TY - JOUR

T1 - Phosphorus and Nitrogen Fertilization Effect on Phosphorus Uptake and Phosphatase Activity in Ryegrass and Tall Fescue Grown in a Chilean Andisol

AU - Paredes, Cecilia

AU - Menezes-Blackburn, Daniel

AU - Cartes, Paula

AU - Gianfreda, Liliana

AU - Luz Mora, Maria

PY - 2011/5

Y1 - 2011/5

N2 - A series of short-term experiments were carried out to assess the effect of phosphorus (P) and nitrogen (ammonium [NH(4) (+)-N] or nitrate [NO(3)(-)-N]) fertilization on P uptake and phosphatase activity in ryegrass and tall fescue cultivated under greenhouse conditions. Ryegrass or tall fescue plants were grown in an acidic Andisol in the presence or absence of P and increasing doses of NO(3)(-)-N or NH(4)(+)-N fertilizers. At the end of the experiment, soil phosphatase activity (P-ase(Rhiz)), pH, and Olsen-P were determined in the rhizosphere soil. Plant biomass, P uptake, and root surface phosphatase (P-ase(Root)) were also assayed for both plant species. Furthermore, soil incubation experiments at increasing doses of P, NO(3)(-)-N, or NH(4)(+)-N were performed to evaluate the fertilizer effect on soil phosphatase activity (P-ase(Bulk)) and microbial biomass carbon in the bulk soil. In the absence of plants, P-ase(Bulk) was inhibited and microbial biomass carbon was raised at increasing P supply levels. In the greenhouse experiments, P uptake by tall fescue was about 67% higher than that of ryegrass at low soil P availability, which suggests that tall fescue was less sensitive to P deficiency than ryegrass. For both plant species, P-ase(Rhiz) did not vary as a consequence of P addition. On the other hand, fertilization with the highest NH(4)(+)-N dose strongly decreased soil pH and shoot P content, as well as it increased P-ase(Root) activity. This fact denotes that P-ase(Root) behaved as a strategic response parameter to P stress with insufficient impact on plant P nutrition in both plant species.

AB - A series of short-term experiments were carried out to assess the effect of phosphorus (P) and nitrogen (ammonium [NH(4) (+)-N] or nitrate [NO(3)(-)-N]) fertilization on P uptake and phosphatase activity in ryegrass and tall fescue cultivated under greenhouse conditions. Ryegrass or tall fescue plants were grown in an acidic Andisol in the presence or absence of P and increasing doses of NO(3)(-)-N or NH(4)(+)-N fertilizers. At the end of the experiment, soil phosphatase activity (P-ase(Rhiz)), pH, and Olsen-P were determined in the rhizosphere soil. Plant biomass, P uptake, and root surface phosphatase (P-ase(Root)) were also assayed for both plant species. Furthermore, soil incubation experiments at increasing doses of P, NO(3)(-)-N, or NH(4)(+)-N were performed to evaluate the fertilizer effect on soil phosphatase activity (P-ase(Bulk)) and microbial biomass carbon in the bulk soil. In the absence of plants, P-ase(Bulk) was inhibited and microbial biomass carbon was raised at increasing P supply levels. In the greenhouse experiments, P uptake by tall fescue was about 67% higher than that of ryegrass at low soil P availability, which suggests that tall fescue was less sensitive to P deficiency than ryegrass. For both plant species, P-ase(Rhiz) did not vary as a consequence of P addition. On the other hand, fertilization with the highest NH(4)(+)-N dose strongly decreased soil pH and shoot P content, as well as it increased P-ase(Root) activity. This fact denotes that P-ase(Root) behaved as a strategic response parameter to P stress with insufficient impact on plant P nutrition in both plant species.

KW - Phosphorus

KW - nitrogen fertilizers

KW - pastures

KW - phosphatases

KW - Andisol

KW - SOIL MICROBIAL BIOMASS

KW - FESTUCA-ARUNDINACEA

KW - RHIZOSPHERE

KW - ENZYMES

KW - RESIDUE

KW - PLANTS

KW - ROOTS

U2 - 10.1097/SS.0b013e3182147fd3

DO - 10.1097/SS.0b013e3182147fd3

M3 - Journal article

VL - 176

SP - 245

EP - 251

JO - Eurasian Soil Science

JF - Eurasian Soil Science

SN - 0038-075X

IS - 5

ER -