Abstract

BERONE, G.D et al. Calibración y validación de un modelo de crecimiento para alfalfa (Medicago sativa L.). RIA. Rev. investig. agropecu. [online]. 2017, vol.43, n.3, pp.256-265. ISSN 1669-2314.

A model originally developed by McCall and Bishop-Hurley to predict the growth of temperate perennial grasses (Modelo McCall) was modified. The aim was to develop a model capable to describe the aboveground growth of alfalfa pastures (Modelo Alfalfa) subjected to several climate and defoliation conditions. We used winter-active alfalfa pastures growing at a central region of Argentina (cities of Manfredi, Rafaela, Susana, Marcos Juárez and Paraná). Modifications realized at calibration step were made to represent the growth of alfalfa pure stands growing under non limiting conditions (i.e. irrigated and fertilized pastures) and that of pastures subjected to different defoliation frequencies. We modified: 1) the relationship between mean air daily temperature and solar radiation use efficiency (parameter α); 2) the equation taking account the use root reserves during a regrowth; and 3) parameter α to simulate pastures subjected to contrasting defoliation frequencies. At the validation step, we observed that Modelo Alfalfa adequately describe changes in aerial growth associated to variations in both, water availability and defoliation management. It was concluded that the Modelo Alfalfa is capable of representing the variations in growth caused by variations of mains biotic (defoliation) and non-biotic (climate) environmental factors.

Keywords : Modelo Alfalfa; Aerial growth; Water availability; Defoliation frequency.

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