Resumen

MONTANO GARCIA, Raimundo Yldon  y  AQUILES ARCE, Laura. Nitrogen export of lettuce (Lactuca sativa) with nitrogen fertilization and water replenishment strategies. RIIARn [online]. 2018, vol.5, n.1, pp. 7-15. ISSN 2409-1618.

Abstract The General Assembly of the United Nations declared 2014asthe international year of family farming, which is part of the production of vegetables such as lettuce, irrigation and the application of nutrients that influence this crop, of which the export of nitrogen was not determined. The objective of the work was to determine the amount of nitrogen export of the lettuce grown with nitrogen levels and strategies for replacing water in the soil in the Tiquipaya municipality, Cochabamba city. The experimental design of sub-subdivided plots was used, the factors studied were: water replacement strategies to the soil (R1:100% replenishment of DPM from 36 DDS to harvest, R2: replenishment to 80% of DPM of the 36 up to 56 DDS, 100% DPM from 57 DDS to harvest, R3: 100% DPM replacement from 36 to 56 DDS, 80% DPM from 57 to 76 DDS and 100% from DPM of 77 DDS until harvest and R4: 100% replacement of DPM from 36 to 76 DDS and 80% of DPM of the 77 DDS until harvest), nitrogen (0 and 100 kg ha^-1) and evaluations (36, 56, 76 and 90 DDS). From the 36 DDS to the harvest, the crop evapotranspiration was 242.13 mm and the precipitation was 36.50 mm; in the same period, with strategy R1, R2, R3 and R4 174.33 were applied; 163.27; 162.94 and 161.93 mm of water. Statistically there was no effect of water replenishment strategies on the factors studied. Applications of 0 and 100 kgN ha^-1of 36 DDS until harvest, the export trend for export of nitrogen; presenting the head of nitrogen export at 90 DDS. The export relationship of nitrogen with dry matter present commercial trend, increase dry matter by increasing the export of nitrogen. With the application of 100 kgN ha^-1there was higher yield and export of nitrogen.

Palabras llave : Nitrogen export; water replenishment,; management deficit; yield.