Abstract

MONTEMAYOR TREJO, José Alfredo et al. Alfalfa production (Medicago Sativa L.) under sub-surface irrigation and different levels of phosphorus. Rev. Mex. Cienc. Agríc [online]. 2012, vol.3, n.7, pp.1321-1332. ISSN 2007-0934.

The over-exploitation of the groundwater in the Laguna region of Coahuila and Durango, Mexico makes it essential to incorporate techniques of ferti-irrigation to improve water efficiency. The obj ective of this research was to evaluate the production of dry matter (DM) and, the water efficiency and water consumption in alfalfa, with four doses of phosphorus (P) injected through the sub-surface irrigation system. The research was conducted during 2007 and 2008 in the company Vermiorganic, S. P. R de R. L, municipality of Torreón, Coahuila. The irrigation system included separated drip tapes at 1.5 m installed at 15 cm depth. The variety Excelente HQ Plus was planted at a density of 40 kg ha^-1. The evaluated treatments were four levels of phosphorus injections applied after each cut: 0, 4, 8 and 12 kg P ha^-1. A randomized complete block design was used with four replications and the experimental plot consisted of an area of 120 m². Six cuts were mate to evaluate the dry matter yield, the irrigation applied, evaporated water from a tank type 'A' and, the efficiency in water-use. The application of 12 kg P ha^-1 increased 26% of dry matter production compared with the control without application. The highest efficiency water-use was obtained in the cuts made at 271 (2.3 kg DM m^-3 of water) and 312 days after planting (2.63 kg DM m^-3 of water). The average water consumption was 0.63 cm day^-1 and the evaporation of 0.84 cm day^-1.

Keywords : alfalfa; drip irrigation; fertilizer.