In the ecosphere, plants interact with environmental biotic and abiotic partners, where unbalanced interactions can induce unfavourable stress conditions. Abiotic factors (temperature, water, and salt) are primarily required for plants healthy survival, and any change in their availability is reflected as a stress signal. In certain cases, the presence of infectious pathogens such as viruses, bacteria, fungi, protozoa, nematodes, and insects can also create stress conditions in plants, leading to the emergence of disease or deficiency symptoms. While these symptoms are often typical of abiotic or biotic stress, however, there are instances where they can intensify under specific conditions. Here, we primarily summarize the viral interactions with plants during abiotic stress to understand how these associations are linked together during viral pathogenesis. Secondly, focus is given to the beneficial effects of root-associated symbiotic bacteria in fulfilling the basic needs of plants during normal as well as abiotic stress conditions. The modulations of plant functional proteins, and their occurrence/cross-talk, with pathogen (virus) and symbiont (bacteria) molecules are also discussed. Furthermore, we have highlighted the biochemical and systematic adaptations that develop in plants due to bacterial symbiosis to encounter stress hallmarks. Lastly, directions are provided towards exploring potential rhizospheric bacteria to maintain plant-microbes ecosystem and manage abiotic stress in plants to achieve better trait health in the horticulture crops.
Core Ideas: Removal of aboveground biomass may affect soil C and N under sweet sorghum. The effect of cover crop and N fertilization on soil C and N under sweet sorghum was examined. SOC and STN were greater with vetch and vetch/rye mixture than other cover crops NH4‐N was greater with rye and NO3‐N greater with vetch/rye than other cover crops. Vetch and vetch/rye can enhance soil C and N storage and optimize N availability. Sustainable production of sweet sorghum (Sorghum bicolor [L.] Moench) grown for bioenergy production depends on practices that maintain soil C and N levels. The objective of this study was to evaluate the effect of winter cover crops (hairy vetch [Vicia villosa Roth], rye [Secaele cereale L.], hairy vetch/rye mixture, and the control [no cover crop]) and N fertilization rates (0 and 90 kg N ha−) on soil organic C (SOC), total N (STN), NH4–N, and NO3–N contents at the 0‐ to 30‐cm depth from 2010 to 2014 in the southeastern USA. Cover crop biomass yield and C content were greater with vetch/rye than vetch and the control and N content greater with vetch and vetch/rye than the control in 2013 and 2014. The SOC and STN at 0 to 5 cm were greater with vetch/rye than the control and at 15 to 30 cm were greater with vetch than vetch/rye. At 0 to 5 cm, SOC increased at 0.55 Mg C ha−1 yr−1 and STN at 0.06 Mg N ha−1 yr−1, regardless of treatments. At most depths, NH4–N content was greater with rye than the control and greater with 0 than 90 kg N ha−1, but NO3–N content was greater with vetch/rye than rye. Because of greater cover crop C and N inputs, soil C and N stocks can be enhanced and N availability can be optimized by growing vetch and vetch/rye mixture cover crops to replace the stocks reduced by the removal of aboveground sweet sorghum biomass.
12 November 2002 in Journal of Sustainable Agriculture
The role of livestock in determining the socio-economic status, food security and sustainability of smallholder mixed farms was studied during 1999 and 2000 in the Harar Highlands of Eastern Ethiopia. Community level information on farm households was collected using semi-structured interviews, key informant interviews, and field observations. A well-being instrument was developed on the basis of community level data to rank the households into poor, medium, and well-to-do categories. Detailed characterization of the households in the three groups was carried out by an in-depth case study of individual farms followed by a wider scale formal survey. Community level interviews revealed that smallholders considered meeting household food requirements and maintaining soil fertility of farm plots most important for farm sustainability. The energy content of the food consumed by a farm family and the soil humus balance of annually cropped plots were used as proxy indicators for household food balance a...
Organic farming has emerged as a sustainable solution to the adverse effects (diminished nutritional value, compromised food quality, environmental contamination, and public health hazards) that are usually associated with harmful chemical pesticides. To overcome such loss, one must explore the plant-associated microbes that are the naturally occurring root commensal and could positively improve crop health. In this review, we highlight the importance of the bacterial genus Rhodococcus, a subset of Actinobacteria that carries immense potential in enhancing crop yield and is associated with bioremediation of toxic pesticides and other chemicals to improve soil health. However, it has been noticed that few species of Rhodococcus are pathogenic for the plant (R. fascians) as well as humans/animals (R. equi). But still, the majority of Rhodococcus isolates are found to be non-pathogenic and carry substantial beneficial traits. Here, we have attempted to comprise those beneficial traits of the different members of the genus Rhodococcus. The main emphasis of this review article is to explore the major areas such as enzyme production, phytohormone synthesis, growth regulation, siderophore production, bioremediation, organic compound degradation, and environmental pollution control. Opinions towards the applications of advanced methodologies for utilizing the cumulative prospective potential of the genus Rhodococcus have also been discussed in the different sections of the review. Conclusively, this article gathers the scattered information from the past and recent literature about this bacteria and provides the future direction about how it can improve plant/soil health and eliminate toxic chemicals and environmental pollutants.