Enrichment of soils with organic amendments could increase the content of available nutrients, improve soil chemical characteristics and increase plant growth. In the current pots experiment, the ...influences of biochar (BC), humic acid (HA), and compost (CO) on barely growth were investigated under saline conditions. Barely plants grown on a clay loam soil and irrigated with saline water concentration of (EC = 13.8 dS m
−1
) were amended with BC, HA and CO at a rate of 1 or 3% of soil weight. The results showed that BC, HA and CO treatments had significant effects on the soil salinity, pH, organic matter (SOM), and plant nutrients. The results showed that the high rate application of BC, HA and CO increased the SOM by 14, 75 and 58% respectively, above the control. Consequently, the total chlorophyll as affected by the treatments can be arranged in descending order: BC
3
> CO
1
> CO
3
> HA
3
> HA
1
> BC
1
> C. The high rates of BC, HA and CO increased the dry biomass by 28.0, 21.6 and 39.7% respectively, above the control %, respectively, above the control. The investigated organic amendments increased the nutrients availability and uptake and enhanced the synthesis of chlorophyll in the plant tissues and this may be the reason of increasing the ability of barley to tolerate salinity.
Exposure of banana plants, one of the most important tropical and subtropical plants, to low temperatures causes a severe drop in productivity, as they are sensitive to cold and do not have a strong ...defense system against chilling. Therefore, this study aimed to improve the growth and resistance to cold stress of banana plants using foliar treatments of chitosan nanoparticles (CH-NPs). CH-NPs produced by nanotechnology have been used to enhance tolerance and plant growth under different abiotic stresses, e.g., salinity and drought; however, there is little information available about their effects on banana plants under cold stress. In this study, banana plants were sprayed with four concentrations of CH-NPs—i.e., 0, 100, 200, and 400 mg L−1 of deionized water—and a group that had not been cold stressed or undergone CH-NP treatment was used as control. Banana plants (Musa acuminata var. Baxi) were grown in a growth chamber and exposed to cold stress (5 °C for 72 h). Foliar application of CH-NPs caused significant increases (p < 0.05) in most of the growth parameters and in the nutrient content of the banana plants. Spraying banana plants with CH-NPs (400 mg L−1) increased the fresh and dry weights by 14 and 41%, respectively, compared to the control. A positive correlation was found between the foliar application of CH-NPs, on the one hand, and photosynthesis pigments and antioxidant enzyme activities on the other. Spraying banana plants with CH-NPs decreased malondialdehyde (MDA) and reactive oxygen species (ROS), i.e., hydrogen peroxide (H2O2), hydroxyl radicals (•OH), and superoxide anions (O2•−). CH-NPs (400 mg L−1) decreased MDA, H2O2, •OH, and O2•− by 33, 33, 40, and 48%, respectively, compared to the unsprayed plants. We hypothesize that CH-NPs increase the efficiency of banana plants in the face of cold stress by reducing the accumulation of reactive oxygen species and, in consequence, the degree of oxidative stress. The accumulation of osmoprotectants (soluble carbohydrates, proline, and amino acids) contributed to enhancing the cold stress tolerance in the banana plants. Foliar application of CH-NPs can be used as a sustainable and economically feasible approach to achieving cold stress tolerance.
Biochar is one of the important recycling methods in sustainable development, as it ensures the transformation of agricultural wastes into fertilizers and conditioners that improve soil properties ...and fertility. In the current study, corn cob-derived biochar (CB) was used to reduce the negative effects of saline water on quinoa (Chenopodium quinoa cv. Utosaya Q37) grown on Aridisols and Entisols, which are the major soil groups of Egyptian soils. Quinoa plants were cultivated in pot experiment and were irrigated with saline water (EC = 10 dS m−1). The experiment contained three treatments, including control without any treatment, biochar at a rate of 1% (w/w) (BC1), and biochar at a rate of 3% (w/w) (BC3). The findings of the current study showed that BC treatments realized significant effects on soil salinity, pH, soil organic matter (SOM), and plant availability and nutrients’ uptake in the two soils types. BC3 increased the SOM in Entisols and Aridisols by 23 and 44%; moreover, the dry biomass of quinoa plants was ameliorated by 81 and 41%, respectively, compared with the control. Addition of biochar to soil increased the nutrients’ use efficiencies by quinoa plants for the two studied Egyptian soils. Biochar addition caused significant increases in the use efficiency of nitrogen (NUF), phosphorus (PUE), and potassium (KUE) by quinoa plants. BC3 increased NUE, PUE, and KUS by 81, 81, and 80% for Entisols, while these increases were 40, 41, and 42% in the case of Aridisols. Based on the obtained results, the application of corn cob biochar improves the soil quality and alleviates the negative effects of saline irrigation on quinoa plants grown on Aridisols and Entisols Egyptian soils. Biochar can be used as a soil amendment in arid and semi-arid regions to reduce the salinity hazards.
Shortage of water in arid and semi-arid regions increases the need of applying efficient drip irrigation system. A two-year field study in the semi-arid region of Upper Egypt was carried in ...randomized complete block design with four replicates. Wheat plants were irrigated by 100 or 75% of water requirements (I100 = 5,370 and I75 = 4,027 m3 ha-1). Irrigation of wheat by I100 increased growth and uptake of nitrogen, phosphorus, and potassium compared to low irrigation level. I100 caused 14 and 5% increase in straw and biological yield, respectively, compared to I75. Grain yield and water use efficiency (WUE) were higher by 20 and 59% in the case of I75 compared to I100. The use of deficit irrigation in drip-irrigated wheat under arid conditions is an effective tool to maximize efficiency of water use; moreover, 4,027 m3 ha-1 is the optimum irrigation rate for maximum WUE and grain yield.
Enrichment of sandy soils with compost and humic acid amendments could increase the contents of nutrient availability, improve soil chemical characteristics and enhance quinoa plants growth and ...alleviating the hazardous effect of saline irrigation water. In the current study, compost (CT) and humc acid (HA) were used to reduce the negative effects of saline water on quinoa growth. The pots experiment treatments were as follows: CF = chemical fertilizer, CT1 = 1% compost, CT3 = 3% compost, HA1 = 1% humic acid, and HA3 = 3% humic acid of soil weight. Quinoa plants are grown on a sandy soil and irrigated with saline water (EC = 10 dS m
−1
). The results showed that Ct and HA amendments had significant effects on the soil salinity, pH, soil organic matter (SOM), nutrient availability, and plant uptake. The SOC of the soil was increased with increasing the application rates of the CT and HA amendments. The CT3 and HA3 application rates increased the SOM by 1.8 and 3.8, respectively, above the CF treatment. The application of CT and HA with different application rates increased the N, P, and K availability significantly as compared to the CF. The application of the CT and HA amendments increased the N, P, and K uptake significantly as compared to the CF as control. The application of CT significantly increased the plant height, dry matter, and fresh weight of quinoa plants compared to the control. Based on the obtained results, the application of CT and HA improves the sandy soil fertility and alleviates the negative effects of saline irrigation water on quinoa plants grown on sandy soil.
This study aimed to use organic fertilizers, e.g., compost and manures, and a halophytic plant wavy-leaved saltbush (Atriplex undulata) to remediate an agricultural soil polluted with toxic elements. ...Compost or manure (1% w/w) was added to a polluted soil in a pot trial. The application of the organic fertilizer, whether compost or manure, led to a significant improvement in the growth of the tested plant. From the physiological point of view, the application of organic fertilizers to polluted soil significantly increased the content of chlorophyll, carotenoid, and proline and, furthermore, led to a clear decrease in malondialdehyde (MDA) in the plant leaves. The highest significant values of organic carbon in the polluted soil (SOC) and cation exchange capacity (CEC) were found for the soil amended by compost and planted with wavy-leaved saltbush. Manure significantly reduced the soil pH to 7.52. Compost significantly decreased Zn, Cu, Cd, and Pb availability by 19, 8, 12, and 13%, respectively, compared to the control. On the other hand, manure increased Zn, Cu, Cd, and Pb availability by 8, 15, 18, and 14%, respectively. Compost and manure reduced the bioconcentration factor (BCF) and translocation factor (TF) of Cd and Pb. Compost was more effective in increasing the phytostabilization of toxic metals by wavy-leaved saltbush plants compared to manure. The results of the current study confirm that the application of non-decomposed organic fertilizers to polluted soils increases the risk of pollution of the ecosystem with toxic elements. The cultivation of contaminated soils with halophytic plants with the addition of aged organic materials, e. g., compost, is an effective strategy to reduce the spreading of toxic metals in the ecosystem, thus mitigating their introduction into the food chain.
Limited water availability in arid and semi-arid wheat production systems increases the need of applying efficient drip irrigation systems. However, there is little information available about the ...optimum level of nitrogen (N) fertilization for drip-irrigated wheat. A two-years field study in the semi-arid region of Upper Egypt was carried out in a randomized complete block design to investigate the response of drip-irrigated wheat to three levels of N fertilization (N120 = 120, N180 = 180, and N240 = 240 kg ha-1). N240 increased the uptake of N, P, and K by 66.3, 48.6, and 43.5%, respectively, as compared to N120. The application of N240 increased the grain yield by 28.4 and 40.4% and water use efficiency by 27.6 and 41.8% the first and second season, respectively, as compared to N120. Based on the obtained results, it is recommended to fertilize drip-irrigated wheat by 240 kg ha-1.
Water scarcity imposes significant constraints on fruit production, especially in arid and semi-arid regions. Deficit water, as one of the policies used in enhancing water use efficiency, leads to ...growth reduction and adversely affects the quality of mango fruit yield. The current study aims to investigate the role of Azolla as a biofertilizer in mitigating the negative effects of water stress on mango (
Mangifera indica
L. cv. Eiwas). A field experiment consisting of 4 different treatments (2 irrigation regimes and 2 Azolla treatments) was conducted in a randomized complete block design with five replicates. Mango trees (12 years old) were irrigated at 80% of the available soil water (normal irrigation) or at 50% of the available soil water (deficit irrigation). Dried Azolla (0 or 5 t ha
−1
) was added to the soil. Mango tree growth and fruit yield were significantly reduced due to the deficit irrigation. In the first year, deficit irrigation reduced the available soil nitrogen (N), phosphorus (P), and potassium (K) by 35, 23, and 20%, respectively, and by 39, 21, and 18% in the second year. The addition of Azolla alleviated water stress and increased nutrient availability and uptake. The addition of Azolla to water-stressed mango plants increased N, P, and K uptake by 25, 25, and 22%, respectively, in the first year and by 33, 22, and 23%, respectively, in the second year. Keeping soil moisture at 50% of the available soil water had a negative impact on mango fruit quality characteristics. Water stress reduced the total soluble solids, total sugar, vitamin C, and pulp by 18, 16, 14, and 8%, respectively (average of 2 years). The addition of Azolla to mango plants under deficit irrigation increased water use efficiency (WUE) by 30 and 27% in the first and second years, respectively, while these increases were 14 and 33% under normal irrigation. The mechanisms employed by Azolla to lessen the detrimental effects of water stress on mango trees in this study include increased leaf area, protection of photosynthesis pigments, and increased secretion of substances that aid in water stress resistance, such as proline. The use of Azolla as a dry manure in arid-degraded soil reduces water stress on mango trees while increasing yield and fruit quality.
Banana is one of the plants with low salt tolerance and raising its ability to withstand salt stress contributes to increasing its production. Silicon (Si) is one of the important elements in ...increasing the salt stress resistance in plants. Therefore, Si-rich biochar has been suggested to improve the salt resistance of Williams (WL) and Grand Nain (GN) banana cultivars. Water salinity (tap water, 2, 4, and 6 dS m−1) and Si-rich biochar with low (LSiB) or high rate (HSiB) in a pot experiment were studied. Si-rich biochar significantly mitigated the salt stress and improved the growth of WL and GN banana cultivars. Si-rich biochar was effective in enhancing chlorophyll, carotenoids, calcium (Ca++) and potassium (K+) in banana leaves. HSiB was more effective than LSiB in mitigating the accumulation of sodium (Na+) in the plant leaves. HSiB raised the phenolic, carbohydrate, and proline in WL leaf tissues by 35, 49, and 14%, while these increases were 20%, 44%, and 21% in the case of GN cultivar. Banana leaves exposed to salt stress had higher levels of malondialdehyde (MDA), while Si-rich biochar reduced those levels. Antioxidant enzymes activity were raised by salt stress, and HSiB performed better than LSiB at boosting antioxidant enzyme activity. The production of osmo-protectants such as phenols, carbohydras, and proline were higher in the banana plants treated with HSiB compared to LSiB ones. Si-rich biochar mitigated the salt stress by increasing the uptake of Ca and K, improving the antioxidant defense, and enhancing the production of combatable solutes.
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•Silicon (Si)-rich biochar was created by pyrolysis of rice husk at 350 °C.•Si-rich biochar mitigated the salt stress on banana growth and improved the plant tolerance.•Na+ uptake in salt stressed-banana was reduced when the soil amended with Si-rich biochar.
Shortage of water in arid and semi-arid maize production systems increases the need of applying deficit irrigation. A two-year field study in the semi-arid region of Upper Egypt was carried out in a ...randomized complete block design (RCBD) during the summer seasons of 2014 and 2015. Maize plants were irrigated by 8276 or 6207 m3 ha-1 (100 or 75% of water requirements, I100 and I75). Uptake of N and K by maize irrigated by I100 increased by 11 and 7% in the first season and by 13 and 15% in the second season compared to I75 . Increasing the irrigation level to 100% caused a 20 and 6% increase in the straw yield in the first and second season, respectively, also it caused a 20% increase in the biological yield in the first season. The grain yield of maize irrigated by I was higher by 5 and 10% in the first and second season, respectively, as compared to I100. Water 75 100 use efficiency (WUE) was higher by 41 and 56% in the first and second season, respectively, in the case of I75 as compared to I100. The data of the current study indicated that slightly water stress caused a slightly 100 significant reduction in the straw and biological yield of maize and saved 2000 m3 of water, moreover, it caused a slightly significant increase in the grain yield.
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