Productividad hídrica de Megathyrsus maximus cv. bajo fertirriego en un suelo con pH variable en el Caribe seco colombiano.

The soils of Cesar present high percentages in degradation and a low productive capacity, so for their management it is necessary to implement technologies such as fertigation, in order to improve the productive capacity of the soil in a sustainable way. In this research the effect was evaluated of the application of fertigation with central pivot on Water productivity (WP) of Megathyrsus maximus cv. Agrosavia Sabanera in a soil with pH variations was evaluated under colombian dry Caribbean conditions. Five treatments corresponding to five pH ranges were determined; within each range, three experimental plots were established. The variables evaluated were dry matter production (MS), green forage (MV), dry matter percentage (% MS), stem height, plant height and macro and microelement content of the forage. Of the soil the apparent density, pH, electrical conductivity (EC) and infiltration were determined. The MS and WP ware higher when soil pH was lower than 7.8 (p < 0.05). Water productivity (WP) was higher 2.83 kg/m3 and dry matter (MS) exceeded 0.72 kg/m2 with soil pH less than 7.8; in the pH range between 5.5 and 7.8 the assimilation of nitrogen, potassium and calcium was higher (p < 0.1); greater plant development was observed in soil with pH between 5.5 and 6.9 (p < 0.05); in relation to edaphic properties, a positive correlation was observed between infiltration and stem growth and a negative correlation of stem growth versus pH, EC and manganese assimilation (p < 0.1); biomass production of Megathyrsus maximus cv. Agrosavia Sabanera is favorable when the soil pH is between 5.5 and 7.8. [ABSTRACT FROM AUTHOR]