Özet:

Irrigation parameters(reference crop evapotranspiration, actual plant water use, amount ofirrigation water, water use efficiency, irrigation water use efficiency, plantwater consumption coefficient, variations in soil moisture based on plant waterconsumption-amount of irrigation water) and yield parameters (seed yield,1000-kernel weight, harvest index) were investigated for soybean grown inHarran Plain under conventional every-furrow and alternate-furrow irrigationmanagement systems, three different compaction levels (control withoutcompaction, low compaction, high compaction) and three different nitrogenlevels (6, 9, 12 kg da-1). Experiments were carried out during 2006and 2007 cropping seasons in Şanlıurfa, Turkey in split-split plotsexperimental design with 3 replications. Irrigation program was created byKanSched simulation model. The amount of applied irrigation water inconventional and alternate furrow systems in 2006 and 2007 were measured as435.61 and 291.59 mm, and 429.51 and 271.72 mm, respectively. ET valuesdecreased with increasing compaction levels. The highest ET value (568 mm) wasobserved in non-compacted control treatment and the lowest value (240 mm) inhigh-compaction treatment. Irrigation water use efficiency increased withdecreased irrigation water and the values were higher than water useefficiencies. While the highest yield (94.78 kg da-1) was observed in controltreatment of the year 2006, conventional furrow system had the highest yield(209.93 kg da-1) in the year 2007. While effects of compaction and irrigationon harvest index were insignificant, nitrogen doses were found to besignificant. Results revealed that KanSched irrigation model could be used forirrigation scheduling but plant coefficients to be used in the model should bedetermined properly based on climate conditions. Negative impacts of soilcompaction in agricultural fields due to traffic and various other reasons canbe eliminated with proper irrigation and fertilization implementations.However, yield losses at high-compaction levels may reach up to 45%.

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