Influence of Foliar Silicic Acid Application on Soybean (Glycine max L.) Varieties Grown across Two Distinct Rainfall Years

The foliar nutrition of silicic acid is considered to be a novel approach in enhancing the performance of many crops worldwide. The present study aimed to assess if the foliar application of silicon (Si) could influence the performance of soybean varieties with distinct crop duration, MAUS-2 (long duration) and KBS-23 (short duration). Field experiments were conducted in two consecutive years (2016 and 2017) of varied rainfall with foliar application of silicic acid @ 2 and 4 mL L−1 for three and two sprays each. The results showed significant enhancement in the yield, seed quality (protein and oil content), and uptake of nutrients (N, P, K, Ca, Mg, S, and Si) by various parts viz., seed, husk, and haulm of both varieties with foliar nutrition of silicic acid. However, the short duration variety, KBS-23, responded well under low rainfall conditions (2016) with two sprays of foliar silicic acid @ 4 mL L−1 and MAUS-2 variety in the second season under higher rainfall (2017) with three sprays of foliar silicic acid @ 2 mL L−1, along with the recommended dose of fertilizer. This research revealed that the effectiveness of foliar silicic acid nutrition differs with the duration of the varieties, number of sprays given, and water availability in the soil during the cropping period.

Heavy metals adsorption from contaminated water using moringa seeds/ olive pomace byproducts

Several approaches have been used to reduce the accumulation of heavy metals in aqueous solutions, including adsorption to the surface of agricultural waste. Batch studies have been performed in this study to explore the adsorption of Fe2+, Mn2+ on olive pomace (OP), and moringa seed husk (MSH). Fourier transform infrared and scanning electron microscopy also characterized the prepared adsorbent. Batch adsorption studies were performed, and the effects of adsorbent chemical structure, adsorbent dosage, pH, contact time, and initial ion concentration were investigated on Fe and Mn ions sorption and mechanism in order to maximize the removal efficiency of Fe and Mn. It was shown that the removal percentage of Fe2+ and Mn2+ were 83% and 91%, respectively, at optimum pH 5 and optimum time of 120 min at 5 g of OP. Although the removal percentage of Fe2+ and Mn2+ were 80.5% and 93%, respectively, at 5 g of MSH. The pseudo-second-order model was followed by the adsorption kinetics of Fe2+ and Mn2+ on OP and MSH, and the Langmuir model worked well with the adsorption isotherms. Based on their adsorption/desorption processes, OP and MSH adsorbents may be regenerated by DI water more than five times. The overall adsorption power of the OP adsorbent for Fe2+ and Mn2+ was 10.406 and 10.460 mg/g, and the MSH was 10.28 and 11.641 mg/g for Fe2+ and Mn2+, respectively.