Nutrient Deposition Research Articles

External nutrients fattening promotes hepatopancreases development, metabolism, nutrient deposition and flavor yield during the maturation stage in female Chinese mitten crab (Eriocheir sinensis)

The nutritive value and maturity status of hepatopancreases dominates the quality of Chinese mitten crab, Eriocheir sinensis. However, the underlying function and regulatory mechanism, as well as the external nutrient factors on the development of hepatopancreases in different growth stages of E. sinensis remains unclear. In this study, we first revealed the function of hepatopancreases feeding with iced trash fish (ITF) during the whole culture period; and further investigated the underlying mechanism on nutrient deposition and flavor yield feeding with formulated feed (FEED) in replacement of ITF in female E. sinensis. From the results, growth performance and metabolism indicate E. sinensis was robustly developed, and ITF promotes growth and hepatopancreases development during the maturation period. Meanwhile, activation of fatty acid and amino acid metabolism in hepatopancreases resulted in depletion of monounsaturated fatty acids (MUFAs) but promoted protein deposition during the maturation stage. Integrated analysis of transcriptome and metabolome reveal metabolism, biosynthesis, and flavor presentation were intensively active during maturation, evidenced by the expression of key genes of ALDH, TBXAs, HADHA, UPB1, CYP2, GST, and γ-GT-X1; as well as the key metabolites of GMP and IMP. Additionally, substitution of ITF with FEED further confirm full price artificial feed could meet the nutrient requirements during the maturation period, evidenced by the growth performance, fatty acid and amino acid derived nutrient and flavor yield in hepatopancreases. In conclusion, nutrient and flavor deposition was associated with the fast development of hepatopancreases, and fatten with full price compound feed contributes to the nutrient requirement and flavor yield during the maturation stage.

STATISTICAL MODEL FOR ESTIMATING N-P-K DEPOSITION FROM PRECIPITATION IN AGROECOSYSTEMS OF THE BRAZILIAN SEMI-ARID REGION

The objective of the study was to adjust a linear statistical model to estimate the input of N, P, and K, through rainfall, in agroecosystems in the Agreste region of Paraíba. The data for the parameterization of the model were obtained in a field experiment conducted in the municipality of Esperança, Paraíba, from January to December. Descriptive, inferential and probabilistic statistics were used for the methodological development of this study. The equations obtained by the linear model can be used to estimate nutrient deposition through rainfall in climatic conditions similar to those of the region under study. The need for comparative studies with other production systems practiced in the region must be highlighted, to validate the data and the model.

High nitrate and sulfate leaching in response to wetter winters in temperate beech forests

Climate models project moderate to large increases in air temperature for most temperate ecosystems with an overall increase in winter precipitation and a shift from snow towards rain. We investigated the effects of increased winter rainfall on the ecosystem functioning of European beech forests at their north-eastern distribution range. In a large-scale field experiment we manipulated winter climate at nine forest sites by increasing the amount of rainfall and excluding snow. Nutrient availability in the topsoil and leaching in 50 cm depth as well as litter decomposition and radial growth of mature European beech trees were analysed. It was hypothesized that (1) wetter winters lead to increased nutrient deposition as well as leaching, with an overall increase in net nutrient availability, (2) decomposition decreases in response to water addition containing also additional nutrients and (3) primary production during the subsequent growing season increases as presumably not all additionally available nutrients would be leached. We found an increase in topsoil nitrate and sulfate availability during winter in response to rain addition, likely as a consequence of collecting more atmospheric deposition, and surprisingly high leaching rates of the additionally available nutrients. During the subsequent early growing season, no difference in nutrient availability could be observed anymore. Enhanced nutrient availability in the topsoil and leaching do not seem to have a strong short-term influence on forest ecosystem processes in ecosystems which are close to their critical load of N deposition. Decomposition rates during winter and early growing season as well as stem diameter growth during the following growing season were not influenced. This indicates that additional nutrients in the topsoil in response to wetter winters are not available for plant growth but pollute ground- and surface waters.

Nitrogen and phosphorus additions alter soil N transformations in a Metasequoia glyptostroboides plantation.

Nitrogen (N) and phosphorus (P) enrichment due to anthropogenic activities can significantly affect soil N transformations in forest ecosystems. However, the effects of N and P additions on nitrification and denitrification processes in Metasequoia glyptostroboides plantations, and economically important forest type in China, remain poorly understood. This study investigated the responses of soil nitrification and denitrification rates, as well as the abundances of nitrifiers and denitrifiers, to different levels of N and P additions in a 6-year nutrient addition experiment in a M. glyptostroboides plantation. Stepwise multiple regression analysis was used to identify the main predictors of nitrification and denitrification rates. The results showed that moderate N addition (N2 treatment, 2.4 mol·m-2) stimulated nitrification rates and abundances of ammonia-oxidizing archaea (AOA) and bacteria (AOB), while excessive N and P additions inhibited denitrification rates and reduced the abundance of nirS-type denitrifiers. AOB abundance was the main predictor of nitrification rates under N additions, whereas microbial biomass carbon and nirS gene abundance were the key factors controlling denitrification rates. Under P additions, tree growth parameters (diameter at breast height and crown base height) and AOB abundance were the primary predictors of nitrification and denitrification rates. Our study reveals complex interactions among nutrient inputs, plant growth, soil properties, and microbial communities in regulating soil N transformations in plantation forests. This study also offers valuable insights for formulating effective nutrient management strategies to enhance the growth and health of M. glyptostroboides plantations under scenarios of increasing elevated nutrient deposition.

Dicranopteris pedata improves soil quality by enhancing nutrient deposition, decreasing metal concentration, and boosting microbial diversity on abandoned rare earth elements mining sites

Rare earth elements (REEs) mining exerts adverse impacts on soil ecosystems. Attempts to recover REEs-contaminated soils have been made through phytoremediation with Dicranopteris pedata. However, how it improves soil quality is still poorly understood. This study fully investigated the effects of D. pedata-aided phytoremediation on abandoned REEs mining sites, focusing on soil properties, REEs speciation, and microbial diversity. Results showed that D. pedata increased soil TC from 488 to 626 mg kg–1, soil TN from 20.1 to 57.0 mg kg–1, and soil TP from 232 to 259 mg kg–1, while decreased concentrations of soil Fe, Mn, and REEs by 37 %, 62 %, and 43 %, respectively. The plant efficiently removed labile REEs and elevated non-labile fractions. Additionally, D. pedata increased microbial diversity and reshaped microbial composition, with microbial communities such as p_Chloroflexota and p_Acidobacteriota being decreased from 22–47 % to 17–27 % (p < 0.01), and p_Pseudomonadota, p_Acidobacteriota, p_GAL15, and p_Bacteroidota being increased from 0.25–16 % to 5.3–26 % (p < 0.01). Several communities belonging to these phyla significantly correlated to soil properties and metal concentrations, suggesting their roles in improving soil quality. This study provides new insights into soil quality improvement after D. pedata aided-phytoremediation and highlights the beneficial use of phyto-microbial technology for remediating abandoned REEs mining sites.

Impact of seasonality and forest stand age on ion deposition inrehabilitated forests.

This study examines the critical interaction between seasonal precipitation variability and forest maturity in determining ion deposition patterns in rehabilitated forest ecosystems. This research was conducted in rehabilitated forest sites in Bintulu, Sarawak, Malaysia that had ecologically similar plant distribution, species, and age in each planting area. This facilitated the standardization of rainfall deposition in the different study plots which streamlined the study of these specific facets of ecosystem dynamics. The goal is to understand how seasonal changes and the age of the forest influence the chemical composition of the flux that relates to the movement and deposition of nutrients through the forest ecosystem. This flux is a key factor in the health of the forest ecosystem and nutrient cycling. Using ion exchange resin (IER) samplers, we accurately measured and compared the deposition of different ions (Ca2+, Na+, Fe2+, Cu2+, NO3 -, NH4 + and SO4 2-) across different seasons and forest ages. The deposition of Ca2+ and NH₄+ was significantly lower in the low-precipitation season than in the high-precipitation season in all forest stands, regardless of the year they were established (1996, 1999, 2002, 2005, and 2009). In contrast, ions such as Na+, Fe2+, Cu2+, NO3 - and SO4 2- showed no clear seasonal fluctuations. In addition, the study shows that through-fall in forest stands from 2002, 2005 and 2009 had higher concentrations of Ca2+ in both seasons than in 1996 and 1999. Interestingly, forest stands from 2009 and 2002 had elevated levels of Na+ and SO₄2- in seasons with low precipitation, while stands from 1996 had higher levels in seasons with high precipitation. Our results emphasize the crucial role of precipitation amount and canopy age in determining ion deposition in forest ecosystems. By demonstrating the significant influence of precipitation seasonality and forest maturity on the chemical composition of throughfall, this study contributes to a deeper understanding of nutrient dynamics in developing forest landscapes and provides valuable insights for ecological restoration measures.

Manipulating fungal growth in engineered living materials through precise deposition of nutrients

One main challenge of emerging fungal-based engineered living materials (ELMs) lies in achieving localized multi-material properties in these structures. Although three-dimensional (3D) printing can efficiently vary local composition and properties, it has not yet been demonstrated in fungal-based ELMs. This work thus explores the concept of using nutrients to manipulate fungal foraging behavior in 3D structures fabricated using direct ink writing (DIW) for the next generation of fungal-based ELMs. Using two fungal strains (Pleurotus ostreatus and Ganoderma lucidum), this study shows that the ink formulation used is suitable for both DIW and mycelium growth. Varying the nutrient content allows for either the inhibition or promotion of exploration and bridging of mycelium in different sections, the control of mycelium density in three dimensions and the fabrication of patterned surfaces. There is potential in fabricating patterned fungal-based ELMs and lab-on-a-chip systems to investigate the effects of other substances and microorganisms on the foraging behavior of mycelium.

Temporal and spatial variation in atmospheric wet deposition of nutrients and organic matter at the southern and northern foothills of the Qinling Mountains

ABSTRACT Wet deposition significantly impacts the basin ecosystem and water quality of the Qinling Mountains (QMs). However, few research focused on the difference in wet deposition between the northern (QN) and southern (QS) foothills due to the barrier effect of the QMs. This two-year investigation studied nutrient and organic matter deposition in QN and QS during summer and autumn. Results showed higher concentrations of nitrogen (N), phosphorus (P), dissolved organic carbon (DOC), and permanganate index (CODMn) in QN's rainwater, particularly in autumn. The CODMn in QN ranged 0.59–7.67 mg/L, and DOC ranged 0.64–4.45 mg/L. For QS, the CODMn ranged 0.71–3.25 mg/L, and DOC ranged 0.28–2.62 mg/L. Backward trajectory analysis revealed the accumulation of pollutants in QN originating from Northern China, intensified by autumn heating and straw burning. Tyrosine-like and humic-like components in rainwater DOM suggested that they primarily originated from autochthonous sources. Rainwater N:P mass ratios range from 39:1 to 145:1, highlighting a higher N input than P in QMs' wet deposition. The findings underscore the importance of atmospheric wet deposition in nutrient and organic matter input to the QMs and establish a foundation for exploring the ecological effects of wet deposition.

Geolocation and immersion loggers reveal year‐round residency and facilitate nutrient deposition rate estimation of adult red‐footed boobies in the Chagos Archipelago, tropical Indian Ocean

Bio‐logging has revealed much about high‐latitude seabird migratory strategies, but migratory behaviour in tropical species may differ, with implications for understanding nutrient deposition. Here we use combined light‐level and saltwater immersion loggers to study the year‐round movement behaviour of adult red‐footed boobies Sula sula rubripes from the Chagos Archipelago, tropical Indian Ocean, to assess migratory movements and estimate nutrient deposition rates based on the number of days they spent ashore. Light levels suggest that red‐footed boobies are resident in the Chagos Archipelago year‐round, although there are large latitudinal errors this close to the equator. Immersion data also indicate residency with tracked birds returning to land every one or two days. Spending an average of 79.86 ± 2.80 days and 280.84 ± 2.64 nights per year on land allows us to estimate that the 21 670 pairs of red‐footed boobies deposit 37.34 ± 0.56 tonnes year−1 of guano‐derived nitrogen throughout the archipelago. Our findings have implications for tropical seabird conservation and phylogenetics, as well as for assessing the impact of seabird nutrients on coral reef ecosystems.

Nitrogen, phosphorus, and potassium co‐limitation in terrestrial ecosystems: A global meta‐analysis

Societal Impact StatementNitrogen, phosphorus, and potassium are essential elements for plant growth and are the primary nutrients in commercial fertilizers. However, the extent to which these nutrients individually limit plant growth is still unclear, as is the influence of their interactions. Using a meta‐analysis approach, plant growth was found to be co‐limited by nitrogen, phosphorus, and potassium. Furthermore, these findings demonstrate that multiple nutrient additions are primarily additive, with the exception of synergistic effects observed with NP additions on plant growth. These findings are important as they provide a timely and valuable reference for assessing the ecosystem‐scale consequences of increasing nutrient deposition caused by human activities.Summary Numerous field studies and a few meta‐analyses have confirmed that terrestrial primary production is individually or jointly limited by nitrogen (N) and phosphorus (P). Meanwhile, a recent synthesis emphasized that potassium (K) limitation in terrestrial ecosystems is more widespread than previously thought. However, it remains unclear whether N, P, and K co‐limit terrestrial production and how their interactions influence plant growth. Therefore, we conducted a globally comprehensive synthesis of a total 2877 observations to explore the individual and interactive effects of N, P, and K additions on plant growth. We found that N, P, K, NP, NK, PK, and NPK additions significantly increased aboveground biomass production (AGP) by 30.8%, 15.3%, 12.3%, 68.4%, 36.5%, 21.1%, and 78.7%, respectively. The combined addition of multiple nutrients resulted in a larger increase in AGP than a single addition of nutrients. These findings suggested that terrestrial production is widely co‐limited by N, P, and K. However, no significant responses of belowground biomass production (BGP) to nutrient additions were observed. Except for synergistic interactions between N and P additions, the responses of AGP to other pairs of nutrient additions were predominantly additive. This meta‐analysis highlights the importance of multiple‐nutrient limitation in regulating terrestrial primary production while pointing out that non‐additive effects (including synergistic and antagonistic) of multiple‐nutrient additions on terrestrial production are relatively rare.

Flow Structure Of A Heterogeneous Seagrass Canopy

Seagrass canopies are widely recognized for their ecosystem services (Barbier et al., 2011) including flow and wave attenuation (Ondiviela et al., 2014), sediment stabilization (De Boer, 2007), carbon sequestration (Duarte &amp; Krause-Jensen, 2017) and nutrient deposition (Gacia et al., 2002). Over the past decades, various studies have delved into the modifications imparted by a seagrass canopy under both unidirectional and oscillatory flow at various scales. However, until recently, the majority of studies have either reported on or modeled seagrass canopies without considering the heterogeneity of species within a single canopy. While simplified prototype models offer valuable insights into system dynamics, they can introduce biases, potentially leading to the reduction or amplification of relevant physical processes (Tinoco et al., 2020). For instance, the study by Weitzman et al. (2015) emphasized the significance of considering vertical heterogeneity in a canopy. They noted that the presence of an understory can modulate near-bed flow processes differently, with flow attenuation significantly increased due to the understory's presence. However, embedded physical mechanisms and quantitative limitations in ecosystem functioning and services are only little understood. Such a knowledge gap is pointed out in the recent review by Risandi et al. (2023) regarding field studies of seagrass meadows in Indonesia. Only few studies explore the interaction between such a heterogeneous canopy (Short et al., 2011) and hydrodynamics despite the abundance of seagrass species in the region (McKenzie et al., 2020). Through physical modeling of four different species of seagrass this study aims to improve the understanding of flow structure modulated by a heterogeneous canopy under unidirectional currents at full scale.

The Effects of Algal Blooms on Oxygen Levels in Lakes Babati and Eyasi, Tanzania

Globally aquatic ecosystems are reportedly overwhelmed by algal blooms due to excessive deposition of nutrients which ultimately cause hypoxia, leading to massive fish death. This study aimed at assessing the relationship between algae contents and dissolved oxygen (DO) in Lake Babati which is threatened by anthropogenic activities, whereas Lake Eyasi was used as a control. Algae contents (chlorophyll a), DO and surface water temperature were measured using standard methods. Results revealed that the mean algae content was significantly higher (4.47±0.88 mg/L) in Lake Babati than in Lake Eyasi (1.6±0.45 mg/L) (P &lt; 0.05) and was beyond the standard permissible levels for domestic water supply and healthy ecosystem. Conversely, DO was significantly lower in Lake Babati than in Lake Eyasi (P &lt; 0.05). There was no significant difference in water temperature in the two lakes (P &gt; 0.05). Furthermore, there was an inverse relationship between algae content and DO in Lakes Eyasi and Babati (r = -0.88 and r = -0.30, respectively) suggesting that algal bloom is partly responsible for lowering DO. Responsible authorities are advised to enforce management policies and regulations to control unsustainable activities around these lakes that contribute to nutrient loading resulting into overgrowth of algae.

Modeling the Oxygen Isotope Anomaly (Δ17O) of Reactive Nitrogen in the Community Multiscale Air Quality Model: Insights into Nitrogen Oxide Chemistry in the Northeastern United States.

Atmospheric nitrate, including nitric acid (HNO3), particulate nitrate (pNO3), and organic nitrate (RONO2), is a key atmosphere component with implications for air quality, nutrient deposition, and climate. However, accurately representing atmospheric nitrate concentrations within atmospheric chemistry models is a persistent challenge. A contributing factor to this challenge is the intricate chemical transformations involving HNO3 formation, which can be difficult for models to replicate. Here, we present a novel model framework that utilizes the oxygen stable isotope anomaly (Δ17O) to quantitatively depict ozone (O3) involvement in precursor nitrogen oxides photochemical cycling and HNO3 formation. This framework has been integrated into the US EPA Community Multiscale Air Quality (CMAQ) modeling system to facilitate a comprehensive assessment of NO x oxidation and HNO3 formation. In application across the northeastern US, the model Δ17O compares well with recently conducted diurnal Δ17O(NO2) and spatiotemporal Δ17O(HNO3) observations, with a root mean square error between model and observations of 2.6 ‰ for Δ17O(HNO3). The model indicates the major formation pathways of annual HNO3 production within the northeastern US are NO+OH (46 %), N2O5 hydrolysis (34 %), and organic nitrate hydrolysis (12 %). This model can evaluate NO x chemistry in CMAQ in future air quality and deposition studies involving reactive nitrogen.

Paleolimnological evidence for primary producer change linked to hydrologic connectivity and human impacts in Lake Carlton, Florida, USA

Hypereutrophic conditions in lake ecosystems are generally associated with nutrient inputs from surrounding terrestrial landscapes. However, some systems can receive primary nutrient inputs through hydrologic connections such as rivers or canals. Lake Carlton, Florida, USA is a small, shallow, polymictic lake that ends a hydrologically connected string of lacustrine systems with hypereutrophic lakes Beauclair and Apopka. Lake Beauclair and Lake Apopka were connected hydrologically when a system of canals was constructed beginning in 1893 CE. These lakes have maintained hypereutrophic conditions despite extensive management to reduce nutrient inputs. Here, we collected a sediment core from Lake Carlton to accomplish two primary research objectives: 1) reconstruct the nutrient input for Lake Carlton throughout the last ~ 150 years to conduct source assessment, and 2) link primary producer changes with management actions between lakes Apopka, Beauclair, and Carlton. Paleolimnological tools were applied to a 165-cm sediment core and analyzed for bulk density, organic matter content, nutrients (C, N, P), photosynthetic pigments, and total microcystins. Sediments were dated using 210Pb and results indicate that the core represents over 150 years of sediment accumulation. Sedimentary nutrient concentrations show that the primary driver of nutrient inputs resulted from canal construction, beginning in 1893 CE, which corresponded to increased nutrient deposition. Photosynthetic pigment data indicate dramatic increases in most primary producer groups coinciding with the hydrologic modification. However, around ~ 1970 CE, primary producer communities shifted from diatom dominance to cyanobacterial dominance, which appeared to be linked to internal nutrient dynamics and competition among phytoplankters within the lake ecosystem. Cyanotoxin production records show a significant lag between cyanobacterial dominance and peak cyanotoxin production with toxins increasing in the last 30 years. These data demonstrate that local nutrient inputs do not govern all phytoplankton dynamics in shallow lake systems but must be interpreted considering hydrologic alterations and management practices.

Nutrients addition decreases soil fungal diversity and alters fungal guilds and co-occurrence networks in a semi-arid grassland in northern China

Anthropogenic eutrophication is known to impair the diversity and stability of aboveground community, but its effects on the diversity, composition and stability of belowground ecosystems are not yet fully understood. In this study, we conducted a 9-year nitrogen (N) and phosphorus (P) addition experiment in a semi-arid grassland of Northern China to elucidate the impacts of nutrients addition on soil fungal diversity, functional guilds, and co-occurrence networks. The results showed that N addition significantly decreased soil fungal diversity and altered fungal community composition, whereas P addition had no impact on them. The relative abundance of arbuscular mycorrhizal fungi and leaf_saprotroph were reduced by N and P addition, but P addition enhanced the abundance of saprotrophic fungi. Co-occurrence network analysis revealed that N addition destabilized fungal network complexity and stability, while P addition slightly increased the network complexity. Additionally, the network analysis of N × P interaction revealed that P addition mitigated negative effects of N addition on network complexity and stability. Structural equation modeling (SEM) results suggested that nutrients addition directly or indirectly influenced the fungal community structure through the loss of plant richness and the increase of perennial grass biomass. These findings indicate that in comparison to P addition, N addition exhibits a pronounced negative effect on soil fungal communities. Our findings also suggest that changes in plant functional groups under nutrients deposition are pivotal in shaping soil fungal community structure in semi-arid grassland and highlight the need for a better understanding of the belowground ecosystem dynamics.

Effects of sex on fat deposition through gut microbiota and short-chain fatty acids in weaned pigs

Nitrogen pollution resulting from excessive feed consumption poses a significant challenge for modern swine production. Precision nutrition technology seems to be an effective way to solve this problem; therefore, understanding the law of pig body composition deposition is a prerequisite. This study investigated the sex effects on growth performance, body composition, nutrient deposition, gut microbiota, and short-chain fatty acids (SCFA) in weaned piglets. Eighty weaned pigs were randomly allocated to 2 treatments according to the sex of pigs. An individual pig was considered as a treatment replicate. Six body weights (BW 5, 7, 11, 15, 20, and 25 kg) were chosen as experimental points; for each point 10 piglets close to the average BW (5 males and 5 females) were slaughtered, and there was one growth phase between each 2 BW points. Results indicated that the males had higher average daily gain (ADG) and average daily feed intake (ADFI) compared to the females (P < 0.05) at growth phases 15 to 20 kg BW and 20 to 25 kg BW. Meanwhile, males at 20 kg BW had higher body fat content than females (P < 0.10). Males showed a higher body fat (P < 0.05) deposition rate at phase 15 to 20 kg BW (P < 0.05) than females. For pigs at 20 kg BW, the relative abundance of RuminococcaceaeUCG-005, Clostridium, Christensenellaceae_R-7_group, and Peptostreptococcaceae was significantly increased in males (P < 0.05) but that of Bifidobacterium was decreased (P < 0.05). At 25 kg BW, the relative abundance of Ruminococcaceae_NK4A214_group, Fibrobacter, RuminococcaceaeUCG-009, Ralstonia, Klebsiel, and Christensenellaceae_R-7_group in males was higher when compared with females (P < 0.05). In terms of SCFA, females exhibited higher concentrations of propionate compared to males (P < 0.05). The results of the current study indicated that sex influenced fat deposition through changes in the composition of gut microbiota and the content of SCFA, which has significant implications for the realization of precision nutrition in modern swine production.

Pengaruh POC Teknologi Nano terhadap Pertumbuhan Bayam Merah (Amaranthus tricolor L.) yang Dibudidayakan secara Hidroponik

The use of AB mix in hydroponic cultivation has side effects on body health because it is a chemical fertilizer. ). Liquid organic fertilizer is fertilizer in liquid form made from a fermented mixture of compost, natural ingredients and water and can provide nutrients according to plant needs. In hydroponic cultivation there are several weaknesses, including the occurrence of nutrient deposition, especially in the wick system because the nutrient water in the wick system is passive. To reduce the occurrence of nutrient solution deposition in the wick system used in this research, technology is needed that can reduce the particle size in the planting medium so that it is more easily decomposed and absorbed by plant roots. The method used was a completely randomized design (CRD) with 3 treatments and 5 repetitions, consisting of: P1 = AB mix 100%, P3 = AB Mix 50% + POC nano 50%, P5 = POC nano 100%. The data obtained were analyzed using ANOVA (Analysis of Variance) using the SPSS (Statistical package for the Social Sciences) application. If there is a real difference, continue with Duncan's New Multiple Range Test (DNMRT) at the 5% level. The results obtained from the influence of POC nanotechnology on the growth of red spinach plants can be seen from the average height of P1 plants, namely 18.74 cm, the average number of leaves 35.2 (strands), wet weight 15.84 g, dry weight 1.4 g. The application of nanotechnology liquid organic fertilizer provides significantly different results on the growth of spinach plants.

Pengaruh Pupuk Organik Cair (POC) Teknologi Nano terhadap Pertumbuhan Pakcoy (Brassica rapa L.) yang Dibudidayakan secara Hidroponik

The use of AB Mix in hydroponic cultivation has side effects on body health because AB Mix is a chemical fertilizer. Liquid organic fertilizer is fertilizer in liquid form made from a mixture of compost and fermented water which can provide nutrients according to plant needs. Providing nutrients in hydroponic cultivation has a weakness, namely that nutrient deposition occurs, especially when using a wick system because the nutrients in the wick system are passive. To reduce the deposition of nutrient solutions in the wick system used in this research, nanotechnology is needed which can reduce the particle size so that it is more efficient use of nutrients. This research used the RAL method with 3 treatments and 5 repetitions P1 Control (AB Mix 100%), P3 AB Mix 50% + POC nano 50%, P5 POC nano 100%. The observation data obtained was analyzed using the ANOVA (Analysis of Variance) test using the SPSS (Statistical Package for the Social Sciences) application. And continued with the DMRT test at the 5% level. The results obtained from the influence of POC nanotechnology on the growth of pakchoy plants can be seen from the average height of P1 plants, namely 17.44 cm, number of leaves 28.2, wet weight 32.44 g, and dry weight 2.1 g. The use of POC nano technology does have effect on the growth of pakchoy plants.

Efficiency of protein combinations in diets for Rhamdia quelen: growth, digestive and metabolic biochemistry and nutrient deposition.

This study was conducted to determine the best combination of protein sources in diets for jundiá, based on growth, metabolism, and nutrient deposition. Five protein combinations were tested: casein + fish meal (control), casein + gelatin, casein + albumin, casein + albumin + fish meal, and albumin + fish meal, in diets containing 370 g Kg-1 of crude protein and 13.4 MJ Kg-1 of digestible energy. The fish (9.38 ± 0.12 g) were allocated in a water recirculation system at a density of 3.35 g L-1 per experimental unit and fed until apparent satiety for 40 days with the diets. The fish fed with the control diet had the highest final weight, specific growth rate, protein and feed efficiency ratio, protein retention, and best apparent feed conversion. On the other hand, fish that received casein + albumin and albumin + fish meal diets showed worse results in growth and body protein retention, low trypsin and chymotrypsin activity, and high intestinal amylase activity. Therefore, the combination referred to as control (casein + fish meal) conclusively provides the best rhythm for nutrient digestion and metabolism processes, enabling fish to reach greater growth and retention of body protein with low whole-fish fat content.

Growth performance, plasma and hepatic biochemistry of jundiá Rhamdia quelen fed dephytinized rice bran protein concentrate.

A 45-day feeding assay was carried out to evaluate the effects of crescent levels of dephytinized rice bran protein concentrate (DRBPC) on growth performance, nutrient deposition, plasma and liver parameters of jundiá Rhamdia quelen. Five experimental diets were formulated with inclusion of 0 (control), 10, 15, 20, and 30% of DRBPC. In total 500 jundiás (initial body weight 6.28 ± 0.12 g) were allocated in 20 tanks (230 L) to give four groups for each treatment. Fish were fed to apparent satiation for 45 days. Weight gain and specific growth rate were evaluated by cubic regression analysis (P < 0.05) and displayed maximal growth on the inclusion level of 25% of DRBPC. The results indicated that fish fed DRBPC15 and DRBPC30 had lower body protein deposition and hepatosomatic index compared to CONTROL diet, respectively. No significant differences (P > 0.05) were assessed in plasma parameters. The alanine aminotransferase activity was higher in fish fed DRBPC30 compared to CONTROL group. The present study has demonstrated that DRBPC displayed significant nutritional quality for the jundiá. Thus, this new ingredient could be included as a protein source in fish for minimizing the use of fish meal.