Nitrogen utilization of different fertilization regimes in lettuce (Lactuca sativa L.) and its efect on biological properties of the soil on Neuquén, Argentina

Abstract

The goal of this work was to determine the effciency of nitrogen use (EUN) in a lettuce crop fertilized with organic and inorganic N sources and to evaluate its effect on some biological properties of the soil.
Treatments were: 1) Control (no N; No), inorganic N (100 kg ha^-1 N applied as ammonium nitrate; Fi) and organic N (chicken manure equivalent to a rate of 100 kg N ha^-1; E) in a complete randomized block design with fve replications. In the soil nitrate levels at the 0-30; 30-60 and 60-90 cm depths, the indices of carbon mineralization, microbial carbon biomass (C-BM) and the soil respiration coeffcient (qCO₂) were determined with each treatment. Total yield was 49.1; 34.6 and 24.7 t/ha for treatments E, Fi and N₀, respectively. The EUN was 25 and 16% for the E and Fi treatments, respectively. The C-BM and RE were higher in the fertilized treatments.