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Among the essential micronutrients, zinc (Zn) affects vital functions in crop plants. The influences of foliar nourishing with certain Zn-containing forms on the growth, productivity, and physiology of carrot plants (cv. Fire wedge F1) and their nutritional contents when grown in Zn-deficient soil were examined in both 2019/2020 and 2020/2021 field trials. Two doses of zinc oxide nanoparticles (ZnO-NPs(1) = 20 and ZnO-NPs(2) = 40 mg L−1), zinc–EDTA (Zn–EDTA(1) = 1 and Zn–EDTA(2) = 2 g L−1), or bulk zinc oxide (ZnO-B(1) = 200 and ZnO-B(2) = 400 mg L−1) were applied three times. The data outputted indicated, in general, that ZnO-NPs(2) were the best treatment that conferred more acceptable plant growth (measured as shoot length and fresh and dry weights), physiology (measured as cell membrane stability index, SPAD readings, and nutrient uptake), and nutritional homeostasis (e.g., P, Ca, Fe, Mn, Zn, and Cu contents). All these positive attributes were reflected in the highest yield, which was measured as fresh weight, dry matter, length, diameter, volume, and total yield of carrot roots. However, there were some exceptions, including the highest membrane stability index in both seasons, the highest Cu uptake and Mn content in the first season, and root fresh weight in both seasons obtained with ZnO-NPs(1). Moreover, the maximum P uptake and root dry matter were obtained with ZnO-B(1) and the highest content of root P was obtained by ZnO-B(2). Based on the above data, foliar nourishing with ZnO-NPs(2) can be recommended for the sustainability of carrot cultivation in Zn-deficient soils.

The use of nano-fertilizers and antioxidants for specific crops to minimize the negative effect of abiotic stresses is imperative. Two field experiments were fulfilled during two summer seasons (2019 and 2020) to study the response of sweet potato (Beauregard cv.) plants grown in calcareous soil (CaCO3 = 10.8–11.3%) to foliar nourishment with zinc oxide nanoparticles (ZnONPs) and ascorbic acid (ASA) applied individually or in a mixture. Both ZnONPs and ASA were applied in three doses: 0, 1000, or 1500 mg L−1 for ZnONPs, and 0, 250 and 500 mg L−1 for ASA. The highest values of iron (Fe) and manganese (Mn) contents were recorded in both seasons, while those of phosphorus (P) and copper (Cu) were recorded in the 2020 season with ZnONPs applied at 1500 mg L−1. Furthermore, in both seasons, the maximum values of nutrient contents, excluding Mn content, were obtained with ASA applied at 500 mg L−1. However, applying both ZnONPs and ASA in a mixture bypassed each applied alone, with the highest overall nutrient contents being recorded, with few exceptions, with the highest dose of the mixture. The trend of the tuber root nutrient contents was correlated with the corresponding values in the leaves. Maximum tuber root yield was obtained with foliar feeding with 1000 mg ZnONP and 250 mg ASA L−1 in both seasons. The resulting data recommend the use of foliar nourishment with fertilizer nanoparticles and antioxidants to enable stressed plants to collect appropriate nutrient contents from the defective soils.

Sustainable agricultural development depends mainly on the recycling of organic wastes to reduce environmental pollution, as well as to reduce the use of mineral fertilizers. Expired milk products are rich in organic carbon and nitrogen, so they are good raw materials for making organic fertilizers. In this study, expired milk products were converted to organic fertilizer (EDPF) by gravity and thermal treatments. The extracted EDPF was used in the nutrition of Williams banana plants under field conditions for two growing seasons. The field experiment consisted of four treatments including: C = control without N fertilization, U = traditional urea, SRU = slow-release urea, and EDPF. EDPF significantly (p &lt, 0.05) improved the growth and yield of Williams banana in comparison to U and SRU. EDPF significantly minimized the soil pH and increased the soil organic-C and cation exchange capacity compared to the other treatments. EDPF increased the total yield of bunches by 20% and 17% in the first and second years, respectively, above U and SRU. EDPF surpassed the traditional and slow-release urea in its ability to supply the banana plants with nitrogen. NH3-N loss from U, SRU, and EDPF reached 172, 132, and 100 kg N ha−1, respectively, which accounted for 34%, 26%, and 20% of the total added nitrogen. Nitrogen loss from the investigated treatments was in the order: U &gt, SRU &gt, EDPF &gt, C. EDPF significantly reduced the ammonia volatilization compared to U and SRU by reducing the soil pH and increasing the soil organic matter. The dynamic of NH3 emissions not only depends on the nitrogen form but also on climatic conditions and concentrations of NH4+ in the soil solution. Protecting the ecosystem and maximizing the benefits of wastes utilization can be done through the recycling of expired dairy products to organic fertilizers.

Field trials for two seasons (2018/2019 and 2019/2020) were conducted to investigate the influence of the addition of three levels of potassium (K) (K1 = 60, K2 = 120, and K3 = 180 kg K2O ha−1) and/or sulfur (S) (S1 = 175, S2 = 350, and S3 = 525 kg CaSO4 ha−1) to the soil, as well as the sowing date (the 1st of September, D1, or the 1st of October, D2) on the potential improvement of physiology, growth, and yield, as well as the quality characteristics of sugar beet yield under soil salinity conditions. With three replicates specified for each treatment, each trial was planned according to a split-split plot in a randomized complete block design. The results revealed that early sowing (D1) led to significant improvements in all traits of plant physiology and growth, in addition to root, top, and biological yields and their quality, gross and pure sugar, and K- and S-use efficiencies based on root yield (R-KUE and R-SUE). The K3 level (180 kg K2O ha−1) positively affected the traits of plant physiology, growth, yield and quality, and R-SUE, and reduced the attributes of impurities, impurity index, and R-KUE. Additionally, the S3 level (525 kg CaSO4 ha−1) affirmatively affected plant physiology, growth, yield and quality traits, and R-KUE, and decreased impurity traits, impurity index, and R-SUE. The interaction of D1 × K3 × S3 maximized the yield of roots (104–105 ton ha−1) and pure sugar (21–22 ton ha−1). Path coefficient analysis showed that root yield and pure sugar content had positive direct effects with 0.62 and 0.65, and 0.38 and 0.38 in both studied seasons, respectively, on pure sugar yield. Significant (p ≤ 0.01) positive correlations were found between pure sugar yield and root yield (r = 0.966 ** and 0.958 **). The study results recommend the use of the integrative D1 × K3 × S3 treatment for sugar beet to obtain maximum yields and qualities under salt stress (e.g., 8.96 dS m−1) in dry environments.

Dairy products are vital components of human food, however, they are rapidly spoiled due to their high content of organic matter which encourages the growth of decomposing microbes. The recycling of dairy wastes is an ideal solution to preserve the environment, as it is in line with the principles of sustainable agriculture. In this experiment, an organic fertilizer was extracted from dairy wastes and was used for the nutrition of wheat grown on sandy soils under two-year field studies. The application rate of the extracted organic fertilizer was 8 ton ha−1. Moreover, the same rates of N, P, and K were added from inorganic fertilizers. The extracted organic fertilizer significantly (p &lt, 0.05) enhanced the wheat growth and increased chlorophyll by 11% and 16% in the first and second season, respectively, in comparison to the inorganic fertilization. The extracted organic fertilizer significantly minimized the soil pH from an initial value of 8.00 to 7.05. The tested organic fertilizer increased the uptake of N, P, and K by 55%, 49%, and 51% above the inorganic nutrition, respectively. The wheat straw and grain yield increased by 16% and 29% as a result of the addition of the organic fertilizer extracted from dairy wastes. The dairy wastes organic fertilizer caused a notable improvement in the soil quality. The extracted organic fertilizer was able to supply wheat with its nutrient requirements as it showed a remarkable superiority over the mineral fertilization. The disposal of expired dairy waste can be managed in a way that preserves the environment by converting it to organic fertilizers. Laboratory and field experiments have proven the efficiency of the extracted organic fertilizer in nutrition of wheat plants in sandy soils with low fertility.

Iron (Fe) deficiency exists as a widespread nutritional disorder in alkaline and calcareous soils; therefore, Fe-enriching strategies may be used to overcome this issue. Field experiments were conducted with a randomized complete design with three replicates for evaluating the effectiveness of iron oxide nanoparticles (Fe-NPs) against traditional Fe compounds (sulfate or chelate), which have various shortcomings on Rose-scented geranium (RSG) herb in terms of plant growth, phytopharmaceuticales, essential oil (EO), and its constituents. Supplementation of Fe-sources considerably improved RSG plant growth and EO yield in the 1st and 2nd cut throughout the two seasons over non-treated control plants. A total of 11 compounds of RSG-EO were identified; the main constituents were citronellol, geraniol, and eugenol. The results indicate that EO composition was significantly affected by Fe-sources. Amendments of Fe-sources considerably augmented photosynthetic pigments, total carbohydrates, nitrogen, phosphorous, potassium, iron, manganese, zinc, phenols, flavonoids, and anthocyanin. Commonly, Fe-NPs with humic acid (Fe-NPs-HA) supplementation was superior to that of traditional sources. The highest values were recorded with spraying Fe-NPs-HA at 10 mg L−1 followed by 5 mg L−1, meanwhile, the lowest values were recorded in untreated control plants. Current findings support the effectiveness of nanoparticle treatment over Fe-sources for improving growth and yield while also being environmentally preferred in alkaline soil. These modifications possibly will be applicable to EO quality and its utilization in definite food and in medical applications.

Sustainability of rice production under flooding conditions has been challenged by water shortage and food demand. Applying higher nitrogen fertilization could be a practical solution to alleviate the deleterious effects of water stress on lowland rice (Oryza sativa L.) in semi-arid conditions. For this purpose, field experiments were conducted during the summer of 2017 and 2018 seasons. These trials were conducted as split-split based on randomized complete blocks design with soil moisture regimes at three levels (120, 100 and 80% of crop evapotranspiration (ETc), nitrogen fertilizers at two levels (N1—165 and N2—200 kg N ha−1) and three lowland Egyptian rice varieties [V1 (Giza178), V2 (Giza177) and V3 (Sakha104)] using three replications. For all varieties, growth (plant height, tillers No, effective tillers no), water status ((relative water content RWC, and membrane stability index, MSI), physiological responses (chlorophyll fluorescence, Relative chlorophyll content (SPAD), and yield were significantly increased with higher addition of nitrogen fertilizer under all water regimes. Variety V1 produced the highest grain yield compared to other varieties and the increases were 38% and 15% compared with V2 and V3, respectively. Increasing nitrogen up to 200 kg N ha−1 (N2) resulted in an increase in grain and straw yields by 12.7 and 18.2%, respectively, compared with N1. The highest irrigation water productivity (IWP) was recorded under I2 (0.89 kg m−3) compared to (0.83 kg m−3) and (0.82 kg m−3) for I1 and I3, respectively. Therefore, the new applied agro-management practice (deficit irrigation and higher nitrogen fertilizer) effectively saved irrigation water input by 50–60% when compared with the traditional cultivation method (flooding system). Hence, the new proposed innovative method for rice cultivation could be a promising strategy for enhancing the sustainability of rice production under water shortage conditions.

To avoid competing with economical plants, weed control must be implemented with a clean and appropriate strategy. Since the efficiency of leguminous crops in biological fixation of the atmospheric N2 is severely affected when grown under stressful conditions (the soil tested in this study was salt-affected, ECe = 8.99 dS m−1), an appropriate level of N fertilization should also be applied. Two field trials were performed in the 2018 and 2019 seasons to investigate the influences of soil-applied nitrogen (N) levels [48 (N1), 96 (N2), and 144 kg N ha−1 (N3)] and critical timing of weed removal (CTWR) on weed control efficiency, improving weed control, yield traits, and quality attributes in peanut (Arachis hypogaea L.). Each trial was conducted with three replicates and planned according to a split-plot in a completely randomized design. The results revealed that N levels had significant (p ≤ 0.01) variations for the dry weight of all weeds tested (narrow-leaved, broad-leaved, and total annual weeds), pods and seed weight and yields, N use efficiency, and oil and protein yields (t ha−1) in peanut in both seasons. N3 outperformed both N1 and N2 with respect to the above-mentioned traits, however, it decreased N use efficiency and seed oil content compared to N1 and N2, respectively. Dry weight of weeds and seed harvest index were significantly (p ≤ 0.01) increased, while seed oil and protein contents, N use efficiency, and yields of pods, seeds, and protein were decreased, with increased weed interference (with peanut plants) period in both seasons. In both seasons, the interaction effect of N × W (weed removal time) was significant (p ≤ 0.01) on the dry weight of weeds and peanut traits, including seed oil content, N use efficiency, and yields of pods, seeds, and protein, and their highest values were obtained with N3 × W6 (weed-free for the whole season). The CTWR had growing degree days (GDDs) of 221.4 and 189. These two GDDs each corresponded to 2 weeks after emergence (WAE) in both growing seasons. The critical weed-free period (CWFP) had GDDs of 1400 and 1380. These two GDDs corresponded to 9.5 and 10 WAE, respectively. The combination of CTWR and CWFP resulted in a critical period of weed control (CPWC) of 2–9.5 and 2–10 WAE in both growing seasons, respectively, for the peanut crop with an acceptable yield loss of 5%. A high positive (p ≤ 0.01) correlation was noted between oil yield and seed yield (r = 0.999 ** and 0.999 **). However, a high negative (p ≤ 0.01) correlation (r = −0.723 ** and −0.711 **) was found between dry total annual weeds and seed weight in the first and second seasons, respectively. The stepwise regression analysis revealed high significant participation of two traits (i.e., seed yield and oil content) and three traits (i.e., seed yield, oil content, and weight of seeds) in the variations in oil yield in the first and second seasons, respectively. These results recommend the use of N fertilization at a rate of 144 kg N ha−1 in conjunction with keeping the soil free of weeds throughout the season to maximize peanut productivity under saline (8.99 dS m−1) conditions.

Salinity combined with a deficiency of potassium (K) and zinc (Zn) negatively affect sugar beet yield and quality. A two-year (2017/18–2018/19) field trial was undertaken to investigate the mediating role of soil-applied K [120 (K120) and 180 (K180) kg ha−1] and foliar-applied Zn [0 (Zn0), 150 (Zn150), and 300 (Zn300) ppm] in alleviating salt-stress (8.60 dS m−1) based on sugar beet morpho-physiological responses, sugar yield and quality, and K-use efficiency in the BTS 301 and Kawemira cultivars. Application of K180 × Zn300 was more effective and resulted in 23.39 and 37.78% higher root yield (RY) and pure sugar yield (PSY), respectively, compared to control (K120 × Zn0). It also enhanced sucrose, pure sugar (PS), and purity but decreased impurities (α-amino N, K, and Na), alkalinity index, and sugar loss. However, the K120 × Zn300 recorded higher K-use efficiency. PSY correlated positively (r = 0.776 **, 0.629 **, 0.602 **, 0.549 **, and 0.513 **) with RY, root fresh weight (RFW), top yield, PS, and root diameter, respectively. The stepwise and path-coefficient analysis demonstrated that RY, PS, and RFW were the most influential PSY-affected attributes. Integration of K180 + Zn300 can correct K and Zn deficiencies in the soil and mitigate salt-stress effects via improving sugar beet growth, yield and quality, and K-use efficiency.