ChileanJAR

During the 1973-74 season a field experiment was conducted at Quilamapu Experimental Station, Chillan (Chile) in a clayloam, paddy soil. The objetivo of this study was to estimate the efficiency of three N fertilizers: urea, calcium nitrate and Chilean nitrate in the nutrition of flooded rice (Oriza sativa, var. Oro) at three rates: 0, 50 and 100 Kg of N/ha.
Grain yield, dry matter production and absorbed nitrogen from the plant canopy were evaluated at harvest time. Urea produced the highest grain yields and was significantly higher than Chilean nitrate. Ammonium nitrate and Chilean nitrate did not significantly differ between them.
N applications produced significant increments in the dry matter production and N absorber by plants. Nitrogen absorption was used as a value criteria for the evaluation of fertilizers.
A multiple lineal regression program was applied for the evaluation of fertilizers through absorbed nitrogen. Urea and ammonium nitrate, gave the highest relative effectiveross (100% and 80.87%) than Chilean nitrate (37%) under the time and methods of fertilizer application and the soil studied.