Exploring pea soaking water as alternative to synthetic fertilizer: Growth and microbial analysis of pea and tomato plants

Abstract

Synthetic fertilizers deplete soil microbiome. Organic fertilizers lack specific nutrients for plant growth. A fertilizer that delivers essential nutrients to plants without deteriorating soil is lacking. This study investigated the viability of using pea soaking water (PSW) as substitute for synthetic fertilizers to enhance the growth of pea and tomato plants. Traits included plant growth stages, shoot and root weight, estimated chlorophyll content, and soil microbial populations. Pea plants exhibited consistent growth stages and rates of development across treatments, whereas tomato plants displayed treatment-dependent growth variations and differences in rates of development. Synthetic fertilizer (NPK) and PSW treatments increased shoot weight and chlorophyll content in both pea and tomato plants, compared with their controls. Interestingly, PSW produced comparable shoot growth to synthetic fertilizer in both crops. Root weights were similar in response to both fertilizer treatments in tomato but only increased in response to synthetic fertilizer in pea plants. Soil microbial analysis highlighted differences in Lactobacillus amount with soil supporting pea plants having higher bacteria counts. Notably, Lactobacillus amounts were reduced by 48% in the synthetic fertilizer treatment, but not by PSW, compared with the control, for tomatoes only. These findings suggest that PSW is a potential alternative to synthetic fertilizer to sustainably support plant growth. Replacement of synthetic fertilizer with PSW could reduce the environmental impact of agriculture by promoting healthy soil microbiota and preventing eutrophication, as well as reducing reliance on fertilizers. Further research is needed to explore its effect on crop yield, and applicability across crop species, field, and environmental conditions