Enhanced wheat productivity in saline soil through the combined application of poultry manure and beneficial microbes

Abstract

Background: Soil salinity is one of the major menaces to food security, particularly in dealing with the food demand of the ever-increasing global population. Production of cereal crops such as wheat is severely affected by soil salinity and improper fertilization. The present study aimed to examine the effect of selected microbes and poultry manure (PM) on seedling emergence, physiology, nutrient uptake, and growth of wheat in saline soil. A pot experiment was carried out in research area of Institute of Soil and Environmental Sciences, University of Agriculture, Faisalabad, Pakistan. Saline soil (12 dS m^{- 1} w/w) was developed by spiking using sodium chloride, and used in experiment along with two microbial strains (i.e., Alcaligenes faecalis MH-2 and Achromobacter denitrificans MH-6) and PM. Finally, wheat seeds (variety Akbar-2019) were sown in amended and unamended soil, and pots were placed following a completely randomized design. The wheat crop was harvested after 140 days of sowing.

Results: The results showed a 10-39% increase (compared to non-saline control) in agronomic, physiological, and nutritive attributes of wheat plants when augmented with PM and microbes. Microbes together with PM significantly enhanced seedling emergence (up to 38%), agronomic (up to 36%), and physiological (up to 33%) in saline soil as compared to their respective unamended control. Moreover, the co-use of microbes and PM also improved soil's physicochemical attributes and enhanced N (i.e., 21.7%-17.1%), P (i.e., 24.1-29.3%), and K (i.e., 28.7%-25.3%) availability to the plant (roots and shoots, respectively). Similarly, the co-use of amendments also lowered the Na⁺ contents in soil (i.e., up to 62%) as compared to unamended saline control. This is the first study reporting the effects of the co-addition of newly identified salt-tolerant bacterial strains and PM on seedling emergence, physiology, nutrient uptake, and growth of wheat in highly saline soil.

Conclusion: Our findings suggest that co-using a multi-trait bacterial culture and PM could be an appropriate option for sustainable crop production in salt-affected soil.

Keywords: Bacteria; Organic amendments; Phytotoxicity; Salinity; Stress alleviation; Wheat.

Fig. 1

Effects of beneficial microbes and poultry manure on photosynthetic pigments of wheat plants grown in saline soil. Columns and error bars represent the means and standard errors of triplicate values of each treatment, respectively. Tukey’s test at P ≤ 0.05 shows that the means with different letters are significantly different from each other. P, Plant; MS1, Microbial strain 1 (i.e., Alcaligenes faecalis MH-2); MS2, Microbial strain 2 (i.e., Achromobacter denitrificans MH-6); MC, Microbial consortium (i.e., Alcaligenes faecalis MH-2 and Achromobacter denitrificans MH-6); PM, Poultry manure; S, Salinity; Chl. a, Chlorophyll a; Chl. b, Chlorophyll b; Total Chl., Total Chlorophyll; LWF, leaf fresh weight

Fig. 2

Effects of beneficial microbes and poultry manure on sodium contents of wheat grown in saline soil. Sodium in root (A), shoot (B), seeds (C) and soil (D) was analyzed on harvesting (i.e., after 140 days of sowing). Columns and error bars represent the means and standard errors of triplicate values of treatments, respectively. Tukey’s test at P ≤ 0.05 shows that the means with different letters are significantly different from each other. P, Plant; MS1, Microbial strain 1 (i.e., Alcaligenes faecalis MH-2); MS2, Microbial strain 2 (i.e., Achromobacter denitrificans MH-6); MC, Microbial consortium (i.e., Alcaligenes faecalis MH-2 and Achromobacter denitrificans MH-6); PM, Poultry manure; S, Salinity

Fig. 3

Correlation plot represents a correlation matrix among different growth, physiological, and nutrient attributes of wheat crop grown in saline and non-saline soil. The size of the square shows the strength of the relationship (high, moderate or low) of different attributes of the wheat crop. The dark red and dark blue colors show a highly positive or negative correlation, respectively. The color legend shown on the right side of the correlation plot indicates the corresponding colors and the correlation coefficient. SL, shoot length; RL, root length; SpL, Spike length; NT, No. of tillers per plant; NS, No. of spikes per plant; NSs, No. of spikelets per plant; SFW, shoot fresh weight; SDW, shoot dry weight; RFW, root fresh weight; RDW; root dry weight; GT, Grain weight per spike; NG, No. of grains per spike; 100 GW, 100 Grains weight; SPAD value, Chlorophyll content; Ft, Fluorescence yield; PAR, Photosynthetically active radiation; YII, Quantum yield; ETR, Electron transport rate; MSI, membrane stability index; RWC, relative water contents; Chl a, chlorophyll a; Chl b; chlorophyll b; Total Chl, Total chlorophyll; CC, Carotenoids content; Na in soil, Sodium in soil; Na in root, Sodium in roots; Na in shoot, Sodium in shoots; Na in seeds, Sodium in seeds; N in roots, Nitrogen in roots; N in shoots, Nitrogen in shoots; P in roots, Phosphorus in roots; P in shoots, Phosphorus in shoots; K in roots, Potassium in roots; K in shoots, Potassium in shoots