Acumulación y lavado de sales en columnas de suelo regadas con agua salina procedente de un pozo petrolero

a greenhouse experiment was designed to study the processes of accumulation and leaching of salts in soil columns irrigated with saline water coming from an oil well located in san silvestre, barinas state, venezuela (ec = 6,7 ds m-1 and ph = 7,44). the experiment was managed with 32 lysimeters planted with brachiaria dictyoneura grass, applying irrigation with saline water without leaching for the initial 16 weeks and leaching with desmineralized water for the remaining 16 weeks. during the irrigation period, 4 treatments were implemented: t0) irrigation with desmineralized water, t1) irrigation with desmineralized water the firsts 10 days and then irrigation with saline water, t2) irrigation with saline water from the beginning and t3) irrigation with saline water from the beginning, diluted to a third of its original concentration. at the end of the irrigation period, 16 lysimeters (4 per treatment) were dismounted and their soil columns divided in 4 strata, collecting unaltered and altered samples in each one; in the unaltered samples hydraulic conductivity, bulk density and porosity were determined and in the altered samples, salinity, sodicity and dispersion. at the end of the leaching period the 16 remaining lysimeters were dismounted, following the same procedure of collection and analysis of samples. grass was cut every 8 weeks, determining dry matter at each cut, and sodium and choride contents during the last 3 cuts. nitrogen was applied as urea after planting and after the first and third cuts. the saline treatments brought about an increase of salinity in the soil due to scarce first and third cuts. the saline treatments brought about an increase of salinity in the soil due to scarce leaching or no leaching during the irrigation period. subsequent leaching with desmineralized water led an important descent of the salinity in soil columns although not a total removal. however, the use of water of production in its different treatments and the posterior l