The purpose of this work was to study the effect of different moisture contents (12, 14, 16 and 18%) of conditioned hull barley and hull-less barley grains prior to milling on physical and sensory properties of bread baked from these barley flours. The results indicated that the specific volume of breads baked from barley flours and wheat-barley composite flours were enhanced with increasing conditioning moisture of barley grains prior to milling; therefore baking loss values decrease. On the other hand, increase the moisture content of barley grains prior to milling lead to improve all the tested parameters of sensory evaluation and retarded the staling rate of barley pan bread and wheat-barley breads.

The purpose of this work was to study the effect of different moisture contents (12, 14, 16 and 18%) of conditioned hull barley and hull-less barley grains prior to milling on physical and sensory properties of bread baked from these barley flours. The results indicated that the specific volume of breads baked from barley flours and wheat-barley composite flours were enhanced with increasing conditioning moisture of barley grains prior to milling; therefore baking loss values decrease. On the other hand, increase the moisture content of barley grains prior to milling lead to improve all the tested parameters of sensory evaluation and retarded the staling rate of barley pan bread and wheat-barley breads.

The purpose of this work was to study the effect of different moisture contents (12, 14, 16 and 18%) of conditioned hull barley and hull-less barley grains prior to milling on physical and sensory properties of bread baked from these barley flours. The results indicated that the specific volume of breads baked from barley flours and wheat-barley composite flours were enhanced with increasing conditioning moisture of barley grains prior to milling; therefore baking loss values decrease. On the other hand, increase the moisture content of barley grains prior to milling lead to improve all the tested parameters of sensory evaluation and retarded the staling rate of barley pan bread and wheat-barley breads.

Biomass and yield are important variables used for assessing agricultural production and performance. However, these variables are difficult to predict for individual plants at the farm scale, and prediction models and accuracies may be affected by abiotic stresses such as salinity. In this study, a diversity panel of the wild tomato species, Solanum pimpinellifolium, was evaluated through field- and unmanned aerial vehicle (UAV) based assessment of 600 control and 600 salt-treated plants. The aim of this research was to determine if red-green-blue (RGB) UAV-based imagery, collected one, two, four, six, seven and eight weeks before harvest could predict fresh shoot mass, tomato fruit numbers, and yield mass at harvest, and if prediction accuracies varied between control and salt-treated plants. Multi-spectral UAV-based imagery was also collected one and two weeks prior to harvest for comparison with the RGB imagery. A random forest machine learning approach was used to model biomass and yield. The results showed that shape features such as plant area, border length, width and length had the highest importance in the random forest models, followed by vegetation indices and the entropy texture measure. The highest explained variances of 87.95%, 63.88% and 66.51% were achieved using multi-spectral UAV imagery two weeks prior to harvest for fresh shoot mass, fruit numbers and yield mass per plant, respectively. The RGB UAV imagery produced very similar results to those of the multi-spectral UAV imagery, with the explained variance reducing as a function of increasing time to harvest. Higher accuracies were achieved with separate models for predicting yield of salt-stressed plants, whereas the prediction of yield for control plants was less affected if the model included salt-stressed plants. This research demonstrates that it is feasible to predict the average biomass and yield up to eight weeks prior to harvest within 4.23% of field-based measurements, and at the individual plant level up to four weeks prior to harvest. Results from this work may be useful in providing guidance for yield forecasting of healthy and salt-stressed tomato plants, which in turn may inform growing practices, logistical planning and sales operations.

Decreasing freshwater supply has led to the consideration of treated wastewater as an alternative source for agricultural irrigation. However, the higher content of heavy metals restricts their use in agricultural purposes. In the current study, a set of 181 SSR markers were used to perform association mapping in a structured sorghum population consisting of 107 accessions evaluated under tap-water and heavy-metals-containing water irrigation conditions. Significant differences between optimal and stressed growing conditions were shown in all evaluated phenotypic traits. Association mapping revealed 14 significant associations between 12 SSR markers and heavy metals stress indices of phenotypic traits (R2 = 11.54–30.85%). BLASTP annotation of QTLs genomic sequences identified 102 gene homologs, of which 19 are known to be implicated in phytoremediation and heavy metals tolerance. All nineteen genes exhibit differential expression patterns in heavy metals tolerant and susceptible sorghum accessions, and their transcriptional levels were highly elevated under heavy metals stress, indicating a possible functional association among these genes and provides strong evidence for their role in phytoremediation and heavy metal stress tolerance. Clustering and expression patterns of pentatricopeptide repeat and zinc finger protein genes suggest crucial roles of those genes in phytoremediation and heavy metals tolerance.

Decreasing freshwater supply has led to the consideration of treated wastewater as an alternative source for agricultural irrigation. However, the higher content of heavy metals restricts their use in agricultural purposes. In the current study, a set of 181 SSR markers were used to perform association mapping in a structured sorghum population consisting of 107 accessions evaluated under tap-water and heavy-metals-containing water irrigation conditions. Significant differences between optimal and stressed growing conditions were shown in all evaluated phenotypic traits. Association mapping revealed 14 significant associations between 12 SSR markers and heavy metals stress indices of phenotypic traits (R2 = 11.54–30.85%). BLASTP annotation of QTLs genomic sequences identified 102 gene homologs, of which 19 are known to be implicated in phytoremediation and heavy metals tolerance. All nineteen genes exhibit differential expression patterns in heavy metals tolerant and susceptible sorghum accessions, and their transcriptional levels were highly elevated under heavy metals stress, indicating a possible functional association among these genes and provides strong evidence for their role in phytoremediation and heavy metal stress tolerance. Clustering and expression patterns of pentatricopeptide repeat and zinc finger protein genes suggest crucial roles of those genes in phytoremediation and heavy metals tolerance.

Local waste recycling has many benefits to environmental, economic, social, and health aspects. Arid regions, especially calcareous sandy soil, where high rates of organic matter decomposition led carbon emission to increase, are poor in their content of organic matter and some nutrients as well as high phosphorus fixation in this soil. The objectives of this study were investigating effects of bagasse pith-vinasse biochar and incubation periods on: carbon (C) sequestration, carbon mineralization, and nutrients availability of calcareous sandy soil. The incubation experiment included four treatments: (1) unamended soil (control), (2) soil amended with 3% (w/w) bagasse pith-vinasse (BPV), (3) soil amended with 3% (w/w) biochar of bagasse pithvinasse (BPVB), and (4) soil amended with 3% (w/w) BPV + BPVB (1:1) and incubated at 3, 7, 21 and 46 days. The results of this study revealed a decline in carbon emission with adding BPVB compared to BPV and BPV + BPVB this in turn leads to enhancing carbon sequestration. Available phosphorus improved significantly with adding bagasse pith-vinasse biochar compared with unamended soil. Phosphorus availability increases with increasing incubating durations for bagasse pith-vinasse biochar. At the end of the incubation, the phosphorus availability increased from 20.08 mg kg−1 soil for control to 20.36, 35.25, and 20.63 mg kg−1 soil for BPV, BPVB and BPV + BPVB, respectively. Moreover, potassium availability showed a significant improvement with BPVB application compared with unamended soil. We recommend adding biochar to low fertility soil because it plays an important role in the environmental management via improving soil fertility, local waste management, and climate change mitigation.

The high cost and environmental problems related to the production of phosphate fertilizers as well as their excessive and continuous applications represent great challenges in modern agriculture. Therefore, we conducted an incubation experiment using sandy soil to evaluate the effects of elemental sulfur, disodium ethylene diamine tetra-acetic acid (Na2-EDTA) and their mixture with cow bone char as well as incubation periods on changes of phosphorus (P) availability, water soluble P, soil pH, electrical conductivity (EC), soluble calcium (Ca) and soluble sulfate (SO4). Applying sulfur (S), Na2EDTA and their mixture with cow bone char improved significantly phosphorus availability in soil, Olsen-P value increased from 7.65 mg kg−1 (control) to 12.20 mg kg−1 (cow bone char + sulfur), 12.80 mg kg−1 (cow bone char + Na2-EDTA) and 13.07 mg kg−1 (cow bone char + sulfur + Na2-EDTA) at the end of incubation periods While, cow bone char + sulfur + Na2- EDTA treatment lead Olsen-P to decline significantly with increasing incubation periods. Amending soil by sulfur with cow bone char treatment caused significant increase in the Olsen-P with increasing incubation periods. Cow bone char + sulfur and cow bone char + Na2-EDTA showed non-significant differences in Olsen-P. Because of the increase in phosphate fertilizer prices, the results of this study demonstrated the great potential of cow bone char usage which is a promising way to improve phosphorus availability in P-poor soil as well as being a clean alternative and renewable source of phosphate fertilizer. Consequently, we recommend utilizing cow bone char with sulfur as slow release fertilizer with time due to their low cost and it is a safe source of phosphorus in sustainable agriculture, rather than using Na2-EDTA due to its high price.

This incubation study assessed the effects of unpyrolyzed Calotropis procera and its biochar produced at different pyrolysis temperatures as well as incubation periods on carbon (C) emission, ammonia (NH3) volatilization, soil quality indicators and nutrient availability of alkaline sandy soil. Five treatments were studied in this experiment: unamended soil (CK), unpyrolyzed calotropis (UPC), calotropis biochar at 250 °C (CB250), calotropis biochar at 400 °C (CB400), and calotropis biochar at 650 °C (CB650). These amendments were applied to the soil at level of 4% (w/w). The results of this study showed that applying unpyrolyzed calotropis residues increased cumulative CO2 emission from the soil by 117.3, 239.4 and 232.0% over CB250, CB400, and CB650, respectively, by the end of incubation. Compared to the unamended soil, applying CB250 reduced cumulative NH3 volatilization in soil by 71.5%, which attributed to ammonia adsorption because of increased cation exchange capacity and decreased soil pH, but CB650 increased cumulative NH3 volatilization by 73.3% after the 3-day incubation as a result of high soil pH. The available phosphorus in soil improved significantly (p ≤ 0.01) with adding unpyrolyzed calotropis residues and its biochar produced at different pyrolysis temperatures compared to the unamended soil. The values of available phosphorus in the soil under study influenced significantly by pyrolysis temperatures of produced biochar; this is due to the pyrolysis of feedstocks increases labile phosphorus. Thenceforth, using biochar is an important strategy for enhancing carbon sequestration, decreasing ammonia volatilization and improving soil quality parameters in arid regions.

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