A Controlled-Release Nanofertilizer Improves Tomato Growth and Minimizes Nitrogen Consumption.

Minimizing the consumption of agrochemicals, particularly nitrogen, is the ultimate goal for achieving sustainable agricultural production with low cost and high economic and environmental returns. The use of biopolymers instead of petroleum-based synthetic polymers for CRFs can significantly improve the sustainability of crop production since biopolymers are biodegradable and not harmful to soil quality. Lignin is one of the most abundant biopolymers that naturally exist.In this study, controlled-release fertilizers were developed using a biobased nanocomposite of lignin and bentonite clay mineral as a coating material for urea to increase nitrogen use efficiency. Five types of controlled-release urea (CRU) were prepared using two ratios of modified bentonite as well as techniques. The efficiency of the five controlled-release nano-urea (CRU) fertilizers in improving the growth of tomato plants was studied under field conditions. The CRU was applied to the tomato plants at three N levels representing 100, 50, and 25% of the recommended dose of conventional urea. The results showed that all CRU treatments at the three N levels significantly enhanced plant growth parameters, including plant height, number of leaves, fresh weight, and dry weight, compared to the control. Additionally, most CRU fertilizers increased total yield and fruit characteristics (weight, length, and diameter) compared to the control. Additionally, marketable yield was improved by CRU fertilizers. Fruit firmness and acidity of CRU treatments at 25 and 50% N levels were much higher than both the 100% CRU treatment and the control. The vitamin C values of all CRU treatments were lower than the control. Nitrogen uptake efficiencies (NUpE) of CRU treatments were 47-88%, which is significantly higher than that of the control (33%). In conclusion, all CRU treatments at an N level of 25% of the recommended dose showed better plant growth, yield, and fruit quality of tomatoes than the conventional fertilizer.

Modification of Fabrication Process for Prolonged Nitrogen Release of Lignin-Montmorillonite Biocomposite Encapsulated Urea.

Crop production faces challenges in achieving high fertilizer use efficiency. To address this issue, slow-release fertilizers (SRFs) have emerged as effective solutions to minimize nutrient losses caused by leaching, runoff, and volatilization. In addition, replacing petroleum-based synthetic polymers with biopolymers for SRFs offers substantial benefits in terms of sustainability of crop production and soil quality preservation, as biopolymers are biodegradable and environmentally friendly. This study focuses on modifying a fabrication process to develop a bio-composite comprising biowaste lignin and low-cost montmorillonite clay mineral for encapsulating urea to create a controllable release fertilizer (CRU) with a prolonged nitrogen release function. CRUs containing high N contents of 20 to 30 wt.% were successfully and extensively characterized using X-Ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and Scanning Electron Microscopy (SEM). The results showed that the releases of N from CRUs in water and soil extended to considerably long periods of 20 and 32 days, respectively. The significance of this research is the production of CRU beads that contain high N percentages and have a high soil residence period. These beads can enhance plant nitrogen utilization efficiency, reduce fertilizer consumption, and ultimately contribute to agricultural production.

Development of multifunctional copper alginate and bio-polyurethane bilayer coated fertilizer: Controlled-release, selenium supply and antifungal.

Bio-based controlled release fertilizers (BCRFs) are cost-effective and renewable thus gradually replacing petroleum-based controlled release fertilizers (CRFs). However, most of the study mainly focused on modifying BCRFs to improve controlled-release performance. It is necessary to further increase the functionality of BCRF for expanding the application. A multifunctional double layered bio-based CRF (DCRF) was prepared. Urea was used as the core of fertilizer, bio-based polyurethane was used as the inner coating, and sodium alginate and copper ions formed the hydrogel as the outer coating. In addition, mesoporous silica nanoparticles loaded with sodium selenate was used to modify the sodium alginate hydrogel (MSN@Se hydrogel). The results showed that the nitrogen longevity of the DCRF was much better than that of urea and BCRF. The selenium nutrient longevity of the DCRF was 40 h, much longer than that of sodium selenate. The DCRF improved the yield and nutritive value of cherry radish (Raphanus sativus L. var.radculus pers) with the elevated contents of selenium, an essential trace element. Moreover, the DCRF showed inhibitory effect on Fusarium oxysporum Schltdl. and could resist soil-borne fungal diseases continuously. Overall, this multifunctional fertilizer has great potential for expanding the use of BCRFs for sustainable development of agriculture.

Performance evaluation of various individual and mixed media for greywater treatment in vertical nature-based systems.

Nature-based systems (NBS) are a cost-effective, energy efficient and aesthetically pleasing approach for greywater treatment, but they are space intensive. Vertical NBS overcome this issue but must utilize lightweight media to reduce their construction costs. This study evaluates four common plant growing media: perlite, coco coir, LECA and sand, and compares them with two new media derived from local waste materials: date seeds and spent coffee grounds (SCG). The media are characterized and tested for their removal of various greywater pollutants. Further tests are conducted comparing mixtures of perlite-coco coir and date seeds-SCG. SCG was found to be an excellent media for greywater treatment, providing a similar degree of treatment as the best traditional media, coco coir and providing improved drainage. Drainage was further improved by mixing SCG with date seeds, which performed better than any mixture of perlite and coco coir. Most pollutants showed a slight deterioration in treatment performance with this mixture, although the removal of suspended solids and chemical oxygen demand was improved. An increased bed height improved the treatment performance with SCG, while increased hydraulic loading resulted in decreased treatment performance for all media. This study demonstrates the potential of date seeds and SCG as locally recycled waste materials to realize treatment of greywater in vertical NBS.

2D Ti3C2Tx (MXene)-reinforced polyvinyl alcohol (PVA) nanofibers with enhanced mechanical and electrical properties.

Novel 2D Ti3C2Tx (MXene)-reinforced polyvinyl alcohol (PVA) nanofibers have been successfully fabricated by an electrospinning technique. The high aspect ratio, hydrophilic surfaces, and metallic conductivity of delaminated MXene nanosheet render it promising nanofiller for high performance nanocomposites. Cellulose nanocrystals (CNC) were used to improve the mechanical properties of the nanofibers. The obtained electrospun nanofibers had diameter from 174 to 194 nm depending on ratio between PVA, CNC and MXene. Dynamic mechanical analysis demonstrated an increase in the elastic modulus from 392 MPa for neat PVA fibers to 855 MPa for fibers containing CNC and MXene at 25°C. Moreover, PVA nanofibers containing 0.14 wt. % Ti3C2Tx exhibited dc conductivity of 0.8 mS/cm conductivity which is superior compared to similar composites prepared using methods other than electrospinning. Improved mechanical and electrical characteristics of the Ti3C2Tx /CNC/PVA composites make them viable materials for high performance energy applications.