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Due to the scarcity of water, raw sewage effluents are often used to irrigate arable suburban soils in developing countries, which causes soil contamination with toxic metals. Soil microorganisms involved in biochemical transformations are sensitive to heavy metals contamination. The study was designed to investigate the effect of organic amendments on the microbial activity of cadmium (Cd), lead (Pb) and zinc (Zn) fractions and their bioavailability in soils contaminated with wastewater irrigation. Three metal contaminated soils under wastewater irrigation were collected, ground, sieved and added to incubation jars. Two organic amendments: wheat straw and chickpea straw, were applied (1% w/w) to the soil before incubation for 84 days at 25 °C. The CO2-C evolution after 1, 2, 3, 5, 7, 10 and 14 days was measured and thereafter was also measured weekly. Soil samples collected at 0, 14, 28, 42, 56, 70 and 84 days after incubation were analyzed for microbial biomass carbon (MBC). Sequential extraction for metal fractionation of samples was carried out collected at 0, 28, 56 and 84 days. Three soils differed significantly in evolved MBC and ∑CO2-C. Chickpea straw addition significantly increased soil MBC as compared to the wheat straw. Organic amendments significantly increased ∑CO2-C evolution from the soils, which was higher from chickpea straw. The addition of crop residues did not affect total Pb, Cd and Zn contents in soils. The concentration of exchangeable, carbonate bound and residual fractions of Pb, Cd and Zn decreased (6–27%), while the organic matter bound fraction increased (4–75%) with straw addition. Overall, the organic amendments improved microbial activity and reduce the bioavailability of toxic metals in wastewater irrigated soils. Furthermore, organic amendments not only reduce economic losses as they are cheap to produce but also minimize human health risks from heavy metals by hindering their entry into the food chain.
Kouser Malik; Khalid Khan; Shah Rukh; Ahmad Khan; Saba Akbar; Motsim Billah; Saqib Bashir; Subhan Danish; Mona Alwahibi; Mohamed Elshikh; Abdullah Al-Ghamdi; Abd Mustafa. Immobilization of Cd, Pb and Zn through Organic Amendments in Wastewater Irrigated Soils. Sustainability 2021, 13, 2392 .
AMA StyleKouser Malik, Khalid Khan, Shah Rukh, Ahmad Khan, Saba Akbar, Motsim Billah, Saqib Bashir, Subhan Danish, Mona Alwahibi, Mohamed Elshikh, Abdullah Al-Ghamdi, Abd Mustafa. Immobilization of Cd, Pb and Zn through Organic Amendments in Wastewater Irrigated Soils. Sustainability. 2021; 13 (4):2392.
Chicago/Turabian StyleKouser Malik; Khalid Khan; Shah Rukh; Ahmad Khan; Saba Akbar; Motsim Billah; Saqib Bashir; Subhan Danish; Mona Alwahibi; Mohamed Elshikh; Abdullah Al-Ghamdi; Abd Mustafa. 2021. "Immobilization of Cd, Pb and Zn through Organic Amendments in Wastewater Irrigated Soils." Sustainability 13, no. 4: 2392.
Continuous application of phosphate (P) mineral to soil renders apatite addition during each crop growing season which is of great concern from a sustainable agriculture viewpoint. Use of efficient phosphate solubilizing microbes (PSB) is one of the most effective ways to solubilize this apatite mineral in the soil. The current study targeted hydroxyapatite mines to explore, isolate and characterize efficient P solubilizers to solubilize apatite in the soil. Efficiency of isolated microbes to solubilize rock phosphate (hydroxyapatite) and tri-calcium phosphate (TCP) as well as indole-3-acetic acid (IAA) and 1-aminocyclopropane-1-carboxylate deaminase (ACC) activity were tested. Identification and phylogenetic analysis of bacterial and fungal isolates were carried out by 16S rRNA and internal transcribed spacer (ITS) rDNA sequence analyses, respectively. The isolated bacterial strains were identified as Staphylococcus sp., Bacillus firmus, Bacillus safensis, and Bacillus licheniformis whereas fungal isolates were identified as Penicillium sp. and Penicillium oxalicum. Results showed that the impact of identified strains in combination with three phosphate fertilizers sources (compost, rock phosphate and diammonium phosphate (DAP)) was conspicuous on maize crop grown in pot. Both bacterial and fungal strains increased the P uptake by plants as well as recorded with higher available P in post-harvested soil. Penicillium sp. in combination with compost resulted in maximum P-uptake by plants and post-harvest soil P contents, compared to other combinations of P sources and bio-inoculants. Screening and application of efficient P solubilizers can be a better option to utilize the indigenous phosphate reserves of soil as well as organic amendments for sustainable agriculture.
Awais Qarni; Motsim Billah; Khadim Hussain; Sabir Shah; Waqas Ahmed; Sadia Alam; Aftab Sheikh; Laila Jafri; Asia Munir; Kouser Malik; Naeem Khan. Isolation and Characterization of Phosphate Solubilizing Microbes from Rock Phosphate Mines and their Potential Effect for Sustainable Agriculture. Sustainability 2021, 13, 2151 .
AMA StyleAwais Qarni, Motsim Billah, Khadim Hussain, Sabir Shah, Waqas Ahmed, Sadia Alam, Aftab Sheikh, Laila Jafri, Asia Munir, Kouser Malik, Naeem Khan. Isolation and Characterization of Phosphate Solubilizing Microbes from Rock Phosphate Mines and their Potential Effect for Sustainable Agriculture. Sustainability. 2021; 13 (4):2151.
Chicago/Turabian StyleAwais Qarni; Motsim Billah; Khadim Hussain; Sabir Shah; Waqas Ahmed; Sadia Alam; Aftab Sheikh; Laila Jafri; Asia Munir; Kouser Malik; Naeem Khan. 2021. "Isolation and Characterization of Phosphate Solubilizing Microbes from Rock Phosphate Mines and their Potential Effect for Sustainable Agriculture." Sustainability 13, no. 4: 2151.
Drought is a major constraint in drylands for crop production. Plant associated microbes can help plants in acquisition of soil nutrients to enhance productivity in stressful conditions. The current study was designed to illuminate the effectiveness of desert rhizobacterial strains on growth and net-return of chickpeas grown in pots by using sandy loam soil of Thal Pakistan desert. A total of 125 rhizobacterial strains were isolated, out of which 72 strains were inoculated with chickpeas in the growth chamber for 75 days to screen most efficient isolates. Amongst all, six bacterial strains (two rhizobia and four plant growth promoting rhizobacterial strains) significantly enhanced nodulation and shoot-root length as compared to other treatments. These promising strains were morphologically and biochemically characterized and identified through 16sRNA sequencing. Then, eight consortia of the identified isolates were formulated to evaluate the growth and development of chickpea at three moisture levels (55%, 75% and 95% of field capacity) in a glass house experiment. The trend for best performing consortia in terms of growth and development of chickpea remained T2 at moisture level 1 > T7 at moisture level 2 > T4 at moisture level 3. The present study indicates the vital role of co-inoculated bacterial strains in growth enhancement of chickpea under low moisture availability. It is concluded from the results that the consortium T2 (Mesorhizobium ciceri RZ-11 + Bacillus subtilis RP-01 + Bacillus mojavensis RS-14) can perform best in drought conditions (55% field capacity) and T4 (Mesorhizobium ciceri RZ-11 + Enterobacter Cloacae RP-08 + Providencia vermicola RS-15) can be adopted in irrigated areas (95% field capacity) for maximum productivity of chickpea.
Azhar Mahmood Aulakh; Ghulam Qadir; Fayyaz Ul Hassan; Rifat Hayat; Tariq Sultan; Motsim Billah; Manzoor Hussain; Naeem Khan. Desert Soil Microbes as a Mineral Nutrient Acquisition Tool for Chickpea (Cicer arietinum L.) Productivity at Different Moisture Regimes. Plants 2020, 9, 1629 .
AMA StyleAzhar Mahmood Aulakh, Ghulam Qadir, Fayyaz Ul Hassan, Rifat Hayat, Tariq Sultan, Motsim Billah, Manzoor Hussain, Naeem Khan. Desert Soil Microbes as a Mineral Nutrient Acquisition Tool for Chickpea (Cicer arietinum L.) Productivity at Different Moisture Regimes. Plants. 2020; 9 (12):1629.
Chicago/Turabian StyleAzhar Mahmood Aulakh; Ghulam Qadir; Fayyaz Ul Hassan; Rifat Hayat; Tariq Sultan; Motsim Billah; Manzoor Hussain; Naeem Khan. 2020. "Desert Soil Microbes as a Mineral Nutrient Acquisition Tool for Chickpea (Cicer arietinum L.) Productivity at Different Moisture Regimes." Plants 9, no. 12: 1629.
Organic materials from various sources have been commonly adopted as soil amendments to improve crop productivity. Phosphorus deficiency and fixation in alkaline calcareous soils drives a reduction in crop production. A two-year field experiment was conducted to evaluate the impact of rock phosphate enriched composts and chemical fertilizers both individually and in combination with plant growth promoting rhizobacteria (PGPR) on wheat productivity and soil chemical and biological and biochemical properties. The present study demonstrates significant increments in crop agronomic and physiological parameters with Pseudomonas sp. inoculated RPEC1 (rock phosphate + poultry litter + Pseudomonas sp.) over the un-inoculated untreated control. However, among all other treatments i.e., RPEC2 (rock phosphate + poultry litter solubilized with Proteus sp.), RPC (rock phosphate + poultry litter), HDP (half dose inorganic P from Single Super Phosphate-SSP 18% P2O5) and SPLC (poultry litter only); RPEC1 remained the best by showing increases in soil chemical properties (available phosphorus, nitrate nitrogen, extractable potassium), biochemical properties (alkaline phosphatase activity) and biological properties (microbial biomass carbon and microbial biomass phosphorus). Economic analysis in terms of Value Cost Ratio (VCR) showed that the seed inoculation with Pseudomonas sp. in combination with RPEC1 gave maximum VCR (3.23:1) followed by RPEC2 (2.61:1), FDP (2.37:1), HDP (2.05:1) and SPLC (2.03:1). It is concluded that inoculated rock phosphate (RP) enriched compost (RPEC1) can be a substitute to costly chemical fertilizers and seed inoculation with Pseudomonas sp. may further increase the efficiency of composts.
Motsim Billah; Matiullah Khan; Asghari Bano; Sobia Nisa; Ahmad Hussain; Khadim Muhammad Dawar; Asia Munir; Naeem Khan. Rock Phosphate-Enriched Compost in Combination with Rhizobacteria; A Cost-Effective Source for Better Soil Health and Wheat (Triticum aestivum) Productivity. Agronomy 2020, 10, 1390 .
AMA StyleMotsim Billah, Matiullah Khan, Asghari Bano, Sobia Nisa, Ahmad Hussain, Khadim Muhammad Dawar, Asia Munir, Naeem Khan. Rock Phosphate-Enriched Compost in Combination with Rhizobacteria; A Cost-Effective Source for Better Soil Health and Wheat (Triticum aestivum) Productivity. Agronomy. 2020; 10 (9):1390.
Chicago/Turabian StyleMotsim Billah; Matiullah Khan; Asghari Bano; Sobia Nisa; Ahmad Hussain; Khadim Muhammad Dawar; Asia Munir; Naeem Khan. 2020. "Rock Phosphate-Enriched Compost in Combination with Rhizobacteria; A Cost-Effective Source for Better Soil Health and Wheat (Triticum aestivum) Productivity." Agronomy 10, no. 9: 1390.