EFFECTS OF FERTIGATION STRATEGIES ON NITRATE-NITROGEN LEACHING AND YIELD PARAMETERS OF CUCUMBER GROWN IN GLASSHOUSE

摘要

In this study, the amount of nitrate leached from the soil and its effects on yield and quality of cucumber plant grown under greenhouse conditions were determined as a result of different fertigation strategies which was formed by changing the application time of the mixture of fertilizer solution during the irrigation cycle. For this purpose, five different fertigation strategies were applied, i.e. feeding of fertilizer solution during the whole irrigation period (F1), feeding of fertilizer solution during the first half of irrigation period (F2), feeding of fertilizer solution during the second half of irrigation period (F3), feeding of fertilizer solution between 1/4'th and 3/4'th irrigation period (F4) and injection of fertilizer solution immediately upon start of irrigation (F5) The highest and least yield was obtained in F1 (16.66 tons da~(-1)) and F3 (15.05 tons da~(-1)) fertigation strategies respectively. It was determined that fertigation strategies did not affect statistically the yield, fruit length, fruit diameter, plant height and stem diameter. On the other hand, it was found that the effect of fertigation strategies on nitrate-nitro gen (NO3-N) leaching was statistically significant. The highest NO_3-N leaching was observed in F2 and the least in F4 fertigation strategy. It was concluded that the best fertigation strategy to prevent the pollution of groundwater by minimizing NO_3-N leaching, the most appropriate strategy is F4, i.e. feeding of fertilizer solution between 1/4'th and 3/4'th irrigation period.