Zahir Ahmad Zahir

University of Agriculture Faisalabad · Institute of Soil and Environmental Sciences

Low soil organic matter contents are among the most predominant reasons behind reduced soil health and decreased agricultural productivity. Sustainable agricultural approaches encourage minimal farmer’s dependence on chemical fertilizers and favor their supplementation with organic and biofertilizers to ensure smooth crop growth and sustained soil...

Plant growth-promoting rhizobacteria (PGPR) increase plant root growth, potentially improving soil nitrogen (N) uptake, and productivity. Legumes, for instance mungbean, could also benefit from a rise in potential infection sites for nodulation, thereby increasing rates of biological N 2 fixation (BNF). Consequently, the objectives of this study we...

Weed infestation is one of the most damaging biotic factors to limit crop production by competing with the crop for space, water, and nutrients. Different conventional approaches are being used to cope with weed infestation including labor intensive manual removal and the use of soil-degrading and crop-damaging, and environment-deteriorating chemic...

Chromium (Cr) contamination of soil has substantially deteriorated soil health and has interfered with sustainable agricultural production worldwide and therefore, its remediation is inevitable. Inoculation of plant growth promoting rhizobacteria (PGPR) in association with nanotechnology has exerted broad based impacts in agriculture, and there is...

Herbicide-based weeds control impacts wheat crops as well. SynComs of Pseudomonas strains reduce the need for high-dose herbicides. 100% Axial provides less weed control compared to 75% Axial with C4 SynCom. Axial 75% with C4 SynCom promotes wheat growth than the 75% Axial alone. To address environmental concerns and manage resistant weeds, there i...

Worldwide, salinity severely affects agricultural production of crops such as mung bean in arid and semi-arid regions. In saline conditions, various species of Rhizobium can be used to enhance nodulation and induce salinity tolerance in maize. The present study conducted a pot experiment to determine the efficiency of three rhizobial isolates under...

Potential of auxin and ACC-deaminase producing rhizobia and PGPR-strains was examined to improve soybean growth individually and in combination with L-tryptophan (L-TRP) in two different experiments conducted in a growth chamber. A consortium of selected PGPR and rhizobial strains was prepared by following the compatibility test. These bacteria wer...

Phosphorous (P) is an important macronutrient for plant growth and often acts as a limiting nutrient. It is mostly provided to plants by inorganic resources, most of which cannot be utilized by plants either due to precipitation or immobilization. Phosphate-solubilizing bacteria (PSB) can improve P availability by dissolving inorganic and mineraliz...

Catalase can decompose hydrogen peroxide in plants under controlled and stressed condi-tions. In a stressed environment, the increase in hydrogen peroxide production makes catalase activity a major defense system for plant growth. The current study was conducted to evaluate the catalase activity of pre-isolated and identified bacterial strains Baci...

Weeds are one of the major limiting factors for wheat production. So, a study was conducted to integrate allelopathic bacteria with reduced dose of chemical herbicide for sustainable wheat production in wild oat infestation. Cyanide-producing Pseudomonas strains were applied in four combinations with and without two chemical herbicides (Axial and A...

Excessive use of synthetic fertilizers is a major bottleneck towards adopting microbial techniques on a large scale and poses great challenge to food security by disrupting soil properties and increasing production costs. Current research must focus on developing suitable alternatives for optimizing crop production along with reduced agricultural c...

This study was undertaken to see how microbial consortia influenced maize development and yield under salt-affected conditions. The efficacy of the pre-isolated bacterial strains Burkholderia phytofirmans, Bacillus subtilis, Enterobacter aerogenes, and Pseudomonas syringae and Pseudomonas fluorescens to decrease the detrimental effects of salt on m...

Cadmium (Cd) contamination is a major environmental concern with well-reported adverse impacts on environment and living entities. It limits the productivity of agricultural crops due to its excessive entry to plant tissues, and subsequent toxic effects on their growth and physiology. Application of metal tolerant rhizobacteria in combination with...

Arsenic (As) contamination of ground water and soil has become a global issue by virtue of its carcinogenicity and toxicity to human and animal health, and is related to both geogenic and anthropogenic sources. Exposure to As occurs primarily by the consumption of contaminated drinking water or food. Its dissolution as a result of redox reactions l...

Heavy metal contamination of soil is an alarming environmental dilemma all over the world. With increasing industrialization, timely development of low-cost and eco-friendly remedial techniques for heavy metal-contaminated soil is needed. Phytoremediation is an emerging technique to remove heavy metals from contaminated soil for environmental susta...

Chemical weed control is an effective method, but has proved hazardous for humans, environment, and soil biodiversity. Use of allelopathic bacteria may be more efficient and sustainable weed control measure. The bacterial inoculants have never been studied in context of their interaction with weed root exudates and precursor-dependent production of...

Owing to inconsistent results of a single bacterial strain, co-inoculation of more than one strain under salinity stress could be a more effective strategy to induce salt tolerance. Co-inoculation of more than one bacterial strain could be more effective due to the presence of several growths promoting traits. This study was conducted to evaluate t...

Halotolerant rhizobacteria, which are able to withstand higher concentrations of salts, are useful for conferring salinity tolerance to agricultural crops and improving soil fertility through their different activities. Among their various mechanisms, the improvement in soil enzyme activities they bring about through production of extracellular enz...

Plant assisted bioremediation of petroleum hydrocarbon contaminated soil is considered an effect�ive green technology whereby accelerated degradation occurs due to converged effect of microor�ganisms and plants. However, survival and growth of microbes and plants under stress conditionsis challenging task for success of the technology. In this stud...

Many agricultural soils fail to supply sufficient boron (B) and phosphorus (P) to growing plants due to their adsorption, precipitation and fixation phenomena. Moreover, the application of individual B sources without a macronutrient fertilizer is impractical owing to the separate handling and poor distribution in the field. The study aimed to deve...

Phosphate-solubilizing bacteria (PSB) have been known to improve soil fixed phosphorus (P) availability to crop. However, PSB performance under thermal stress is poorly understood. The purpose of this study was to isolate thermo-tolerant PSB from the cotton (Gossypium hirsutum L.) rhizosphere, cultivated in the alkaline soil of a semi-arid region....

Iron deficiency is one of the major causes of disability and mortality in the world, impacting an estimated 2 billion people. Nutritional iron deficiency occurs when dietary iron absorption is insufficient to meet physiological needs. Dietary iron bioavailability is poor in those who eat a monotonous plant-based diet. Iron deficiency is common in t...

Sunflower (Helianthus annuus L.) growth and yield are severely compromised by boron (B) deficiency in alkaline calcareous soils of Pakistan. Biochar produced through low-temperature pyrolysis helps to maintain acidic functional groups in such soils. The aim of this study was to enhance B availability in biochar-amended alkaline calcareous soils in...

Salt-tolerant plant growth-promoting rhizobacteria (PGPR) can improve soil enzyme activities, which are indicators of the biological health of the soil, and can overcome the nutritional imbalance in plants. A pot trial was executed to evaluate the effect of inoculation of different salt-tolerant PGPR strains in improving soil enzyme activities. Thr...

Iron deficiency is one of the most prevailing micronutrient deficiencies throughout the globe. Iron malnutrition affects billions of people around the world especially children and pregnant women. Its deficiencies can be overcome through microbial biofortification: a process of deliberately increasing desirable nutrients in crop plants. Plant growt...

Global climate change accelerates the coincidence of a variety of abiotic stresses, viz., salinity, drought, flooding, high and low temperature, and biotic stresses, viz. phytopathogens which degrade agricultural productivity. In such circumstances, plant growth-promoting rhizobacteria (PGPR) are eco-friendly and sustainable candidates to combat th...

Differential effects of biological weed control agents should be established before they are recommended for application in field conditions. Our previous studies have reported five strains of weed antagonistic bacteria (WAB) controlling three most noxious weeds of wheat. This work has evaluated selectivity of these strains through study of growth,...

The current study investigated the influence of exopolysaccharides (EPSs) producing plant growth–promoting rhizobacteria (PGPR) on the growth, physiology, and soil properties. The pre-isolated and compatible EPS producing PGPR strains were first screened based on improvement in soil aggregates in an incubation study. The screened strains (Rhizobium...

Pesticides are widely used for managing pathogens and pests for sustainable agricultural output to feed around seven billion people worldwide. After their targeted role, residues of these compounds may build up and persist in soils and in the food chain. This study evaluated the efficiency of bacterial strains capable of plant growth promotion and...

Zinc (Zn) deficiency is a widespread micro-nutritional disorder in humans. The present research aimed at investigating the enzymatic and physiological roles of zinc solubilizing bacteria (ZnSB) to solubilize the insoluble form of Zn and in increasing Zn content in chickpea. Bacterial strains (50) were isolated from chickpea rhizosphere and were scr...

Agricultural soils are receiving higher inputs of trace elements (TEs) from anthropogenic activities. Application of nanoparticles (NPs) in agriculture as nano-pesticides and nano-fertilizers has gained rapid momentum worldwide. The NPs-based fertilizers can facilitate controlled-release of nutrients which may be absorbed by plants more efficiently...

To feed the burgeoning human population, there is dire need to enhance the crops yield. Limited crop production is the result of many biotic and abiotic stress factors. One of the most important factors causing a reduction in crop yield is drought stress. It adversely affects the physiological attributes of crop plants along with a disturbance in b...

The application of boron (B) fertilizers is challenging due to the high solubility of commonly used B compounds, the small requirement by crops, and the narrow range between toxicity and deficiency levels for plants. The application of a B-only fertilizer without a macronutrient carrier is inefficient due to the high cost of double handling and the...

Development of successful biological weed control can help to resolve various environmental challenges created by the chemical and mechanical weed control. The current study is aimed at investigating the potential of allelopathic bacteria (hereinafter as AB) for biological weed control in wheat rather than the traditional areas of plant allelopathy...

Plant growth promoting rhizobacteria (PGPR) are associated with rhizosphere as well as non-rhizosphere. PGPR are involved in plant growth promotion through different direct and indirect mechanisms. The excessive and imbalanced use of chemical fertilizers is a burning issue. The scientists are emphasizing on reducing the use of chemical fertilizers...

Nutrient deficiency occurs in plants either by the inadequacy of nutrients in the soil or by their unavailability in plant-absorbable forms. Nutrient deficiency is a very old issue caused by increased food demand by humans, which has resulted in the development of varieties with enhanced nutrient-uptake. Inadequacy of nutrients in the soil is a maj...

Application of allelopathic bacteria (AB) for weed suppression may be helpful to solve various environmental challenges posed by conventional weed control techniques. In our earlier studies, around 400 strains of rhizobacteria of five weeds and wheat were isolated, screened for production of phytotoxic substances, and tested for phytotoxic activity...

Conventional weed control practices have generated serious issues related to the environment and human health. Therefore, there is a demand for the development of alternative techniques for sustainable agriculture. The present study performed a large-scale screening of allelopathic bacteria from the rhizosphere of weeds and wheat to obtain biologic...

Rhizobacteria containing 1-aminocyclopropane-1-carboxylic acid-deaminase (ACC-deaminase) and exopolysaccharides (EPS) activity are important to induce stress tolerance in plants. The present study was conducted to screen and characterize plant growth promoting rhizobacteria (PGPR) with ACC-deaminase and EPS-producing activity for improving maize gr...

Chromium is a toxic heavy metal. Plants, animals and human metabolic processes are disturbed due to higher levels of chromium. PGPR are involved in seed germination, growth improvement, metabolic process and in most of the physiological processes of plants. Press mud in soil provides substrate to the microbes. PGPR can convert the more toxic form o...

Arid and semi-arid regions are characterized by high temperature and low rainfall, leading to degraded agricultural soils of alkaline calcareous nature with low organic matter contents. Less availability of indigenous nutrients and efficacy of applied fertilizers are the major issues of crop production in these soils. Biochar application, in combin...

Aquatic pollution caused by industrial effluents is an environmental issue, imposing deleterious impacts on the overall environment, specifically, on humans, by disrupting the balance of the ecosystem. Among all the industries, tanneries are considered some of the most polluting due to heavy use of toxic organic and inorganic compounds during leath...

The phytoremediation potential of macrophytic species has made them an inevitable component of constructed wetlands (CWs) for the treatment of industrial effluents. The macrophytes must have tolerance for the harsh conditions imposed by effluents for an effective establishment of the CW system. In this context, the basic purpose of this work was to...

Abstract: The phytoremediation potential of macrophytic species has made them an inevitable component of constructed wetlands (CWs) for the treatment of industrial effluents. The macrophytes must have tolerance for the harsh conditions imposed by effluents for an effective establishment of the CW system. In this context, the basic purpose of this w...

Conventional weed control methods often have environmental impact. The present study was conducted to screen selected accessions of Pseudomonas for both potential biocontrol of Phalaris minor and Avena fatua and potential concurrent growth promotion of wheat. The four Pseudomonas strains (B11, T19, T24, and T75) were found positive for cyanide prod...

Cereal crops are a major part of our daily dietary intake. However, they are reported to have poor zinc (Zn) content. Bio-activation of zinc oxide with zinc solubilizing bacteria (ZSB) is considered a relatively newer approach to enrich cereal grains with Zn. The present study was conducted to evaluate the role of four bio-activated ZnO (BOZ) formu...

Bio-activated organic fertilizers (BOZ) were produced by enriching the zinc oxide (ZnO)-orange peel waste composite with Zn solubilizing bacteria (ZSB: Bacillus sp. AZ6) in various formulations (BOZ1 (9:1), BOZ2 (8:2), BOZ3 (7:3) and BOZ4 (6:4)). The produced BOZs, along with ZnO, ZnSO 4 , ZSB were applied to maize crop (Zea mays L.) under field co...

The application of liquid bacterial consortia to soil under natural conditions may fail due to various environmental constraints. In this study, the suitability and efficiency of compost, biogas slurry, crushed corn cob, and zeolite as carriers to support the survival of plant growth-promoting rhizobacteria (PGPR) and improve the performance of mul...

The present study was conducted to evaluate five pre-characterized lead tolerant plant growth promoting rhizobacteria: Pseudomonas gessardii strain BLP141 (S2), Pseudomonas fluorescens A50 (S5), Pseudomonas syringae pv. syringae B728a (S6), Pseudomonas stutzeri strain 28a24 (S8) and Pseudomonas fluorescens strain LMG 2189 (S10), for their plant gro...

Chickpea is an important leguminous crop that improves soil fertility through atmospheric nitrogen fixation with the help of rhizobia present in nodules. Non-rhizobia endophytes are also capable of inducing nodulation and nitrogen fixation in leguminous crops. The aim of the current study was to isolate, characterize and identify the non-rhizobia e...

Zinc (Zn) occurs in high concentrations in heavy metal polluted ecosystems which are colonized by bacterial populations. Some members of these communities are attractive candidates for phytoremediation of Zn-contaminated soils as they are able to convert insoluble forms of Zn into soluble forms, making Zn available to plants as a micronutrient. How...

Soil salinity being a significant character of the arid and semi-arid climate, causes enormous reduction in the crop production. It does so by disturbing the hormonal and nutritional balances which are important for plant growth. Using plant growth promoting rhizobacteria to mitigate salinity stress is an emerging potential technology. By employing...

Global food security is the major challenge for agricultural scientists, but it should not be on the cost of depletion of nonrenewable resources such as soil. Due to the decrease in agricultural land, the use of synthetic chemical fertilizers to increase crop productivity has placed extra strain on fragile agroecosystem, thereby deteriorating its h...

Due to continuous growth of world population, there is dire need of serious efforts and innovative approaches to meet food demands through sustainable production practices, improvement in supply chain, and control of food wastage. All these efforts should ensure the access to nutritious food to all suffering from hunger and malnutrition. Due to int...

The salt-tolerant microorganisms also referred to as halotolerant including bacteria and fungi have the ability to promote growth of plant in salty environment. Presence of certain particular traits like exopolysaccharide production ability, 1-aminocyclopropane-1-carboxylate (ACC) deaminase, production of osmolytes, enhancing nutrient acquisition a...

Soil contamination with toxic metals is a widespread environmental issue resulting from global industrialization within the past few years. Therefore, decontamination of heavy metal contaminated soils is very important to reduce the associated risks and for maintenance of environmental health and ecological restoration. Conventional techniques for...

Sandy soils are known for dry spells due to low rainfall in arid-semiarid climatic regions. A study was conducted to identify the effectiveness of moderately drought tolerant and characteristically plant growth promoting bacterial strain Mesorhizobium ciceri-CR-39 for improving growth, physiology, nutrition and yield of wheat (cultivar: Sahar) unde...

Boron (B) and phosphorus (P) application is mandatory as most of the Pakistani soils, being calcareous in nature, fail to supply nutrients in sufficient quantity to plants. Few bacteria have been reported as B-tolerant but their features for enhancing nutrient supply to plants have not been studied yet. In this study, growth of six bacterial strain...

Deficiency of plant available phosphorus (P) is prevailing across the globe. Farming community in Pakistan is also facing the issue of poor availability of P due to high soil pH and calcareous nature of soils resulting in lower P-fertilizer use efficiency (FUE) of expensive fertilizers. Cow manure and elemental sulfur (S°) were bio-augmented with s...

Soil salinity affects the growth and yield of crops. The stress of soil salinity on plants can be mitigated by inoculation of plant growth promoting bacteria (PGPR). The influence of PGPR inoculation on wheat (Triticum aestivum L.) crop productivity under salinity stress has not been properly addressed so far. Therefore, the present study was condu...

Chickpea is an important leguminous crop that improves soil fertility through atmospheric nitrogen fixation with the help of rhizobia present in nodules. Non-rhizobia endophytes are also capable of inducing nodulation and nitrogen fixation in leguminous crops. The aim of the current study was to isolate, characterize and identify the non-rhizobia e...