Search Results (279)

Traditional intensive agricultural system impedes ecological functions, such as nutrient cycling and biodiversity conservation, resulting in excessive nitrogen discharge, CH₄ emission, and ecosystem service losses. To enhance critical ecosystem services and mitigate environmental externalities in paddy fields, we developed a multi-objective agricultural system (MIA system), which combines two eco-functional units: paddy wetlands and Beitang (irrigation water collection pond). Pilot study results demonstrated that the MIA system enhanced biodiversity and inhibited pest outbreak, with only a marginal reduction in rice production compared with the control. Additionally, the paddy wetland effectively removed nitrogen, with removal rates of total nitrogen and dissolved inorganic nitrogen ranging from 0.06 to 0.65 g N m⁻² d⁻¹ and from 0.02 to 0.22 g N m⁻² d⁻¹, respectively. Continuous water flow in the paddy wetland reduced the CH₄ emission by 84.4% compared with the static water conditions. Furthermore, a simulation experiment indicated that tide flow was more effective in mitigating CH₄ emission, with a 68.3% reduction compared with the drying–wetting cycle treatment. The emergy evaluation demonstrated that the MIA system outperformed the ordinary paddy field when considering both critical ecosystem services and environmental externalities. The MIA system exhibited higher emergy self-sufficiency ratio, emergy yield ratio, and emergy sustainable index, along with a lower environmental load ratio. Additionally, the system required minimal transformation, thus a modest investment. By presenting the case of the MIA system, we provide a theoretical foundation for comprehensive management and assessment of agricultural ecosystems, highlighting its significant potential for widespread application. Full article

Climate change presents urgent and complex challenges to agricultural sustainability and food security, particularly in regions reliant on resource-intensive staple crops. Smart agriculture—through the integration of crop modeling, satellite remote sensing, and artificial intelligence (AI)—offers data-driven strategies to enhance productivity, optimize input use, and mitigate greenhouse gas (GHG) emissions. This study introduces Farmdee-Mesook, a mobile-first smart agriculture platform designed specifically for Thai rice farmers. The platform leverages AquaCrop simulation, open-access satellite data, and localized agronomic models to deliver real-time, field-specific recommendations. Usability-focused design and no-cost access facilitate its widespread adoption, particularly among smallholders. Empirical results show that platform users achieved yield increases of up to 37%, reduced agrochemical costs by 59%, and improved water productivity by 44% under alternate wetting and drying (AWD) irrigation schemes. These outcomes underscore the platform’s role as a scalable, cost-effective solution for operationalizing climate-smart agriculture. Farmdee-Mesook demonstrates that digital technologies, when contextually tailored and institutionally supported, can serve as critical enablers of climate adaptation and sustainable agricultural transformation. Full article

Heavy metal contamination in paddy fields poses serious risks to food safety and crop productivity. This study evaluated the potential of native soil fungi as bioinoculants to reduce metal uptake in rice cultivated under contaminated conditions. Eight fungal strains—four indigenous and four allochthonous—were selected based on their plant growth-promoting traits, including siderophore production and phosphate solubilization. Additional metabolic analysis confirmed the production of bioactive secondary metabolites. In a greenhouse experiment, three rice cultivars were grown under permanent flooding (PF) and alternate wetting and drying (AWD) in soil enriched with arsenic, cadmium, chromium, and copper. Inoculation with indigenous fungi under AWD significantly reduced the arsenic accumulation in rice shoots by up to 75%. While AWD increased cadmium uptake across all cultivars, fungal inoculation led to a moderate reduction in cadmium accumulation—ranging from 15% to 25%—in some varieties. These effects were not observed under PF conditions. The results demonstrate the potential of native fungi as a nature-based solution to mitigate heavy metal stress in rice cultivation, supporting both environmental remediation and sustainable agriculture. Full article

Intergovernmental Panel on Climate Change (IPCC) guidelines have been standardized and widely used to calculate methane (CH₄) emissions from paddy fields. The emission factor (EF) is a key parameter in these guidelines, and it is different for each location globally and regionally. However, limited studies have been conducted to measure locally specific EFs (EFlocal) through on-site assessments and modeling their spatial distribution effectively. This study aims to investigate the potential of multisensor satellite data to develop a spatial model of CH₄ emission estimation on rice paddy fields under different water management practices, i.e., continuous flooding (CF) and alternate wetting and drying (AWD) in Subang, West Java, Indonesia. The model employed the national EF (EFnational) and EFlocal using the IPCC guidelines. In this study, we employed the multisensor satellite data to derive the key parameters for estimating CH₄ emission, i.e., rice cultivation area, rice age, and EF. Optical high-resolution images were used to delineate the rice cultivation area, Sentinel-1 SAR imagery was used for identifying transplanting and harvesting dates for rice age estimation, and ALOS-2/PALSAR-2 was used to map the water regime for determining the scaling factor of the EF. The closed-chamber method has been used to measure the daily CH₄ flux rate on the local sites. The results revealed spatial variability in CH₄ emissions, ranging from 1–5 kg/crop/season to 20–30 kg/crop/season, depending on the water regime. Fields under CF exhibited higher CH₄ emissions than those under AWD, underscoring the critical role of water management in mitigating CH₄ emissions. This study demonstrates the feasibility of combining remote sensing data with the IPCC model to spatially estimate CH₄ emissions, providing a robust framework for sustainable rice cultivation and greenhouse gas (GHG) mitigation strategies. Full article

Despite the essential role of phosphorus (P) in rice growth, P-use efficiency (PUE) remains low due to limited bioavailable P in soils and an over-reliance on chemical fertilizers, leading to resource waste and environmental risks, such as eutrophication. This study investigates whether and how alternating wetting and moderate drying (AWMD) irrigation promotes P absorption and transport in rice. This study was conducted over two years using a pot experiment. Conventional flooding (CF) irrigation was applied throughout the growing season, while AWMD irrigation was imposed from two weeks after transplanting to one week before harvest. AWMD improved shoot biomass by 8.7–9.4% and the photosynthetic rate by 12–15%, significantly enhanced PUE, and optimized root traits and enzyme activities related to P uptake. It also promoted leaf acid phosphatase and ribonuclease activities, facilitating P remobilization to grains. In conclusion, AWMD enhanced the ability of roots to absorb P and optimized the redistribution of P between vegetative organs and grains, synergistically increasing grain yield and PUE in rice. Full article

Rice sustains a large global population, making its sustainable production vital for food security. Alternate wetting-and-drying (AWD) irrigation offers a promising approach to reducing water use in rice paddies but can impact grain yields. Plant growth-promoting rhizobacteria (PGPR) can enhance rice productivity under AWD cultivation conditions. This review explores integrating PGPR into AWD systems, focusing on their mechanisms for promoting growth and water stress resilience. It examines diverse microbial communities, particularly bacteria, and their contributions to nutrient acquisition, root development, and other beneficial processes in rice under fluctuating moisture, as well as the influence of AWD on rice’s structural and physiological development. The challenges and opportunities of AWD are also addressed, along with the importance of bacterial selection and interactions with the native soil microbiome. This synthesizes current research to provide an overview of PGPR’s potential to improve sustainable and productive rice cultivation under AWD. Future studies can leverage powerful tools such as e-DNA and NGS for a deeper understanding of these complex interactions. Full article

Rice milling in Sub-Saharan Africa (SSA) remains highly dependent on water availability and favorable weather conditions, making local millers vulnerable to water- and weather-related pressures (WWrP). This study examines how rice millers in Makurdi and Adikpo, Benue State, Nigeria, adapt to these pressures. Data were collected through snowball sampling involving 21 rice millers and two workshops attended by 14 millers. Content and thematic analyses of data were carried out using NVivo 11. Findings indicate that rice milling operations are highly exposed and sensitive to flooding, excessive wetness, dryness, high humidity, and water scarcity. These pressures are likely to intensify due to climate change and pronounced climate variability. To adapt, millers employ endogenous strategies, including temporarily relocating or evacuating mills, rotating drying schedules, modifying drying methods, reducing or suspending parboiling during floods, and digging wells. In spite of these adaptation measures, locally milled rice continues to face issues of poor quality and diminished competitiveness. Consequently, this study highlights upgrading milling technologies and infrastructure, promoting proactive and long-term adaptation measures, and supporting collective adaptation strategies among millers to enhance resilience in the rice value chain. Full article

Rice (Oryza sativa L.), a key global staple crop; requires optimized nitrogen (N) and water management to achieve sustainable production under water-limited conditions while minimizing environmental pollution. Improving nitrogen use efficiency (NUE) under limited water availability is essential for sustainable rice production. This study investigated the combined effects of alternate wetting and drying (AWD) water management and slow-release fertilizer (SRF) on NUE photosynthesis; and growth in two rice cultivars; Samgwang (SG) and Milyang#360 (ML). Growth traits; including shoot and grain biomass; were significantly improved under AWD; especially when combined with SRF in the SG cultivar. Photosynthetic rate (Pn) was highest in SG under SRF + AWD treatment. Gene expression analysis revealed that AWD and SRF modulate the expression of nitrogen uptake and assimilation-related genes in a genotype-specific manner. The total nitrogen (N) content; NUE; and nitrogen uptake efficiency (NUpE) were highest under the SRF + AWD treatment. Additionally; the SRF + AWD treatment promoted carbohydrate accumulation in roots; potentially enhancing nutrient uptake under water-limited conditions. These findings highlight the combined application of SRF + AWD as a synergistic and genotype-responsive strategy that improves NUE and crop yield while conserving water and nitrogen resources. Our study provides a practical basis for integrating water and nitrogen management to improve resource efficiency and sustainability in rice cultivation Full article

Aiming at the problem that rotary tiller knife rollers are prone to entanglement with straw in the wet and sticky soil environment of rice fields in the middle and lower reaches of the Yangtze River in China, an antitangling and sticking cutter was designed. The cutter reduces knife roller entanglement in order to reduce rotary tiller energy consumption and improve work efficiency, and its effectiveness was verified through theoretical analysis, discrete element simulation, and field trials. The design’s validity was verified through theoretical analysis, discrete element simulation, and field tests. The blade inclination design was completed through motion force analysis, and the tool geometry was optimized with a 36.87° inclination baffle and staggered arrangement. A simulation model of the soil–straw–rotary tillage knife interaction was established and we used the discrete element method to analyze the variation in torque between the antisticking knife and the China standard rotary tillage knife (IT245) at four different cutter shaft rotational speeds. In the simulation, the average torque for the antisticking knives was smaller than that of the national standard rotary tillage knives, with reductions of 37.1%, 52.1%, 52.8%, and 50.0%, respectively, demonstrating a remarkable effect. Field tests showed that the average operational efficiency of the antisticking knife was 0.57 hm²/h, with an operation qualification rate of 95.72%. The average torque results from simulation (with and without the antisticking knife) and field tests were analyzed, yielding correlation coefficients of 0.994 and 0.973 for the change curves of average torque between the antisticking knife and the national standard rotary tillage knife. This result confirms the accuracy of the simulation model and the consistency between the simulation and field test results. This study can provide some references for the design and test of antisticking of rotary tillers. Full article

The primary ingredients in poultry feed, cereals, are among the most widely used crops in worldwide agriculture, with principal staples being wheat, rice, corn (maize), sorghum, barley, oat and millet. The scope of this review is to provide a detailed comparative analysis of the nutritive values of cereal crops, and the antinutrients they contain, with reference specifically to their use for feeding poultry. These cereal crops range in biological value from 55 to 77.7%, in protein digestibility from 77 to 99.7%, and in net protein utilization from 50 to 73.8%. Most essential amino acids, including lysine, are found in cereal grains, whereas the nutritional value of cereals is impacted by antinutritional elements. These include non-starch polysaccharides (NSPs), such as pentosans (arabinoxylans) and β-glucan, as well as alkylresorcinols. Around 100 g/kg of pentosans are found in rye, 50–80 g/kg in wheat and 68–92 g/kg in triticale. There are strategies to reduce NSPs and other antinutrients and maximize the effectiveness of utilizing grains in compound feed for poultry. These include the application of enzyme preparations, along with dry and wet extrusion methods, for processing grains. By restricting our narrative to a direct comparison of all major staples for poultry feed, we conclude that further research is required specifically in the area of determining how economically viable it is to feed adult and young chickens with compound feeds containing various cereal crops. Furthermore, we speculate on the utility of employing enzyme preparations and extrudates to maximize feed efficiency. Full article

Rice direct seeding for bunch planting is a sustainable agricultural production method that reduces production costs, improves rice lodging resistance, and conserves irrigation water in the field. However, there are notable differences in seed treatment between direct seeding on dry land and in paddy fields, which can impact the seeding process’s accuracy. This study employs the numerical simulation methods of computational fluid dynamics (CFDs) and discrete element method (DEM) to examine the motion characteristics of dry and wet rice seeds in a fluid–solid coupled domain and their impact on seeding accuracy. The aim is to guide the optimization of the rice air-suction seed metering device. Rice seeds were divided into dry and wet groups, and their physical properties were measured. Discrete element models of rice seeds were constructed and calibrated using a polyhedral method. The results show that the static friction coefficient between the seed meter and the seed ranged from 0.902 to 0.950, and the thousand-grain weights ranged from 25.89 to 32.42 g, which were higher than those of the dry rice seed, which ranged from 0.774 to 0.839, and from 25.89 to 32.42 g. After calibration, the errors between the simulated dynamic stacking angles of HHZD, HYD, YLYD, HHZW, HYW, and YLYW and the physical–dynamic stacking angles were 0.12%, 0.13%, 0.75%, 0.62%, 0.08%, 0.75%, 0.59%, and 1.24%, respectively, which indicated that the discrete element model for rice was reliable. Additionally, a seeding accuracy test revealed that wet seeds of the same variety had higher missing and single indices, while dry seeds had higher triple and multiple indices. Furthermore, CFD-DEM simulations demonstrated that wet seeds’ normal and tangential forces were more significant than those on dry seeds during the seed-filling process. At 40 rpm, the normal and tangential forces during the seed-filling process of HYW are 37.69 × 10⁻³ N and 12.47 × 10⁻³ N, respectively, which are higher than those of HYD (25.18 × 10⁻³ N and 9.19 × 10⁻³ N). The action force of suctioned rice seeds was directly proportional to the missing and single indices. The primary factors contributing to the discrepancy in seeding accuracy between dry and wet rice are the thousand-grain weight, the static friction coefficient between the seed meter and the seed, and the action force exerted between the rice seeds. In addition, using a shaped hole structure and optimizing the seed chamber structure can reduce normal and tangential forces and improve seeding accuracy. This study provides a reference for the simulation of rice seed flow-solid coupling and optimization of air-suction seed metering devices. Full article

In this study, liquid chromatography–mass spectrometry (LC-MS) was employed to conduct untargeted metabolomics analysis on black rice (BR), milled black rice (MBR), wet germinated black rice (WBR), and high-temperature and high-pressure-treated WBR (HTP-WBR). A total of 6988 positive ions and 7099 negative ions (multiple difference ≥1.2 or ≤0.8333, p < 0.05, and variable importance in projection ≥1) were isolated, and 98 and 100 differential metabolic pathways were identified between the different samples in the positive and negative ion modes, respectively. Distinctive variations in the metabolic compositions of BR, MBR, WBR, and HTP-WBR were observed. Flavonoids, fatty acids, lipids, phenylpropanoids, polyketides, benzenoids, and organooxygen were the dominant differential metabolites. Milling removed the majority of bran-associated bioactive components such as phenolic acids, anthocyanins, micronutrients, fatty acids, antioxidants, and dietary fiber. The germination process significantly reduced the number of flavonoids, polyketides, and lipid-related metabolites, while enzymatic activation notably increased the number of organic acids and amino acids. HTP treatment synergistically enhanced the content of heat-stable flavonoids and polyketides, while simultaneously promoting fatty acid β-oxidation. These findings establish novel theoretical foundations for optimizing processing methodologies and advancing functional characterization in black rice product development. Full article

Increased saltwater intrusion likely causes a significant reduction in food production in alluvial river deltas worldwide. One of the mitigation measures for saltwater intrusion is to increase natural flow through irrigation water conservation and land-fallowing policies to prevent the saltwater from moving further inland. However, economic estimates of the costs of such measures under uncertainty are scant. Herein, we develop an integrated modeling framework for estimating the costs of saltwater intrusion mitigation policies by 2050 in the Mekong Delta. The integrated model combines hydrodynamic, advection-dispersion, statistical, crop yield, and economic models, thus allowing us to account for the risk and uncertainty of saltwater intrusion and the costs of mitigation policies. We found that a 95% confidence interval of the saltwater intrusion-impacted area is estimated to be 186,000–201,000 hectares for the baseline, 193,000–209,000 hectares for a sea level rise of 22 cm, and 204,000–219,000 hectares for a sea level rise of 53 cm scenarios, respectively. To bring the saltwater intrusion under the sea level rise of 22 cm back to the baseline level, 100,000–150,000 hectares of currently cultivated rice would need to be fallowed at least once a year. This is equivalent to annual economic losses, with a 50% chance, ranging from $100.03–$176.67 million, implying a substantial economic cost of sea level rise-induced saltwater intrusion even under a modest sea level rise scenario. Under the sea level rise of 53 cm scenario, the results show that widespread adoption of alternate wetting and drying and approximately 300,000 ha of land-fallowing would be needed to push saltwater intrusion back to the baseline level. The findings indicate that saltwater intrusion in the Mekong Delta is more likely than not to intensify considerably and is much less predictable, posing a greater risk to one of the most important rice-producing regions in the world. Full article

Adhesion behavior between wet rice leaves and metal surfaces exacerbates the difficulty in separating and removing grains in the cleaning device. Reducing the adhesion between the wet rice leaves and the cleaning device is an important factor in improving the harvesting performance of rice combine harvesters. This paper investigates the possibility of reducing the adhesion between them. By studying the liquid shape characteristics between the removed grains and the surface, it was found that the adhesion force between the leaf and the surface is greatest when additional pressure is present. Based on biomimetic principles and the convex hull structure of a dung beetle’s head, a convex hull structure for the metal surface was designed to balance the atmospheric pressure on both sides of the leaf in order to eliminate additional pressure. Using the liquid bridge model between a spherical and a flat surface, a liquid bridge model for the leaf and convex hull surface was established. By optimizing the minimum liquid bridge force, the convex hull radius and distance were determined to be 2.47 mm and 1.38 mm, respectively. Contact and collision experiments verified that the convex hull surface is more effective in reducing the adhesion of moist leaves, providing a reference for future research on the cleaning methods of moist rice grains. Full article

The way in which alternate wetting and drying irrigation (AWD), as a water-saving practice promoted in rice (Oryza sativa L.) production systems, could enhance the productivity and water use efficiency (WUE) attracts broad attention. This study selected six mid-season indica rice varieties to investigate the impacts of AWD and conventional irrigation (CI) on grain yield, WUE, grain filling, and root traits. A two-year field experiment demonstrated that grain yields and WUE were significantly increased with varietal improvements. With the improvement of varieties, the maximum grain filling rate and mean grain filling rate for both apical superior and basal inferior spikelets were progressively enhanced during the grain filling stage. Compared to CI, AWD significantly enhanced grain yield and WUE. Flag leaf photosynthetic rate and root characteristics, including root weight, root length, root absorbing surface area, root oxidation activity, and zeatin (Z) + zeatin riboside (ZR) contents in panicles, roots, and root bleeding, were superior under AWD across early, mid, and late grain filling stages. Correlation and path analysis showed that improved grain filling in basal inferior spikelets was attributed to delayed root senescence during the grain filling stage under AWD. These results indicated that AWD would be a better irrigation regime to improve yield and WUE by optimizing grain filling and root growth for modern varieties. Full article