Effects of Microbial Fertilizer on the Growth, Physiology, and Chlorophyll Fluorescence Response of Spinach Seedlings

Abstract

We investigated the effects of different types of bacillus on the growth, physiological characteristics, and chlorophyll fluorescence of spinach seedlings in the soil environment of a Qinxi demonstration garden in Taibai County. Five different fertilization treatments were conducted in the growing room: no fertilizer (CK), addition of Bacillus subtilis (Bs, T1), addition of Bs and Bacillus mucilaginosus (Bm) (T2), addition of Bs and Bacillus amyloliquefaciens (Ba) (T3), and addition of Bs and Ba (T4). There were significant differences in the plant height (PH), leaf length (LL), and leaf weight (LW) of the spinach seedlings (F=54.37, 13.30, and 46.03, respectively; P<0.01). The growth and physiological characteristics of the spinach seedlings attained a maximum under the Bs and Bm treatments. There were differences in the activities of the PSII reaction centers between the five treatments. Under the Bs and Bm treatments, the ABS/RC, TR0 /RC, and ET0 /RC increased significantly, while the DI0 /RC decreased. The OJIP curve increased under different types of fertilization, and the growth trends under the Bs and Bm treatments were the largest. The leaf light response curve (LC) increased significantly under the Bs and Bm treatments. The plant growth characteristics (LL, LW, PH) were positively correlated with the J-I-P test chlorophyll fluorescence parameters (PIABS, φP0, φE0, ψ0, TR0/RC, and ET0/RC), and negatively correlated with φD0 and DI0/RC. The leaf physiological characteristics (SP, SC, Chla, Chlb, Chla+b, Chla/b, and WP) were positively correlated with the J-I-P test chlorophyll fluorescence parameters (PIABS, φP0, φE0, ψ0, ABS/RC, TR0 /RC, and ET0 /RC), and negatively correlated with φD0 and DI0 /RC. The leaf MDA was significantly positively correlated with φD0 and DI0 /RC, and positively correlated with other J-I-P test chlorophyll fluorescence parameters. The Bs and Bm treatments promoted the growth of the spinach seedlings and improved the adaptability of the crops to soil by enhancing the effective phosphorus utilization rate.

Effects of Organic Fertilizer on Growth Performance and Postharvest Quality of Pak Choy (Brassica rapa subsp. chinensis L.)

“…In another study, application of biochar with the treatment dosage 0 t ha -1 (B0), 5 t ha -1 (B1), 10 t ha -1 (B2), 15 t ha -1 (B3) had no significant effect on the growth performance of Pak choy (Situmeang et al, 2017). However, a positive growth of spinach in terms of plant height, leaf length and leaf weight were observed under microbial compost using Bacillus subtilis and Bacillus mucilaginosus (Jing et al, 2020). To date, there is no comprehensive study on the effects of vermicompost, biochar and microbial compost on plant growth of Pak choy.…”