Organic produce sales have increased over time as many consumers are willing to pay a higher price for organically-grown produce compared to conventionally-grown. Previous research has shown that liquid organic fertilizers outperform substrate-incorporated organic fertilizers in containerized production with soilless substrates. Therefore, developing new production protocols with water soluble organic fertilizers may increase yield and provide easier nutrient management. The objective of the current study was to identify water-soluble organic fertilizer combinations for growth and development of cucumber, Cucumis sativus ‘Picolino F1’, grown in a 40:60 wood fiber : coir substrate for ten weeks. Five fertilizer treatments were: molasses-based Pre-Empt (PE) at either 120 or 170 mg.L-1 nitrogen (N) in combination with 100 mg.L-1 calcium (Ca) from either calcium chloride (CaCl2) or FoxFarm’s Cal-Mag. A synthetic fertilizer treatment (Hydro-Gro Vine; N: 4.40% - P: 13.00% - K: 34.00% and calcium nitrate) was included as a control. The Cal-Mag 170 mg.L-1 N treatment had a similar yield to the control. However, there was no significant difference between all organic treatments for growth parameters measured. Additionally, leaf tissue analyses revealed boron increased by 22% to 37% and manganese by 37% above the sufficiency range for most of the organic fertilizer treatments. Meanwhile, N and potassium (K) concentration dropped below the required range by 45% and 49%, respectively, in all organic treatments. Future experiments will identify sources of supplemental N and K with the goal of supplying sufficient levels of all macro and micronutrients using water soluble organic fertilizers.
