Although salinity and sodicity are worldwide problems, information on greenhouse gas (GHG) emissions from agricultural salt-affected soils is scarce. The CO 2 -C and N 2 O-N emissions were quantified from three zones intertwined within a single U.S.northern Great Plains field: a highly productive zone (electrical conductivity with 1:1 soil/water mass ratio [EC 1:1 ] = 0.4 dS m -1 ; sodium adsorption ratio [SAR] = 1.8), a transition zone (moderately salt-affected; EC 1:1 = 1.6 dS m -1 ; SAR = 4.99), and a saline/sodic zone (EC 1:1 = 3.9 dS m -1 ; SAR = 22). In each zone, emissions were measured every 4 h for 7 d in four randomly placed chambers that were treated with two N rates (0 and 224 kg N ha -1 ). The experiment was conducted in 2018 and 2019 during similar seasonal periods. Soil samples taken from treatments after GHG measurement were analyzed for soil inorganic N, and microbial biomass from different communities was quantified using phospholipid fatty acid analysis. Realtime polymerase chain reaction was used to quantify the number of copies of some specific denitrification functional genes. The productive zone had the highest CO 2 -C, the lowest N 2 O-N emissions, and the greatest microbial biomass, whereas the saline/sodic zone had the lowest CO 2 -C, the highest N 2 O-N emissions, and the lowest microbial biomass. Within a zone, urea application did not influence CO 2 -C emissions; however, N 2 O-N emissions from the urea-treated saline/sodic zone were 84 and 57% higher than from the urea-treated productive zone in 2018 and 2019, respectively. The copy number of the nitrite reductase gene, nirS, was 42-fold higher in the saline/sodic zone than in the productive soil, suggesting that the saline/sodic soil had a high potential for denitrification. These findings suggest N 2 O-N emissions could be reduced by not applying N to saline/sodic zones.

Dwindling supplies of fossil fuels and their deleterious impacts on human health and the global environment have intensified the search for substitute energy sources. Biodiesel has been identified as a promising renewable energy substitute for diesel fuel due to several comparable and sustainable properties. However, approximately 95% of biodiesel is derived from edible oil crops, threatening the current food supplies. Therefore, the biodiesel production potential from inexpensive, non-edible, and non-conventional bioenergy crops, such as Jatropha (Jatropha curcas L.), has attracted the attention of many researchers, policymakers, and industries globally. Jatropha is considered to be the second-generation biofuel feedstocks for biodiesel production. However, sustainable biodiesel generation from J. curcas oil has not yet been attained, owing to different socio-economic, ecological, and technical factors. This study aimed to synthesize the information from the existing literature on the present status and to identify the knowledge gaps for future research on Jatropha by providing comprehensive information regarding its origin and distribution, morphology, phenology, and reproduction, genetic diversity, its productivity, oil content, and fatty acid composition, the methodology used for extracting biodiesel, and agronomic, economic, and environmental aspects of biodiesel production. The germplasm screening of J. curcas and the exploration of its adaptability and agronomic potential across diverse climates are highly desired to promote this crop as an alternative biofuel crop, particularly in arid and semi-arid regions. Moreover, future research should focus on developing, optimizing, and modernizing the technologies involving seed collection, the processing of seeds, oil extraction, and the production of biodiesel.

Climate prediction models suggest that agricultural productivity will be significantly affected in the future. The expected rise in average global temperature due to the higher release of greenhouse gases (GHGs) into the atmosphere and increased depletion of water resources with enhanced climate variability will be a serious threat to world food security. Moreover, there is an increase in the frequency and severity of long-lasting drought events over 1/3rd of the global landmass and five times increase in water demand deficits during the 21st century. The top three cereals, wheat (Triticum aestivum), maize (Zea mays), and rice (Oryza sativa), are the major and staple food crops of most people across the world. To meet the food demand of the ever-increasing population, which is expected to increase by over 9 billion by 2050, there is a dire need to increase cereal production by approximately 70%. However, we have observed a dramatic decrease in area of fertile and arable land to grow these crops. This trend is likely to increase in the future. Therefore, this review article provides an extensive review on recent and future projected area and production, the growth requirements and greenhouse gas emissions and global warming potential of the top three cereal crops, the effects of climate change on their yields, and the morphological, physiological, biochemical, and hormonal responses of plants to drought. We also discuss the potential strategies to tackle the effects of climate change and increase yields. These strategies include integrated conventional and modern molecular techniques and genomic approach, the implementation of agronomic best management (ABM) practices, and growing climate resilient cereal crops, such as millets. Millets are less resource-intensive crops and release a lower amount of greenhouse gases compared to other cereals. Therefore, millets can be the potential next-generation crops for research to explore the climate-resilient traits and use the information for the improvement of major cereals.

Bioenergy has potential to reduce greenhouse gas (GHG) emissions through sustainable resource development and the use of efficient bioenergy systems (Chum et al., 2011). One of the important components for this system is liquid biofuel. Most common biofuel includes bioethanol derived from corn (Zea mays L.), sugar beet (Beta vulgaris L.), and sugarcane (Saccharum officinarum L.), which is mixed with gasoline, whereas oilseed crops-based biofuel, soybean (Glycine max L. Merr.), consumes high energy due to short hydrocarbon chains, to produce fuel (Perlack, 2005). Carinata (Brassica

Core ideas  Brassica carinata is an emerging new crop in the Northern Great Plains of the USA.  Sulfur has a synergistic relationship with N.  Carinata seed and oil yields were optimized at 112 kg N ha-1.  Carinata seed yield was optimized at 45 kg ha-1 S.