Salt Stress Amelioration in Maize Plants through Phosphogypsum Application and Bacterial Inoculation

Abstract

The use of phosphogypsum (PG) and plant growth-promoting rhizobacteria (PGPR) for agricultural purposes are good options to improve soil properties and increase crop yield. The objective of this study was to investigate the effect of different rates of PG (ton ha−1; 0 (PG1), 3 (PG2), 6 (PG3), and 9 (PG4)) combined with PGPR inoculation (Azospirillum lipoferum (control, T1), A. lipoferum + Bacillus coagulans (T2), A. lipoferum + B. circulance (T3), and A. lipoferum + B. subtilis (T4)) on soil properties, plant physiology, antioxidant enzymes, nutrient uptake, and yield of maize plants (Zea mays L., cv. HSC 10) grown in salt-affected soil. Over two growing seasons, 2019 and 2020, field experiments were conducted as a split-plot design with triplicates. The results show that applying PG (9 ton ha−1) and co-inoculation (A. lipoferum + B. circulance) treatment significantly increased chlorophyll and carotenoids content, antioxidant enzymes, microbial communities, soil enzymes activity, and nutrient contents, and showed inhibitory impacts on proline content and pH, as well as EC and ESP, thus improving the productivity of maize plant compared to the control treatment. It could be concluded that PG, along with microbial inoculation, may be an important approach for ameliorating the negative impacts of salinity on maize plants.

The Integration Efficacy between Beneficial Bacteria and Compost Tea on Soil Biological Activities, Growth and Yield of Rice Under Drought Stress Conditions

“…The main reason is that soil enzyme activity is closely related to the class, counts, and abundance of soil microbes (Wei and Yan 2018), and the metabolism as well as reproduction of a soil microbial community has been adopted to be influenced by temperature, precipitation and moisture over time (Zhang et al 2015). These results are confirmed in rice plant (Hafez et al 2019;Qu et al 2020); Eucalyptus plant (Ren et al 2020(Ren et al , 2021; maize plant (Khalifa et al 2021); wheat plant (Omara et al 2022).…”

“…Hafez et al (2019) showed that the application of PGPR (Azospirillum brasilense and Azotobacter chrococcum) increased soil microbial activity which led to increase field capacity and available soil water in the rhizosphere of wheat plants. In addition, Khalifa et al (2021) found that the soil amended with PGPR inoculation (Azospirillum lipoferum, B. coagulans, B. circulance and B. subtilis) improved significantly microbial growth in the rhizosphere of maize plants.…”

“…These elements are very important for the plant growth, as they are involved in the formation of enzymes, amino acids, proteins and DNA, as well as in the processes of photosynthesis. Therefore, soil microorganisms and foliar spray with compost tea can increase plant nutrients by using traits that are appropriate and can be identified as growth promoters for plants (Khalifa et al 2021;Omara et al 2022).…”

Recycling phosphogypsum in road construction materials and associated environmental considerations: A review

“…Three field trials were conducted over two growing seasons by Khalifa et al. The results showed that application of PG (9 t/ha) significantly increased chlorophyll and carotenoid content, antioxidant enzymes, microbial communities, soil enzyme activity, and nutrient content, increased maize plant productivity, and improved the negative impact of salinity on maize plants ( Khalifa et al., 2021 ). Microorganisms grow and multiply quickly, and combining them with PG in agriculture can increase crop yields while reducing damage to the ecosystem and protecting the ecological balance.…”

The combined application of salt-alkali tolerant phosphate solubilizing microorganisms and phosphogypsum is an excellent measure for the future improvement of saline-alkali soils

“…phosphaticum and Pseudomonas fluorescens to the soil can increase the available phosphorus in the soil by ∼80%, and increase the dry weight of corn (mg per plant) from 398 to 624 (Al-Enazy et al, 2017). Meanwhile, the application of PG (9 t ha −1 ) and bacteria (A. lipoferum + B. circulance) can significantly improve the physiological status, antioxidant enzyme activity, microbial activity, nutrient absorption, and productivity of maize plants under salinesodic soil conditions (Khalifa et al, 2021). It is worth noting that the combination of microorganisms and PG can also reduce potentially harmful elements in PG, such as Fe, Al, F, etc., through their own cells and secretions (such as, extracellular polymers) (Jalali et al, 2016;Chen et al, 2021).…”