Eco-friendly approach to decrease the harmful effects of untreated wastewater on growth, yield, biochemical constituents, and heavy metal contents of carrot (Daucus carota L.).

Here, the impact of irrigation using untreated wastewater (WW) on carrots (Daucus carota L.) was examined. We hypothesized that the addition of ethylenediaminetetraacetic acid (EDTA), dry algal powder (Spirulina platensis or Chlorella vulgaris), and Salix alba leaves powder would function as chelators for harmful contaminants in wastewater. The findings showed that irrigation of carrot plants with the sampled untreated wastewater led to significant decreases in the shoot lengths, fresh, dry weights of shoots and roots at stage I, the diameter of roots, pigment content, carotenoids, total soluble carbohydrate content, and soluble protein content. Furthermore, a significantly increased level of proline, total phenols, and the activities of polyphenol oxidase (PPO), peroxidase (POX), superoxide dismutase (SOD), and catalase (CAT) was identified in stage I samples. In contrast to the stage I, the length of the roots, the number of leaves on each plant, wet and dry weights of the stage II roots were all greatly enhanced. In spite of the increased yield due to the wastewater irrigation, carrot roots irrigated with wastewater had significantly more cadmium (Cd), nickel (Ni), cobalt (Co), and lead (Pb) than is considered safe. Our data clearly show that the application of Spirulina platensis, Chlorella vulgaris, EDTA, and leaves powder of salix was able to alleviate the toxicity of wastewater on carrot plants. For example, we recorded a significant decrease in the accumulation of carrot's Cd, Ni, Co, and Pb contents. We conclude that the treatments with Spirulina platensis and Chlorella vulgaris can be utilized as eco-friendly tools to lessen the damaging effects of wastewater irrigation on carrot plants.

Radiation cross-linked ultra-absorbent hydrogel to rationalize irrigation water and fertilizer for maize planting in drought conditions.

The study addresses the potential negative impacts of climate change on water resources, specifically irrigation water for crops. The radiation technique produces the biomaterial hydrogel as a soil conditioner by polymerizing hydroxy ethyl cellulose/acrylamide (HEC/AAm) at various irradiation doses and copolymer concentrations. A maximum swelling of 23.4 g/g is attained by (HEC/PAAm) hydrogel at 1/7.5 ratio, prepared by 10 kGy gamma irradiation. The study introduces a new class of ultra-absorbent hydrogel (UAH) to address the low swelling limitation for soil conditioner applications. The alkaline hydrolysis treatments with NaOH, LiOH, and KOH enhance the water absorbency of (HEC/PAAm) hydrogel, with the highest capacity of 1220 g/g achieved by the KOH treatment, surpassing NaOH (622 g/g) and LiOH (540 g/g). The cumulative release of fertilizers from the UAH sample shows a slow and controlled release behavior. Urea takes 22 days to reach 100 % release. The UAH demonstrates water retention for 28 days, improving the growth of Zea mays L. at drought stress levels of 0 %, 25 %, 50 %, and 100 %, revealing an increase in shoot length by 16 %, 19 %, 24 %, and 20 %, respectively. Also, UAH increased the contents of chlorophyll a, b, a + b, and carotenoid on maize plant leaves compared to the control sample.