Comparing the effect of chemical and biol fertilization on the yield and quality of greenhouse-grown Cucumber (Cucumis sativus)

Cucumber (Cucumis sativus) production in greenhouses has proven to be an efficient alternative for achieving higher yields and better quality compared to open-field cultivation. However, successful greenhouse cultivation also depends on well-balanced fertilization. Conventionally, this is achieved using inorganic fertilizers, but there is a growing push to change this, given the environmental impact of such chemical inputs. This study aims to compare two conventional fertilization treatments using chemical sources and two treatments using biol (liquid organic fertilizer) on the quality and yield of cucumber fruits (Centauro 1 variety). Each treatment repetition was allocated to a greenhouse cultivation bed of 25 m² in a completely randomized design where 120 cucumber seedlings were planted. The fertilization treatments evaluated were Biol30 (100L of 3% biol applied every 30 days), Biol70 (100L of 7% biol applied every 30 days), Nitro (1.9kg urea in 3 applications), and Comp [complete fertilization: 2kg Ca(NO₃)₂, 1.6kg MgSO₄, 0.8kg (NH₄)₂HPO₄, 1.6kg KNO₃, and 1.6kg urea]. Phosphorus and potassium were applied 14 days after planting (dap), and the rest were split into three applications: 14, 42, and 63dap. Fifteen plants per bed were sampled to evaluate size (length and diameter), yield, and fruit weight by harvesting their fruits starting at 50dap. The results showed no significant differences between the organic and chemical treatments regarding yield (p=0.094), but Biol70 produced 1.44x higher yields than Nitro, 1.18x higher than Comp, and only 1.09x higher than Biol30. This improvement in yield was caused by the number of harvested fruits in the Biol (Biol30:133; Biol70:149) and Comp (134) treatments, given that Nitro consistently produced the longest, widest, and heaviest (p≤0.029) but lowest number of fruits (p=0.046). In summary, organic fertilization treatments performed favourably, producing fruits of similar quality and greater yield when compared to recommended chemical fertilization treatments.