Eco-Physiological Properties of Open-Field Cucumbers Responded to Organic Liquid Fertilizers

Abstract

This study was initiated to determine the effect of organic farm-derived liquid fertilizer (LF) on (1) the performance of open-field cucumbers (Cucumis sativus L.) and (2) the soil environment. Treatments included fertigation with a 0.2% solution of an equal T-N concentration on each LF, including long-term non-treatment (LNT, groundwater), non-treatment (NT, groundwater), oil cake (OC), bone meal + fish residue (BF), fish extract + active phosphoric acid (FP), sesame oil (SO), and starfish (SF). Electrical conductivity (EC) in LF was increased in the SF or BF, with high concentrations of T-C observed in the OC and BF and high P in the SO. LNT treatment decreased soil mineral nutrient concentrations and numbers of bacterial operational taxonomic units, invertebrates, and earthworms, significantly increasing infection of powdery mildew and downy mildew for the plants but reducing foliar concentrations of T-N, P, Ca, and SPAD values, and vegetative growth parameters. Soil bulk density decreased in the SF and SO plots. Total fruit yield and fruit yield efficiency were enhanced by BF, FP, SO, and SF treatments, with the highest top grade values observed on the FP- and SO-fruit. Overall, all the organic LF, in particular the SO treatment, would have improved eco-physiological sustainability and provided an alternative organic fertilizer for a short growing period.