Release Fertilizer Research Articles

Study on the Effect of Digital Technology Adoption and Farmers’ Cognition on Fertilizer Reduction and Efficiency Improvement Behavior

Based on the field survey data for 1216 apple growers in three provinces from China’s Loess Plateau Region, this paper adopted Multivariate Probit (MVP) model and intermediary effect model to analyze the influence mechanisms of digital technology adoption (DTA) on farmers’ choices of Fertilizer-reduction and Efficiency-improving Technologies (FETs) from the perspective of farmers’ cognition (FC). The correlation effects of three typical FETs of soil testing and formula fertilization, integrated water-fertilizer fertilization and slow/controlled release fertilizer, were tested empirically. The results showed that DTA could significantly affect the adoption of FETs by apple growers, and FC played a partial mediating role, and there were complementary effects among the three typical FETs. The results were further confirmed by the propensity score matching (PSM) robustness test and the instrumental variable (IV) endogeneity test conducted in the conditional mixed-process (CMP). The results of our heterogeneity analysis showed that the promotion effect of DTA on FETs in the group with junior high school education or below was more significant than that in the group with higher education, and the promotion effect was more significant in the group with large operation scale. Therefore, the improvement in Internet penetration should not be taken as the ultimate goal, but more attention should be paid to farmers’ mastery and effective use of DTA, promote the improvement in farmers’ cognitive level, and implement the “bundled” publicity and guidance strategy of FETs adoption, so as to help in the green transformation of agriculture.

Synthesis of a superabsorbent hydrogel from Artocarpus heterophyllus Lam seed polysaccharides and its application in relieving drought stress in plants

AbstractSustainability in agriculture can only be achieved by protecting important resources, one of them being water. Availability of water in the soil greatly influences agricultural productivity. Hydrogels play a key role in ensuring water availability and achieving agricultural sustainability. A novel superabsorbent hydrogel was synthesized from Artocarpus heterophyllus Lam seed polysaccharides. The synthesized hydrogel was characterized using Fourier transform infrared spectroscopy, X‐ray diffraction, thermogravimetric analysis, and scanning electron microscopy. Swelling capacity of the hydrogel in different solutions, water retention duration, its influence on the soil water holding capacity (SWHC), and degradation in soil were assessed. The hydrogel absorbs up to 326 g/g and degrades naturally at around 1.4 wt% daily. The hydrogel improved the SWHC by 34% at a concentration of 0.3% w/w. Further pot experiments with black gram (Vigna mungo (L.) Hepper) plants showed that the superabsorbent hydrogel ensured water availability for 35 days and relieved the plants from drought‐induced stress. The data presented here indicates that the synthesized hydrogel can potentially be used as a soil conditioner for the sustained release of water and fertilizer.

Agriculture 4.0: Polymer Hydrogels as Delivery Agents of Active Ingredients.

The evolution from conventional to modern agricultural practices, characterized by Agriculture 4.0 principles such as the application of innovative materials, smart water, and nutrition management, addresses the present-day challenges of food supply. In this context, polymer hydrogels have become a promising material for enhancing agricultural productivity due to their ability to retain and then release water, which can help alleviate the need for frequent irrigation in dryland environments. Furthermore, the controlled release of fertilizers by the hydrogels decreases chemical overdosing risks and the environmental impact associated with the use of agrochemicals. The potential of polymer hydrogels in sustainable agriculture and farming and their impact on soil quality is revealed by their ability to deliver nutritional and protective active ingredients. Thus, the impact of hydrogels on plant growth, development, and yield was discussed. The question of which hydrogels are more suitable for agriculture-natural or synthetic-is debatable, as both have their merits and drawbacks. An analysis of polymer hydrogel life cycles in terms of their initial material has shown the advantage of bio-based hydrogels, such as cellulose, lignin, starch, alginate, chitosan, and their derivatives and hybrids, aligning with sustainable practices and reducing dependence on non-renewable resources.

Multifunctional 3D-printed composites based on biopolymeric matrices and tomato plant (Solanum lycopersicum) waste for contextual fertilizer release and Cu(II) ions removal

The production of tomatoes faces significant challenges, including the high amount of waste generated during the harvest stage and copper-contaminated soil due to pesticide use. To address these issues and to promote a more sustainable agriculture, innovative biodegradable green composites for contextual controlled soil fertilization and Cu removal were produced by 3D-printing technology. These composites were made by incorporating NPK fertilizer flour and tomato plant waste particles (SLP) into three different biodegradable polymeric matrices: polylactic acid (PLA); a commercial blend of biodegradable co-polyesters (Mater-Bi®, MB) and their blend (MB/PLA, 50:50). Rheological characterization suggested the potential processability of all of the composites by FDM. Morphological analysis of printed samples confirmed the good dispersion of both filler and fertilizer, which also acted as reinforcement for MB and MB/PLA composites. SLP and NPK moduli were evaluated by powder nanoindentation and, for almost composites, the theoretical Halpin-Tsai model satisfactorily fitted the actual tensile moduli. The decrease in NPK fertilizer release rate and the increase in Cu(II) removal efficiency were achieved using whole 3D-printed composites. By selecting the appropriate matrix and incorporating SLP particles, it was possible to tune the NPK release rate and achieve copper absorption efficiency. Notably, MB samples containing SLP particles displayed the fastest release and the highest Cu(II) removal efficiency.Graphical abstract

Characterizing Microplastic Pollution and Microbial Community Status in Rice Paddy Soils Across Varied Environmental Settings in Songjiang, Shanghai: An Analysis of Morpho-Chemical Characteristics

Microplastic (MP) pollution poses a huge threat to rice fields, but the distribution characteristics of MPs in farmlands of different types of areas are still uncertain. In this work, 24 samples from 12 rice fields of four different land-use types (Factory, highway, greenhouse/mulching and normal fields) were collected from Songjiang, Shanghai. From our selected sites, it was found that MP abundances were in the range of 233.33- 173.33 particles/kg in rhizosphere and bulk soil. MP distribution results showed that over 40% of particles were less than 1 mm and MP sizes ranging between 1 and 5 mm represented the greatest proportion. According to our study, MP in rhizosphere soil has the highest abundance (233.33 ± 57.73 particles/kg) than bulk soil. The particle shape classified as fragment (with edges and angular) was the most frequent shape found near factory areas, with an abundance of approximately 37.10%. Copolymers of polypropylene- polyethylene (PP/PE) at 24.30% were the most abundant polymers in rice lands in both bulk and rhizosphere soils; following is polystyrene (PS) at 21.40%, respectively. Most of the particles found in soils were white. Statistical analyses showed that fields near factories and fields where plastic mulching (mulch film and greenhouse crops) was used had a significantly higher particle abundance for bulk and rhizosphere soils, hence identifying plastic mulching as a major contributor to MP pollution in paddy soils. In industrial areas, MP can also be generated by released waste or by air. Microbial studies in rice roots, rhizosphere soil, and bulk soil show variation in the abundance of different species and genera. The dominant bacterial phyla in rice roots are Proteobacteria, Actinobacteriota, Firmicutes, and Bacteroidota. These microbes have been observed and can be impacted by the presence of MPs. Rhizosphere soil and bulk soil have an abundance of Chloroflexi, Actinobacteriota, Proteobacteria, Firmicutes, and Acidobacteriota. The specific effects on the microbial community structure depend on factors like MP type, concentration, and exposure duration. As our study was field-based, the significant effect of a specific type or concentration of MP was difficult to identify. Variation analyses of MP characteristics revealed that paddy lands were more likely to contain fragment shapes and large MP particles (1-5 mm). Also, rhizosphere soils were likely to contain fragment shapes and pony-size MPs (0.02-0.2 mm). Differences among rice fields may depend on various reasons, such as using slow- release fertilizers, mulching plastic application, irrigation, atmospheric fallout, etc. This study provides some proper evidence about the characteristics of MP pollution in rice fields of Songjiang and explores some probable conditions and predominant MP sources in rice fields.

Revealing nitrate uptake and dispersion dynamics using high-frequency sensors and two-dimensional modeling in a large river system

Nitrate pollution of water bodies is a critical issue in many parts of the world because of its negative effects on aquatic ecosystem and human health. Effective management of pollution, such as the continuous or instantaneous release from point-sources, requires an understanding – with high spatial and temporal resolution – of how nitrate is dispersed and cycled within rivers. Nitrate sensing data show promise for this purpose, but their integration into numerical models is scarce; thus, questions remain regarding the necessary spatial grid size and temporal resolution required to resolve sensor readings. In this study, we developed an unsteady two-dimensional model to simulate nitrate transport, dispersal, and cycling along a 33-km stretch of the Kansas River (USA), following a strategic release of nitrogen from a decommissioned fertilizer plant. To validate modeled estimates of dispersion and uptake, we integrated 15-minute nitrate and temperature data from two aquatic sensors, one located proximal to the fertilizer release point and a second further downstream after complete lateral mixing. Model results at the site near to the contamination (0.4 km) were highly sensitive to river grid size and turbulent mixing, but insensitive to uptake. Results at the site far downstream of the contamination (31 km) were unaffected by grid size or mixing parameterization but were very sensitive to selection of uptake rate. High-frequency sensors allowed us to resolve diel variability in nitrate signals, which we incorporated into the model to improve performance and model realism. The 33-km study reach assimilated 14% of the total nitrate load in the river, or approximately half of what was contributed by the fertilizer release, during the two-month study period. Regarding nitrate cycling, modeled Cdiel/Cmax ranged from 0.04 to 0.11 whereas sensor observations showed much higher Cdiel/Cmax values of 0.11 to 0.25. Disagreements between data observations and model simulations in cycling are hypothesized to exist due to potential breakdown of the first-order rate kinetics. Together, our study shows the potential of combining numerical models and high-frequency data for a better understanding of the physical and biogeochemical processes that control nitrate dynamics in aquatic environments.

Composite hydrogels fabricated from konjac glucomannan and gellan gum: Rheological characterization and their potential application in sustainable agriculture

In this study, konjac glucomannan (KG) was incorporated in high acyl gellan (HAG) and low acyl gellan (LAG) hydrogels in different ratios. The addition of KG increased pseudoplasticity and thermal hysteresis values of the hydrogels. Improvement in elasticity and water holding capacity (WHC) was observed in KG-LAG hydrogels. The highest WHC (98.5 %) was observed for 1K1H (KG:HAG = 1:1) and 3K7L (KG:LAG = 3:7) hydrogels. The crystallinity of the composite hydrogels was lower than hydrogels prepared from individual biopolymers. The hydrogels exhibited a rough surface with minute pores in the cross-section, due to the aggregation of glucomannan on the gellan network in the composite hydrogels. While HAG and 1K1H hydrogels exhibited greater swelling at low pH (3.0), LAG and 3K7L exhibited greater swelling at high pH (11.0). At pH 7.0, the hydrogels exhibited swelling indices >300 %. Incorporation of 1K1H hydrogel at 10 % (w/w) in sandy loamy soil under semi-arid conditions increased the germination of fenugreek microgreens from 60 % to 80 % on the 15th day. Furthermore, the moisture evaporation rate of the soil reduced from 35 % to <15 %, positively impacting the physicochemical properties of the microgreens. The composite hydrogels were successful in achieving a controlled release of phosphate fertilizer.

Polyvinyl alcohol-soy protein isolate hydrogels: Controlled release of fertilizer and matrix nutrients for sustainable agriculture

Controlled release of fertilizers using hydrogels is one of the sustainable methods for increasing the effectiveness of chemical fertilizers and reducing their adverse effects on the environment. Here, we report an eco-friendly hydrogel based on polyvinyl alcohol (PVA) and soy-protein isolate (SPI) crosslinked with citric acid (CA) for the controlled release of fertilizer. Initially, PVA-SPI blends (PS) were prepared by solvent casting method and studied their physiochemical properties. The optimized blend (PS 8/2) was crosslinked with various weight percentages (5– 30%) of citric acid (CA). Hydrogels with 20% CA exhibited optimum properties which were then loaded with urea to prepare controlled release fertilizer hydrogel (CRFH). Spectrophotometry studies showed that 74.1% of urea was released by the samples in 28 days. Additionally, the soy-protein matrix released the nutrients along with urea, which can be considered an added benefit. Kinetics study revealed that the release of nutrients followed the Ritger-Peppas model. The water retention study indicated that the samples could retain water for up to 30 days with an increase in gel content. Plant growth performance, germination and drought resistance study were evaluated using amaranthus and pea seedlings as model plants. The results indicated a significant improvement in the growth performance of the plants. Also, a degradation rate of 65% was attained for hydrogel samples when it was buried in the soil for 100 days. The prepared hydrogels can therefore be regarded as a potential candidate for sustainable agriculture due to their controlled-dual release properties, water-retaining capacity, affordability, non-toxicity, and environmental friendliness.

Layered double hydroxide for slowing selenium fertilizer release and improving selenium utilization efficiency in vegetables

Selenium (Se) is a beneficial plant micronutrient, and the application of Se fertilizers can promote plant growth and enhance the Se content in crops. However, traditional soluble Se fertilizers have low utilization efficiency of Se due to adsorption or leaching. Here, selenite (SeO32−) -intercalated Mg/Al layered double hydroxide (Se-Mg/Al) for SeO32− slow-release was synthesized by co-precipitation and characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). Se-Mg/Al possessed a typical lamellar structure, combining with selenite by electrostatic interaction in interlayer and chemisorption on the surface. The release mechanism of selenite in distilled water from Mg/Al layered double hydroxide (Mg/Al LDH) was Fickian diffusion with gradually released 97.86% after 20 h (Over 90% within 2 h for sodium selenite). At pH range 4.0–8.0, Se-Mg/Al had a stable slow-release ability. And, the sulfate and phosphate anions could effectively trigger the release of selenite through anions exchange. The pot experiments showed that Se-Mg/Al increased Se content of vegetables, more than twice that of directly using sodium selenite. Compared with control treatment, the average stem height and fresh weight per 10 plants with Se-Mg/Al treatment improved approximately 1.48 times and 2.34 times, respectively. This work provides a feasible way for achieving crops selenium supplementation and improving selenium utilization efficiency.

Biodegradable Dextrin-Based Microgels for Slow Release of Dual Fertilizers for Sustainable Agriculture.

In this research, we report dextrin-based biodegradable microgels (PDXE MGs) having phosphate-based cross-linking units for slow release of urea and a potential P source to improve fertilization. PDXE MGs (∼200 nm) are synthesized by cross-linking the lauroyl-functionalized dextrin chains with sodium tripolyphosphate. The developed PDXE MGs exhibit high loading (∼10%) and encapsulation efficiency (∼88%) for urea. It is observed that functionalization of PDXE MGs with lauroyl chains slows down the release of urea (90% in ∼24 days) as compared to nonfunctionalized microgels (PDX MGs) (99% in ∼17 days) in water. Further studies of the developed formulation display that Urea@PDXE MGs significantly boost maize seed germination and overall plant growth as compared to pure urea fertilizer. Moreover, analysis of maize leaves obtained from plants treated with Urea@PDXE MGs reveals 3.5 ± 0.3% nitrogen content and 90 ± 0.7 mg/g chlorophyll content. These values are significantly higher than 1.4 ± 0.6% nitrogen content and 48 ± 0.05 mg/g chlorophyll content obtained by using bare urea. Further, acid phosphatase activity in roots is reduced upon treatment with PDXE MGs and Urea@PDXE MGs, suggesting the availability of P upon degradation of PDXE MGs by the amylase enzyme in soil. These experimental results present the developed microgel-based biodegradable formulation with a slow release feature as a potential candidate to move toward sustainable agriculture practices.

Effects of Pyrolysis Temperature and Acid-Base Pre-Treatment on the Synthesis of Biochar-Based Slow-Release Selenium Fertilizer and Its Release in Soil.

Plant-derived selenium is an important source of selenium (Se) for humans, which, however, has been restricted by a low content of Se in soil. Traditional Se fertilizers have tended to result in low selenium utilization. Thus, it was necessary to develop a new slow-release material to control Se fertilizer release. In this study, biochar pyrolyzed at 300 °C and 800 °C was cross-linked with polyethyleneimine (PEI) after being treated with HNO3 or NaOH (which were labeled Acid-W300, Acid-W800, Alkali-W300, and Alkali-W800). The results showed that the maximum adsorption capacities of Acid-W300, Alkali-W300, Acid-W800, and Alkali-W800 were 329.16 mg/g, 321.93 mg/g, 315.04 mg/g, and 344.33 mg/g, respectively. Among them, Acid-W800 and Alkali-W800 were mainly imine- and amide-bonded with SO32-, while Acid-W300 and Alkali-W300 were loaded with SO32- by forming the C-Se bonding as well as through imine- and amide-bonding. The release of four biochar-based selenium fertilizers in the red soil and brown soil extracts conformed to the pseudo-second-order kinetic model. The release rate and release amount of four biochar-based selenium fertilizers in the red soil extract were higher than those in the brown soil extract. Alkali-W800-Se had a higher proportion of Se-exchangeable release, accounting for 87.5% of the total loaded selenium, while Acid-W300-Se had the lowest proportion at 62.2%. However, the Se releases of Alkali-W800-Se were more than 42.49% and 37.67% of the total Se-loading capacity during 5 days of continuous red soil extraction and brown soil extraction, respectively. Acid-W300-Se released less than 20% of the total Se-loading capacity. Thus, Acid-W300-Se was the recommended slow-release Se fertilizer in red soil and brown soil.

Obtaining micrometric-scale hollow fibers from wastes aged coir by oxidative chloro-sulfonation of lignin: HClO/H2SO4

Coconut fiber is a lignocellulosic material extracted from the coconut mesocarp. Due to its mechanical properties, coconut fiber has been used as reinforcement in composite materials, which contrasts with a relatively small number of studies where coconut fiber is evaluated as a functional polymeric material. In this research, the extraction and transformation of aged coconut biofibers are proposed for their use as substrate/support into making of functional polymers, specifically for slow release of fertilizers. An interesting property of this material is its hollow-type morphology at micrometric scale. Thus, coconut biofibers (BFs) were mechanically extracted and delignified using mixed-oxidizing system constituted by NaClO and H2SO4 at different pH values (2.0 ≤ pH ≤ 12.0). BFs were thermal, spectroscopic and functionally characterized by different techniques, including infrared and ultraviolet-visible spectroscopies, thermogravimetric analysis, scanning electron microscopy, among others. The bleaching of the fibers and the removal of lignin were evidenced by microscopy. The best results of this stage were seen at pH 4.0, 7.0 and 8.0, being possible obtain different materials depending on three acidity regimens (2.0 ≤ pH ≤ 4.0, 4.0 < pH ≤ 8.0 and 8.0 < pH ≤ 12.0). In addition, delignification achieved is function on pH with a value close to 80 % according to the change of surface color intensity. It is concluded that coconut biofibers are natural structure which can be used as support for the making of functional materials.

Influence of Soil Type and Temperature on Nitrogen Mineralization from Organic Fertilizers

Organic vegetable producers in Georgia, USA, utilize a range of amendments to supply nitrogen (N) for crop production. However, differences in soil type, fertilizers and environmental conditions can result in variability in N mineralization rates among commonly utilized organic fertilizers in the region. In this study, the effects of temperature on N mineralization from three commercial organic fertilizers [feather meal (FM), pelleted poultry litter (PPL) and a mixed organic fertilizer (MIX)] in two soil types from Georgia, USA (Cecil sandy clay loam and Tifton loamy sand) were evaluated for 120 d. Net N mineralization (Net Nmin) varied with soil type, fertilizer and temperature. After 120 d, Net Nmin from the FM fertilizer ranged between 41% and 77% of total organic N applied, the MIX fertilizer ranged between 26% and 59% and the PPL fertilizer ranged between 0% and 22% across all soil types and temperatures. Incubation at higher temperatures (20 °C and 30 °C) impacted Net Nmin of FM fertilizer in the Tifton series soil. Temperature and soil type had a relatively minor impact on the potentially mineralizable N of the PPL and MIX fertilizers after 120 d of incubation; however, both factors impacted the rate of fertilizer release shortly after application, which could impact the synchronicity of N availability and plant uptake. Temperature-related differences in the mineralization of organic fertilizers may not be large enough to influence a grower’s decisions regarding N fertilizer inputs for vegetable crop production in the two soils. However, organic fertilizer source will likely play a significant role in N availability during the cropping season.

Comparative Analysis and Characterization of Varying Molar Ratios of Urea Formaldehyde (UF) Modified Rice-Straw as Slow – Release Fertilizer

A comparative analysis and characterization of varying molar ratios of urea formaldehyde (1:2, 1:2.5 and 1:3) modified Rice-straw was done. The swell index, cold water insoluble nitrogen (% CWIN) at 250C and hot water insoluble nitrogen (% HWIN) at 980C were determined. Also, the slowly available nitrogen and the activity index (AI) were evaluated. The result from these characterizations shows that rice-straw has a good water retention capacity due to its high swell index of 1535% facilitating the slow release of nutrients. All the various formulations of urea formaldehyde in this work have their % CWIN values above the 60 % minimum, 78 % for UF 1:2, 80 % for UF 1:2.5 and 84 % for UF 1:3 while the activity indices stood at 17.9 %, 41.3% and 25% for UF 1:2, UF1:2.5 and UF 1:3 respectively. UF modified Rice-straw with molar ratio 1:2.5 whose AI is 41.3% which is within the good quality level and has the highest amount of slowly release nitrogen is therefore adduced to be a better slow- release fertilizer than the rest.

Insights into hydrophobic (meth)acrylate polymers as coating for slow-release fertilizers to reduce nutrient leaching

To solve the problem of the low utilization rate of fast-release water-soluble fertilizers and to minimize their environment impact, slow- release fertilizers have emerged as a sustainable solution to limit their losses and improve crop production.

Enhancing agricultural sustainability through plant growth-promoting rhizobacteria and nanotechnology

The challenges facing the global agricultural system in the twenty-first century, such as declining productivity and ecosystem sustainability, are worsened by predictions of a growing population, which is expected to reach 9.7 billion by 2050. Factors related to climate change, such as rising temperatures and abiotic stresses, such as salinity and drought, put agricultural production at risk. Sustainable agriculture has become crucial, as it offers long-term environmental and social benefits by reducing the use of synthetic pesticides and fertilizers. One promising solution for sustainable agriculture is the use of plant growth-promoting rhizobacteria (PGPR). These bacteria, which are abundant in the rhizosphere, enhance plant growth both directly and indirectly by promoting root growth, biofertilization, and controlling phytopathogens. However, despite their potential, challenges still exist in terms of the inconsistent performance and mechanisms of PGPR, which limits their widespread adoption. Biofertilizers containing PGPR provide a sustainable alternative to conventional fertilizers by enhancing nutrient availability and soil fertility. Additionally, the integration of nanotechnology holds promise in improving agricultural sustainability by facilitating efficient nutrient uptake and the controlled release of fertilizers, thus reducing environmental impacts. PGPR have been shown to be effective in various crops such as maize and sugarcane, offering solutions for soil nutrient deficiencies and pathogen control. Nevertheless, the beneficial effects of PGPR may be influenced by certain bacterial traits, underscoring the importance of selecting appropriate strains for optimal outcomes. In conclusion, the integration of PGPR and nanotechnology offers a comprehensive approach to sustainable agriculture, addressing the complex challenges.

Review: Modified Urea Fertilizers and Their Effects on Improving Nitrogen Use Efficiency (NUE)

Urea has served as the primary nitrogenous fertilizer globally since the early 1950s. It is widely recognized as the most concentrated nitrogen source, containing approximately 46% nitrogen. Presently, around 220 million t/year of urea compounds are manufactured globally to fit the requirements of the agricultural sector. However, a significant drawback of this is that approximately 30–35% of the urea used in soil can be lost to the environment because of its limited effectiveness. Enhancing the efficiency of urea utilization can be achieved by regulating the release of urea-nitrogen in the soil. Numerous researchers have reported that the use of slow or controlled fertilizers can regulate the release and accumulation of nitrogen in the soil. Moreover, the augmentation of soil nitrogen levels can be accomplished by using the slow or controlled release of urea fertilizers. The regulation of the release process can play a vital role in the peril of N loss. This can be effectively alleviated by delaying the release of nitrogen in ammonium form configuration for several days. This delay functions to diminish nitrogen losses, which are caused by the rapid hydrolysis of urea, and loss by leaching or volatilization. Therefore, this review aims to comprehensively explore the use of conventional urea and various materials employed for modifying urea. It will explain the distinctions among modification processes and their respective mechanisms. This review will also discuss the pros and cons of applying slow- and controlled-release nitrogen, the impact of modified urea compounds on crop productivity, and nitrogen use efficiency (NUE).

Enhanced-efficiency fertilizers on the growth of coffee plants under weed (Bidens Pilosa) competition stress

The interference of weeds in coffee cultivation is one of the factors contributing to losses and impairments in crop growth and productivity. Consequently, it becomes necessary to employ strategies aimed at mitigating this stress and facilitating optimal crop development through enhanced nutritional practices. This study aimed to assess the impact of various sources and modes of release of enhanced-efficiency phosphate fertilizers on the initial growth of Coffea arabica L. plants in competition with the weed Bidens pilosa in a greenhouse. The experiment was conducted at the Federal University of Vales do Jequitinhonha and Mucuri – Diamantina MG, Brazil, employing a block design in a 4 x 6 factorial arrangement with four replications. The factors corresponded to four levels of B. pilosa infestation and six phosphorus sources (Super Single, Conventional, MAP, Granulated Organomineral, Pelleted Organomineral, MAP Coated with Polymer, and a control treatment without fertilization). The findings suggest that under the experimental conditions of this research, the escalating density of weed competition from B. pilosa negatively impacts the initial growth of coffee plants. However, this effect is dependent on the source of phosphate fertilization. Fertilizers with slow-release phosphate sources are recommended for coffee plantations, as they contribute to reduced weed growth in comparison to coffee plants.

Soybean-Oil-Modified Petrochemical-Source Polyester Polyurethane Improves the Nutrient Release Performance of Coated Urea

Due to the difficult degradation and high cost of polyester polyols (PPs), their further development in controlled-release fertilizers (CRFs) has been limited. It was of great significance to partially substitute PPs with soybean oil polyols (SOPs) in the preparation of CRFs, which can adjust the proportion of substitution to balance the nutrient release period and membrane degradability. And it is possible to adjust the nitrogen release curve and prepare coated urea with different release days without changing the coating thickness. In this study, a two-factor five-level interaction experiment was designed with different SOP addition ratios (70%, 60%, 50%, 40%, and 30%) and mass ratios of polyols to PAPI (1:1.2; 1:1; 1.2:1; 1.4:1; and 1.6:1). In 25 groups of soybean-oil-modified polyester polyurethane-coated urea (SMPCU) treatments, with the increase in SOP, the thermal decomposition performance of the coated urea was improved, and the residual ash contents of the coating material was reduced. The coating surface was made smoother and denser with a reasonable ratio of polyols to PAPI, preventing the release of non-film-forming substances. When the proportion of soybean oil was 60% and the ratio of polyols to PAPI was 1.2:1, the N release days of the prepared SMPCU reached 137 days. Compared to soybean-oil polyol-coated urea (SOPCU) and polyester polyol-coated urea (PPCU), the nitrogen release days increased by 73.42% (79 days) and 234.15% (41 days), respectively. The ratio of polyols to polyaryl polymethylene isocyanate (PAPI) was explored, as well as the effect of polyol composition on coatings, and prepared SMPCUs with different nitrogen release days. According to the growth needs of crops and soil environmental characteristics, adjusting the proportion of coating materials, prolonging or shortening the nitrogen fertilizer release time, meets the nutritional needs of crops under different planting systems and provides conditions for farmers to plant different crops.

Novel Hybrid ZnO Nanoparticles Entrapped Aqua Zeolite Matrix for Controlled Release of Fertilizer for Sustainable Growth of Plants

Novel Hybrid ZnO Nanoparticles Entrapped Aqua Zeolite Matrix for Controlled Release of Fertilizer for Sustainable Growth of Plants