The document summarizes a seminar presentation on investigating the effect of plant growth-promoting rhizobacteria (PGPR) on maize growth and yield in combination with organic amendments and chemical fertilizer. The objective was to study this under field conditions. The literature review summarized two studies that found combinations of PGPR and amendments promoted plant growth while reducing fertilizer requirements. The future work proposed isolating and characterizing PGPR strains and conducting field trials to evaluate PGPR and amendment combinations on maize growth and yield.

1. National Pingtung University of Science and Technology
Department of TropicalAgriculture and International Cooperation
The effect of plant growth-promoting rhizobacteria
(PGPR), in combination with chemical fertilizer and
organic amendments, on maize performance
Seminar 1
Presenter: Brandon Itza (M11122064)
Advisor: Chang, Pei-Chun (Ph.D.)
Instructor: Chang, Pei-Chun (Ph.D.)
Date: March 16th, 2023

2. Overview
Introduction
Objective
Literature review
Conclusions
Future works
Acknowledgements
References
2

3. Introduction
3
Current problem
Figure 1. Agriculture intensification and impact on environment. Source
(Kopittke et al., 2019).

4. Introduction
 Maize (Zea mays L.),
domesticated in Southern
Mexico
 Food, feed, and other uses
 Cereals require large
amounts of nitrogenous
chemical fertilizer
4
(Erenstein et al., 2022; Gómez-Godínez et al., 2019)
Maize
Figure 2. Top-dressing of maize with urea.
Source (Botha, 2021).

5. Introduction
Natural methods
 Organic amendments (biochar, manure, compost etc.)
 Beneficial microorganisms as biofertilizers (bacteria,
fungal, etc.)
5
(Gómez-Godínez et al., 2019; Hussain et al., 2020)
How to maintain
productivity and reduce
impact on the environment?

6. Introduction
6
Organic amendments
Figure 3. Organic amendments vs synthetic fertilizers. Source
(Cesarano et al., 2017).

7. Introduction
7
PGPR
Figure 4. Direct and indirect mechanism of PGPR. Source (Bamdad et al., 2021).

8. Objective
• To investigate the effect of PGPR on maize growth and
yield in combination with organic amendments and a low
level of chemical fertilizer under field conditions
8

9. Literature review
9
Journal 1
(Shahzad et al., 2013)

10. Literature review
10
Results (1)
(Shahzad et al., 2013)
Table 1. Effect of inoculation with PGPR containing ACC-deaminase on plant height, root
dry weight, and fresh biomass of maize under field conditions
• The effect of STF3 + 75% CF was equal or greater than 100% CF

11. Literature review
11
Results (1)
(Shahzad et al., 2013)
Table 2. Effect of inoculation with PGPR containing ACC-deaminase on yield of maize
under field conditions
• The use of PGPR can effectively promote plant growth while reducing
fertilizer requirements

12. Literature review
12
Journal 2
(Hassain et al., 2020)

13. Literature review
13
Results (2)
Figure 5. Effects of biochar (BC), rock phosphate enriched compost (CM), humic
acid (HA), mixture (MX), and Alcaligenes sp. AZ9 on maize plant height and root
length (different letters indicate significant differences according to least
significance difference test at P < 0.05). Values are means of three replicates ±
standard errors of means. (Hassain et al., 2020)
• Combination of PGPR
and amendment
significantly promoted
plant height but not root
length

14. Literature review
14
Results (2)
Figure 6. Effects of biochar (BC), rock phosphate enriched compost (CM), humic
acid (HA), mixture (MX), and Alcaligenes sp. AZ9 on maize shoot fresh and dry
weight (different letters indicate significant differences according to least
significance difference test at P < 0.05). Values are means of three replicates ±
standard errors of means. (Hassain et al., 2020)
• Soil amendments have
favorable characteristics
(availability of OM,
nutrients, change in pH
and porosity) for AZ9 to
colonize and reproduce

15. Future works
15
Isolation and characterization
Field trial 1
Field trial 2
Evaluation and selection of 1 PGPR
Selection of effective combination
CF
CK P1 A1 A2 P1 + A1 P1 + A2
- -
+ 100% P1 +
50%
A1 +
50%
A2 +
50%
P1 + A1 +
50%
P1 + A2 +
50%
Research Design
Phase 1
Phase 2
CF
CK P1 P2 P3 P4 A
- - - - - - -
+ 100% P1 +
50%
P2 +
50%
P3 +
50%
P4 +
50%
A +
50%

16. 16
Name Identification N2 fixing Phosphate
Solubilization
IAA ACC-
deaminase
Siderophore Chitinase GA
E2*
SLE1*
B2*
LU2**
Staphylococcus
sciuri
Bacillus
velezensis
NA
+
NA
NA
++
+
++
+
-
+
+
+
-
+
+
-
+
-
+
+
+
NA
NA
NA
+
+
+
-
Table 3. Plant growth-promoting traits of selected PGPR
Materials and methods
Phase 1
*Isolated from saline soils
** Isolated from compost

17. Phase 2- Trial 1
17
Materials and methods
• Four PGPR strains
• Maize (Huazhen No.2)
• Biochemical characterization (ACC-deaminase, IAA,
siderophore, phosphate solub., etc.)
• RCBD with 2 replicates (7 treatments, n = 24/ t)
• Soil application every 2 weeks (30 mL/plant)
• Urea and 12-18-12 (50 and 100% CF)
• Plant growth and yield assessment
• One-way ANOVA
• Tukey’s HSD test at P < 0.05

18. Conclusions
• PGPR efficiency depends on fertilizer input levels
• The integrated application of organic amendments along
with PGPR is effective in promoting plant growth
• Might be an alternative way to reduce fertilizer requirements
while promoting plant growth
18

19. Acknowledgements
• Advisor: Chang, Pei-Chun
(Ph.D.)
• NPUST and DTAIC
19

20. References
20
1. Kopittke, P.M.; Menzies, N.W.; Wang, P.; McKenna, B.A.; Lombi, E. Soil and the intensification of
agriculture for global food security. Environ Int 2019, 132, 105078,
doi:10.1016/j.envint.2019.105078.
2. Erenstein, O.; Jaleta, M.; Sonder, K.; Mottaleb, K.; Prasanna, B. Global maize production,
consumption and trade: trends and R&D implications. Food Security 2022, 1-25.
3. Gómez-Godínez, L.J.; Fernandez-Valverde, S.L.; Romero, J.C.M.; Martínez-Romero, E.
Metatranscriptomics and nitrogen fixation from the rhizoplane of maize plantlets inoculated
with a group of PGPRs. Systematic and applied microbiology 2019, 42, 517-525.
4. Hussain, A.; Ahmad, M.; Mumtaz, M.Z.; Ali, S.; Sarfraz, R.; Naveed, M.; Jamil, M.; Damalas, C.A.
Integrated Application of Organic Amendments with Alcaligenes sp. AZ9 Improves Nutrient
Uptake and Yield of Maize (Zea mays). Journal of Plant Growth Regulation 2020, 39, 1277-1292,
doi:10.1007/s00344-020-10067-7.
5. Cesarano, G.; De Filippis, F.; La Storia, A.; Scala, F.; Bonanomi, G. Organic amendment type and
application frequency affect crop yields, soil fertility and microbiome composition. Applied Soil
Ecology 2017, 120, 254-264.
6. Bamdad, H.; Papari, S.; Lazarovits, G.; Berruti, F. Soil amendments for sustainable agriculture:
Microbial organic fertilizers. Soil Use and Management 2021, 38, 94-120,
doi:10.1111/sum.12762.
7. Botha, P. Top-dressing fertiliser: timing is key. Available online: https://www.grainsa.co.za/top-
dressing-fertiliser-timing-is-key (accessed on accessed on 5 March 2023).
8. Shahzad, S.M.; Arif, M.S.; Riaz, M.; Iqbal, Z.; Ashraf, M. PGPR with varied ACC-deaminase activity
induced different growth and yield response in maize (Zea mays L.) under fertilized conditions.
European Journal of Soil Biology 2013, 57, 27-34, doi:10.1016/j.ejsobi.2013.04.002.

21. Thank you!
21