Search Results (70)

A 56-day trial was conducted to assess the effects of rice straw (RS) and bamboo flour (BF) on growth performance, water quality, gill histology, and the bacterial community of water and the intestine of mandarin fish (Siniperca chuatsi) in biofloc technology systems. The results showed that mandarin fish in the RS and BF groups had comparable survival rates of 100.00 ± 0.00 and 93.33 ± 3.85%; feed conversion ratios of 1.13 ± 0.02 and 1.40 ± 0.15; and weight gain rates of 112.21 ± 1.56 and 100.92 ± 6.45%, respectively. From days 11 to 56 of the farming period, the BF group was more effective than the RS group in removing total ammonia nitrogen (TAN) and NO₂⁻-N, maintaining TAN levels below 0.24 ± 0.05 mg/L. During the early stage of the experiment, the TAN level in the RS group was higher; however, with the supplementation of a carbon source, it gradually decreased and eventually stabilized at 0.13 ± 0.03 mg/L later in the farming period. The secondary gill lamella in the RS group was curved and showed hyperplasia, and the basal gill lamellae showed an increase in the volume of interlamellar cell mass in the BF group. Genes related to denitrification (narG, napA, nirS, nirK, and nosZ) and anammox showed higher expression levels in the BF group than in the RS group, although the differences were not statistically significant (p > 0.05). The results of 16S rRNA sequencing research showed that both treatment groups’ intestinal and water bacterial communities had comparable levels of richness and diversity. Pseudomonas mosselii was the dominant bacterial species in the water. In the BF group, the dominant intestinal species were Bacillus halodurans and Caldalkalibacillus thermarum, while in the RS group, the dominant species was Plesiomonas shigelloides. In conclusion, rice straw and bamboo flour are applicable in BFT systems for mandarin fish culture, with good growth performance and water quality. The BF group showed higher nitrogen removal efficiency and denitrification gene expression than the RS group. Full article

Integrated agriculture–aquaculture (IAA), represented by integrated rice–fish farming, offers a sustainable production method that addresses global food issues and ensures food security. Partitioned recirculating renovation based on traditional integrated rice–fish farming is an effective way to facilitate the convenient harvesting of aquatic products and avoid difficulties associated with mechanical operations. To elucidate the impact of partitioned recirculating renovation on the bacterial communities within paddy field ecosystems, we investigated the soil environmental conditions and soil bacterial communities within integrated rice–fish farming, comparing those with and without partitioned recirculating renovations. The findings indicated a significant reduction in the bacterial community richness within paddy soil in the ditch (fish farming area), along with noticeable changes in the relative proportions of the predominant bacterial phyla in both the ditch and the rice cultivation area following the implementation of partitioned recirculating renovation. In both the ditch and the rice cultivation area, partitioned recirculating renovation diminished the edges and nodes in the co-occurrence networks for soil bacterial communities and considerably lowered the robustness index, negatively impacting the stability of bacterial communities in paddy soil. Simultaneously, the partitioned recirculating renovation substantially influenced the bacterial community assembly process, enhancing the relative contributions of stochastic processes such as dispersal limitation, drift, and homogenizing dispersal. In addition, partitioned recirculating renovation significantly altered the soil environmental conditions in both the ditch and the rice cultivation area, with environmental factors being markedly correlated with the soil bacterial community, especially the total nitrogen (TN) and total phosphorus (TP), which emerged as the primary environmental drivers influencing the soil bacterial community. Overall, these results elucidated the ecological impacts of partitioned recirculating renovation on the paddy soil from a microbiomic perspective, providing a microbial basis for optimizing partitioned rice–fish systems. Full article

Rice–fish coculture, a traditional integrated agriculture–aquaculture system, has been recognized as a “Globally Important Agricultural Heritage System” due to its ecological and socio-economic benefits. However, the impact of rice–fish coculture on greenhouse gas emissions remains controversial. This study investigated the effects of rice–fish coculture on methane (CH₄) and nitrous oxide (N₂O) emissions in the Qingtian rice–fish system, a 1200-year-old terraced paddy field system in Zhejiang Province, China. A field experiment with two treatments, rice–fish coculture (RF) and rice monoculture (RM), was conducted to examine the relationships between fish activities, water and soil properties, microbial communities, and greenhouse gas fluxes. Results showed that the RF system had significantly higher CH₄ emissions, particularly during the early rice growth stage, compared to the RM system. This increase was attributed to the lower dissolved oxygen levels and higher methanogen abundance in the RF system, likely driven by the grazing, “muddying”, and burrowing activities of fish. In contrast, no significant differences in N₂O emissions were observed between the two systems. Redundancy analysis revealed that water variables contributed more to the variation in greenhouse gas emissions than soil variables. Microbial community analysis indicated that the RF system supported a more diverse microbial community involved in methane cycling processes. These findings provide new insights into the complex interactions between fish activities, environmental factors, and microbial communities in regulating greenhouse gas emissions from rice–fish coculture systems. The results suggest that optimizing water management strategies and exploring the potential of microbial community manipulation could help mitigate greenhouse gas emissions while maintaining the ecological and socio-economic benefits of these traditional integrated agriculture–aquaculture systems. Full article

Integrated rice–fish farming, crucial for sustainable agriculture, relies on the judicious use of pesticide. This study evaluates the toxicity of six common rice-field pesticides on Procypris merus (rice flower carp), a key species in these systems. We conducted acute and chronic toxicity tests, assessing survival, growth, oxidative stress (SOD, CAT, MDA, 8-OHdG), and neurotoxicity (AChE). Results revealed a spectrum of toxicity: abamectin and trifloxystrobin were highly toxic; pretilachlor was moderately so; and glufosinate-ammonium, triflumezopyrim, and thiazole zinc were low. Notably, triflumezopyrim induced significant oxidative stress and DNA damage, while all three low-toxicity pesticides inhibited AChE activity, indicating potential neurotoxicity. Despite these effects, all observed toxicities were reversible within 7–14 days. Considering that the tested concentrations exceeded typical field application rates, glufosinate-ammonium, triflumezopyrim, and thiazole zinc are deemed relatively safe for P. merus at recommended dosages. Our findings provide critical insights for optimizing pesticide selection in rice–fish farming, balancing pest control with ecological safety, thereby informing sustainable agricultural practices. Full article

This study examines the relationship between the 1141 most consumed foods in Brazil and their individual and combined health and environmental impacts. Foods are analyzed across different food system clusters, based on the health burden (DALYs) in minutes of healthy life using the Health Nutritional Index (HENI), greenhouse gas emissions, and water use. The most consumed foods were in natura products, such as rice, beans and meat, and a few ultra-processed products such as biscuits and soft drinks. Our results revealed an average HENI of −5.89 min, with values varying from −39.69 min of healthy life (stuffed cookies) to 17.22 min (freshwater fish). Animal-derived products, particularly red meat, had the highest environmental costs, contributing significantly to greenhouse gas emissions and water use. In contrast, plant-based foods like beans and fruits had better HENI scores and lower environmental impacts. We also found that greenhouse gas emissions reached up to 21.3 kg CO_2eq (beef dish), and water use peaked at 306.1 L (mozzarella pizza). Our findings provide valuable insights into the real-world consequences of individual and institutional food choices, demonstrating their measurable impacts on health and the environment. By moving beyond theoretical assumptions, this evidence strengthens the case for integrating sustainability into public food policies, including dietary guidelines that consider regional specificities and environmental concerns alongside nutritional recommendations. Full article

The high-input production mode of rice monoculture (RM) has caused severe soil degradation and biodiversity loss, necessitating a transition toward more sustainable practices. The traditional rice-fish co-culture (RF) may provide valuable insights for this situation. However, it remains elusive how long-term RF system influences soil microbial community structure, enzyme activities, and carbon (C) sequestration. Here, a study was conducted at two representative RF areas in Lianshan Zhuang and Yao Autonomous County. At Shatian (P1), three treatments included rice monoculture (RM1) and 2-year and 5-year RF (RF2, RF5). At Gaoliao (P2), the experimental treatments included rice monoculture (RM2) and 15 and 30 years of RF (RF15, RF30). We collected the surface layer (0–20 cm) soils. Then, we analyzed the chemical properties, phospholipid fatty acids (PLFA), and enzyme activities to investigate the effects of their variation on soil C sequestration. The results showed that RF treatments significantly increased soil organic C (SOC) content. Specifically, RF2 and RF5 treatments promoted the SOC content by 4.82% and 13.60% compared with RM1 treatment at P1, respectively; RF15 and RF30 treatments increased the SOC content by 23.41% and 31.93% compared with RM2 treatment at P2, respectively. Additionally, RF5 treatment significantly increased the biomass of the soil microbial community in comparison with RM1 treatment, as did RF15 treatment and RF30 treatment compared with RM2 treatment, including the contents of total PLFA and the PLFA of gram-positive bacteria (G+), gram-negative bacteria (G−), actinomycetes, fungi, and bacteria. Activities of β-glucosidase, cellobiohydrolase, β-1,4-N-acetylglucosaminidase, and urease significantly increased in RF5 and RF30 treatments. The piecewise SEM results indicated that the changes of total PLFA content and the PLFA content ratio of fungi to bacteria were related to contents of dissolved organic C (DOC) and total N (TN) under different RF durations, which are key indicators affecting SOC content. Overall, SOC storage increases with the RF durations, and soil microbial community structure may drive soil C sequestration under long-term RF, which provides a scientific significance and practical value in promoting the sustainability of agricultural ecosystems, enhancing the potential of soil as a carbon sink, and addressing global climate change. Full article

Rice–fish culture, an ancient agronomic practice, integrates aquaculture with rice farming, a sustainable solution for enhancing food security and agricultural productivity. The recent advancements and historical perspectives on rice–fish culture have increased its ecological, economic, and social impacts. The practice spans over 2000 years and has seen significant technological improvements, especially in regions like China, Thailand, and Bangladesh. Implementations of modernized rice–fish systems demonstrate increased rice yields, reduced pest and weed prevalence, improvements in soil quality, and higher profits for farmers. For example, in China, it was reported that a rice–fishing system produced 6000–7000 kg of rice and 1500–7500 kg of fish per hectare per year. Furthermore, the fish reduce herbivore insect abundance and weed abundance, effectively eliminating the need for pesticides. Despite its advantages, challenges such as water management, the availability of quality fish seed, and socio-economic barriers remain. By synthesizing findings from various studies, we will highlight the potential of rice–fish culture to contribute to sustainable agriculture and rural development, recommending strategies for optimizing its adoption and addressing existing constraints. Full article

This study presents a simulation–optimization framework that integrates deficit irrigation strategies with ecological considerations to mitigate the impact of water abstraction on potential fish populations in river ecosystems. The framework addresses two primary objectives: minimizing fish population loss, an ecological index reflecting environmental impacts, and minimizing the yield reduction of rice crops caused by deficit irrigation. Regression models and adaptive neuro-fuzzy inference systems were employed to simulate the physical and water quality parameters of the river. Additionally, a multivariate linear regression model was developed to estimate potential fish populations using combined physical and water quality indices as inputs. Multi-objective particle swarm optimization was applied to achieve the defined objectives. Results from the case study demonstrate the model’s ability to balance ecological requirements with rice production through deficit irrigation. The ecological degradation of river ecosystems was found to be comparable during dry and normal years, while rice yield decreased by approximately 10% in dry years. Comparisons with unsustainable practices, where ecological flow was disregarded, revealed that significant reductions in rice production are inevitable to sustain river ecosystems. The proposed method provides a practical approach for achieving a fair balance between agricultural benefits and environmental sustainability in river basins, making it a valuable tool for water resource management. Full article

Gabon depends heavily on food imports to safeguard its food security; yet household food consumption patterns remain underexplored. This study investigates the structure of food demand in the Estuaire region, incorporating demographic determinants such as the age of the household head, household size, youth proportion, and residential distance from shopping centers. Using primary data collected from a randomized survey of 410 households, the analysis employs the Quadratic Almost Ideal Demand System (QUAIDS) model to estimate expenditure and price elasticities. The results indicate that expenditure elasticities are universally positive, with luxury items, including meat, eggs, and fish, exhibiting greater sensitivity compared to staple foods such as poultry, oil, rice, cassava, and bananas, which display inelastic demand. Price elasticities for meat, poultry, fish, eggs, and rice are negative, adhering to the law of demand. Demographic factors, including education, age, and residential location, significantly influence the consumption of meat, cassava, bananas, and oil. Household size, employment type, and youth composition also emerge as critical determinants of increased demand for poultry, fish, and rice. These findings offer policy-relevant insights to strengthen food security and address socioeconomic disparities. Full article

Rice-fish farming is an ancient and enduring aquaculture model in China. This study aimed to assess the variations in digestive enzymes, antioxidant properties, glucose metabolism, and nutritional content between Carassius auratus reared in paddy fields and ponds. Notably, the levels of amylase and trypsin in C. auratus from rice paddies were considerably higher compared to those from ponds. Additionally, the hepatic catalase (CAT) activity in fish from paddy (2.45 ± 0.16 U/mg) exceeded that of their pond counterparts (2.27 ± 0.25 U/mg). Regarding glucose metabolism, the activities of key enzymes such as Na+/K+-ATPase (NKA) (paddy: 82.45 ± 6.11 U/g; pond: 78.53 ± 7.18 U/g), hexokinase (HK) (paddy: 9.55 ± 0.58 U/g; pond: 8.83 ± 0.72 U/g), glucokinase (GK) (paddy: 4.09 ± 0.21 IU/g; pond: 3.44 ± 0.33 IU/g), glucose-6-phosphatase (G6Pase) (paddy: 85.71 ± 4.49 IU/g; pond: 79.12 ± 9.34 IU/g), and glucose-6-phosphate dehydrogenase (G6PDH) (paddy: 47.23 ± 3.22 U/g; pond: 42.31 ± 4.93 U/g) were significantly elevated in rice paddy-cultured fish compared to those in ponds. Conversely, phosphor-pyruvate kinase (PK) (paddy: 418.15 ± 31.89 U/g; pond: 570.16 ± 56.06 U/g) activity was markedly reduced in the paddy group. Hepatic glycogen content (paddy: 15.70 ± 0.98 ng/g; pond: 14.91 ± 1.24 ng/g) was also substantially higher in fish from paddy, although no significant differences in muscle glycogen content (paddy: 7.14 ± 0.59 ng/g; pond: 6.70 ± 0.52 ng/g) were observed between the two environments. In terms of nutritional composition, fish raised in paddy exhibited higher crude protein (paddy: 18.46 ± 0.47 g/100 g muscle; pond: 15.57 ± 0.25 g/100 g muscle) and crude ash (paddy: 1.19 ± 0.02 g/100 g muscle; pond: 0.97 ± 0.02 g/100 g muscle) than those in ponds, whereas the crude fat (paddy: 0.87 ± 0.04 g/100 g muscle; pond: 1.66 ± 0.04 g/100 g muscle) was notably lower in paddy fish. Furthermore, fish from rice paddies had a greater total content of monounsaturated fatty acids (MUFA) (paddy: 4.25 ± 0.24 g/100 g muscle; pond: 6.73 ± 0.27 g/100 g muscle), non-essential amino acids (NEAA) (paddy: 9.04 ± 0.3 g/100 g muscle; pond: 7.19 ± 0.21 g/100 g muscle), and delicious amino acids (DAA) (paddy: 7.11 ± 0.2 g/100 g muscle; pond: 5.45 ± 0.19 g/100 g muscle) compared to those from pond cultures. These findings suggest that rice-fish co-culture systems can yield healthier and more environmentally sustainable aquatic products by improving feed digestion and optimizing nutrient metabolism. Full article

Integrated rice–fish farming is an innovative agricultural production pattern that combines rice cultivation with fish farming, enhancing agricultural productivity and ensuring food security. Partitioned rice–fish farming, an advancement of the traditional approach, addresses challenges such as difficulties in fish harvesting and the inconveniences of mechanized operations encountered in paddy fields. To evaluate the environmental impacts of partitioned rice–fish farming on the agricultural ecosystem, we investigated the impacts of partitioned rice–fish farming on the diversity, composition, functionality, co-occurrence networks, and assembly processes of bacterial communities within paddy water. Our results revealed significantly improved Chao1, Observed species, and Pd_faith indices for the bacterial community in the partitioned rice–fish farming system. The relative abundances of the Bacteroidota, Gemmatimonadota, Proteobacteria, and Fluviicola in paddy water were altered by the partitioned system. The partitioned system considerably impacted the bacterial co-occurrence networks within the paddy water, with the planktonic bacterial co-occurrence network in rice cultivation area having more nodes (205) and edges (2085), and its robustness being significantly higher than that of other groups, resulting in a more complex and stable structure of the planktonic bacterial community. In addition, the partitioned system significantly promoted the contribution of stochastic processes to bacterial community assembly in the paddy water, with the main enhanced stochastic processes being homogenizing dispersal and drift. The total proportion of these processes for bacterial community assembly increased from 60% to 70%. Nitrate concentrations in the paddy water were remarkably associated with the water bacterial communities and contributed most to the variations in water bacterial communities. Hence, partitioned rice–fish farming is a feasible and good agricultural production pattern, and from the perspectives of bacterial community diversity and stability it offers both theoretical insights and data-supported foundations for advancing sustainable agricultural practices. Full article

This study investigated the effects of integrating various fish species in a rice field co-culture system on water quality and soil properties. The species included common carp (Cyprinus carpio), Nile tilapia (Oreochromis niloticus), silver barb (Barbonymus gonionotus), snakeskin gourami (Trichopodus pectoralis), and giant freshwater prawn (Macrobrachium rosenbergii). The key water quality parameters measured included water temperature, dissolved oxygen, pH, transparency, ammonia, and nitrite. Soil properties were evaluated through pH, electrical conductivity, organic matter, nitrogen, phosphorus, and potassium. All the selected aquatic animals showed high adaptability in co-culture systems, with survival rates exceeding 80%. Additionally, rice yields increased by approximately 16%, with the highest yield observed in plots stocked with prawns. The results indicated that the presence of aquatic animals enhanced nutrient cycling, leading to significant improvements in both water quality and soil fertility. Differences in water quality and soil properties throughout the culture period were specific to the species present. These findings suggest that rice-fish co-culture systems serve as an effective nature-based solution for enhancing productivity, sustainability, and food security. Full article

Integrated rice–fish farming, an agricultural practice that combines cultivating rice and breeding fish in the same field, has attracted widespread attention. However, there is limited research on how the rice–carp coculture impacts the community structure of phytoplankton and microzooplankton in paddy water. This study employed eDNA metabarcoding sequencing to analyze the composition of phytoplankton and microzooplankton in a rice monoculture system (RM) and a rice–carp coculture system (RF). Following annotation, we identified 9 phyla, 89 families, 275 genera, and 249 species of phytoplankton, along with 20 phyla (or subphyla and classes), 85 families, 222 genera, and 179 species of microzooplankton. The alpha diversity indices revealed significantly higher richness, diversity, and evenness in the RF group compared to the RM group during grain-filling stage. Principal coordinates analysis (PCoA) demonstrated notable differences in the phytoplankton and microzooplankton compositions between the two groups across various rice growth stages. Composition analysis showed that rice–carp coculture increased the relative abundance of dominant phytoplankton phyla such as Bacillariophyta, Chrysophyta, and Euglenophyta while decreasing that of Cryptophyta. In microzooplankton, the coculture resulted in an increased abundance of Intramacronucleata (subphylum) and a decrease in Conoidasida (class). In conclusion, the rice–carp coculture enhances the diversity of plankton, particularly during the grain-filling stage, and simultaneously alters the composition and abundance of dominant plankton species in the paddy water. These findings enhance understanding of the broader impacts of integrated rice–carp farming on agricultural ecosystems, emphasizing alterations in the diversity and composition of aquatic microorganisms Full article

To evaluate the effects of filter-feeding fishes on water quality and bacterial community in the rice–crayfish coculture system, four different stocking densities of bighead carp (0, 500, 1000, 1500 ind./200 m²) were set up in rice–crayfish coculture systems. Water samples in the systems were collected biweekly to detect dissolved oxygen (DO), temperature (T), potential of Hydrogen (pH), ammonia nitrogen (NH₄⁺-N), nitrite nitrogen (NO₂⁻-N), nitrate nitrogen (NO₃⁻-N), total nitrogen (TN), total phosphorus (TP), and Chlorophyll-a (Chl-a); the bacterial community in the water was analyzed simultaneously, then the correlation between water quality and microorganisms were studied. The results showed that concentrations of TN, TP, NO₂⁻-N, and NH₄⁺-N decreased while DO and NO₃⁻-N increased along with the breeding process. NO₂⁻-N, NO₃⁻-N, TN, and NH₄⁺-N were important environmental factors affecting the bacterial community structure in water (p < 0.05). Bighead carp stocking had an impact on the diversity, richness, and evenness of the bacterial communities in the systems. The dominant bacteria in the four different carp density groups were Proteobacteria, Actinomycetes, Bacteroidetes, and Cyanobacteria. Bighead carp increased the abundance of Bacteroidea but reduced that of Actinomycetes, Cyanobacteria, and Proteobacteria. The introduction of bighead carp promoted the conversion of nitrogen and phosphorus, reducing the risk of cyanobacterial blooms. Group 1000 ind./200 m² exhibited the best effect on the removal of nitrogen and phosphorus from the water body. Full article

To investigate difference in the quality of the different parts (back, tail muscles, and fish skin) of Opsariichthys bidens from pond and rice field cultures, a comparative study was conducted in terms of nutritional composition, volatile flavor profiles and gut microbiota. In detail, the texture, free amino acids, fatty acids were further assessed. The results suggested that the moisture content, crude protein and crude fat content in the skin of O. bidens are higher than those in the back and tail muscles, regardless of breeding modes. The fish cultured in the rice field had a higher protein content than those from the pond culture, while the fat content of the rice field-cultured fish was significantly low compared to the fish from the pond culture, especially in the back and tail parts. A total of 43 volatile components were detected by Gas Chromatography–Mass Spectrometry (GC-MS), with a maximum of 18 types of aldehydes and the highest concentration being nonanal. Compared to pond cultures, the fish from the rice field cultures showed more abundant flavor composition and odor-active compounds. The total content of DHA (Docosahexaenoic Acid) and EPA (Eicosapentaenoic Acid) in the rice field-cultured fish was higher than that of the pond group, while no significant disparity in amino acid composition was observed (p > 0.05). Comparative and clustering analyses of gut microbiota revealed notable discrepancies in the gut microbiota of O. bidens from two aquaculture systems. However, an inherent correlation between the gut microbiome and meat quality would be further emphasized in further studies. This study can offer a theoretical reference for the development of high-quality aquatic products by selecting the appropriate aquaculture models. Full article