MACNBR   00242
MUSEO ARGENTINO DE CIENCIAS NATURALES "BERNARDINO RIVADAVIA"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Festuca-Lotus pure or mixed and fertilized with N and P in a Natraquoll deficient in nutrients
Autor/es:
MENDOZA R. E.; GARCIA, ILEANA; FERNANDEZ LOPEZ CAROLINA; DEPALMA DANIELA
Lugar:
Chascomús
Reunión:
Workshop; VI Workshop of Lotus spp; 2016
Resumen:
Lotus tenuis-Festuca arundinacea is an option for improving quality and quantity of forage yield in grasslands. Fast initial growth is crucial for legumes since grasses establish easily and compete better for resources than legumes. Adding N, P or NP on Lotus and Festuca pure or mixed on growth, symbiotic associations with arbuscular-mycorrhizae and rhizobia in pots was study. Root length, root diameter and root surface area were calculated. Aims: a) increasing quality and quantity of forage; b) studying the competition between species; c) knowing that nutrient promotes the competition of a species over another; d) studying root morphology. Pure or mixed Lotus produced more than Festuca, with N, P or NP. Comparing with mixed stands in P and N+P fertilized soils, Lotus decreased shoot and root biomasses; whereas Festuca increased both in pure stands. Root surface area was greater and the roots thinner in Festuca than in Lotus. MC was above 0.8 in control and N fertilized pots on both plants. P or NP increased rhizobia nodulation in Lotus roots but decreased MC in both plants. Under P-deficiency, competition between species was balanced, with P and more with NP competition of Festuca over Lotus increased. Under P-sufficiency, Festuca responded to N and competed better than Lotus for resources. The ability of the grass for competing with Lotus is centered in root morphology. a) With limitation of N and P, N does not necessarily favor grasses growth if there is a marked P-deficiency; b) adding P a good strategy to weaken the ability of grasses for competing with legumes; c) from an agronomic point of view; optimization of P nutrition might help in maximizing N inputs into grasslands through symbiotic N fixation; and, in turn, decrease in inorganic-N inputs from fertilization would decrease the N2O output into the atmosphere.