Conservation tillage: a way to improve yield and soil properties and decrease global warming potential in spring wheat agroecosystems.

Climate change is one of the main challenges, and it poses a tough challenge to the agriculture industry globally. Additionally, greenhouse gas (GHG) emissions are the main contributor to climate change; however, croplands are a prominent source of GHG emissions. Yet this complex challenge can be mitigated through climate-smart agricultural practices. Conservation tillage is commonly known to preserve soil and mitigate environmental change by reducing GHG emissions. Nonetheless, there is still a paucity of information on the influences of conservation tillage on wheat yield, soil properties, and GHG flux, particularly in the semi-arid Dingxi belt. Hence, in order to fill this gap, different tillage systems, namely conventional tillage (CT) control, straw incorporation with conventional tillage (CTS), no-tillage (NT), and stubble return with no-tillage (NTS), were laid at Dingxi, Gansu province of China, under a randomized complete block design with three replications to examine their impacts on yield, soil properties, and GHG fluxes. Results depicted that different conservative tillage systems (CTS, NTS, and NT) significantly (p < 0.05) increased the plant height, number of spikes per plant, seed number per meter square, root yield, aboveground biomass yield, thousand-grain weight, grain yield, and dry matter yield compared with CT. Moreover, these conservation tillage systems notably improved the soil properties (soil gravimetric water content, water-filled pore space, water storage, porosity, aggregates, saturated hydraulic conductivity, organic carbon, light fraction organic carbon, carbon storage, microbial biomass carbon, total nitrogen, available nitrogen storage, microbial biomass nitrogen, total phosphorous, available phosphorous, total potassium, available potassium, microbial counts, urease, alkaline phosphatase, invertase, cellulase, and catalase) while decreasing the soil temperature and bulk density over CT. However, CTS, NTS, and NT had non-significant effects on ECe, pH, and stoichiometric properties (C:N ratio, C:P ratio, and N:P ratio). Additionally, conservation-based tillage regimes NTS, NT, and CTS significantly (p < 0.05) reduced the emission and net global warming potential of greenhouse gases (carbon dioxide, methane, and nitrous oxide) by 23.44, 19.57, and 16.54%, respectively, and decreased the greenhouse gas intensity by 23.20, 29.96, and 18.72%, respectively, over CT. We conclude that NTS is the best approach to increasing yield, soil and water conservation, resilience, and mitigation of agroecosystem capacity.

Genetic diversity, chemical constituents and anatomical analysis of eight popular Olive (Olea europaea L.) cultivars in Al-Jouf region, Saudi Arabia.

In light of the multitude of olive trees cultivated and the lack of the genetic diversity of available genotypes to select varieties and lines that are characterized by high diversity and better performance under the corresponding conditions, A comparison analysis of the genotyping and morphological characteristics of eight olive cultivars growing in Saudi Arabia's Al-Jouf region was conducted and analyzed. Morpho-anatomical and chemical characteristics along with both inter-simple-sequence repeats (ISSRs) and start-codon-targeted (SCoT) markers were used to evaluate the genetic diversity among eight olive varieties in Al-Jouf, Saudi Arabia. Analyses of 27 morphological, chemical, and anatomical characteristics concluded the existence of genetic differences among the studied varieties. Moreover, six ISSR and eight SCoT primer combinations produced a total of 48 loci, of which 18 (10 ISSR and 8 SCoT) were polymorphic. The average polymorphism information content (PIC values of 0.48 and 0.44, respectively) and marker index (MI of 0.79 and 0.48, respectively) detected for ISSR and SCoT markers revealed the prevalence of high genetic diversity among the studied olive varieties. Based on chemical and anatomical characteristics and the selected molecular markers, the eight olive cultivars were grouped into two distinct clusters. Clusters in the adjacent joint dendrogram produced using ISSR, SCoT and combined data were similar, and grouped all individuals into two groups. However, the dendrogram generated on the basis of SCoT separated individuals into subgroups containing at least two varieties. The findings showed that both methods were effective in assessing diversity, and that SCoT markers can be used as a reliable and informative method for assessing genetic diversity and relationships among olive varieties and can serve as a complementary tool to provide a more complete understanding of the genetic diversity available in Olea europaea populations in Saudi Arabia.

Effect of Co-Application of Azospirillum brasilense and Rhizobium pisi on Wheat Performance and Soil Nutrient Status under Deficit and Partial Root Drying Stress.

Water management techniques are improving at the farm level, but they are not enough to deal with the limited availability of water and increased crop yields. Soil microbes play a vital role in nitrogen fixation, improving soil fertility and enhancing plant growth hormones under drought conditions. Therefore, this study was conducted to investigate the impact of water management combined with Azospirillum brasilense and Rhizobium pisi on wheat crop productivity and soil properties in dry regions. Three water management techniques were compared, normal irrigation as a control (C), deficit irrigation (DI), and partial root drying irrigation (PRD), together with the interaction of plant-growth-promoting rhizobacteria (PGPR). Experiments were conducted with six treatments in total: T1 = C + No PGPR, T2 = C + PGPR, T3 = DI + No PGPR, T4 = DI + PGPR, T5 = PRD + No PGPR, and T6 = PRD + PGPR. The highest grain yield was achieved in the control irrigation treatment using seeds inoculated with rhizobacteria, followed by control treatment without any inoculation, and the lowest was recorded with deficit irrigation without rhizobacteria inoculated in the seeds. However, PRD irrigation resulted in significantly higher plant growth and grain yield than the DI treatment. PGPR inoculation combined with PRD resulted in a 22% and 20% higher number of grains per spike, a 19% and 21% higher grain yield, and a 25% and 22% higher crop growth rate compared to rhizobacteria inoculation combined with the DI system in 2021-22 and 2022-23, respectively. This increase was due to the higher production of growth hormones and higher leaf area index under water-limited conditions. A greater leaf area index leads to a higher chlorophyll content and higher food production for plant growth.

Antibiotic-resistant bacteria in hospital wastewater treatment plant effluent and the possible consequences of its reuse in agricultural irrigation.

Wastewater from hospitals should be monitored precisely and treated properly before discharge and reuse to avoid epidemic and pandemic complications, as it contains hazardous pollutants for the ecosystem. Antibiotic residues in treated hospital wastewater effluents constitute a major environmental concern since they resist various wastewater treatment processes. The emergence and spread of multi-drug-resistant bacteria, that cause public health problems, are therefore always a major concern. The aims and objectives of this study were mainly to characterize the chemical and microbial properties of the hospital effluent of wastewater treatment plant (WWTP) before discharge to the environment. Special attention was paid to the presence of multiple resistant bacteria and the effects of hospital effluent reuse in irrigation on zucchini as an economically important plant. The risk of cell-free DNA carrying antibiotic resistance genes contained in the hospital effluent as a long-lasting hazard had been discussed. In this study, 21 bacterial strains were isolated from the effluent of a hospital WWTP. Isolated bacteria were evaluated for multi-drug resistance ability against 5 antibiotics (Tetracycline, Ampicillin, Amoxicillin, Chloramphenicol, and Erythromycin) at a concentration of 25 ppm. Out of them, three isolates (AH-03, AH-07, and AH-13) were selected because they recorded the highest growth in presence of tested antibiotics. Selected isolates were identified using 16S rRNA gene sequence homology as Staphylococcus haemolyticus (AH-03), Enterococcus faecalis (AH-07), and Escherichia coli (AH-13). Their susceptibility to ascending concentrations of tested antibiotics indicated that they were all susceptible at a concentration above 50 ppm. Results of the greenhouse experiment regarding the effect of hospital WWTP effluent reuse on zucchini plant fresh weights compared to that irrigated with fresh water indicated that the former recorded a limited increase in total fresh weights (6.2 g and 5.3 g/plant, respectively). Our results demonstrated the low impact of the reuse of Hospital WWTP effluent in agriculture irrigation compared to its greater risk in transferring multiple antibiotic bacteria and antibiotic resistance genes to soil bacteria through natural transformation.

Correction: Youssef et al. Foliar Spray or Soil Drench: Microalgae Application Impacts on Soil Microbiology, Morpho-Physiological and Biochemical Responses, Oil and Fatty Acid Profiles of Chia Plants under Alkaline Stress. Biology2022, 11, 1844.

There were three errors in the original publication [...].

Biochar Stimulated Actual Evapotranspiration and Wheat Productivity under Water Deficit Conditions in Sandy Soil Based on Non-Weighing Lysimeter.

The major climate-related hazard to worldwide agricultural productivity is drought, which is becoming more common because of ongoing climate change, especially in the arid and semi-arid regions. Herein, we investigated the influence of biochar soil application at 0, (B1), 7.5 ha-1 (B2), and 15 t ha-1 (B3) on the productivity and drought-tolerance indices of wheat (Triticum aestivum L., cv. Sakha 93) grown in sandy soil under irrigation levels of 100 (I1), 80 (I2), and 60% (I3) of crop evapotranspiration (ETc), as well as soil properties based on non-weighing lysimeter units. Increasing water deficiency significantly decreased the actual evapotranspiration (ETa) values. A growing biochar rate caused a significant increase in ETa values, water use efficiency, and wheat productivity compared to the untreated control. Additionally, biochar supplementation revealed an improvement in soil quality as measured by the reduction in the bulk density and hydraulic conductivity with an increase in the total porosity and void ratio of the experimental soil. The correlation analysis exhibited a highly significant and positive correlation (0.98 **) between biological yield and grain yield traits. Therefore, it may be stated that these traits are the most significant components of the evaluated grain yield in wheat plants. The productivity of I1 plants was not significantly different and slightly higher than that of I2 plants. Therefore, it can be recommended that exposed wheat plants cultivated in sandy soil with I2 × B3 treatment significantly provide the highest yield while saving 20% of the irrigation water.

Foliar Spray or Soil Drench: Microalgae Application Impacts on Soil Microbiology, Morpho-Physiological and Biochemical Responses, Oil and Fatty Acid Profiles of Chia Plants under Alkaline Stress.

Alkaline soil inhibits the growth and productivity of chia plants (Salvia hispanica L.). Microalgae as biofertilizers have been reported to induce alkalinity tolerance and enhance yield and quality. However, limited information is known concerning the influence of microalgae application on medical plants, including chia. Our experiments were performed to evaluate the effect of microalgae strains of Arthrospira platensis, Chlorella vulgaris, Nostoc muscorum, and Anabaena azollae with two application methods, foliar spray and soil drench, on morpho-physiological and biochemical parameters, yield, seed and oil quality, and fatty acid profiles of chia plants cultivated under alkaline soil conditions, as well as the on soil microbial activity. The results obtained reveal that both application methods positively influenced the growth and productivity of chia plants. However, the foliar application showed significant differences in the herb's fresh and dry weights and leaf pigments, whereas the drenching application caused more effect than the foliar spray application at the reproductive stage. Untreated chia plants showed a slight decline in the growth, productivity, and antioxidant level with an increase in Na content. However, microalgae applications significantly ameliorated these impacts as they induced an enhancement in the growth, leaf pigments, total protein and carbohydrate contents, nutrient content, seed and oil yields, as well as an increase in linolenic and linoleic fatty acids, with a reduction in saturated fatty acids, namely, palmitic and lauric acid. Soil drenching generated an improvement in the soil microbial activity and caused a reduction in the pH. The treatment of A. platensis with drenching application resulted in higher seed and oil yield, with an increase of 124 and 263.3% in seed and oil yield, respectively.