Resumo

PERALTA, NAHUEL RAÚL et al. AGRICULTURA DE PRECISIÓN: DOSIS VARIABLE DE NITRÓGENO EN CEBADA. Cienc. suelo [online]. 2015, vol.33, n.1. ISSN 1850-2067.

Precision Agriculture (PA) allows to delimit management zones (MZ) that express different yield potentials. The objectives of this study were to: (l) determine the interaction between MZ and nitrogen (N) fertilization on crop yield of malting barley cv. Scarlett.; (ll) estimate the optimal economic (DOE) availability of N for each MZ and; (lll) determine whether the delimitation of MZs improves efficiency in the use of N fertilizer. This study was conducted on a 156 ha-commercial field located at Lobería (37°57'45,82"S, 59°6'24,67"O), province of Buenos Aires, Argentina. The MZ were generated using apparent soil electrical conductivity measurements, terrain elevation and soil depth. Barely yield data was collected with a yield monitor. The experimental design was a randomized complete block with 12 replications for MZ. Blocks were divided into three plots. Each plot received a different N fertilizer rate (38, 83 and control-0 kg N ha-1). The interaction effect between available N and MZ was significant (p <0,05), indicating that the response to fertilization differed among MZ. For low MZ potential, DOE was lower compared to high potential MZ. Furthermore, the efficiency of fertilizer use showed significant differences (p <0,05) between MZ, being higher in the high potential MZ. The application of AP technology showed that DOE were different among MZ. Variable rate N application optimizes NUE on every MZ . This decreases the risk of N loss, and therefore, the likelihood of environment contamination, thereby increasing the sustainability of production systems.

Palavras-chave : Management zones, soil depth, spatial variability, Southeast Buenos Aires.

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