Festuca-Lotus pure or mixed and fertilized with N and P in a Natraquoll deficient in nutrients

MENDOZA R. E.; GARCÍA I. V; FERNÁNDEZ LÓPEZ C.; D. DEPALMA

Workshop; VI Workshop of Lotus spp; 2016

Intech

Lotustenuis-Festuca arundinacea is an option for improving quality and quantity offorage yield in grasslands. Fast initial growth is crucial for legumes sincegrasses 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 witharbuscular-mycorrhizae and rhizobia in pots was study. Root length, rootdiameter and root surface area were calculated.  Aims: a) increasing qualityand quantity of forage; b) studying the competition between species; c) knowingthat nutrient promotes the competition of a species over another; d) studyingroot morphology.    Pure or mixed Lotus produced more than Festuca, with N, P or NP. Comparing withmixed stands in P and N+P fertilized soils, Lotusdecreased shoot and root biomasses; whereas Festucaincreased both in pure stands. Root surface area was greaterand the roots thinner in Festuca thanin Lotus. MC was above 0.8 in controland N fertilized pots on both plants. P or NP increased rhizobia nodulation in Lotus roots but decreased MC in bothplants. UnderP-deficiency, competition between species was balanced, with P and more with NPcompetition of Festuca over Lotus increased. Under P-sufficiency, Festuca responded to N and competedbetter than Lotus for resources. Theability of the grass for competing with Lotusis centered in root morphology.     a)With limitation of N and P, N does not necessarily favor grasses growth if there is a markedP-deficiency; b) adding P a good strategy to weaken the ability of grasses forcompeting with legumes; c) from an agronomic point of view; optimization of Pnutrition might help in maximizing N inputs into grasslands through symbiotic Nfixation; and, in turn, decrease in inorganic-N inputs from fertilization woulddecrease the N2O output into the atmosphere.