Soil and fertilizer phosphorus: Effects on plant P supply and mycorrhizal development

Abstract

. 2005. Soil and fertilizer phosphorus: Effects on plant P supply and mycorrhizal development. Can. J. Plant Sci. 85: 3-14. Plants require adequate P from the very early stages of growth for optimum crop production. Phosphorus supply to the crop is affected by soil P, P fertilizer management and by soil and environmental conditions influencing P phytoavailability and root growth. Phosphorus uptake in many crops is improved by associations with arbuscular mycorrhizal fungi. Cropping system and long-term input of P through fertilizers and manures can influence the amount and phytoavailability of P in the system and the development of mycorrhizal associations. Optimum yield potential requires an adequate P supply to the crop from the soil or from P additions. Where early-season P supply is low, P fertilization may improve P nutrition and crop yield potential. Alternately, under low-P conditions, encouragement of arbuscular mycorrhizal associations may enhance P uptake by crops early in the growing season, improving crop yield potential and replacing starter fertilizer P applications. Soil P supply that exceeds P requirements of the crop may preclude mycorrhizal development. To encourage arbuscular mycorrhizal association, threshold levels of soil solution P that restrict mycorrhizal development must not be exceeded. Sustainable P management practices must be applied both in conventional and in alternative biologically based agricultural systems.Key words: Microbiology, fertility, colonization Grant, C., Bittman, S., Montreal, M., Plenchette, C. et Morel, C. 2005. Le phosphore dans le sol et les engrais : incidence sur l'absorption du P par les plantes et sur le développement des mycorhizes. Can. J. Plant Sci. 85: 3-14. Les plantes ont besoin d'une quantité suffisante de P dès le début de leur croissance si l'on veut que leur culture donne un rendement optimal. Les apports de P dépendent de la concentration de cet élément dans le sol, de l'application d'engrais phosphatés et des conditions environnementales qui affectent la quantité de P disponible pour la plante et la croissance des racines. Chez maintes cultures, l'association avec des mycorhizes à arbuscules améliore l'absorption du phosphore. Les pratiques agricoles et l'apport prolongé de P résultant de l'application d'engrais et de fumier peuvent modifier la quantité de P dont les plantes disposent dans le milieu et le développement d'une symbiose avec les mycorhizes. Pour atteindre son meilleur rendement, la culture a besoin de tirer une quantité suffisante de P du sol ou des amendements. Quand la concentration de P ne suffit pas au début de la période végétative, la fertilisation facilite parfois l'assimilation de cet élément et accroît le rendement potentiel de la culture. Dans les mêmes conditions, favoriser l'association avec les mycorhizes à arbuscules peut aider la plante à mieux absorber le P au début de la saison de croissance, ce qui en accroîtra le rendement éventuel et remplacera l'épandage initial d'engrais phosphatés. Lorsqu'il contient plus de P...

Influence of <i>Bradyrhizobium japonicum</i> and Phosphorus on Micronutrient Uptake in Cowpea. A Case Study of Zinc (Zn), Iron (Fe), Copper (Cu) and Manganese (Mn)

“…Phosphorus is known for its functions on root formation in plants [13,34,35]. The improved uptake of different micronutrients in different plant tissues in this study, might have been caused by the possibility of increased root system which explored the bulk of soil for water and other mineral nutrients uptake which comes in contact with the roots [36]. However, the data from this study (Tables 2-5) showed that phosphorus supplementation either did not show significant difference (shoot) or significantly decreased the uptake of Zn and Fe in different plant organs tested.…”

Crop response to current and previous season applications of phosphorus as affected by crop sequence and tillage

“…Spring wheat (Triticium aestivum L.) and canola (Brassica napus L.) are major crops in western Canada. Spring wheat readily forms mycorrhizal associations while canola does not (Grant et al 2005). Therefore, tillage system may have different effects on P dynamics in canola than in spring wheat, due the effects of tillage on mycorrhizal association.…”

“…Therefore, mycorrhizal activity and hence P supply may be influenced by both crop sequence and tillage system. Flax is more reliant on mycorrhizal associations than are spring wheat or canola (Grant et al 2005). Increasing mycorrhizal association in flax, through RT or sequencing flax after a mycorrhizal crop, may improve early-season P status of the crop and reduce the reliance on P fertilization.…”

Arbuscular Mycorrhiza Fungi as an Indicator of Soil Fertility

“…This shows that in the certain value of P concentration AMF would increase, but in the more value of P concentration, it could reduce AMF. Grant et al (2005) supported this statement and stated that AMF symbiosis decreased with increasing tissue P concentration. Therefore in the high P level in the soil, probably it could increase or decrease AMF association depending on the certain quantity of P concentration.…”