depleted by plant uptake. Rapid changes inreversibly available soil P forms (NaOH-Pi andHCl-Pi) were observed during the experiment.Our results suggest the occurrence of very rapidand dynamic changes between available andunavailable soil P forms in response to fertilizerapplication and plant uptake, supporting the ideaof a continuum among the P forms. 2005 artículo científico 0377-9424 https://www.redalyc.org/articulo.oa?id=43629207 en http://www.redalyc.org/revista.oa?id=436 Agronomía Costarricense application/pdf Universidad de Costa Rica Agronomía Costarricense (Costa Rica) Num.2 Vol.29