Application of Extremophiles in Sustainable Agriculture

With the increasing demands for foods and other agriculture-based products, sustainable agricultural practices are the cornerstone for improving low-input agricultural production. In contrast to crop production, plant-microorganism interaction (PMI) plays a crucial role. PMI significantly raises productivity as well as maintaining the overall health of the crop. During harsh and extreme physiological conditions, plant-associated extremophilic microbes (PAEM) are known to contribute to crop production, survivability, and fitness. Thus, the application of extremophiles either in the form of biofertilizer or biopesticides is highly beneficial. Extremophiles have been adapted to withstand diverse harsh environmental conditions. They possess unique mechanisms at the molecular level to produce enormous potential extremozymes and bioactive compounds. Consequently, extremophiles represent the foundation of efficient and sustainable agriculture. This chapter introduces the significance and application of plant-associated extremophilic microbes in sustainable agriculture.

Harnessing soil bacteria and their benefits for sustainable agriculture with changing climate.

Soil bacteria contribute effectively to key biogeochemical reactions in the soil rhizosphere. They support plants in the rhizosphere to adapt quickly to changing climatic conditions. Differences in root exudates, trace gas chemistry, chemical compounds and nutrient exchange contribute to the recruitment of diverse microorganisms by plant roots. This review highlights the importance of characterizing novel microorganisms to support sustainable agricultural practices. We discuss about tools for characterizing microbes and agricultural practices that influence microbial diversity, and have reviewed how microorganisms may have important but unidentified roles in climate change. Beneficial microbes could improve the turnover of carbon, nitrogen, phosphorus and other minerals thereby avoiding the use of chemical inputs, which are not only causing serious environmental harm but also pose danger to human and animal health.

Biological Control Strategies of Plant Pathogens

Food security has become a major concern worldwide in recent years due to ever increasing population. Providing food for the growing billions without disturbing environmental balance is incessantly required in the current scenario. In view of this, sustainable modes of agricultural practices offer better promise and hence are gaining prominence recently. Moreover, these methods have taken precedence currently over chemical-based methods of pest restriction and pathogen control. Adoption of Biological Control is one such crucial technique that is currently in the forefront. Over a period of time, various biocontrol strategies have been experimented with and some have exhibited great success and promise. This review highlights the different methods of plant-pathogen control, types of plant pathogens, their modus operandi and various biocontrol approaches employing a range of microorganisms and their byproducts. The study lays emphasis on the use of upcoming methodologies like microbiome management and engineering, phage cocktails, genetically modified biocontrol agents and microbial volatilome as available strategies to sustainable agricultural practices. More importantly, a critical analysis of the various methods enumerated in the paper indicates the need to amalgamate these techniques in order to improve the degree of biocontrol offered by them.

Optimal selection of agricultural crops for sustainable farming in nutrient-rich Wadi areas of Saudi Arabia using MCDM

In the Kingdom of Saudi Arabia (KSA), Wheat, Barley, fruits, vegetables, and fodders are the most common agricultural products. Agricultural sustainability depends on socioeconomic and climatic conditions. Proper crop selection is vital to maximize productivity, yielding more revenue to the farmer at a lower cost. To rank the crop alternatives based on the available natural resources and cost, a multicriterion based decision-making model (MCDM) may be applied to identify the best suitable crop, encouraging sustainable agricultural practices. To make the agricultural activities sustainable, most of the critical criteria are taken into account. Four criteria linked to sustainability are included in this study. The research focuses on developing a model for sustainable agricultural practices in KSA employing MCDM. Three MCDM techniques were employed to evaluate the most suitable crop,and the results are compared and validated. The results from all three methods gave consistent results. Fruits emerged as the most productive crop, followed by Wheat, vegetables, fodders, and Barley. Such methodology shall be further extended across the other regions and over various crops for sustainable agricultural practices. The study is expected to help the Ministry of Water, Environment, and Agriculture, KSA, draft a suitable agricultural policy.

Genotoxic Evaluation of Fe3O4 Nanoparticles in Different Three Barley (Hordeum vulgare L.) Genotypes to Explore the Stress-Resistant Molecules

Sustainable agricultural practices are still essential due to soil degradation and crop losses. Recently, the relationship between plants and nanoparticles (NPs) attracted scientists’ attention, especially for applications in agricultural production as nanonutrition. Therefore, the present research was carried out to investigate the effect of Fe3O4 NPs at low concentrations (0, 1, 10, and 20 mg/L) on three genotypes of barley (Hordeum vulgare L.) seedlings grown in hydroponic conditions. Significant increases in seedling growth, enhanced chlorophyll quality and quantity, and two miRNA expression levels were observed. Additionally, increased genotoxicity was observed in seedlings grown with NPs. Generally, Fe3O4 NPs at low concentrations could be successfully used as nanonutrition for increasing barley photosynthetic efficiency with consequently enhanced yield. These results are important for a better understanding of the potential impact of Fe3O4 NPs at low concentrations in agricultural crops and the potential of these NPs as nanonutrition for barley growth and yield enhancement. Future studies are needed to investigate the effect of these NPs on the expression of resistance-related genes and chlorophyll synthesis-related gene expression in treated barley seedlings.

Co-inoculation With Rhizobacteria and Mycorrhizae Can Improve Wheat/Faba Bean Intercrop Performance Under Field Conditions

Current challenges of climate changes and demographic expansion have imposed increasing awareness about innovation in sustainable agricultural practices. Farming practices like intercropping have many benefits in terms of nutrient use and yield stability. Improving the performance of intercropping systems by the application of beneficial microorganisms (rhizobacteria and/or mycorrhizae) constitutes a promising strategy. In this regard, this study aimed to assess the effect of inoculation with beneficial microorganisms on wheat as monocrop or intercrop with faba bean, using four inoculation treatments: (i) inoculation with rhizobacteria, (ii) inoculation with mycorrhizae, (iii) inoculation with the rhizobacteria-mycorrhizae consortium, and (iv) a control treatment consisting of uninoculated plants. Results showed that rhizobacteria-mycorrhizae co-inoculation under intercropping system improved plant dry weight and spike weight of wheat by 375 and 162%, respectively, compared with uninoculated intercropped wheat. The thousand-seed weight was improved by 86% in wheat intercropped and inoculated with the rhizobacteria-mycorrhizae consortium. Furthermore, higher P and N concentrations were observed in shoots and spikes of wheat intercropped with faba bean, and this increase was also observed in response to inoculation with the rhizobacteria-mycorrhizae consortium in terms of P in shoots and spikes (by 74 and 18%) of intercropped wheat. In addition, intercropped wheat has significantly accumulated sugar in the seeds for all inoculated treatments (except inoculation with mycorrhizae). Overall, these findings revealed that intercropping and inoculation yielded better, suggesting that intercropping combined with the application of beneficial microorganisms, such as rhizobacteria and mycorrhizae, have the potential to improve overall crop yield.