Shrimp Waste Research Articles

Reusable carbon dot/chitin nanocrystal hybrid sorbent for the selective detection and removal of Cr(VI) and Co(II) ions from wastewater

The last few decades have seen a dramatic increase in heavy metal ions in industrial wastewater, especially Cr6+ and Co2+ ions, which have been shown to adversely affect human health; thus, there is a great need for their removal. Existing removal methods are time-consuming, expensive, and require high technical skills; therefore, there exists a need for a quick, simple, and cost-effective method. Chitin was selected from natural materials (shrimp waste), and an inexpensive, biodegradable, fluorescent carbon dot/chitin nanocrystal (C-dot/ChNC) sorbent for the simultaneous detection and removal of heavy metal ions from wastewater was synthesized from it. C-dot/ChNC shows high selectivity and sensitivity to Cr6+ and Co2+ ions and has high chromium(VI) and cobalt(II) adsorption capacities. These ions are weakly adsorbed on the C-dot/ChNC surface and are easily removed during regeneration, showing high cyclability. Thus, C-dot/ChNC is a viable sorbent for the removal of heavy metal ions during wastewater treatment.

Application of Seaweed (Eucheuma cottonii) Extract and Shrimp Waste as Biofertilizer for Mustard (Brassica juncea L.)

The extensive use of chemical fertilizers in agriculture poses serious collateral problems such as environmental pollution, pest resistance development and food safety decline. Researches focused on developing organic fertilizers from waste to partially replace chemical fertilizer use is increasing due to the requirement of sustainable agriculture development. Therefore, a pot experiment was carried out to study the effect of organic fertilizer made from seaweed and shrimp waste in improving crop growth and soil pH in green mustards. Three treatments were set up: seaweed and shrimp waste fertilizer (SSF), organic fertilizer (OF) and chemical fertilizer (CF). Although the SSF treatment had the highest number of leaves and plant height, ANOVA showed no significant differences between the three treatments. Soil pH in the SS treatment (pH= 7.43) was also higher than OF (pH= 6.49) and CF (pH= 7.07) though no significant differences were observed. Therefore, the fertilizer produced using seaweed and shrimp waste is comparable to other organic and chemical fertilizer and is suitable for growing leafy vegetables. The production and use of organic fertilizers made from seaweed extract and shrimp head waste can be a new wave of organic fertilizer in promoting plant growth and increasing crop yields.

Intrinsic properties of chitosan on the characteristics of gold nanoparticles and its application as smart packaging device.

Storage temperature fluctuation is a major problem faced in food and pharmaceutical industry, apart from prevailing fraud in marketing frozen products as fresh. The present work aimed to study the effect of intrinsic properties of chitosan on synthesis and performance of gold nanoparticles as smart packaging devices. Different types of Chitosan from shrimp waste were used as reducing and capping agent in the synthesis of metal nanoparticle. Time is taken to reduce gold atom to gold nanoparticles varied with the type of reducing agent, between 6 min 40 s to 15 min 02 s. The maximum absorbance (λmax) for AuNPs was observed between 517 and 530 nm. An increase in the concentration of chitosan resulted in smaller and uniform size AuNPs with size ranging from 8.09 to 9.95 nm compared with 14.44 to 19.88 nm for lower concentration of chitosan. Visible ruby red colour of AuNPs synthesised using trisodium citrate (TSC) and lower concentration of chitosan (0.1%) changed to colourless and grey to blue, respectively upon exposure to frozen condition (-18 °C ± 1 °C). UV Visible spectra indicated distinctly different (broader) spectrum with reduced peak intensity. A visible change in colour from ruby red to bluish and colourless state indicates that irrespective of the properties of available chitosan, it can be used for synthesis of gold nanoparticles as smart packaging to distinguish packed fresh/chilled/refrigerated products from frozen ones.

Impact of chitin nanofibers and nanocrystals from waste shrimp shells on mechanical properties, setting time, and late-age hydration of mortar

Every year ~ 6–8 million tonnes of shrimp, crab, and lobster shell wastes are generated, requiring costly disposal procedures. In this study, the chitin content of shrimp shell waste was oxidized to produce chitin nanocrystals (ChNC) and mechanically fibrillated to obtain chitin nanofibers (ChNF) and evaluated as additives for mortar. ChNF (0.075 wt%) and ChNC (0.05 wt%) retarded the final setting time by 50 and 30 min, likely through cement dispersion by electrostatic repulsion. ChNF (0.05 wt%) with a larger aspect ratio than ChNC resulted in the greatest improved flexural strength and fracture energy by 24% and 28%. Elastic modulus increased by up to 91% and 43% with ChNC and ChNF. Solid-state nuclear magnetic resonance (NMR) showed ChNF (0.05 wt%) enhanced calcium–silicate–hydrate structure with a 41% higher degree of polymerization, 9% more silicate chain length, and a 15% higher degree of hydration at 28 days. Based on the findings, chitin seems a viable biomass source for powerful structural nanofibers and nanocrystals for cementitious systems to divert seafood waste from landfills or the sea.

Screening and Characterization of Chitinolytic Bacteria from Shrimp Waste

Shrimp waste is a perishable material. The degradation process is carried out by decaying microbes by producing degrading enzymes. The presence of chitin content in shrimp waste causes the emergence of chitinase enzyme-producing bacteria. Chitin is a linear homopolymer composed of N-acetyl-D-glucosamine monomers with -(1,4) glycosidic bonds. Chitin has unique properties, namely; biodegradable, biocompatible and non-toxic. This causes chitin and its derivatives to be widely used in various industrial and biomedical applications so that chitin and its derivatives have great economic value. There were 10 isolates of chitinolytic bacteria from shrimp waste with varying morphological characteristics. The ten bacterial isolates were NR02, NR03, NR04, NR05, NR06, NR07, NR08, NR09, NR10, NR11 and PU01. Chitinolytic index CI value > 2 was produced by 4 bacterial isolates, namely; NR02, NR07, NR09 and PU01. The lowest IK value was generated by NR08 with a value of 0.01. The chitinolytic bacteria obtained have different characters and it is very likely that they come from different types

SYNTHESIS AND CHARACTERIZATION OF CHITOSAN FROM RAW SHRIMP SHELL WASTE

Chitosan is a polysaccharide that is completely natural, non-toxic, biocompatible and biodegradable. Various commercial and biomedical applications exist for chitosan. The objective of this research was to synthesis chitosan nanopowders and then characterizes them. Waste shrimp shell is employed in this study as the starting point for the production of chitosan. Through the use of X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR), the structural and chemical characteristics of the nanopowders have been explored. The examination of the thermal stability of synthesized chitosan performed using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The present study revealed that chitosan nanopowders were successfully synthesized by chemical method with minor modification. The XRD study showed two characteristics crystalline peaks approximately at 2θ = 9.63° and 19.93° which is similar to the previous papers. Therefore, it can be said that chitosan nanopowders were successfully synthesized.

Physical and Oxidative Water-in-Oil Emulsion Stability by the Addition of Liposomes from Shrimp Waste Oil with Antioxidant and Anti-Inflammatory Properties.

Liposomes made of partially purified phospholipids (PL) from Argentine red shrimp waste oil were loaded with two antioxidant lipid co-extracts (hexane-soluble, Hx and acetone-soluble, Ac) to provide a higher content of omega-3 fatty acids. The physical properties of the liposomes were characterized by Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS) and Differential Scanning Calorimetry (DSC). The antioxidant and anti-inflammatory activity of the lipid extracts and liposomal suspensions were evaluated in terms of Superoxide and ABTS radical scavenging capacities and TNF-α inhibition. Uni-lamellar spherical liposomes (z-average ≈ 145 nm) with strong negative ζ potential (≈ -67 mV) were obtained in all cases. The high content of neutral lipids in the Hx extract caused structural changes in the bilayer membrane and decreased entrapment efficiency regarding astaxanthin and EPA + DHA contents. The liposomes loaded with the Hx/Ac extracts showed higher antioxidant and anti-inflammatory activity compared with empty liposomes. The liposomal dispersions improved the physical and oxidative stability of water-in-oil emulsions as compared with the PL extract, inducing pronounced close packing of water droplets. The liposomes decreased hydroperoxide formation in freshly made emulsions and prevented thio-barbituric acid-reactive substances (TBARS) accumulation during chilled storage. Liposomes from shrimp waste could be valuable nanocarriers and stabilizers in functional food emulsions.

Shrimp waste protein for bio-composite manufacturing: Formulation of protein-cornstarch-mimosa-tannin wood adhesives

The present work aims to isolate protein from shrimp waste for the formulation of wood adhesive. The obtained proteins were successfully characterized in terms of their morphology, physical and chemical properties. Then, the effect of protein (P) formulated with corn-starch–mimosa-tannin (CSMT) at different ratios of CMST/P (w/w) on mechanical properties such as internal bond (IB) modulus of elasticity (MOE), modulus of rupture (MOR) and surface of soundness (SS) as well as on physical performance such as thickness swelling (TS) and water absorption (WA) was investigated. Results show that the mechanical and physical properties were enhanced, particularly for particleboards glued with CSMT/P (99.2/0.8; w/ w) wood adhesive. Comparing to neat CSMT the IB, MOE, MOR and SS of particleboards bonded with CSMT/P (99.2/0.8; w/w) were increased by 18.18%, 19.56%, 34.61% and 17.03%, respectively. Additionally, a significant decrease in TS and WA was observed (~ 43.33% and 19.76% after 2 h, and 21.05% and 14.57% after 24 h of wetting in water, respectively), was observed.

Extraction, Characterization, and In Vivo Antimicrobial Activity of Chitosan Derived from the Egyptian Shrimp (Metapenaeopsis Stridulans) Wastes

Extraction, Characterization, and In Vivo Antimicrobial Activity of Chitosan Derived from the Egyptian Shrimp (Metapenaeopsis Stridulans) Wastes

Physicochemical and Biological Characteristics of Shrimp Pond Sludge in the Thua Thien Hue Province, Vietnam

This study has been carried out to analyze the physical and biological indicators of shrimp pond sludge samples obtained from the Phu Vang and Phu Loc districts of the Thua Thien Hue Province, Vietnam. All standard methodologies have been used to analyze the selected parameters like pH, organic carbon, total nitrogen, total phosphate, and microbial density. The results of the study revealed that the sludge was characterized by a neutral to alkaline pH (6.9 - 7.5), and the total organic carbon content was in the range of 103.8–173.5 mg/kg. The sludge was rich in organic matter (17.8–29.9%), total nitrogen (13.5–32.5 g/kg), and total phosphate (7.9-20.1 g/kg). Further, in the case of the microbial density of pathogenic microorganisms, the density of total bacteria, coliform, E.coli, Salmonella spp., Vibrio spp., and Clostridium spp. was also estimated at two opposing weather conditions (spring, February to March; summer, June to July). The microbial community increased rapidly during the cool spring months. The total bacterial levels were recorded as 8.77 log10 CFU/mL in the Phu Loc district and 9.11 log10 CFU/mL in the Phu Vang district. The levels decreased during the hot summer months, and the level of total bacteria, Coliform, E.coli, Salmonella spp., and Vibrio was reported 2.57, 1.49, 1.06, 0.56, and l2.54 log10 CFU/mL respectively from the Phu Loc district of Vietnam. The results obtained using the anaerobic decomposition model showed that on the 60th day, the amount of CH4 generated at the high output value for the Phu Vang district was 22385 ppm. The results reported here revealed that CH4 gas can be potentially produced from shrimp waste sludge in this province.

A Review of the Chemical Extraction of Chitosan from Shrimp Wastes and Prediction of Factors Affecting Chitosan Yield by Using an Artificial Neural Network.

There are two viable options to produce shrimp shells as by-product waste, either within the shrimp production phases or when the shrimp are peeled before cooking by the end user. This waste is considered a double-edged sword, as it is possible to be either a source of environmental pollution, through dumping and burning, or a promising source from which to produce chitosan as a biodegradable, biocompatible biopolymer which has a variety of agricultural, industrial, and biomedical applications. Chitosan is a deacetylated form of chitin that can be chemically recovered from shrimp shells through the three sequential stages of demineralization, deproteinization, and deacetylation. The main aim of this review paper is to summarize the recent literature on the chemical extraction of chitosan from shrimp shells and to represent the physicochemical properties of chitosan extracted from shrimp shells in different articles, such as chitosan yield, moisture content, solubility, ash content, and degree of deacetylation. Another aim is to analyze the influence of the main predictors of the chemical extraction stages (demineralization, deproteinization, and deacetylation) on the chitosan yield percentage by using a multilayer perceptron artificial neural network. This study showed that the deacetylation alkali concentration is the most crucial parameter, followed by the concentrations of acid and alkali of demineralization and deproteinization, respectively. The current review was conducted to be used in prospective studies for optimizing the chemical extraction of chitosan from shrimp wastes.

Shrimp-Waste-Derived Biochar Induces Metal Toxicity Tolerance of Wastewater-Irrigated Quinoa (Chenopodium quinoa)

The scarcity of high-quality water resources may lead to the use of lower quality water for plant production. Quinoa (Chenopodium quinoa) plants have great potential for human nutrition, but poor water quality, such as metal contamination in wastewater, affects the seed quality. This study aims to investigate the effects of shrimp-waste-derived biochar (SWB) on the uptake of toxic metals from wastewater by quinoa plants. Additionally, the study investigates how quinoa plants’ antioxidant defenses respond to wastewater and SWB treatments. Shrimp-waste-derived biochar (SWB) was prepared by pyrolysis at 350 °C for 3 h and added to the soil at the levels of 0, 1, and 2% (based on soil weight), which are namely C, SWB1, and SWB2, respectively. SWB was applied to quinoa plants cultivated in pots filled with sandy soil and irrigated with fresh or wastewater for a continuous 90 days. The wastewater was contaminated with manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), cadmium (Cd), and lead (Pb). Quinoa seeds that were irrigated with wastewater had Cd and Pb concentrations that were above the allowable levels (for human consumption) in the absence of biochar (C) or addition of SWB1. Wastewater significantly reduced quinoa growth and photosynthetic pigments, while SWB significantly mitigated the metal toxicity and improved growth. SWB2 significantly reduced the Pb and Cd concentrations in quinoa leaves by 29 and 30% compared with C. The Cd and Pb concentrations in quinoa seeds were safe for human consumption and below the maximum allowable limits when the soil was amended with SWB2. SWB improved the synthesis of photosynthetic pigments and increased the activity of antioxidant enzymes such as polyphenol oxidase and ascorbate peroxidase. SWB reduced the toxic metal availability and uptake, mitigated the oxidative stress, and minimized the levels of malondialdehyde and hydrogen peroxide. The SWB addition stimulated quinoa’s antioxidant defense and protected plant cells by eliminating reactive oxygen species. The addition of 2% (w/w) shrimp waste biochar improved the quality of quinoa seeds irrigated with wastewater and decreased their toxic metal content. The obtained results contribute to sustainable development and the exploitation of wastewater to irrigate quinoa plants in arid degraded soil; additionally, it also helps in the recycling of shrimp waste.

Evaluation of the Potential of Fungal Acid Proteases of <em>Aspergillus flavus, Aspergillus niger</em> and <em>Penicillium</em> sp. to Produce Shrimp-Waste Protein Hydrolysates with Degraded Antigenic Proteins

The waste produced by the shrimp industry can be a great source for the recovery of important bioactive compounds with potential applications in food industry. The present study aimed to characterize extracted proteases of Aspergillus flavus, Aspergillus niger and Penicillium sp. to be utilized as potential sources to produce shrimp waste protein hydrolysates with degraded antigenic proteins. The extracellular fungal acid protease enzymes were extracted under solid substrate fermentation and partially characterized the enzyme activities, concerning the reaction temperature and pH of the reaction medium. Then, the capabilities of extracted fungal protease enzymes to reduce the potential allergens of shrimp waste protein hydrolysates were examined by SDS-PAGE. After incubation of all three fungal species at 37°C and pH 3.0 for 5 days, the highest protease yield, 527.40 μg/mL was achieved from A. flavus. The optimum temperature for A. flavus for the highest protease activity was 45°C, while for other two microorganisms the optimum temperature was 50°C. The optimum pH values for all three proteases were pH 3. According to the SDS-PAGE protein hydrolyzing patterns, the crude acid protease extracted from A. flavus was the best protease to degrade the potential antigenic proteins over the other two acid proteases extracted from A.niger and Penicillium sp., while all three enzymes had shown the potential to reduce the allergenic capacity of shrimp waste proteins through enzymatic hydrolysis.

Shrimp waste meal (Pandalus borealis) as an alternative ingredient in diets for juvenile European lobster (Homarus gammarus, L.)

The use of sustainable ingredients in the formulation of aquafeeds remains ever important. The European lobster (Homarus gammarus) is an emerging species for aquaculture, the success of which relies on knowledge of its nutritional requirements and the selection of dietary ingredients that facilitate viable production and future commercialization. In this study, we investigated the feasibility of using shrimp waste meal (SWM) as an ingredient in formulated diets for juvenile lobsters (stages VII – VIII, ∼ 164 mg) during an 8-week feeding experiment. The experimental diets were isoproteic (∼ 54 % crude protein) and isolipidic (∼ 11 % crude fat), in which either 7 %, 14 %, 21 %, or 28 % of the dietary protein was supplied by SWM. Experimental diets were benchmarked against a control diet without SWM (SWM 0 %). Diet performance was evaluated based on survival, body mass gain, carapace length increment, and moulting cycle duration. Nitrogen metabolism was evaluated from the nitrogen excretion rates of individual lobsters, determined before and following the ingestion of a single meal. The exoskeleton colouration of individual lobsters was assessed using digital colour analysis at the end of the growth trial. The results indicate that the inclusion of SWM at 28 % protein significantly enhanced survival and had no effect on growth performance, postprandial nitrogen metabolism, and exoskeleton colouration. Therefore, we recommend the use of SWM, at least up to 28 % of dietary protein, as a potential alternative ingredient in the formulation of future commercial feeds for juvenile H. gammarus.

Circular Economy Policy of Shrimp Waste as an Effort to Implement Green Economy

This study aims at determining the conditions and characteristics of shrimp waste, the economic value of the potential for shrimp waste, as well as the policy direction for implementing the Circular Economy of Shrimp Waste as a Green Economy Alternative in the Bulak Banteng Kenjeran Coastal Area, Surabaya City. The research method used is descriptive qualitative and quantitative with the process hierarchy analysis technique (AHP). The data collection method was carried out by distributing questionnaires and in-depth interviews with selected respondents. The results showed that the characteristics of shrimp waste in the form of shrimp heads and shells were still not used for economic value activities, and people dumped them in gutters around homes and at sea. The priority policy directions that can be applied to the Circular Economy of Shrimp Waste as an Alternative to a Green Economy are; 1) providing innovation and technology for economic-based shrimp waste processing with a total CR (consistency ratio) value of 1.878; 2) to improve environmental health by not disposing of shrimp waste around the house, the total value of CR is 1.127; and, 3) the government provides a shrimp processing industry for fishermen with a total CR value of 0.094. Each policy priority can be carried out in synergy so that shrimp waste can be handled properly.

Metal-Free N-Doped Carbons for Solvent-Less CO2 Fixation Reactions: A Shrimp Shell Valorization Opportunity.

High anthropogenic CO2 emissions are among the main causes of climate change. Herein, we investigate the use of CO2 for the synthesis of organic cyclic carbonates on metal-free nitrogen-doped carbon catalysts obtained from chitosan, chitin, and shrimp shell wastes, both in batch and in continuous flow (CF). The catalysts were characterized by N2 physisorption, CO2-temperature-programmed desorption, X-ray photoelectron spectroscopy, scanning electron microscopy, and CNHS elemental analysis, and all reactivity tests were run in the absence of solvents. Under batch conditions, the catalyst obtained by calcination of chitin exhibited excellent performance in the conversion of epichlorohydrin (selected as a model epoxide), resulting in the corresponding cyclic carbonate with 96% selectivity at complete conversion, at 150 °C and 30 bar CO2, for 4 h. On the other hand, in a CF regime, a quantitative conversion and a carbonate selectivity >99% were achieved at 150 °C, by using the catalyst obtained from shrimp waste. Remarkably, the material displayed an outstanding stability over a reaction run time of 180 min. The robustness of the synthetized catalysts was confirmed by their good operational stability and reusability: ca. (75 ± 3)% of the initial conversion was achieved/retained by all systems, after six recycles. Also, additional batch experiments proved that the catalysts were successful on different terminal and internal epoxides.

Biowaste and by-products as rearing substrates for black soldier fly (Hermetia illucens) larvae: Effects on larval body composition and performance.

Black soldier fly (Hermetia illucens) larvae can convert biowaste and by-products into body mass high in protein (~40% dry matter, DM) and lipid (~30% DM). However, the type of rearing substrate also affects the larval body composition and thus its nutritional value. Hitherto, it remains unclear how and to what extent the larval body composition can be altered by the substrate. This study was therefore performed to examine the possibilities of modifying larval body composition using different rearing substrates. To investigate this, 5-days old larvae were reared for seven days on different locally available waste and by-products: brewer’s spent grain, mitigation mussels (Mytilus edulis), rapeseed cake, and shrimp waste meal (Pandalus borealis). Larval composition and performance were compared to larvae reared on a commercial chicken feed as well as a mixed feed (mixture of chicken feed and by-products, with a similar macronutrient composition to chicken feed). Larval body weight was recorded daily to determine growth over time whereas larvae and substrates were sampled at the start and end of the trial and analysed for their nutritional composition. The type of rearing substrate affected both larval body composition and growth performance. There was a clear relation between the nutritional composition of the substrate and larvae for certain fatty acids. Larvae reared on marine-based waste substrates contained a higher share of omega-3 fatty acids than larvae reared on the other substrates, indicating an accumulation of omega-3 fatty acids from the substrate. There was a strong positive linear correlation between the ash content in the substrate and larvae whereas larval lipid, protein, amino acid, and chitin content seemed more affected by larval development. Overall, this study showed that the rearing substrate affects larval composition and development, and that larval composition of certain nutrients can be tailored depending on further food and feed applications.

Effect of Additional Feed Supplement Fermentation Shrimp Waste Extract on Digestibility in Sentul Chicken Growth Phase

This study aims to determine the effect of adding feed supplements of fermented shrimp waste extract in the ration on the digestibility of local chicken rations in the growth phase. The research was carried out in Jatinangor District as well as the Laboratory of Ruminant Animal Nutrition and Animal Feed Chemistry, Faculty of Animal Husbandry, Padjadjaran University, Sumedang. The method used in this study was experimental with a Complete Randomized Design (RAL). The data were analyzed by fingerprint test (ANOVA) with further tests using the Dunnet test. The object of this study consisted of 20 Sentul chickens raised from the age of 1 day to 12 weeks, divided into 5 treatments and 4 tests. The treatment consists of P0 = Basal ration without the addition of feed supplement fermented shrimp waste extract, P1 = Basal ration + 0.5% feed supplement fermented shrimp waste extract, P2 = Basal ration + 1.0% feed supplement fermented shrimp waste extract, P3 = Basal ration + 1.5% feed supplement fermented shrimp waste extract, and P4 = Basal ration + 2.0% feed supplement fermented shrimp waste extract. The changes observed are the digestibility of dry matter, the digestibility of organic matter, and the digestibility of proteins. The results showed that the addition of feed supplements for fermented shrimp waste extract had a significantly different influence on the digestibility of dry matter, the digestibility of organic matter, and the digestibility of protein. This study concludes that the addition of a feed supplement of 2% fermented shrimp waste extract in the ration can produce a high ration digestibility value for Sentul chicken in the growth phase.

Impact of Green Chitosan Nanoparticles Fabricated from Shrimp Processing Waste as a Source of Nano Nitrogen Fertilizers on the Yield Quantity and Quality of Wheat (Triticum aestivum L.) Cultivars.

Waste from crustaceans has adverse effects on the environment. In this respect, shrimp waste was valorized for producing chitosan nanoparticles as a source for eco-friendly nano-nitrogen fertilizer. The application of nano-nitrogen fertilizers is a valuable alternative approach in agriculture due to its potential for reducing the application of mineral nitrogen fertilizers and increasing yield quality and quantity, thereby helping to reduce the worldwide food shortage. Chitosan nanoparticles were foliar sprayed at three volumes (0, 7, and 14 L/ha) and compared with mineral nitrogen fertilizer (M-N) sprayed at three volumes (0, 120, and 240 kg N/ha) and their combination on two wheat cultivars (Misr-1 and Gemaiza-11) during two consecutive seasons (2019/2020 and 2020/2021) in order to evaluate the agronomic response. The synthesized chitosan nanoparticles displayed characteristic bands of both Nan-N and urea/chitosan from 500–4000 cm−1. They are stable and have a huge surface area of 73.21 m2 g−1. The results revealed significant differences among wheat cultivars, fertilization applications, individual or combined, and their interactions for yield-contributing traits. Foliar application of nano-nitrogen fertilizer at 14 L/ha combined with mineral fertilizer at 240 kg/ha significantly increased total chlorophyll content by 41 and 31% compared to control; concerning plant height, the two cultivars recorded the tallest plants (86.2 and 86.5 cm) compared to control. On the other hand, the heaviest 1000-grain weight (55.8 and 57.4 g) was recorded with treatment of 120 kg Mn-N and 14 L Nan-N/ha compared to the control (47.6 and 45.5 g). The Misr-1 cultivar achieved the highest values for grain yield and nitrogen (1.30 and 1.91 mg/L) and potassium (9.87 and 9.81 mg/L) in the two studied seasons when foliarly sprayed with the combination of 120 kg Mn-N/ha + 14 L Nan-N/ha compared to the Gemaiza-11 cultivar. It can be concluded that Misr-1 exhibited higher levels of total chlorophyll content, spike length, 100-grain weight, grain yield in kg/ha, and nitrogen and potassium. However, Gemaiza-11 displayed higher biomass and straw yield values, plant height, and sodium concentration values. It could be economically recommended to use the application of 120 kg Mn-N/ha + 14 L Nan-N/ha on the Misr-1 cultivar to achieve the highest crop yield.

The Effect of Shrimp Waste Fertilizer Application on Spinach (Amaranthus tricolor L.) with the Presence of Weeds

The presence of weeds in spinach cultivation land is strongly influenced by the application of fertilizer. Fertilizer has a different content so that it will have an impact on the weed species growth. Identification in this study aims to determine the types of weed species that grow and the dominant types of weed species that grow on spinach cultivation land before and after the application of shrimp waste fertilizer. This research was conducted from June to August 2021, on horticultural crop cultivation in the Sinar Harapan Farmers Group, Tarakan City. The sampling method was a random method using a square plot method with a size of 1 x 1 m as many as 30 samples before and after the application of shrimp waste fertilizer. Observation parameters are counting the number of weed species and the name of the weed species. The data obtained in the field is then processed to determine the level of density, frequency, significant value index (INP), Summed Dominance Ratio (SDR), Margalef Index, Shanon-Wiener Index, Evennes Index and Sorensen Index. The results showed that the weed species before the application of shrimp waste fertilizer on spinach plants were 27 species with the dominant weed species being Cyperus compressus with a Summed Dominance Ratio value of 22.72%. Weed species before the application of shrimp waste fertilizer on spinach plants were 25 species with the dominant weed species namely Cyperus compressus with a Summed Dominance Ratio value of 20.51%. The Margalef index before the application of shrimp waste fertilizer was 3.20 and after the application of shrimp waste fertilizer was 3.05. The Shanon-Wiener index before the application of shrimp waste fertilizer was 2.60 and after the application of shrimp waste fertilizer was 2.40. Evennes index before the application of shrimp waste fertilizer is 0.79 and after the application of shrimp waste fertilizer is 0.74 and the Sorensen index is 85%