Search Results (6,509)

Over the years, aquaponics has become a powerful technological tool that allows the sustainable production of food, integrating conventional fish farming with vegetable production. The present study evaluated the production of late seedlings of açai Euterpe oleraceae in an aquaponic system with tambaqui Colossoma macropomum. A total of 36 tambaquis with an initial average weight and length of 1086.75 ± 16.38 g and 38.49 ± 0.90 cm were distributed in 12 independent aquaponic units, totaling 3.62 kg m⁻³. The fish were fed three times daily with commercial feed at a rate of 3%. Three flooding levels of 5, 10 and 15 cm, with constant water flow through the hydroponic bed (0.5 m²), were evaluated, and a control-hydroponic bed with flooding levels of 10 cm was established, all in triplicate. In the 5 and 10 cm treatments, 3450 açai seedlings with an initial height of 12.3 ± 1.9 cm were used (575 per aquaponic units), while the 15 cm treatment contained non-germinated açai seeds. The control group did not receive açai seeds and remained empty. Analyses to monitor total dissolved solids (TDS), electrical conductivity, dissolved oxygen, temperature, pH, alkalinity, hardness, nitrogenous compounds, and phosphate levels were performed. At the end of the 30-day trial, the growth performance of tambaqui and plants was evaluated. Water quality was significantly (p < 0.05) affected by different flooding levels. Electrical conductivity and TDS decreased with an increasing in flooding levels. The flooding levels significantly influenced (p < 0.05) the concentration of total ammonia and nitrate between the treatments. The 5 cm flooding level showed the best plant development indexes for total height, aerial portion height, root height and aerial portion fresh mass. No significant differences (p < 0.05) were observed in tambaqui growth performance. The aquaponic system proved to be effective in reusing fish waste (excreta and feed leftovers) generated in the system. The biotransformation of waste into nutrients allowed the growth of plants and nitrifying bacteria, which, through their metabolic pathways, ensured the purification and reuse of water, avoiding the discharge of this waste into the environment. Full article

A synchronous-profiling, low-position-cutting, flexible-reel-belt-conveyor, low-loss soybean header was designed to address the problems of a lack of soybean harvesting machines supporting soybean-corn strip intercropping, the few existing soybean headers, and the high loss rate of soybean headers. By establishing a dynamic model of the synchronous-profiling cutting device, the key structure and operation parameters that affect the performance of synchronous profiling were determined, while the key parameters of the flexible-reel-belt conveyor device were determined by theoretical analysis. Based on ADAMS rigid-flexible coupling, simulation analysis was conducted on the working process of the synchronous-profiling cutting device, verifying that the profiling cutting device can effectively control the height of the cutter off the ground with undulating ground and that the cutting device can accurately and quickly respond to ground excitation, meeting the requirements of synchronous-profiling, low-position cutting. Field tests showed that the loss rate and stubble height of the soybean headers are 1.34% and 70.36 mm, respectively, which are 55% and 22.7% lower than the existing reel-type rigid soybean headers, meeting the actual production requirements. This study can provide a reference for the structural design of soybean harvesting headers and the reduction of header losses. Full article

To enhance the working efficiency and aerodynamic performance of the centrifugal fan in the air system of a cotton picker, a new type of centrifugal fan blade was designed by extracting the mid-arc section from the prototype blade and integrating an airfoil, which was transplanted and coupled to the mid-arc section. The design aimed to improve the airflow characteristics and performance of the centrifugal fan. By combining experimental data from centrifugal fans used in existing cotton-picker air systems and employing computational fluid dynamics (CFD) methods, the internal flow field structure of the centrifugal fan was simulated. This study focused on investigating the aerodynamic performance of the new centrifugal fan blade and its impact on improving the internal flow patterns within the centrifugal fan. The results of the flow field visualization analysis indicate that the new blade design exhibits excellent aerodynamic performance, improving the flow distribution within the centrifugal fan. It enhances the uniformity of the outlet airflow, reduces the occurrence of localized “jet-wake” phenomena at the impeller’s outlet, suppresses the generation and development of vortices in the flow channel, and reduces local energy losses within the impeller. These improvements contribute to an increase in the fan’s efficiency. Under rated operating conditions, the efficiency of the prototype fan was measured at 60.3%, while the optimized fan achieved an efficiency of 64.8%. This signifies a significant improvement in the efficiency of the centrifugal fan. Full article

In view of the low level of mechanized harvesting of white radish in China and other developing countries and the current situation of “no machine can be used” due to the expensive imported machines, a self-propelled white radish combine harvester was designed based on the material, growth characteristics, and agronomic pattern of white radish. This combines harvester can realize the functions of white radish tassel gathering, deep soil loosening, clamping and conveying, tassel cutting, and collecting. In this research, the overall design of the harvester is described, and the structural and working parameters and kinematic requirements of the tassel gathering device, clamping and conveying device, tassel cutting device, and vibrating deep loosening device are determined by mechanical and kinematic analysis. Innovatively, a range of values for the tassel gathering speed ratio of 1.7–4.2 is proposed for the operation of the tassel gathering device suitable for white radish harvesting. The prototype was bench tested with the loss rate, damaged rate, and impurity rate as performance evaluation indexes. The results show that under the pitch of 240 mm between the taper angle of the tassel-raising device, a speed of 80 rpm for the tassel gathering device gathering claw belt rotation, a speed of 120 rpm for the clamping and conveying pulley rotation, a vibration frequency of 2 Hz and an amplitude of 15 mm for the vibrating deep loosening device, and a forward speed of 0.5 m/s (tassel gathering speed ratio: 1.7). The loss rate was 2.75%, the damage rate was 4.99%, and the impurity rate was 1.64%. During the operation, the innovatively designed white radish leaf gathering device can better fulfill the function of tassel gathering, and the systems worked well together, meeting the requirements of mechanized combined harvesting of white radish, but the adaptability to complex working conditions in the field needs to be further strengthened. This research can provide a reference for the design and optimization of mechanized white radish harvesting equipment. Full article

The objective was to determine the effect of calcium propionate (CaPr) inclusion in the diet, at different periods on the growth performance, carcass characteristics, and meat quality of finishing lambs. Thirty-six Dorper × Katahdin crossbred male lambs (39.1 ± 0.44 kg BW) were housed in individual pens during a 42 d feeding period and assigned to four treatments (n = 9) consisting of CaPr administered at a dose of 10 g/lamb/d for 0 (control), 14, 28, or 42 d before slaughter. Final BW (FBW), average daily gain (ADG), dry matter intake (DMI), and ADG:DMI ratio increased quadratically (p < 0.05) by CaPr supplementation, being optimal at an estimated inclusion period of 25 d for FBW and ADG, 15 d for DMI, and 28 d for ADG:DMI ratio. Hot carcass weight (HCW), cold carcass weight (CCW), and dressing were quadratically improved (p < 0.05) at an estimated inclusion period of 24 d for HCW and CCW, and 20 d for dressing. The increased inclusion period (42 d) augmented fat thickness (linear effect, p < 0.05). At 28 d of CaPr supplementation, maximal response (quadratic effect, p < 0.05) was estimated in the empty body weight at 28 d, forequarter at 26 d, and neck at 24 d, but a longer inclusion period (42 d) increases the weight of leg and rack and reduced the proportion of loin as a percentage of CCW (linear effect, p < 0.05). In conclusion, dietary CaPr can be included for a period of 24 to 28 d to improve growth performance and carcass weight, without affecting organ mass or meat quality. Full article

Japonica-specific markers are crucial for the analysis of genetic diversity, population structure, evolutionary traits, and genome-wide association study (GWAS) of japonica germplasm accessions. This study developed 402 insertion–deletion (InDel) polymorphic markers based on the re-sequencing of four japonica rice landraces and three japonica rice cultivars. These InDel markers were uniformly distributed across 12 rice chromosomes with high polymorphism and good amplification specificity. The average density of InDel markers on each chromosome was 0.95 Mb per locus. On the basis of these InDel markers, genetic diversity analyses and GWASs for 12 salt-tolerance-related traits were performed using 182 japonica rice accessions. In total, 1204 allelic variants were detected, with an average of 3.00 alleles and 2.10 effective alleles per locus. Based on population structure analysis, 182 japonica rice accessions were divided into four subgroups. The GWAS analyses revealed a total of 14 salt-tolerance-related InDels, which were located on chromosomes 1–5, 9, 10, and 12. Twenty-eight allelic loci were identified, explaining 6.83% to 11.22% of the phenotypic variance. Haplotype analysis detected six InDel markers associated with salt-tolerance-related traits that were significantly different (p < 0.05) or highly significantly different (p < 0.01) among different haplotypes. These markers can be utilized for the molecular identification of salt-tolerant rice germplasm accessions. Full article

China has implemented an environmental protection tax for large-scale agricultural farming to address environmental pollution caused by livestock and poultry breeding. Studying the environmental management of large-scale pig farming is crucial for controlling agricultural pollution. However, the economic impact and effectiveness of the current tax design, including responsibility sharing, tax rates, and taxpayers, are unclear. This study aims to address these gaps. Firstly, two types of taxation principles, production-based and consumption-based, are established, and their effects on pollution emissions distribution between pig production and marketing areas are comparatively analyzed. Secondly, the economic impact of consumption-based environmental taxes is estimated from inter-provincial and rural–urban perspectives under the current tax mechanism. Thirdly, a new alternative tax rate aligned with inter-provincial pig consumption levels is proposed based on the consumption principle. By comparing alternative tax systems, the potential impact of the current environmental tax on the regional economic burden is analyzed. The results highlighted that a production-based tax system resulted in 83% of regions experiencing varying degrees of implicit emission transfers, and a consumption-based tax system helped coordinate the environmental economic burden between pig production and marketing regions. Additionally, a linear relationship between tax rates and pork consumption expenditure not only alleviated the overall economic burden, leading to tax savings in 30% of regions, but also increased the national environmental revenue from the pig farming industry, resulting in a remarkable 147% rise in overall environmental tax revenue. These findings provide theoretical support for adjusting responsibility and economic burden through environmental tax modifications, facilitating the establishment of a compensation mechanism for the benefits between pig production and marketing areas. Full article

Extensive collar rot, sunken and bleeding cankers, shoot blight, and fruit rot symptoms on olive trees have recently been observed in several orchards in Italy. Since there is little information about the etiology of these diseases and given the high economic relevance of this iconic crop, a study was conducted from autumn 2017 to summer 2022, in four Italian regions, to define the occurrence, distribution and impact of the main pathogens involved. A total of 1064 symptomatic olive samples were collected and processed. Based on colony appearance, micromorphological analysis and DNA sequence data, thirty-eight species, including eighteen Botryosphaeriaceae species belonging to five genera and fifteen Phytophthora species, were isolated and identified, thirteen of which, Diplodia africana, D. fraxini, D. subglobosa, Dothiorella omnivora, Do. sarmentorum, Do. sempervirentis, Sardiniella urbana (Botryosphaeriaceae), Phytophthora cactorum, P. cinnamomi, P. citricola, P. crassamura, P. niederhauserii and P. pseudocryptogea, are reported here for the first time in olive trees. Pathogenicity tests performed on unripe drupes and on potted olive seedlings completed Koch postulates and highlighted that several species of Botryosphaeriaceae and Phytophthora represent a growing threat to olive trees. Full article

Fungus gnats (Sciaridae) are one of the most devastating pests on mushroom farms. Generally, they are controlled using relatively inefficient physical means, like sticky or pheromone traps, or with chemical pesticides. Here, we have proposed an integrated fungus gnat control system combining a UV-A LED source at 365 nm and a high-power laser diode at 445 nm. The 365 nm UV-A LED serves a light trap, since previous studies have concluded that fungus gnats show maximum attraction in the range of 365–390 nm. The UV-A LED is also modulated at different frequencies, and the response of the gnats corresponding to these different frequencies was observed. We utilized an Arduino Uno microcontroller to run the integrated device, and a BASLER USB camera was used to capture the images. Our experiments indicated that a frequency of 40 Hz is the optimal choice for attracting the gnats most rapidly. Within 20 s of exposure, the UV-A LED operated at 40 Hz was found to trap approximately 80% of the gnats. In a restricted trapping zone measuring 2.5 × 2.5 × 3 cm³, our integrated module, which includes a 40 Hz modulated UV-A LED and a laser, resulted in a survival rate of only 50% for the total number of gnats. This outcome was accomplished through periodic 200 ms long exposures, amounting to a total duration of 2 min for a group of 100 gnats. Full article

In order to provide basic data and a theoretical basis for waste mulch film crushing and separation equipment, the mechanical and suspension properties of waste mulch film and cotton stalk were determined in this study. In the mechanical properties test, the tensile properties of waste mulch film and the shear properties of different parts of cotton stalk were investigated. In the suspension properties test, the suspension properties of different qualities of waste mulch film and different parts of cotton stalk were investigated. The results showed that the average maximum tensile forces and fracture displacements of the waste mulch film were 1.70 N (horizontal), 0.80 N (vertical) and 254.75 mm (horizontal), 145.22 mm (vertical). The shear properties of the cotton stem after wrapping the mulch film were greatly improved; the maximum shearing force was 186.89% higher than that of the unwrapped specimens. When the total suspension velocity was from 3.09 to 4.07 m/s, separation of mulch film and cotton stalk could be achieved by wind. Full article

In recent times, there has been a growing interest in the role of food trade in achieving food security. This study presents a comprehensive analysis of the relationship between food trade and food security within the context of the Belt and Road Initiative (BRI). This study employs complex networks alongside the quadratic assignment procedure (QAP) regression method on trade data of 46 countries under BRI for the period 2008 to 2018. The resulting complex network showed an enhancement in the food trade relationships and food security levels after BRI, indicating a mutually positive effect. In addition, the closeness centrality measure showed a strong correlation with food security, indicating that food trade has positive spillovers on food security in the proximate countries. Using geographical distance as an instrumental variable, the QAP regression model proved the positive effects of food trade on food security. More investment in trade infrastructure is recommended to reduce the negative effect of geographical distance on food security. Full article

Straw return benefits soil nutrient circulation and avoids the environmental pollution caused by incineration. The straw return effect is determined by many factors, such as the returning mode and tillage method. To find the most suitable straw return mode in the hilly areas of south China, we conducted experiments with preceding maize straw in Nanchong (Sichuan Province, China) for three years. Five treatments were tested: (A) rotary tillage without straw return (RT), (B) crushed straw return with rotary tillage (CRT), (C) crushed straw return without rotary tillage (CSR), (D) whole straw return with rotary tillage (WRT), and (E) whole straw return without rotary tillage (WSR). The results indicated that CRT had the fastest decomposition rate, followed by CSR. Moreover, CRT had the fastest nutrient release rates for nitrogen, phosphorus, potassium, cellulose, hemicellulose, and lignin, as well as the highest maize yield (6.62% higher than RT). CRT increased the content of organic matter, total nitrogen, total phosphorus, and total potassium in the soil, as well as improved the soil pH. Furthermore, the numbers of bacteria, Actinomycetes, and fungi in the soil under CRT, CSR, and WSR treatments were higher than those under the other two treatments. This study has important reference value for exploring the most favourable straw return method for improving farmland fertility. Full article

Germination of castor seeds of seven dwarf hybrid genotypes, compared to a ‘Local’ genotype, selected from a Tunisian population by the University of Catania well adapted to the Mediterranean environment, were studied at six different temperatures (8, 12, 16, 25, 32, and 40 °C). The results indicate that the optimal temperature (25 °C) and near-optimal temperature (32 °C) are the best temperatures for ensuring castor germination (final germination percentage (FGP) ≥ 82.81%). Furthermore, these temperatures positively influenced the vigour index (VI) and the radicle elongation. At a temperature of 8 °C, no germination occurred, while temperatures of 12 and 40 °C negatively affected the seed germination, which, in some genotypes, was null or negligible (<21.25%). A temperature of 16 °C allowed good results to be reached for the FGP and the other considered parameters. Overall, the dwarf hybrids performed better at high temperatures than at low temperatures, thus, making them suitable for late sowings, with the exception of the genotype ‘C1020’, which resulted the best performance at 16 and 40 °C, being suitable for both early and late sowings. On the other hand, the ‘Local’ castor genotype, being the best-performing genotype at 12 and 16 °C, and the most tolerant to low temperature (base temperature (Tb) 12.1 °C), could be used in the early sowing in spring. Full article

Accurate segmentation of lotus pods and stalks with pose variability is a prerequisite for realizing the robotic harvesting of lotus pods. However, the complex growth environment of lotus pods causes great difficulties in conducting the above task. In this study, an instance segmentation model, LPSS-YOLOv5, for lotus pods and stalks based on the latest YOLOv5 v7.0 instance segmentation model was proposed. The CBAM attention mechanism was integrated into the network to improve the model’s feature extraction ability. The scale distribution of the multi-scale feature layer was adjusted, a 160 × 160 small-scale detection layer was added, and the original 20 × 20 large-scale detection layer was removed, which improved the model’s segmentation accuracy for small-scale lotus stalks and reduced the model size. On the medium-large scale test set, LPSS-YOLOv5 achieved a mask mAP₀.₅ of 99.3% for all classes. On the small-scale test set, the mAP₀.₅ for all classes and AP₀.₅ for stalks were 88.8% and 83.3%, which were 2.6% and 5.0% higher than the baseline, respectively. Compared with the mainstream Mask R-CNN and YOLACT models, LPSS-YOLOv5 showed a much higher segmentation accuracy, speed, and smaller size. The 2D and 3D localization tests verified that LPSS-YOLOv5 could effectively support the picking point localization and the pod–stalk affiliation confirmation. Full article

The purpose of this study was to determine the relationship between plant protection and fertilizer use efficiency, on one side, and overinvestment in Polish agriculture, on the other. This is an important topic because of a number of essential issues, such as the concern for the environment, the development of sustainable agriculture, or the need to ensure food security which can only be achieved by keeping production volumes at least at the same level. Reconciling these goals often requires investment which, however, involves the risk of overinvesting, i.e., a situation where the value of assets grows without a proportional increment in labor productivity. This paper uses the author’s own method of farm classification by overinvestment level. The study revealed some differences in the cost intensity of fertilizing and using plant-protection products between investment levels. The most rational results were found in farms at optimum investment levels, whereas the greatest cost intensity was recorded in farms affected by overinvestment. Full article