Effect of the water stress in maize crop production and N-fertilizer fate.

RIMSKI-KORSAKOV H, RUBIO G, LAVADO RS

JOURNAL OF PLANT NUTRITION

TAYLOR & FRANCIS INC

Año: 2009 vol. 32 p. 565 - 578

0190-4167

Maize production is affected by water and nitrogen (N) deficit either separately orjoined, but this fact is not completely defined. The aim was to evaluate the fate of Nin maize fertilized and subjected to water stress in controlled conditions. A greenhouseexperiment was carried out at the University of Buenos Aires campus. The design wasa2 × 2 factorial with four replications. The factors were N: 70 and 140 kg N ha−1aslabeled urea (15N), and water: 100% or 50% of the potential evapotranspiration. Theharvest of aerial and root biomass was carried out at R1 stage. Nitrogen in plants, soilsnitrate, ammonia volatilization, and 15N percentage were determined. Obtained resultsonly partially agree with previous research. Water stress depressed aerial biomass pro-duction independently of N doses. When water was limiting, the uptake of N fromfertilizer was independent of N. When water was not limiting, N uptake increased withthe higher N doses. Volatilization losses were 3.7 to 7.8% of N applied as fertilizer.Plant N recovers was around 45% of the N applied, except in treatment water stressedwith high N rate (19%). Nitrate-N from the fertilizer in the soil at harvest and accu-mulated N from the fertilizer in plant were lineally related (r2= 0.54; p < 0.001).Important destinations of N were accumulation in plant, volatilization and incorpo-ration into soil organic matter. However, residual nitrate was a main fate in heavilyfertilized and water deficit treatment. This process could lead to the eventual nitrateleaching.