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Drying involves the evaporation of moisture, accompanied by simultaneous heat transfer, mass transfer, and momentum transfer. While the diffusion law is considered an applicable model for explaining the drying phenomenon, the actual drying process cannot be accurately predicted using an analytical solution with a constant diffusion coefficient. Energy efficiency in the drying process is low due to an insufficient understanding of the mechanisms governing moisture migration from solids to air. The development of drying theory has stalled due to an unsolvable discrepancy between experimental results and analytical results. This study analyzes the effect of the binding energy of moisture in paddy rice on the diffusion coefficient. The theoretical relationship between water activity and drying rate in paddy rice was investigated, and the drying process was successfully explained by analyzing free energy transfer and transition theory. The mechanism of rice grain drying was described using a new theoretical solution for the drying process. These results provide new insights into the development of a scientific evaluation standard for assessing the efficiency of actual drying processes. [ABSTRACT FROM AUTHOR]

The Experiment was conducted at the Livestock Research Station, Garividi, Vizianagaram District, Andhra Pradesh for 90 days i.e. from July to October, 2023 to assess the impact of incorporating Rice Distillers Dried Grains with Soluble (RDDGS) by substituting soybean meal in the concentrate mixture on the growth, digestibility, and cost economics of Nagavali ram lambs. Twenty-four lambs were randomly assigned into four treatment groups. In the treatment groups, soybean meal was replaced with RDDGS at 0% (T1 ), 50% (T2 ), 75% (T3 ), and 100% (T4 ) levels. Our results inferred that replacing of soyabean meal with different concentrations of RDDGS did not significantly (p>0.05) affect dry matter intake (DMI and feed conversion ratio. Further, gross digestibility of different nutrients and cell wall constituents were also unaffected. The cost of feed kg-1 of weight gain was significantly (p<0.05) reduced. The cost of feed kg-1 gain was significant (p<0.05) because of the replacement of soybean meal with RDDGS. T2, T3 and T4, showing decreases of ₹11.23, ₹17.59, and, respectively, in comparison to the control (T1 ). The study concludes that RDDGS can completely replace soybean meal in sheep diets without affecting nutrient efficiency. This replacement maintains the same growth and digestibility while significantly reducing the cost of production per kilogram of body weight by 12.7%. Consequently, RDDGS emerges as a cost-effective alternative to soybean meal, offering economic benefits while sustaining the nutritional quality of the feed. [ABSTRACT FROM AUTHOR]

This paper is concerned with a numerical approach for grain drying process in a packed moving grain dryer, where the grain drying process is regarded as steady process based on a newly proposed steady state equation for moisture content of grain. The present method is compared with antecedent results suggested by Zare (Zare D. Computer simulation of rough rice drying in a batch dryer. Energy Convers Manag 2006;47:3241–54) conducted experiments for moisture content and temperature of grain dried in a fixed bed dryer, and shows good agreement. The present model is then extended to the case of the cylindrical dryer with a packed falling bed. The effects of operating parameters of the dryer (i.e. temperature and flow rate of inlet hot air and moving velocity of packed bed) on moisture content of grain are considered. The present approach can be applied to predict the positional distribution of physical quantities such as temperatures of air and grains as well as the relative humidity of air and the moisture content of grains in an arbitrarily-shaped packed moving grain dryer. [ABSTRACT FROM AUTHOR]

BACKGROUND: Barnyardgrass (Weed Science Society of America recommended) or Barnyard grass (Britannica recommended) (Echinochloa crus‐galli (L.) P. Beauv.) is one of the most problematic and dominant weeds in world agricultural systems, especially in paddy fields, where tillering and grain yield can be reduced by 50–70% because of its competitive pressure. The frequent use of chemical herbicides to control E. crus‐galli has led to the evolution of herbicide resistance. Developing bioherbicides using pathogenic fungi to control E. crus‐galli could be an alternative option. RESULTS: In a previous study we showed that a strain of Bipolaris yamadae (HXDC‐1‐2) was promising in controlling gramineous weeds. Here we present a study that evaluated this fungus as a mycoherbicide against E. crus‐galli in greenhouse and paddy fields, characterized mycelium growth and conidial production, and examined the infection development. The median effective dose (ED50) and 90% effective dose (ED90) values of microcapsulated B. yamadae strain HXDC‐1‐2 on E. crus‐galli in the greenhouse were 7.17 × 102 and 9.35 × 103 conidia mL−1, respectively. Conidial germination, mycelial growth, and attachment formation occurred on E. crus‐galli leaves within 1 to 6 h. The hyphae directly invaded cells and stomata, primarily from the appressorium on the epidermis, and necrotic lesions were observed on the leaf surface within 20 to 24 h. Applied to E. crus‐galli plants at 1 × 105 conidia mL−1, the fungus reduced the weed's fresh weight of 75%. CONCLUSION: B. yamadae strain HXDC‐1‐2 has the potential to be developed as a bioherbicide against E. crus‐galli plants, especially in rice fields. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Background: Production of entomopathogenic fungi on a solid substrate, mostly on rice, is preferred by many producers due to its low technological requirements. Drying may be needed after fermentation to preserve the viability of the conidia until use. This study aimed to introduce some uncomplicated drying techniques and study their effectiveness in terms of drying time and extent, as well as their impact on the quantity of conidia produced and their biological activity. Four techniques were studied, i.e., condensing water vapor (by cooling), desiccant (using NaOH), air drying on a net, and air drying on a solid (impermeable) surface. Results: Condensing water vapor and desiccant techniques were the fastest and most efficient, resulting in the lowest moisture content, ranging between 12 and 13%. While drying on a solid surface was the slowest and resulted in the highest moisture content of 32.98%. All of the dried samples yielded a lower quantity of conidia compared to the fresh samples. Samples of condensing water vapor, desiccant, and net techniques yielded approximately a similar quantity of conidia, ranging between 74 and 71% of the yield of the fresh sample. The solid surface sample yielded the lowest quantity of conidia, representing 63.78% of the fresh sample yield. A bioassay test on the mite, Tetranychus urticae Koch (Acari: Tetranychidae), showed that conidia dried via condensing water vapor and desiccant techniques kept their pathogenicity similar to the fresh sample, while samples dried on a net and solid surface significantly lost part of their pathogenicity. Conclusion: The condensing water vapor and desiccant techniques were the most efficient regarding the time needed, conidia yield, and pathogenicity. Drying on a solid surface was the least effective regarding the same factors. [ABSTRACT FROM AUTHOR]

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The rice waterlogging stress test was conducted at the experimental base of the College of Agriculture, Yangtze University, using Yangxian You 418 as the test subject, in order to investigate the impact of waterlogging on rice growth during the period from July to August each year. Six waterlogging stress tests with different waterlogging depth (1/4 plant height (1/4PH), 2/4 PH, and 3/4 PH) and duration (5 d and 7 d) were set up at the jointing–booting stage of rice (T1: 1/4 PH, 7 d; T2: 2/4 PH, 7 d; T3: 3/4 PH, 7 d; T4: 1/4 PH, 5 d; T5: 2/4 PH, 5 d; T6: 3/4 PH, 5 d;) with shallow water irrigation (CK) as control. The plant height, population leaf area, above-ground dry matter, and the yield of rice were measured. The correlation between the waterlogging depth and rice yield reduction was analyzed, and the flood disaster threshold index of rice was established. The results showed that at the end of stress, the plant height of all waterlogged treatments exceeded CK, and the plant height of T3 and T6 treatments significantly increased by 31.90% and 15.93%, respectively. The leaf area of rice treated with T1, T3, T4, and T5 was higher than CK (p < 0.05), and the above-ground dry matter of rice treated with T2, T3, T4, T5, and T6 was higher than CK (p < 0.05). When normal irrigation was restored to the maturity stage, the plant height of all rice treated with waterlogging was still higher than CK (p < 0.05). However, as the degree of waterlogging increased, rice yield decreased significantly, with a notable reduction of 31.68% observed in the T3 treatment compared to CK. Assuming a drainage index based on a 20% decrease in rice yield, it is imperative that the ratio of flooded depth to plant height remains below 37% when waterlogging persists for 7 days in rice cultivation. These research findings offer crucial scientific insights for implementing effective drainage management measures during flood disasters in rice paddies. [ABSTRACT FROM AUTHOR]

To comprehensively understand temperature and moisture changes in a continuous microwave rice grain drying system, this study proposes a simulation strategy that facilitates the continuous movement of rice grains. The study establishes a three‐dimensional model concerning multiple physical fields, including electromagnetism, heat, and mass transfer. It examines the effects of rice grain layer thickness and microwave intensity on the moisture and temperature of rice grains. The results indicate that the drying rate is negatively correlated with material thickness but positively correlated with temperature. The optimal thickness for the rice grain layer is 8 mm. Furthermore, both the microwave drying rate and temperature increase with microwave intensity. These findings contribute to a deeper understanding of the hydrothermal change mechanisms in rice grains during microwave drying. Practical applications: Microwave drying, as an emergent drying technology, has garnered widespread attention for its selective heating, efficient drying, energy savings, and environmental protection. Nevertheless, enhancing uniformity during the microwave heating process constitutes an important research topic in scientific research and technological applications. Numerical simulation methods can visually analyze electric field distribution, thereby optimizing microwave heating uniformity and improving drying effects. This article aims to accurately predict the continuous microwave drying time of paddy and maximize energy usage by optimizing drying thickness and microwave power parameters establishing a mathematical model for the process. The study not only provides a solid theoretical basis for microwave dryer design but also scientifically guides the continuous microwave drying of rice and other food crops. [ABSTRACT FROM AUTHOR]

The rice dry direct-seeding planting mode is a typical shallow sowing operation, and the traditional compacting mechanism with only longitudinal profiling ability is difficult to ensure the seedbed uniformity, resulting in the seedling emergence rate always lower than 80%. This study innovatively proposed a novel bidirectional-micro-profiling compacting device (BMPCD). In this study, the coupled DEM-MFBD simulation technique was utilised to find that the core design parameters k (elasticity coefficient of the reset spring) and t (thickness of the elastic sheet) of the BMPCD would significantly affect the seedbed uniformity by changing the resistance value F r during the profiling process (P ≤ 0.01). The simulation results showed that when k was taken as 7.8 N mm−1 and t was taken as 1.6 mm, the seedbed uniformity could be most greatly improved. The field experiments showed that compared with the bidirectional profiling compacting device (BPCD) and longitudinal profiling compacting device (LPCD), BMPCD could reduce the coefficient of variation of soil firmness (CVSF) by 33.1% and 40.1%, and the coefficient of variation of sowing depth (CVSD) by 37.1% and 51.8%, respectively, and then improve the seedling emergence rate of dry direct-seeded rice by 5.8% and 12.2%. This indicated that bidirectional and micro-profiling compaction technology could tackle the problem of low seedling emergence rate in rice dry direct-seeding. Meanwhile, the results of the DEM-MFBD coupling simulation were not significantly different from the test results of the field experiments (P > 0.05), indicating that it could be used as an efficient and accurate new method to study the dynamic characteristics between the soil and machinery. • The BMPCD can improve the compacting stability of rice dry direct-seeding. • The DEM-MFBD coupling simulation can realise high precision optimisation of BMPCD. • The BMPCD can increase the seedling emergence rate of dry direct-seeded rice by 12.2%. [ABSTRACT FROM AUTHOR]

There are many applications, such as fruits, paddy rice drying, and so on, where air heaters are comprehensively used. The provision of ribs in solar energy‐based air heaters has been accredited to be a beneficial approach for escalating its thermal performance. This investigation reveals the performance evaluation of a rectangular sectioned solar air heater duct placed with the curved type of ribs organized in noncontinuous and truncation patterns. Influence of variation of pitch ratio (4.0–12.0), block‐age ratio (0.06–0.1), the ratio of rib height to the radius of rib curvature (0.75–1), and the ratio of rib truncation gap to its height (0–0.75) at different values of Reynolds's numbers (Re) in the range 12,000–37,000 on the performance revealing factors explicitly heat transfer augmentation factor, the ratio of friction factor, as well as overall thermal performance enhancement (OTPE) have been discussed. The experimentation was performed on a similar rectangular air heater as that of numerical simulation with the same boundary conditions. It is figured out from numerical simulation that the provision of a central truncation gap in the arrangement of ribs helped in the development of vortices with minimal pressure loss due to friction. The greatest Nusselt number augmentation ratio between ribbed and plain plates that was attained is of the order of 2.01 for a pitch ratio of 9.0, blockage ratio of 0.08, the ratio of rib height to the radius of rib curvature 0.25 at the highest value of Re. The obtained friction factor ratio between the ribbed plate and the plain plate is of the order of 2.34 for p/y = 9.0 at maximum Re. The highest value of overall thermal performance enhancement (OTPE) is attained as 1.52 at the pitch ratio of 9, at the maximum value of Re. The central truncation gap of the rib pattern promoted the creation of vortices with a decreased pressure loss penalty. The uppermost value of the factor presenting overall thermal performance enhancement in this work is far superior to unity. This suggests that adding curved ribs to the air heater's duct is a helpful way to improve its overall performance. Empirical correlations have been established between the Nusselt number and geometrical parameters, likewise the friction factor and geometrical parameters using the regression study. The values of the Nusselt number, and friction factor that come from experimental work and developed empirical correlations fall between the highest deviation limits of ±9% and ±8%, respectively. This work is certainly helpful in the context of solar air heaters used for applications such as drying paddy rice. [ABSTRACT FROM AUTHOR]

Rough rice lots harvested on the field contain varying kernel thicknesses within the panicles. These variations influence the drying characteristics of seeds and, thus, the seed germination and vigor. In this study, two hybrid long-grain rice cultivars (RTv 7303 & RT 7301) with harvest moisture contents (HMC) ranging from 19% to 21% and 15% to 17% wet basis (w.b.) for medium and low MC seeds were used, respectively. These rough rice samples were size fractionated into two thickness fractions (thick >2.03 mm and thin 1.91>>2.03 mm), with non-fractionated samples labeled as unsorted or control samples. Kernels from each sub-lot were dried to 12.5% MC at 40°C and 60°C air temperatures and 25% constant relative humidity (RH). Immediately after drying, samples were selected for seed germination and vigor assessments. RTv 7303 had higher seed germination compared to RT 7301, indicating that the two cultivars were genetically different from each other. Thick kernels had significantly higher seed germination (SG) than thin kernels, but there was no significant difference compared to unsorted kernels. Additionally, the percentage points difference between the thick versus unsorted and thin kernels varies from -1-pp to 8-pp for low MC seeds and from 2.5-pp to 6-pp for medium MC seeds. The seed vigor index (SVI) difference between the two cultivars is around 3.0 m.% and 1.5 m.% for medium and low MC, respectively. Harvested rice seeds with a medium MC (19% to 21%) and dried at a temperature of 60°C resulted in greater seed germination and vigor. Ultimately, these findings highlight the role of thickness grading in seed assessments. Thus, it was concluded that if the thin kernels could be screened out from the harvested rice lots, seed germination and vigor would increase significantly. [ABSTRACT FROM AUTHOR]

As the pre-process of storage and processing, rice drying is a key link to ensuring grain quality. A scientific and reasonable drying process can maintain grain quality and realize grain loss reduction, energy savings, and emission reduction. By establishing the response surface (RSM) regression model, the relationship between various experimental factors and quality indicators was analyzed, and the reasons for the results were explained. The optimized parameter combination was a hot air temperature of 43.14 °C, hot air humidity of 48.00%, initial moisture content of 23.80%, hot air velocity of 0.70 m/s, and hysteresis ratio of 3.55. Under this parameter combination, the drying characteristics (net drying time = 157.61 min, germination rate = 94.15%), processing quality (burst waist increase rate = 3.48%, whole rice rate = 70.458%), and nutritional quality (fatty acid value = 20.93 mg, resistant starch concentration = 195.26 μg/g, protein content change = 8.53 g/100 g, fat content change = 2.37 g/100 g) of rice after drying improved. The relative error between the validation results and the optimized results was 4.68%, indicating that the optimized process parameters can improve the efficiency and quality of rice drying. According to the regression model, the process reference chart with the process retrieval and prediction function was drawn, and the corresponding high-quality control scheme was given, providing a reference for the parameter settings of actual drying operations. The optimized drying process parameter combination effectively reduced the moisture gradient inside rice grains, drying stress, and the occurrence of cracks, thereby improving the appearance, quality and nutritional value of rice after drying. Moreover, the process reference chart can provide a reference for the actual preliminary processing technology of rice after production and a theoretical basis for an in-depth exploration of the mechanism of changes in rice quality. [ABSTRACT FROM AUTHOR]

Improper drying of rice can cause significant kernel defects. A rice material state diagram consisting of glass transition temperature (Tg) at various moisture content (MC) levels is a tool that helps predict the appropriate drying temperatures to employ. The present diagrams were however developed for old rice cultivars which may be inadequate for predicting the drying behavior of contemporary cultivars. The objective of this study was therefore to develop material state diagrams along with updated Tg prediction models tailored to accommodate the contemporary rice cultivars presently grown. In the study, 23 rice cultivars were analyzed and revealed average Tg values of approximately 39, 41, 43, 45, and 47 °C at MC levels of 20%, 18%, 16%, 14%, and 12%, respectively. The updated material state diagrams developed from the results incorporated a Tg prediction model, indicating elevated Tg values and an improved R2 value of 0.72, when compared to prior research findings. [ABSTRACT FROM AUTHOR]

Vegetable transplanters that are fully automated have been developed to reduce the labor-intensive and yield-influencing process of transplanting; however, the majority of these transplanters are heavy and costly. Based on a traditional Japanese rice transplanter, we created a low-cost, high-efficiency vegetable transplanter in this study. Because a rice transplanter can only be utilized in flooded fields, certain mechanical parts have been adjusted to allow for the transplantation of rice on dry fields. In order to precisely slice the nursery mat one by one without harming the seedlings, the rotor case and end-effector parts were modified. Additionally, a long guide and a leaf spring-type retainer were created in order to securely hold heavier and larger vegetable seedlings than those of rice, and a cuttable nursery mat (CNM) was introduced as a new kind of solid nursery bed. The prototype could transplant up to 250 cabbage plants min−1 row−1 for planting speed of 1.0 m s−1. Conventional plug seedlings (PS) are not as suitable for transplanting and cultivation as CNM seedlings (CNMS). Unlike PS, CNMS were only cultured for a brief period prior to transplantation since the CNM itself has sufficient stiffness, negating the need for root spread. This study is the first demonstration of the possible applications of this rice transplanter- based vegetable transplanting system. [ABSTRACT FROM AUTHOR]

BACKGROUND: Dry cultivation of rice is a water‐saving, emission reduction and labor‐saving rice farming method. However, the development of rice under dry cultivation is hampered by the limitations of dry cultivation on rice yield and rice quality. We hypothesized that additional silicon (Si) would be a measure to address these limitations or challenges. RESULTS: In the present study, we set up field trials with three treatments: flooded cultivation (W), dry cultivation (D) and dry cultivation plus Si. Yield and quality were reduced under D treatment compared to W treatment. The addition of Si promoted root development, increased plant height and leaf area, increased photosynthetic enzyme activity, net photosynthetic rate and SPAD values, and increased biomass under dry crop conditions. Under the drought conditions, silica up‐regulated the expression of AGPSI, SBEI, SBEIIb, SSI and SSII‐1 genes and the activities of ADP‐glucose pyrophosphorylase (AGPase), soluble starch synthetase (SSS) and starch branching enzyme (SBE) enzymes, which reduced protein, amylose, chalkiness percentage and chalkiness degree, increased brown rice rate, milled rice rate and head milled rice rate, and also improved rice quality. In addition, the increase of AGPase, SSS and SBE enzyme activities promoted the filling rate and the number of spikes was guaranteed, whereas the yield was improved by promoting the seed setting rate and 1000‐grain weight. CONCLUSION: The results of the present study indicate that adding appropriate amounts of Si fertilizer can improve the yield and quality of rice under dry cultivation by regulating source supply capacity and grain starch synthesis. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Radiofrequency (RF) heating utilizes high-frequency electromagnetic waves to induce heat within materials via molecular friction. This method offers rapid, even heating, deep penetration, and energy efficiency. Nevertheless, there is a dearth of research on RF exposure parameters concerning food processing. Investigating these parameters is crucial for RF process optimization, setting safety guidelines, and guaranteeing product quality. This research clarifies RF exposure parameters through the one-pass drying of high moisture content (MC) long-grain paddy rice (cultivar [cv.] XL-753) at an initial MC of 20.4% wet basis (w.b.) to a final of MC of ≤ 13.5% w.b. (safe MC for storage). The specific objectives of this research were to: 1. Advocate the utilization of standardized RF exposure parameters (Specific Absorption Rate, SAR; Electric Field Intensity, E; and Power Density, S) of food and agricultural products, aiming to simplify RF processing, fostering consistency and safety in operations. 2. Estimate the RF exposure parameters associated with the one-pass RF drying process. 3. Determine the RF exposure parameters’ influence on rice physicochemical attributes of Milled Rice Yield (MRY), Head Rice Yield (HRY), Color Parameters (L* a* b*), Surface Lipid Content (SLC), and Pasting Properties. Using a pilot-scale parallel-plate RF heating system (6 kW, 27.12 MHz) with a 105 mm product-to-emitter gap, RF exposure parameters were determined: E = 46.82 V/m; EEff = 33.11 V/m; S = 300,000 W/m²; SAR = 2,224.95 W/kg. Rice samples underwent RF exposure durations of 360, 600, and 840 s, resulting in SARAdjusted levels of 0.80 × 106, 1.33 × 106, and 1.87 × 106 J, respectively. Half of the RF-processed paddy rice underwent tempering, which involved immediately transferring paddy rice after RF treatments into sealed glass jars and then into an incubator set to a constant temperature of 60°C for a duration of 4 h. RF processed samples at the highest SARAdjusted tested (1.87 × 106 J) followed by tempering resulted in MC reductions of 6.7% pt. w.b., final MC of 14.0% w.b., MRY, HRY, and SLC of 70.80%, 47.38%, and 0.47%, respectively. Non-tempered samples at the same SARAdjusted level had MC reductions of 7.34% pt. w.b., final MC of 13.1% w.b., MRY, HRY, and SLC of 60.91%, 4.53%, and 0.43%. Tempering and SARAdjusted values slightly affected rice physicochemical characteristics of color and viscosity. However, the differences were minor and inconsistent. To ensure optimal quality in largescale RF drying of rice, it is crucial to avoid SARAdjusted levels exceeding 1.33 × 106 J. Exceeding this threshold has been shown to cause overheating, adversely impacting the grain’s quality. Moreover, implementing a tempering process postdrying is also essential in mitigating these detrimental effects. [ABSTRACT FROM AUTHOR]

This study explores the existing literature on specific energy consumption (SEC) use for paddy drying and consolidates all relevant data for comparisons across technologies. Energy consumption data for a range of drying technologies are consolidated from published literature and normalized to enable comparison. A large proportion of the source data are generated from operational performance in industrial or laboratory settings, while the remainder is derived from computer simulations. The SEC of paddy drying is driven primarily by technology type; however, operational factors (such as the system size, temperature, and airflow) and external factors (such as the local climate and paddy moisture content) also heavily influence system energy use. The results of our analysis show that the industrial drying technologies explored in this study have an average SEC of 5.57 ± 2.21 MJ/kg, significantly lower than the 20.87 ± 14.97 MJ/kg observed in a laboratory setting, which can potentially be attributed to differences in processing capacity. Multi-stage drying typically has higher energy efficiency when tempering stages are incorporated. The self-circulating design of some drying systems may provide additional opportunities for heat exchange, leading to efficient drying performance without the need for a separate tempering stage. Beyond traditional methods, we have observed a notable shift towards solar-assisted and infrared drying technologies in laboratory settings, reflecting an increasing interest in sustainable and efficient drying solutions. In summary, this review consolidates SEC data for rice drying technologies, analyzes the energy intensity and performance of each drying technology, and identifies data gaps that might be addressed in future research. [ABSTRACT FROM AUTHOR]

Thailand is the foremost global producer of rice, benefiting from its hot and humid climate which results in harvested rice with a high moisture content. This promotes the rapid growth of microorganisms that harm the paddy. Consequently, the utilization of drying techniques is necessary to uphold the quality of the product. For the sake of efficiency and dependability, forced draft convection drying is commonly utilized, despite its high energy consumption. In general, the paddy is subjected to the flow of hot air, which exits the drier at a reduced temperature, leading to energy dissipation. Heat pipes have been widely employed to reclaim wasted energy through the preheating of fresh air, owing to their straightforward design and lack of reliance on external power sources. Nevertheless, there has been a scarcity of research conducted on the utilization of the oscillating heat pipe in these particular applications. Thus, a pilot‐scale oscillating heat pipe is utilized in this study. The primary aim of this study is to evaluate the efficiency of waste heat recovery using the recently developed oscillating heat pipe, as well as the resulting energy conservation. Various thicknesses of rice paddy layers are examined to compare the duration it takes for them to dry. It is seen that the drying time increases as the bulk of the paddy increases. When the layer thickness is increased, a multimodal drying rate behavior is observed which is due to the fact that when the heated air ascends, it repeatedly heats each layer of the grain. The study focuses on analyzing the temperature profiles at the heat pipe and within the evacuated air. The rate of heat recovery is also computed. An investigation is conducted to determine the energy savings achieved through the use of heat pipes. The results indicate a decrease in energy consumption ranging from 39.4% to 63.7%. This study showcases the utilization of a research‐scaled oscillating heat pipe in the rice drying procedure, serving as a foundation for the future enhancement of the heat recovery system in industrial rice drying. Practical applications: Thailand is the world's top rice producers and because it is hot and humid, the harvested rice has a high moisture content, which encourages the growth of bacteria. In most cases, forced draft convection drying is used, which uses a large amount of energy. In general, this is due to energy loss in the exhaust. Heat pipes have been widely employed to recover wasted energy. However, research on the utilization of oscillating heat pipes in such applications has been limited. Hence, a pilot‐scale oscillating heat pipe is used in this work to evaluate the efficacy of waste heat recovery as well as the energy savings. The drying time is shown to increase with the thickness of the paddy layer. The temperature profiles at the heat pipe and in the evacuated air, as well as the heat recovery rate, are investigated. The results show an energy reduction of 41.7%–53.9%. [ABSTRACT FROM AUTHOR]

Rice provides ~20% of human dietary energy and, for many people, a similar share of their protein. Rice cultivation, however, produces significant greenhouse gas (GHG) emissions, comparable to those from the aviation sector. The main GHG from rice production is methane, mostly a result of conventional rice cultivation (CRC) keeping rice fields continuously flooded during the crop cycle. There is extensive evidence that alternate wetting and drying (AWD) of rice fields substantially reduces methane emissions. AWD is one component of the System of Rice Intensification (SRI), an agroecological approach to the management of plants, water, soil, and nutrients. This article reviews field studies measuring GHG emissions associated with the adoption of AWD and SRI. The review confirms that both AWD and SRI offer substantial reductions in methane emissions per hectare compared with CRC. These benefits are, however, partly offset by increases in emissions of nitrous oxide and carbon dioxide. The studies also show that SRI (but not AWD) improves yield and therefore further reduces GHG emissions per kg of rice. The review concludes that while both AWD and SRI substantially reduce emissions per hectare and per kilogram of rice, SRI can simultaneously contribute to food security while addressing the drivers of climate change. Further investigation of carbon emissions and sequestration under different rice cultivation methods is needed to strengthen the evidence base. [ABSTRACT FROM AUTHOR]

Rice, a crucial staple in China, is cultivated through various techniques, including seedling transplanting, dry direct seeding, and film mulching. Despite its significance, rice production is a considerable environmental burden. Using a life cycle assessment (LCA) methodology, this study aimed to evaluate the environmental impacts of four rice cultivation methods (transplanting rice, dry direct-seeding rice, dry direct-seeding rice with polyethylene film (PE), and dry direct-seeding rice with biodegradable film) in Northeast China. The results indicate that the magnitude of environmental impacts among treatments was consistent across years. The potential values of all environmental impacts of the four different cultivation methods of rice in the 2021 field trial were smaller than the results of the same cultivation method of rice system in the 2022 field trial. Among the four rice cultivation methods, the consumption of energy showed inconsistency over the two years, with the highest energy consumption in the first year being for dry seeding with PE film and in the second year for dry seeding without film. Additionally, transplanting exhibited the highest impact on water resource consumption and climate change. Dry direct-seeding rice displayed the highest eutrophication and ecotoxicity. Dry direct-seeding rice with a biodegradable film had the least impact in terms of acidification. Moreover, dry direct-seeding rice with a biodegradable film minimized water consumption and greenhouse gas emissions without compromising yield. [ABSTRACT FROM AUTHOR]

Background: Rice is the major crop in India in terms of area, production and consumption. Rice occupies about 23% of the gross cropped area and 35% of the total area under food grains in the country. Rice is of one key importance to the economy as well as a staple food for Telangana people, requiring about 50 lakh tons annually to feed the state population. In recent times the area under rice cultivation has been increased and is expected to hit the one crore acre mark by rabi season 2022. In any type of crop production system an accountability of inputs, energy spent, yield and costs must be monitored, by that one can modify it or substitute it for obtaining the better results. Methods: Due to decline in the share of agriculture workers in the country, there is a need to adopt new technologies in rice cultivation. Dry direct seeding of rice refers to direct sowing of rice seeds in the dry field rather than by transplanting seedlings from the nursery. A study was conducted to compute the inputs and energy consumptions in manual transplanted rice production (MTR) and dry direct seeding rice production (DDSR) methods of paddy cultivation in the combined Nalgonda district of Telangana State, during 2020-21. Firstly, the different operations performed in these two methods were listed out, then by using suitable energy equivalents total energy consumed in two methods of operations were calculated. Result: The human energy spent in the manual transplanted rice production and dry direct seeded rice productions were 506 and 92.84 MJ/ha respectively. Specific energy noted for dry direct seeded rice production and manual transplanted rice productions were 2.10 and 2.28 MJ/kg respectively. A total saving of Rs. 16,000/-ha-1 was recorded by practicing the dry direct seeded rice production method over the manual transplanted rice production method. On comparing both the methods for overall energy consumption, manual energy consumption and cost of cultivation DDSR method was found to be more efficient than MTR method in the district. [ABSTRACT FROM AUTHOR]

Based on the rice bran instant powder obtained by enzymolysis and spray drying of rice bran in the earlier stage, this study investigated the effects of the addition of soybean protein, konjac flour and vanillin on the pancreatic lipase inhibition rate, sodium cholate adsorption rate, water absorption index, water solubility index and electronic tongue intelligent sense of meal substitute powder, and finally established the best formula of rice bran nutritional meal substitute powder. The meal substitute powder has the characteristics of high protein (32.31 ± 0.12%), low fat (1.76 ± 0.11%), low carbohydrate (35.91 ± 0.58%), low energy (288.72 ± 0.47 kcal), balanced nutrition, and strong antioxidation. The in vitro hypolipidemic activity showed that the in vitro digestion of ice bran meal replacement powder could significantly reduce the triglyceride, total sterol, and low-density lipoprotein contents of an HepG2 hyperlipidemic cell model, and increase the high-density lipoprotein content of an HepG2 hyperlipidemic cell model. Therefore, this study further expanded the space for the comprehensive development of rice bran and realised the value-added utilisation of rice bran. [ABSTRACT FROM AUTHOR]

In the realm of agriculture, biodegradable films are emerging as a promising substitute for traditional polyethylene (PE) films. Despite their potential, there has been a notable lack of extensive research on their effectiveness in the context of dry direct-seeded rice cultivation. Addressing this gap, a comprehensive biennial study was conducted in the northeastern regions of China, focusing on the 'Baonong 5' rice variety. This study meticulously compared three distinct cultivation methods: (1) employing biodegradable film mulching, (2) using conventional plastic film mulching, and (3) cultivating without any mulch. The findings revealed that biodegradable film mulching significantly enhanced soil moisture control, increased leaf area, and improved rice yield and water utilization efficiency (p < 0.05) compared to the plots without mulch. Notably, there was no marked difference in outcomes between the plastic film mulching and the unmulched plots. This research underscores the profound benefits of biodegradable film in rice cultivation, particularly from an environmental sustainability perspective. This innovative method not only boosts agricultural productivity but also addresses critical environmental challenges like climate change and water conservation. The application of biodegradable mulch has proven to be remarkably effective in improving irrigation efficiency and crop water conservation, leading to enhanced rice development and higher yields. The study recorded a substantial increase in water productivity—30% in 2021 and between 52.85% and 60% in 2022—compared to traditional cultivation practices. Furthermore, the use of biodegradable mulch resulted in significantly higher rice yields than the non-mulched plots, thus contributing to increased profitability. Such methods not only yield higher crop outputs but also mitigate environmental issues like water pollution and help alleviate prevalent water shortages in rice farming. [ABSTRACT FROM AUTHOR]

Hanyou 3015 is a new Indica hybrid of water-saving and droughtresistance rice (WDR), combining rapid maturation and high yield potential. Whole genome sequencing results show that Hanyou 3015 carries many superior alleles that could explain its drought tolerance, high water use efficiency, rapid maturation, and wide adaptability. [ABSTRACT FROM AUTHOR]

The rice drying process in a rotary dryer gives the benefit of producing uniformly dried rice in a short drying time. This work investigated a rotary dryer's efficiency and heat consumption at various temperatures (40, 50, and 60 °C) and capacities (10, 20, 30, and 40 kg). When loaded with 10 to 30 kg of rough rice and operated at 60 °C, the dryer produced dry rice with 14% w.b. moisture content for less than 3 hours. The energy efficiency and consumption were evaluated based on the experiment and theoretical analysis. According to the observation, a high temperature significantly shortened drying time. Thus, the total energy and fuel consumption decreased even at the higher capacity. The lowest carbon dioxide emission was achieved at the highest temperature and capacity. [ABSTRACT FROM AUTHOR]

Based on the arable land situation in Gejiu City, upland dry planting of indica hybrid rice is being expanded in Karst mountain areas with a rainfall of over 1 400 mm and an altitude of 1 100-1 600 m to develop grain production. This paper gives a specific description of hybrid rice upland dry seedling technology, upland transplanting technology, fertilization technology, field management, weed prevention and control technology, and disease and pest control. [ABSTRACT FROM AUTHOR]

Extreme dry and wet events can result in significant crop yield losses. However, the impact of consecutive occurrence of dry and wet extremes on crop yield remains unclear. Here, we investigate the hotspots of compound dry and wet (CDW) extremes across global rice croplands and their impacts on rice yield. We identify a significant increasing trend in the frequency of CDW extremes during 1981–2016. The risk of yield loss caused by CDW extremes can be twice as high as the risk from individual wet and dry extremes. Furthermore, we find that global rice croplands face a 43% higher risk of rice yield loss due to dry‐to‐wet extremes compared to wet‐to‐dry extremes. Our findings provide new insights into the sustainability of global rice production and food security in the face of compound hydrological extremes. Plain Language Summary: It is widely recognized that compound events may exert larger impacts on crop production compared to individual extremes. Here, we investigate the consecutive occurrence of dry and wet (CDW) extremes during the rice‐growing season and estimate their impacts on rice yield. We observe a significant increase in the frequency of CDW extremes across global rice croplands during the rice‐growing season from 1981 to 2016. The CDW extremes exert a larger impact on rice yield loss compared to individual wet and dry extremes. The CDW extremes, characterized by longer durations of both dry and wet extremes and faster transitions between them, have an even more adverse influence on rice yield. The risk of yield loss caused by CDW extremes is 200% higher than the risk from individual wet and dry extremes. Furthermore, global rice croplands face a 43% higher risk of yield loss due to dry‐to‐wet extremes than wet‐to‐dry extremes. Key Points: A significant increasing trend in the frequency of compound dry and wet (CDW) extremes was observed across global rice croplandsThe risk of rice yield loss caused by CDW extremes can be twice as high as the risk from individual wet and dry extremesGlobal rice croplands face a 43% higher risk of rice yield loss caused by dry‐to‐wet extremes compared to wet‐to‐dry extremes [ABSTRACT FROM AUTHOR]

The rumen is a complex ecosystem containing a variety of fungi, which are crucial for the digestive activities of ruminants. Previous research on rumen fungi has mainly focused on anaerobic fungi, given the rumen's reputation as a mainly anaerobic environment. The objective of this study was to investigate rumen fungal diversity and the presence of aerobic fungi in buffalo fed on different diets. Three adult buffaloes were used as experimental animals. Alfalfa hay, oat hay, whole corn silage, sugarcane shoot silage, fresh king grass, dried rice straw, and five kinds of mixed diets with concentrate to roughage ratios of 20:80, 35:65, 50:50, 65:35, and 80:20 were used as the experimental diets. The experimental animals were fed different diets for 22 days. Rumen fluid was collected from the rumen fistula for ITS (Internal Transcribed Spacer) sequencing 2 h after feeding on the morning of day 22. The results indicate the presence of large quantities of aerobic fungi in the rumen of the buffaloes 2 h after feeding and suggest that Ascomycota and Basidiomycota are the dominant fungal groups under different feeding conditions. The study also identified 62 different fungal types, which showed significant differences among the 11 experimental diets. [ABSTRACT FROM AUTHOR]

The frequent occurrence of drought–flood abrupt alternation (DFAA) seriously affects crop yield. It is particularly important to explore the dynamics of material accumulation and distribution under DFAA stress to analyze the mechanism of yield formation. In this study, a bucket experiment with DFAA stress groups, drought control (DC) groups, flood control (FC) groups, and normal irrigation (CK) groups was set up from the jointing to the heading stage of rice to analyze the interaction effects of DFAA stress on rice yield and dry matter partitioning. The results showed that compared with the CK group, the average yield reduction rate of rice in the DFAA groups was 23.03%, and the number of grains per panicle, total grain number, thousand-seed mass, and seed setting rate decreased. Compared with the DC groups, the DFAA groups had a significant reduction in yield and its components during the flooding period. Compared with the FC groups, the DFAA groups showed a compensation phenomenon in the yield and its components during the drought period. From the end of DFAA stress to the harvest period, the root partitioning index (PI) of the DFAA groups decreased, the stem PI increased first and then decreased, the leaf PI decreased, and the panicle PI increased. The results showed that the rice leaves increased and thickened, and the stems thickened under DFAA conditions to enhance the ability to resist drought and flooding stress, but the panicle rate was reduced, the growth period of rice was delayed, and the redundant growth of stems and leaves was increased. It is suggested that the depth and duration of stagnant water storage during the flood period of DFAA should be controlled, and the transfer and supply of photosynthetic products to grains should be increased to avoid serious yield reductions. The research results provide a theoretical basis for the rational development of farmland DFAA mitigation measures. [ABSTRACT FROM AUTHOR]

The majority of the rural areas in developing countries are not connected to the electric grid. Rice production produces a significant amount of rice husk as a byproduct/waste but this waste can be used as a source of energy for drying of the rough rice. The aim of this research was to evaluate the performance and improve the design and operation of a rice husk fueled mixed flow grain dryer for small scale rural farmers using a validated 3-D computational fluid dynamics (CFD) model. The model was applied to predict the airflow and heat and mass transfer characteristics of the designed prototype rough rice dryer. The model took into account the geometrical detail of the dryer assembly, the relevant boundary and initial conditions, and model input parameters. The results identified relatively stagnant regions at the top and the side walls of the dryer. The observed relatively high variation in drying air velocity distribution caused a relatively high variation in drying characteristics of the rice grain. The model was applied to modify the design and operation procedure of the dryer to improve the performance in terms of drying uniformity and drying time. After 2 h drying time, the difference between the maximum and minimum moisture content values for the original and modified design was 12.9% and 8.5%, respectively. There was an exponential relationship between drying time and drying air temperature and specific flowrate. Mixing and recirculation of the grain at 30 min interval significantly improved the uniformity of drying, and the difference between maximum and minimum moisture content after 2 h of drying was clearly reduced to 1.9%. The study indicated the capability of 3-D CFD model to improve the design and operation of mixed flow rice husk fueled dryer to attain the required performance. [ABSTRACT FROM AUTHOR]

BACKGROUND: White rice is poor in health‐promoting phytochemicals; therefore, the production of a phenol‐enriched commodity is highly desirable. Recent findings on its enrichment via cooking in plant extracts are promising, yet studies employing aqueous extracts of olive leaves (OLs), containing well‐recognized bioactive phenols (e.g. oleuropein) are absent. In addition, little is known about the levels of phenols that are maintained after rice drying and rehydration, an important aspect for the future design of 'ready‐to‐eat' functional rice. RESULTS: The examination, for the first time, of white rice adsorption capacity of phenols from OLs upon cooking in infusions containing different levels of phenols, after freeze‐drying and rehydration, showed the following: (i) the total phenol content, the antioxidant activity (assessed via 2,2‐diphenyl‐1‐picrylhydrazyl radical and ferric reducing antioxidant power assays), the oleuropein and luteolin‐7‐O‐glucoside levels increased dose dependently; (ii) upon rehydration, the average decrease of total phenol content and antioxidant activity values was significantly lower when an exact volume of water was used compared with an excess (~10% versus 63%). A similar trend was observed for oleuropein (36% versus 83%) and the luteolin‐7‐O‐glucoside (24 versus 82%) levels; (iii) the dried enriched kernels were less bright with a hay‐yellow hue (CIELab coordinates). CONCLUSION: White rice enrichment with biophenols from OLs, a by‐product of olive tree cultivation, was successful using a simple approach. Despite leaching upon freeze‐drying/rehydration, sufficient amounts were maintained to obtain a functional rice that could serve as an alternative dietary source of OLs phenols to non‐traditional olive tree product consumers or those refraining from sodium and fats. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The deep‐bed drying process of rice grains was investigated through numerical simulation, employing the porous medium flow field theory and the local thermal nonequilibrium method. Moisture field of rice grains described using thin‐layer equations. On this basis, the deep‐bed drying of rice grains modeled with COMSOL, and verified its plausibility. The results showed that the drying rate of rice grains was significantly accelerated when the hot air temperature was increased from 40°C to 70°C, but the inhomogeneity of rice grains temperature increased by 29.79%, 22.31%, and 17.41% for every 10°C increase. Drying grains faster with vertically arranged an angular air duct, with a 4.88% increase in drying speed in 300 min. The temperature difference between the top and the bottom of an angular air duct with a small width is smaller, about 11°C, and the heating efficiency is better at the top, by 31.28%. Practical Applications: Grain dryers are often used in high‐volume grain drying operations and it has been a great challenge to save the energy consumption of the drying process. It is necessary to use numerical simulation to design a reasonable structure of the heating section to improve the energy utilization efficiency of the heating section of the grain dryer. The numerical model proposed in this article can effectively simulate the spatial distribution of moisture content of rice under different structures of grain drying units, which can be used not only for the prediction of drying time but also for analyzing the optimal heating structure from it. A technical basis is provided for the design of grain dryers. [ABSTRACT FROM AUTHOR]

Drought hampers global rice production. Abscisic acid (ABA) plays versatile roles under different environmental stresses. While the link between drought and ABA is known, its effect on ABA biosynthesis genes and metabolites is unclear. This study explored the impact of drought on various metabolites, namely beta‐carotene, zeaxanthin, antheraxanthin, violaxanthin, neoxanthin, and candidate genes viz. zeaxanthin epoxidase (ZEP) and 9‐cis epoxycarotenoid dioxygenase (NCED) of ABA biosynthesis pathway in rice cultivars (N22 and IR64) at anthesis {65 DAT (Days after transplanting)} with different stress levels. In stressed plants, zeaxanthin significantly increased (92%), while the concentration of beta‐carotene, antheraxanthin, violaxanthin and neoxanthin decreased as drought stress progressed. The concentration of metabolites in roots was notably lower than in leaves in both genotypes. The ZEP expression was upregulated in roots (8.24‐fold) under drought stress. Among five NCED isoforms, NCED3 showed significant upregulation (7.29‐fold) in leaf and root tissue. NCED1 was significantly downregulated as stress progressed and was negatively correlated with ABA accumulation. NCED2, NCED4 and NCED5 showed no significant change in their expression. Drying and rolling of rice leaves was observed after imparting drought stress. The findings revealed that drought stress significantly influenced the expression of candidate genes and the concentration of metabolites of the ABA biosynthesis pathway. There was a significantly higher accumulation of ABA in N22 leaves (47%) and roots (30%) compared to IR64. The N22, a drought‐tolerant genotype, exhibited significantly higher concentrations of intermediates and demonstrated increased expression of ZEP and NCED3, potentially contributing to its resilience against drought. [ABSTRACT FROM AUTHOR]

Internal fluid flow during rice drying generates a stress gradient inside the material. If the stress gradient becomes too large or certain rice layers undergo glass transition under a significant stress gradient, stress cracks can form. In this study, modeling equations based on the Hybrid Mixture Theory were solved to simulate moisture transport and the viscoelastic stress that occurs during rice drying. The model's accuracy was evaluated using experimental moisture content data for two rice varieties: Pusa Basmati 1121 (MAEs: 0.0079–0.0162 g/g solids) and California M206 (MAEs: 0.0022–0.0061 g/g solids). Simulations were then conducted under continuous and time-varying drying conditions to determine the best drying strategy for minimizing stress crack formation. The results showed that gradually increasing the inlet air temperature by 5 °C every 5 min after an initial 28.5 min at 40 °C could reduce stress crack formation effectively while drying rice in only 38.5 min. [ABSTRACT FROM AUTHOR]

Background: Water and energy shortages and food security challenges associated with global warming are essential issues affecting human survival and development. Rice is one of the world's top three staple food crops. In the present study, the energy footprint (EF), carbon footprint (CF), energy production efficiency (EPE), carbon production efficiency (CPE), and economic benefit (EB) of dry direct‐seeded rice (DSR), wet direct‐seeded rice (WSR), and transplanted rice (TPR), respectively, were integrated and assessed. Results: The yield of WSR and TPR was 9.64% and 13.76% higher than that of DSR, respectively. However, DSR has less irrigation and less intensive field tillage; therefore, its energy input, and CF, were 37.47% and 44.29%, and 29.35% and 34.77%, lower than those of WSR and TPR, respectively; the EPE and CPE were obviously improved; and the EB was not lower than that of WSR and TPR. Current rice production relies heavily on non‐renewable energy inputs such as nitrogen fertilizer, diesel, and machinery. Therefore, the key to improving EPE, CPE, and EB in rice production at the same time as reducing CF was to improve water use efficiency and decrease the intensity of paddy tillage. Conclusion: The DSR has higher social, economic, and ecological benefits and can be the preferred rice planting method for rice production areas. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Copyright of Science & Technology of Cereals, Oils & Foods is the property of Science & Technology of Cereals, Oils & Foods Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Accurately estimating aboveground dry biomass (ADB) is crucial. The ADB of rice has primarily been estimated using vegetation indices with several discrete bands; nevertheless, these indices cannot take advantage of continuous bands available with hyperspectral remote sensing. This study analyzed the quantitative relationship between canopy hyperspectral characteristic parameters (HCPs) and the ADB of rice. Twenty HCPs were used, including red edge area (SDr), blue edge area (SDb), and others. The variable-screening methods involved stepwise regression (SR), a regression coefficient (RC), variable importance in projection (vip), and random forest (RF). Stepwise and partial least squares regression methods were employed with traditional linear regression as well as machine learning methods including random forest (RF), a support vector machine (SVM), a BP artificial neural network (BPNN), and an extreme learning machine. Whole- and screening-variable models were constructed to estimate rice ADB at jointing, booting, heading, and maturing stages and across growth stages. Screening-variable models include SVM models based on SR (SVM-sr), RF models based on vip (RF-vip), and others. The results show that the HCPs had a significant correlation with ADB containing elements in the red edge region, namely SDr, SDr/SDb, and (SDr − SDb)/(SDr + SDb) at each growth stage. In addition, the screening performance of vip and SR was better than that of RC and RF, and fewer variables were screened. Moreover, the HCPs of the red edge region were screened using different screening methods at each growth stage. Among them, SDr/SDb and (SDr − SDb)/(SDr + SDb) appeared frequently, indicating they are important. Furthermore, at each growth stage, ADB could be well-estimated using diverse models with the RF modeling method based on vip screening variables found to be the best modeling method for ADB estimation; the independent variables of the RF-vip model involved the (SDr − SDb)/(SDr + SDb) at each growth stage. [ABSTRACT FROM AUTHOR]

Rice drying is a complex and nonlinear process, with product quality being easily influenced by numerous factors. This study aimed to investigate the characteristics causing variation in rice quality and provide novel insights for regulating and controlling rice drying operations. To this end, response surface methodology was employed to examine the hot air drying of rice. The study was centered on investigating the impact of different levels of drying temperature (35–55 °C), relative humidity (30–50%), initial moisture content (20–28%), air velocity (0.36–0.84 m/s), and tempering ratio (1–4) on the process. The measured parameters included the net drying time, total drying time, additional crack percentage, and head rice yield. The experimental data were analyzed using Design–Expert, and the results indicated that all the response quadratic polynomial models were statistically significant. All the linear terms had a significant impact on the response variables except for the impact of air velocity on head rice yield. Finally, process reference charts of actual drying operating conditions were established based on the regression models to provide a scientific reference for guiding the control of rice drying quality and integrating into intelligent grain drying control systems in the future. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the effect of variable temperature levels on the drying characteristics and quality indices of rice in continuous drying and multi‐stage intermittent drying (MID). The quality indices of rice were assessed in terms of stress crack index, head rice yield (HRY), color, sensory characteristics, and taste value. Moreover, the microstructure of the cross‐section of rice was analyzed at different variable temperature levels. In addition, the quality indices evaluation of rice was carried out by principal component analysis. The results showed that drying temperature at the same temperature level was positively correlated with stress cracking index and total color difference, negatively correlated with drying time, HRY, whiteness index, and taste value. The MID with Δ5 (45–50°C) temperature level had the highest comprehensive score of 1.431. The results provide a reference for optimizing the drying process for rice. Practical applications: Drying is a key control step in relation to the yield and quality of rice. A reasonable and effective variable temperature drying process can improve drying efficiency and solve the problem of the limitations of a single temperature heating method. The quality indices evaluation of rice can provide a reference for the optimization of drying parameters for different variable temperature drying processes. Moreover, the variable temperature drying method in this study can improve the adaptability of the process and provide research ideas and technical references for the industrial production and automatic control of variable temperature in rice. [ABSTRACT FROM AUTHOR]

Partial root-zone drying (PRD) is an effective water-saving irrigation strategy that improves stress tolerance and facilitates efficient water use in several crops. It has long been considered that abscisic acid (ABA)-dependent drought resistance may be involved during partial root-zone drying. However, the molecular mechanisms underlying PRD-mediated stress tolerance remain unclear. It's hypothesized that other mechanisms might contribute to PRD-mediated drought tolerance. Here, rice seedlings were used as a research model and the complex transcriptomic and metabolic reprogramming processes were revealed during PRD, with several key genes involved in osmotic stress tolerance identified by using a combination of physiological, transcriptome, and metabolome analyses. Our results demonstrated that PRD induces transcriptomic alteration mainly in the roots but not in the leaves and adjusts several amino-acid and phytohormone metabolic pathways to maintain the balance between growth and stress response compared to the polyethylene glycol (PEG)-treated roots. Integrated analysis of the transcriptome and metabolome associated the co-expression modules with PRD-induced metabolic reprogramming. Several genes encoding the key transcription factors (TFs) were identified in these co-expression modules, highlighting several key TFs, including TCP19, WRI1a, ABF1, ABF2, DERF1, and TZF7, involved in nitrogen metabolism, lipid metabolism, ABA signaling, ethylene signaling, and stress regulation. Thus, our work presents the first evidence that molecular mechanisms other than ABA-mediated drought resistance are involved in PRD-mediated stress tolerance. Overall, our results provide new insights into PRD-mediated osmotic stress tolerance, clarify the molecular regulation induced by PRD, and identify genes useful for further improving water-use efficiency and/or stress tolerance in rice. [ABSTRACT FROM AUTHOR]

To solve the problems of poor stability and low monitoring precision in the online detection of rice moisture in the drying tower, we designed an online detection device for rice moisture at the outlet of the drying tower. The structure of a tri-plate capacitor was adopted, and the electrostatic field of the tri-plate capacitor was simulated using COMSOL software. A central composite design of three factors and five levels was carried out with the thickness, spacing, and area of the plates as the influencing factors and the capacitance-specific sensitivity as the test index. This device was composed of a dynamic acquisition device and a detection system. The dynamic sampling device was found to achieve dynamic continuous sampling and static intermittent measurements of rice using a ten-shaped leaf plate structure. The hardware circuit of the inspection system with STM32F407ZGT6 as the main control chip was designed to realize stable communication between the master and slave computers. Additionally, an optimized BP neural network prediction model based on the genetic algorithm was established using the MATLAB software. Indoor static and dynamic verification tests were also carried out. The results showed that the optimal plate structure parameter combination includes a plate thickness of 1 mm, plate spacing of 100 mm, and relative area of 18,000.069 mm2 while satisfying the mechanical design and practical application needs of the device. The structure of the BP neural network was 2-90-1, the length of individual code in the genetic algorithm was 361, and the prediction model was trained 765 times to obtain a minimum MSE value of 1.9683 × 10−5, which was lower than that of the unoptimized BP neural network with an MSE of 7.1215 × 10−4. The mean relative error of the device was 1.44% under the static test and 2.103% under the dynamic test, which met the accuracy requirements for the design of the device. [ABSTRACT FROM AUTHOR]

Adoption of the right rice variety and water-saving irrigation method could reduce greenhouse gas (GHG) emissions in lowland rice cultivation. A study was conducted at the research farm of Bangladesh Agricultural University, Mymensingh, Bangladesh, in 2019 during the Boro (dry) season to determine the impacts of different rice varieties (BRRI dhan29, BRRI dhan47, BRRI dhan69, Binadhan-8, Binadhan-10, and Binadhan-17) on methane (CH4) emissions under two irrigation methods, i.e., alternate wetting and drying (AWD) and continuous flooding (CF). The treatments were laid out in a split-plot design, considering water regime as the main plots and rice variety as the sub-plots. The emission rates of CH4 were determined by collecting air samples using the closed chamber technique and measuring the concentrations using a gas chromatograph. CH4 emission rates varied with the growth and development of the rice varieties. The lowest cumulative CH4 emission rate was observed in Binadhan-17, particularly under AWD irrigation. Across the rice varieties, AWD irrigation significantly reduced the cumulative CH4 emissions by about 35% compared with CF. No significant variation in rice yield was observed between AWD (5.38 t ha−1) and CF (5.16 t ha−1). This study suggests that the cultivation of Binadhan-17 under AWD irrigation could be effective at reducing the carbon footprint of lowland rice fields. [ABSTRACT FROM AUTHOR]

In the rice–rapeseed rotation system, straw incorporation plays an important role in achieving the rational utilization of resources and maintaining crop production. However, in the study of rice–rapeseed rotation, there was no study on the effect of straw and nitrogen (N) fertilizer in the rice season on the dry matter accumulation (DMA) and nutrient accumulation of subsequent rapeseed. So, this study relied on the localization experiment of rice–rapeseed rotation and annual straw incorporation (full straw returning to the field, SR; the control is full straw removal from the field, CK) with different N fertilizer application rates (N1: 0 kg ha−1, N2: 75 kg ha−1, N3: 150 kg ha−1, and N4: 225 kg ha−1) in the rice season. Based on the fourth year of experiment implementation, the effects of annual straw incorporation combined with the N fertilizer application rate in the rice season on the leaf area index (LAI), photosynthetic potential (PP), DMA and its distribution proportion and rate, and nutrient uptake and its allocation proportion in rapeseed were discussed. At the bolting stage (BS), initial flowering stage (IFS), terminal flowering stage (TFS), and mature stage (MS), the DMA of rapeseed in SR was significantly higher than that in CK by 69.90, 64.27, 62.90, and 41.27%, respectively. The accumulation of N, phosphorus (P), and potassium (K) in SR was significantly higher than that in CK at the BS, IFS, TFS, and MS. Straw treatment had a significant impact on the apparent surplus of N, P, and K in the rice, rapeseed, and annual seasons, while the application of N fertilizer in the rice season had a significant or extremely significant impact on the apparent surplus (AS) of N in the rice, rapeseed, and annual seasons, indicating that fertilization of previous crops had a certain aftereffect. Therefore, straw incorporation is a sustainable farmland management measure. [ABSTRACT FROM AUTHOR]

Nitrogen (N) recovery efficiency in dry-direct seeded rice (DSR) is less than 30%, hence, requires special consideration. Nitrogen management strategies such as splitting N in appropriate dose and application time synchronize with crop demand to improve nitrogen use efficiency (NUE). This two-year field study compared two- and three- N splits top-dressed at different crop stages using 80, 120 and 160 kg ha− 1 with 0 kg ha− 1 as control in dry DSR. Results showed that two N- splits performed similar as three-splits for agronomic, quality and NUE traits including SPAD-chlorophyll and normalized difference vegetation index (NDVI). Similar and higher straw and grain yields including harvest index was found for 120 and 160 kg N ha− 1 that was attributed to reduced spikelet sterility (24–29%), improved filled kernels (16–19%) and productive tillers (21–31%). Two- N splits at 160 kg ha− 1 resulted in higher net income and benefit: cost ratio (BCR) of dry DSR. Improved plant N status reduced kernel chalkiness and improved kernel length, proteins contents and water absorption ratio. Agronomic and physiological efficiency reduced with increasing N application while recovery efficiency (31–58%) was improved. Strong association of NDVI with leaf N, and total N uptake with sufficiency index (SI) and grain yield indicated that rice crop achieved optimal N concentration to support growth during active tillering period. Thus, additional N applied in three splits might be reduced to economize N use and SI can be used to predict and optimize the N schedule during panicle initiation or heading stages to reduce the sink limitation. [ABSTRACT FROM AUTHOR]

In this study, the effect of drying approaches in conjunction with variable temperature and tempering on the physicochemical quality of rice was investigated. The development of fissures, head rice yield, taste quality, textural properties, and microstructure of rice with different drying approaches were evaluated by employing principal component analysis (PCA). The results showed that increasing the tempering treatment could enhance the physicochemical quality of rice, and that the different drying approaches had a significant influence (P < 0.05) on the development of fissures, head rice yield, taste quality, and textural properties. High temperatures result in partial gelatinization of the starch, destruction of the starch granules, and an increase in fissures, as revealed by the microstructure of rice with different drying approaches. In addition, the drying approaches with a variable temperature of Δ0 (35 °C), Δ5 (45 °C–50 °C), and Δ0 (45 °C) in combination with the tempering treatment exhibited a high overall physicochemical quality. This study offers a point of reference for further research into the changes in the physicochemical quality of rice during drying. [ABSTRACT FROM AUTHOR]

Rice fissuring and breakage have negative economic impacts on rice processing. Many advances in multipass conventional rice drying technologies have not been successful in completely preventing rice fissure formation. Thankfully, novel drying technologies such as the 915 MHz industrial microwave have been shown to have a great potential for rice drying and may reduce rice fissuring (or increase head rice yield) due to the volumetric heating property of microwaves. This review assessed the mechanism of fissure formation in conventionally and microwave-dried grains to provide recommendations for managing fissure formation during the drying of freshly harvested paddy rice. Literature search indicates that fissure formation during microwave drying may be mainly a combination of different phenomena, such as the buildup of high internal temperature and pressure in the kernel, stresses generated from a higher flux of liquid at high microwave intensities, and other mechanisms that are yet to be discovered. Fissure formation in rice during conventional drying of the rice kernels can be explained using the glass transition phenomenon. [ABSTRACT FROM AUTHOR]

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Dry direct seeding of rice (DDSR) is being increasingly used in water-scarce areas across Asia. When drought occurs, deep sowing may enable germinating seeds to utilize the residual moisture below the surface. Our objective was to examine the effects of different sowing depths on DDSR crop growth. Two yield experiments, one in the Philippines and the other in Japan, were established in rainfed lowlands, but drought did not occur. Across the experiments, sowing at a depth of 6 to 7 cm reduced the percentage of emergence compared with sowing at a depth of 1 to 2 cm (25% vs. 73%), which resulted in lower yield (3.5 vs. 4.4 t ha−1). The relative yield (deep-sowing/shallow-sowing) was positively correlated with the percentage emergence under deep sowing. Cultivars with no significant yield reduction under deep sowing maintained high emergence (>30%) under deep sowing. Seedling's ability to emerge after deep sowing greatly differed among cultivars: the percentage emergence ranging from 0% to 18% from a depth of 8 to 10 cm, and from 11% to 44% from a depth of 6 to 7 cm. An ancillary field experiment was conducted under drought during the dry season in the Philippines: deep sowing increased the percentage emergence compared with shallow sowing (41% vs. 5%), when the soil surface was severely dry. Our results suggest that choosing cultivars that can tolerate deep sowing is a prerequisite for using deep sowing in DDSR, and that future breeding of DDSR should focus on this tolerance. [ABSTRACT FROM AUTHOR]