Rotation Cycle Research Articles

Corn grain yield, residue production, and nutrient concentration and extraction is affected by different residue incorporation rates in two biannual crop rotations

Abstract Conservation practices in agriculture using crop rotations and residue management benefit the productivity; these can vary depending on climate and soil conditions, crops, and amount of incorporated residue. The present study evaluated the effect of two biannual rotations; canola (Brassica napus L.) – corn (Zea mays L.) and bean (Phaseolus vulgaris L.) – corn rotations with four residue incorporation rates (0%, 50%, 100%, and 200%) of the preceding crop on corn grain yield, residue production, and nutrient concentration and extraction after two rotation cycles in a volcanic soil of moderate depth in south-central Chile. Grain yield varied between 17.04 and 17.40 Mg/ha, residue production between 16.41 and 16.50 Mg/ha. The preceding crop affected concentration and extraction of some nutrients in both grain and residue. The residue rate affected both concentration and extraction of some nutrients only in the grain. The Ca distribution to the corn grain was negatively affected by both the preceding bean crop and increasing residue incorporation rate. The ranking of total macronutrient extraction in the corn crop was K > N > Ca > P > Mg > S. The extraction means ranged from 320 to 326, 56.0 to 57.1, 365 to 374, 86.5 to 99.3, 39.4 to 42.4, and 22.6 to 23.7 kg/ha, whereas grain nutrient distribution coefficients ranged from 64.5 to 66.8, 90.1 to 90.9, 23.1 to 23.7, 1.3 to 2.0, 50.8 to 57.5, and 60.3 to 60.6 for N, P, K, Ca, Mg and S, respectively.

Study on the Temporal Evolution of the Radial Differential Rotation of Solar Corona Using Radio Emissions

The daily measurements of the disk-integrated solar radio flux, observed by the Radio Solar Telescope Network, at 245, 410, 610, 1415, 2695, 4995, and 8800 MHz during the time interval of 1989 January 1 to 2019 December 17, are used to investigate the temporal evolution of radial differential rotation of the solar corona using the methods of ensemble empirical mode decomposition (EEMD) and wavelet analysis. Overall, the results reveal that over the 30 yr period, the rotation rates for the observed solar radio flux within the frequency range of 245–8800 MHz show an increase with frequency. This verifies the existence of the radial differential rotation of the solar corona over long timescales of nearly three solar cycles. Based on the radio emission mechanism, to some extent, the results can also serve as an indicator of how the rotation of the solar upper atmosphere varies with altitude within a specific range. From the temporal variation of rotation cycle lengths of radio flux, the coronal rotation at different altitudes from the low corona to approximately 1.3 R ⊙ exhibits complex temporal variations with the progression of the solar cycle. However, in this altitude range, over the past 30 yr from 1989 to 2019, the coronal rotation consistently becomes gradually slower as the altitude increases. Finally, the EEMD method can extract rotation cycle signals from these highly randomized radio emissions, and so it can be used to investigate the rotation periods for the radio emissions at higher or lower frequencies.

Novel passive flow control method using leading-edge prism-shaped cylinder: Performance enhancement of vertical-axis wind turbines

Due to periodic dynamic stall at low tip speed ratios (TSRs), vertical-axis wind turbines (VAWTs) experience notable performance challenges during rotation, which leads to fluctuations in torque and a decrease in energy capture. This research aims to boost the aerodynamic performance of Darrieus VAWTs by employing a leading-edge (LE) prism cylinder (PC) to enhance energy extraction. This novel small-scale device functions as a passive method for controlling flow separation, aiming to energize the boundary layer and adjust the pressure distribution on the blades. Its effectiveness depends on factors such as size, shape, and placement, necessitating careful optimization. A three-dimensional (3D) computational fluid dynamics (CFD) analysis, combined with Taguchi optimization and analysis of variance, is conducted to determine the optimal design parameters for the LE PC tool. This 3D CFD method captures the full complexity of flow dynamics, including vortex structures and wake behavior, leading to more accurate wind turbine performance predictions than two-dimensional (2D) CFD models. The results highlight the crucial role of PC size (Factor A), which contributes nearly 85% to the total contribution factor, while the angle of PC influence is minimal. The optimized rotor demonstrates a 36% increase in maximum average power coefficient (CP) compared to an uncontrolled rotor at TSR = 1.5. However, the effectiveness of this control method diminishes at higher TSRs because the blades encounter angles of attack below the critical stall angle throughout the rotation cycle, naturally preventing flow separation and making the flow separation control method unnecessary. The PC installed on the optimized blade delays flow separation to 55% of the blade chord length, compared to 40% for the base blade. Consequently, the rotor operates efficiently, ensuring consistent, and reliable power generation without flow separation issues.

The Circadian Brain and Cognition.

Circadian rhythms are inherent to living organisms from single cells to humans and operate on a genetically determined cycle of approximately 24hours. These endogenous rhythms are aligned with the external light/dark cycle of the Earth's rotation and offer the advantage of anticipating environmental changes. Circadian rhythms act directly on human cognition and indirectly through their fundamental influence on sleep/wake cycles. The strength of the circadian regulation of performance depends on the accumulated sleep debt and the cognitive domain, and it has been suggested to involve the activation of ascending arousal systems and their interaction with attention and other cognitive processes. In addition, attention-related cortical responses show extensive circadian rhythms, the phases of which vary across brain regions. This review discusses the impact of the circadian system on sleep/wake regulation and cognitive performance. It further addresses the health implications of circadian disruption, particularly in relation to mental and neurological disorders.

PID Controller with an Override Mode for a Wall-Following Robot with a Rotating Sensor Compartment

This paper presents the design of a wall-following robot (WFR) with a rotating sensor compartment to reduce the number of distance sensors used. Two infrared (IR) sensors were fitted in the compartment that rotates back and forth at 45°, producing four measurement values at each rotation cycle. The WFR was regulated using a novel control scheme of PID controller with an override mode. A discrete PID controller in position form was used to run the WFR to follow straight wall segments or walls turning left, while an override mode governed the WFR to follow walls turning right. The sampling time was set to 300 ms. The parameters of the PID controller were tuned using a trial-and-error method. The Mean Absolute Errors (MAE) was selected as the cost function. The WFR conducted twelve trial runs along a trial track with a length of 200 cm, consisting of one right turn and one left turn. The parameters that yielded the lowest MAE of 0.90 cm were used for further tests. Subsequently, a closed track for testing was constructed with a length of 845 cm, consisting of 7 right turns and 2 left turns. The WFR completed five test runs successfully, each elapsing the test track twice. The lowest MAE during the tests was 1.06 cm. The favorable performance of the proposed WFR strengthens future development efforts to equip the robot with more hardware to fulfill specific tasks and to put the completion time into optimization consideration.

Effects of Different Nitrogen Application Measures on N2O Emissions in Wheat-maize Rotation System

To investigate the response of N2O emissions from farmland soil to different nitrogen application measures and the factors affecting it in the wheat and jade rotation system in North China, we analyzed the results of the one-time application of fertilizer in the following six treatments： without fertilization （CK）, conventional nitrogen application （urea, one instance of follow-up fertilization, U1）, optimized nitrogen application （20% nitrogen reduction, one instance of follow-up fertilization, U2）, one-time fertilization of controlled-release doped fertilizers （50% urea + controlled-release urea 50%, nitrogen reduction 20%, SRU1）, controlled-release fertilizer one-time fertilization （nitrogen reduction 20%, SRU2）, and inhibitor-type controlled-release fertilizer one-time fertilization （nitrogen reduction 20%, ISRU）, and the differences in N2O emission fluxes and soil physicochemical properties were determined. The results showed that soil N2O emission fluxes were dynamic during the wheat and jade crop rotation, and the N2O emission peaks of the CK, U1, and U2 treatments appeared in the corn season at 4-7d of basal fertilizer and 6-10d of fertilizer, and out of the wheat season its emission peaks appeared in the basal fertilizer at 4-8 d and 6-9 d of fertilizer. The emission peaks of SRU1, SRU2, and ISRU appeared in the basal fertilizer at 10-21 d, 12-20 d, and 12-20 d of fertilizer, respectively, in the corn season and the wheat season. At 21 d and 12-20 d, the application of controlled-release fertilizer significantly reduced the peak and frequency of N2O emission. Compared with those in U1, the N2O emission fluxes of the U2, SRU1, SRU2, and ISRU treatments were significantly reduced by 8.5%, 20.0%, 33.8%, and 43.6%, respectively, and the N2O emission fluxes were higher in the corn season than in the wheat season, which accounted for 58.1%-65.1% of the whole crop rotation cycle. Yield was reduced by 5.9% and 1.9% for the U2 and SRU1 treatments and increased by 1.7% and 7.0% for the SRU2 and ISRU treatments, respectively, compared to that in U1. In the maize season, the ISRU yield increased by 14.6%, the environmental benefit was $581, and the net economic benefit increased by up to 18.6% compared to that in U1, whereas the wheat season showed a decrease in yield and net economic benefit, which resulted in a one-time application of the inhibitor controlled-release fertilizers being more suitable for the maize season. Correlation analysis of N2O emission fluxes with the physicochemical indices of soil properties revealed that N2O was correlated with moisture, ammonium N, nitrate N, and microbial carbon and nitrate N and nitrogen. N2O and moisture, ammonium N, nitrate N, and microbial amount of carbon and nitrogen were significantly positively correlated. Thus, the one-time application of inhibitor-type controlled-release fertilizers played a positive role in reducing labor inputs and environmental benefits, and it could be an effective method of N fertilizer management for maize cultivation in North China.

Soil nitrous oxide emissions from wheat-based rotations with different types of pulse crops

Production of agricultural crops with a low greenhouse gas (GHG) footprint is essential to mitigate the adverse effects of climate change. The inclusion of pulse crops in cereal-based rotations can enhance environmental quality by providing biologically fixed N and thereby reducing the amount of synthetic N fertilizer required for the crop rotation. The inclusion of pulse crop has the potential to reduce N2O emissions from the agricultural system in both the legume phase and the subsequent wheat phase of the rotation. However, long-term studies are necessary to thoroughly investigate N2O emissions from rotations with pulse crops, particularly in the semiarid region where pulse crops are frequently grown. In the present study, we evaluated cumulative N2O emissions and emission intensity during the rotation cycle. The assessment was conducted over 4 years, during two complete 2-yr cycles of an established rotation (years 9–12), under the climatological conditions of 2018–2021. Four rotations including wheat-wheat, pea-wheat, lentil-wheat, and chickpea-wheat were selected from a trial in Swift Current, Saskatchewan (semiarid prairies/Brown Chernozem). Our experiment was subjected to below normal precipitation, with interannual variations in climate and the last 2 years (2020–21) were drier than the first two years (2018–2019). Under such climate, PW and LW demonstrated to be environmentally sustainable, always exporting the highest N in grains (133 kg N ha−1 averaged across PW and LW and cycles) and consistently achieving the lowest N2O intensity (2.8 g N2O-N per kg exported N averaged across PW and LW and cycles). Continuous wheat presented inconsistent results, with a significant reduction in exported N from years 9–10 to 11–12 (the driest cycle). Because WW also promoted the highest cumulative N2O emissions, N2O intensity over the 2-yr was always the highest for WW. The CW consistently promoted the lowest N exports and was not resilient to dry soil conditions, with 23% lower exported N in years 11–12 than in years 9–10. Hence including pulse crops with pea or lentil in the rotation reduced N2O emissions and enhanced wheat yield resiliency.

Response of β-glucosidase enzyme activity of soil to biochar applications in a crop rotation at Blacksea agroecosystem

The use of biochar has emerged a potentially effective approach to improve soil function and promote crop performance. However, the specific impact of biochar on β-glucosidase enzyme activity (BGA) within crop rotation systems in the Black Sea agroecosystem requires further investigation. This study was conducted to determine the effects of rice husk biochar (RHB) and poultry manure biochar (PMB) on BGA in soils. Six biochar doses (0-control, 10, 20, 30, 40 and 50 t ha-1) were applied at the beginning of two wheat-cabbage red pepper rotation periods. The mean BGA at second rotation (73.71 µg pNP g-1) was significantly lower compared to the BGA of the first period (93.39 µg pNP g-1). The BGA value in control (94.51 µg pNP g-1) decreased with increasing biochar application doses (76.05 µg pNP g-1, 50 t ha-1) treatment. The mean BGA value in PMB treatment was slightly higher than that of RHB, but it was not statistically different between two biochar types. However, the decrease in BGA value (25.0%) in the highest RHB dose compared to control was more than two-fold compared to the decrease in PMB application (12.1%). The difference in carbon/nitrogen ratio between RHB and PMB can be attributed to the variation in BGA values observed at the application of same biochar doses. The decrease in BGA over the course of the two rotation cycles implies that biochar may have a long-term influence on soil carbon cycling.

Medium-Term Monitoring of Greenhouse Gases above Rice-Wheat Rotation System Based on Mid-Infrared Laser Heterodyne Radiometer

The rice-wheat rotation system is a major agricultural practice in China as well as an important source of greenhouse gas (GHG) emissions. In this study, the developed mid-infrared laser heterodyne radiometer (MIR-LHR) was used for the remote sensing of atmospheric CH4 and N2O concentrations above the rice-wheat rotation system. From April 2019 to May 2022, the atmospheric column concentrations of CH4 and N2O above the rice-wheat rotation system were continuously observed in Hefei, China. The peak values of the N2O column concentration appeared 7~10 days after wheat seasonal fertilization, with additional peaks during the drainage period of rice cultivation. During the three-year rice-wheat crop rotation cycle, a consistent trend was observed in the CH4 column concentrations, which increased during the rice-growing season and subsequently decreased during the wheat-growing season. The data reveal different seasonal patterns and the impact of agricultural activities on their emissions. During the observation period, the fluctuations in the CH4 and N2O column concentrations associated with the rice-wheat rotation system were about 40 ppbv and 6 ppbv, respectively. The MIR-LHR developed for this study shows great potential for analyzing fluctuations in atmospheric column concentrations caused by GHG emissions in the rice-wheat rotation system.

Assessing the Effectiveness of Rotation Growing of Industrial Hemp and Alfalfa in Post-Mining Agricultural Reclamation: Using Soil Fauna as an Indicator

The reclamation of post-mining land for agricultural purposes has continued to be a big challenge. Our study concerns the use of soil microfauna (nematodes) and mesofauna (mites and springtails) as indicators of soil quality after 6 years of agricultural reclamation of a post-mining area in west–central Poland. A new method, which involves rotation growing of industrial hemp (H) and alfalfa (A) and incorporating the resulting biomass into the soil, was used to reclaim two sites (5 and 15 years after mining) representing different types of post-mining deposits (clayey and sandy). On each site, two plots were established, where each crop was grown for three years, but in a different order during the rotation cycle (3H3A and 3A3H). The results showed significant differences in the abundance and structure of the fauna communities between 3H3A and 3A3H reclamation practices, as well as between the reclaimed plots and non-reclaimed (NR) plots, where spontaneous succession proceeded. The three animal groups were more abundant in the reclaimed soil compared to the NR soil. The highest densities for nematodes were observed in the 3H3A plots and for the mesofauna in the 3A3H plots. The reclamation practices had a positive effect on groups involved in the regulation of C and N mineralisation, particularly bacterial- and hyphal-feeding nematodes and oribatid mites, and a negative effect on plant-feeding nematodes and euedaphic collembolans. The finding that most of the parameters of the studied biota had values resembling those of agricultural soils after 6 years of reclamation clearly indicates the effectiveness of the applied practices for transforming degraded land into soils that mirror soils under agricultural use.

Yield and profit comparison of diversified versus conventional crop rotation systems in South Dakota

AbstractDiversified crop rotations with no‐till management are considered fundamental to sustainable agroecosystems; however, associated uncertainty in economic returns may hinder farmers’ decisions to adopt these practices. The objectives of this study were to compare economic performance (gross revenue, net revenue, and production cost) among various low‐input diversified versus conventional crop rotations. The experiment was initiated in the fall of 2000 with winter wheat (Triticum aestivum L.) planting and planting of remaining crops in the spring of 2001 near Brookings, SD. Economic analysis was performed from data collected during the fifth complete 4‐year crop rotational cycle (2017–2020) of six crop rotations: (1) 4‐year corn (Zea mays L.)‐soybean [Glycine max L. (Merr.)]‐spring wheat‐sunflower (Helianthus annus L.) (CSSwSf), (2) 4 year corn‐soybean‐spring wheat‐pea (Pisum sativum L.) (CSSwP), (3) 4‐year corn‐pea‐winter wheat‐soybean (CPWwS), (4) 4‐year corn‐oat (Avena sativa L.)‐winter wheat‐soybean (COWwS), (5) 2‐year corn‐soybean (CS), and (6) continuous corn (CCC, treatment initiated in 2017). Corn yield in CSSwP rotation, where corn followed peas, was higher (p < 0.05) by 20%, 25%, 45%, and 89%, compared to CPWwS, CSSwSf, CS, and CCC rotations, respectively. Similarly, soybean yield following winter wheat was significantly higher by 16%–38% in COWwS and 13%–38% in CPWwS compared to CSSwP, CSSwSf, and CS. Overall, diversified crop rotations improved both corn and soybean yield and net revenue compared to 2‐year CS and monoculture CCC rotations. Moreover, 4‐year diversified systems, specifically COWwS, CPWwS, and CSSwP, demonstrated economic resilience by maintaining stable production costs.

Fertility and tillage intensity affect weed community diversity and functional structure in long-term organic systems.

Knowledge of how agricultural management interacts with weed seed banks and emergent weed communities is crucial for proactive weed management. Though studies have detailed how differences in disturbance and nutrient applications between organic and conventional herbicide-based systems affect weed communities, few have focused on these same factors in contrasting organic systems. This study assessed the seed banks and emergent weed communities from the most recent crop rotation cycle (2017-2022) of a long-term experiment, which compared four organic grain and forage cropping systems differing in nutrient inputs and soil disturbance. The high fertility (HF) system received high-rate nutrient applications, low fertility (LF) received low-rate applications, enhanced weed management (EWM) focused on weed control through frequent soil disturbance, and reduced tillage (RT) prioritized soil health with less intense or frequent soil disturbance. Soil samples for greenhouse germination assays were collected at the beginning (2017) and end (2022) of the rotation to explore how these four systems influenced seed bank dynamics over time. Weed community biomass was also sampled in each crop during this time. Treatment effects on weed abundance, taxonomic diversity, and community-weighted means and functional dispersion of weed traits were analyzed with generalized mixed-effect models. The RT system had the highest weed seed bank taxonomic diversity, and EWM had the lowest. RT and LF had higher functional dispersion of traits than HF in the seed bank. Weed seed bank communities in HF and RT were characterized by short, small-seeded, and early germinating weed species. However, seed banks were also labile: Differences between systems in seed density and all other mean trait values were dependent on the crop, which preceded seed bank sampling. Likewise, differences among emergent weed communities in the four systems depended on an interaction between crop species and their planting year. Results suggest that resource availability and intensity of disturbance act as weed community assembly filters in organic cropping systems. Organic growers seeking to design systems that balance weed management and production goals can use relatively low soil disturbance and nutrient application to increase weed community taxonomic or functional diversity without necessarily increasing weed biomass or seed bank density.

Spatially Selective Ultraprecision Polishing and Cleaning by Collective Behavior of Micro Spinbots

Untethered magnetic actuation is an attractive technique for controlling a batch of micrometer‐sized soft robots. Recent advancements have enabled each robot to follow its path independently using a single magnetic device. However, applications of magnetic soft microrobots are mostly biased toward the biomedical field. In this study, thermoplastic polyurethane–Fe3O4 nanocomposite soft spinning microrobots, that is, spinbots that actuate on a tabletop magnetic stirrer, were utilized as innovative precision manufacturing tools for spatially selective precision polishing and cleaning. The pivot motion of the revolving spinbots, which involves repetitive sweeping during rotation cycles, is explored. This sweeping action physically removes nanometer‐sized surface contaminants from the workpiece, achieving a cleaning efficiency of 99.6%. Multiple spinbots, up to 42 in total, simultaneously operated along their own orbital pathways on three vertically stacked wafers, thereby demonstrating an unprecedented cleaning method. In addition, the spinbots precisely removed materials from the workpiece using a three‐body abrasion mechanism. Furthermore, the spinbots contributed to precise material removal, resulting in remarkable surface polishing (R a ≈ 1.8 nm). This novel polishing system, which uses the collective behavior of multiple spinbots on a tabletop magnetic stirrer, is 1000‐fold lighter than current state‐of‐the‐art equipment aimed at achieving similar levels of fine finishing.

Crop Residue Biochar Rather Than Manure and Straw Return Provided Short Term Synergism Among Grain Production, Carbon Sequestration, and Greenhouse Gas Emission Reduction in a Paddy Under Rice‐Wheat Rotation

ABSTRACTReturn of crop residues directly as straw, animal manure, or biochar are recommended management options for biowaste recycling and soil organic carbon (SOC) maintenance in agriculture. However, to address the soil health challenges associated with soil degradation and climate change, it is critical to determine if or which of these different forms of crop residues could deliver a synergic improvement in SOC storage, emission reduction, and crop productivity following field application. In this study, maize straw in the form of air‐dried biomass (CS), manure via cattle digestion (CM), and biochar via pyrolysis (CB) was respectively amended once at a dose of 10 t C ha−1, in comparison to no maize straw addition (CK), in a paddy field under rice‐wheat rotation. Changes in soil properties, SOC storage, greenhouse gas (GHG) emissions, and rice/wheat yield were examined over two consecutive rice/wheat rotation cycles following soil amendment. The total rice grain yield considerably increased by 6% under CM and CB, while it reduced by 6% under CS compared to CK. Soil nutrient content persistently increased under CM and CB by 4.2% ~ 17% and 11% ~ 26% for total nitrogen, 26% ~ 61% and 20% ~ 53% for available P, and 2% ~ 82% and 30% ~ 115% for available K, respectively. Topsoil SOC storage increased considerably by 8% under CM and 20% under CB, while remained unchanged under CS, compared to CK. The total methane (CH4) and nitrous oxide (N2O) emissions were considerably increased by 7 folds and 15% under CS and 3.5 folds and 61% under CM, respectively, compared to CK. In contrast, these emissions considerably decreased under CB by 33% for CH4 and 29% for N2O. Consequently, the C emission efficiency considerably reduced under CS and CM but increased under CB over the two rotation cycles monitored. Moreover, the soil quality index (SQI) considerably improved under CM and CB but remained unchanged under CS compared to CK. Among the different forms of straw return, manure, and biochar, straw amendments differed considerably in their effects on C sequestration, GHG emissions, and crop productivity. Only biochar from crop residues synergistically improved these functions in the short‐term following application to paddy soil.

Unsteady CFD simulation of a rotor blade under various wind conditions

Wind and gusts can significantly impact the performance of rotors and turbines. The transient behavior of the rotor should be carefully examined to account for these effects. This paper investigates the unsteady aerodynamic characteristics of a rotor blade under different wind conditions, such as direction, speed, and angle. A 3D transient Computational Fluid Dynamics (CFD) simulation using the dynamic mesh technique is performed to analyze the rotor dynamics. The unsteady Reynolds-averaged Navier–Stokes (URANS) equations with the k-ω SST turbulence model are solved. The rotor blade used for this study is the U15XXL Combo KV29 industrial blade, which has not been numerically analyzed before. The results show that wind in the same direction as the rotation reduces the thrust more than lateral or opposite wind. Lateral wind with a speed lower than 5 m/s decreases the blade performance, but higher speeds increase it. Higher lateral wind speeds also cause two peaks in the torque curve, forming a butterfly wing shape in the polar torque plot and multiple extrema in the torque curve with increasing speed. The maximum thrust shifts slightly to the left with increasing lateral wind speed. The lateral angle does not affect the average thrust produced in one blade revolution but only causes a spatial shift. The thrust production decreases as the angle approaches the opposite direction of rotation. The motion amplitude decreases, and the curve becomes smoother as this angle increases. A nearly straight line similar to no side wind is observed at 60 and 90 degrees, which is attributed to the constant effective angle of attack during the rotation cycle.

Volumetric and energy production assessment of wood in managed forest in the Brazilian arid biome

There is a growing demand for wood products from forests located in dry regions, which includes the Caatinga, a biome in Northeast Brazil. This study evaluates the relationship between volumetric production, energy potential, and the rotation cycle. Information was collected from forest stands in different stages of regeneration located in an arid region of Brazil. Based on the forest management plan, four fields were selected with post-logging ages of 9, 11, 13, and 16 years. This inventory recorded circumference at chest height, circumference at base height, total height, volume, stored energy, technical cutting age, and rainfall index. The results showed that the species that presented the most significant quantity of stems did not always correspond to those that obtained the most significant amount of biomass. The technical cutting age was determined at 16 years, aiming to maximize wood utilization. Regarding energy density, the 9-year-old field reached 7,281 kcal ha-1, the 11-year-old field obtained 14,448 kcal ha-1, the 13-year-old field recorded 41,526 kcal ha-1, and the 16-year-old field reached 98,190 kcal ha-1. The species that contributed most to energy accumulation included Mimosa tenuiflora with 3,740 kcal m–³, Piptadenia stipulacea with 3,271 kcal m-3, and Cenostigma pyramidale with 3,101 kcal m-3.

Effect of Organic Manure on Crop Yield, Soil Properties, and Economic Benefit in Wheat-Maize-Sunflower Rotation System, Hetao Irrigation District.

The combined application of manure and mineral fertilizer represents an effective strategy for enhancing crop yield. However, the relationship between soil fertility and crop yield remains unclear in saline-alkaline soil. Here, a 9-year field experiment (2015-2023) was conducted to investigate the effects of manure application and crop rotations on crop yield and economic efficiency as well as potential associated mechanisms in the Hetao Irrigation District. The results showed that in the third cropping rotation cycle, combined application of manure and mineral fertilizers (NPKO) caused a 6.2%, 38.9%, 65.3%, and 132.2% increase in wheat, sunflower, wheat equivalent yield, and the economic income of sunflower, respectively. The average grain yield had a positive correlation with soil organic matter and nutrient supply. This suggested that the soil organic matter had a positive effect on the crop yield due to its impact on nutrient supply. Simultaneously, the sunflower seed setting rate increased by 65.2% under NPKO. The linear regression model revealed that each additional input of 20 Mg ha-1 of manure resulted in an increase of 3.56 kg ha-1 in crop phosphorus harvest and a 0.05 Kg ha-1 increase in wheat equivalent yield compared to NPK. In conclusion, our results highlighted that manure application promotes soil properties and improves crop yield.

Primary Non-Inversion Shallow Tillage Versus Moldboard Plowing Prior to Growing Potatoes: Short-Term Impacts on Potato Yield and Soil Properties in Eastern Canada

Potato (Solanum tuberosum L.) production often requires intensive tillage with the moldboard plow (MP), which involves deeper soil tillage and turning of the soil to provide enough loose soil for proper tuberization. Although tillage with the MP allows better potato seedbed preparation and lower weed pressure, it is also associated with increased soil compaction, soil aggregate destruction, and increased soil organic matter (SOM) mineralization. The objective of this four-year (2019–2022) study conducted in 14 commercial fields was to compare the use of MP with primary non-inversion shallow tillage (ST) in terms of their effect on selected soil health indicators, soil moisture, potato petiole nitrate concentration, potato yield, and specific gravity. Commercial fields ranged from 1.5 ha to 19 ha where the main field was split in half, with one side tilled using MP (22.5–30 cm plowing depth) and the other half using ST (15–30 cm plowing depth). Soil and plant tissue samples were taken within four sub-replicates (91 m2) created per each treatment per each site and three to four sites were used as replicates per each year. Compared to MP, ST increased active carbon by an average of 9%, soil respiration by an average of 26%, and aggregate stability by an average of 8%. Biological N availability (BNA) increased by an average of 20% with ST, and the effect was statistically significant in three out of four years. Soil moisture at 20 cm depth tended to be higher with MP than ST in three out of four years. Although not statistically significant, when averaged across four years, potato petiole nitrate concentrations were 5% and 12% higher with ST than MP in samples collected at the flowering and post-potato flowering stages, respectively. Total and marketable potato yields, along with specific gravity, were comparable for the two tillage regimes. Signs of soil improvement were observed at the early stages of ST adoption. Marketable yield was negatively correlated with the soil nitrate levels measured during the growing season but was positively correlated with active carbon, aggregate stability, and soil moisture. Future studies could compare both tillage regimes over multiple growing seasons to assess their impacts over a full cycle of rotation. The novelty of the present study was that it was conducted in real-life conditions across large growers’ fields with different conditions and across four years.

Aging Delays Completion of Head Rotation Cycles in Continuous Gaze Stabilization Exercises despite Putative Healthy Vestibular Function

Introduction: Aging is associated with loss of balance, with falls being one of the leading causes of death among the elderly in the USA. Gaze stabilization exercises (GSE) improve balance control in vestibular populations and could be useful to prevent falls in healthy individuals. However, the extent to which aging affects head kinematics in GSE is unknown. Methods: Forty-eight younger (n = 25, 24 ± 6 years, 60% female) and older (n = 23, 66 ± 5 years, 56% female) adults completed six 30-s GSE. Participants were asked to maintain gaze fixation on a stationary target while continuously performing head movements in pitch (e.g., vertical) and yaw (e.g., horizontal) directions. The visual target was placed on the wall 1 m or 2 m away or handheld at arm’s length. Head kinematics were recorded with an inertial measurement unit placed on the back of the participants’ head. Results: Older adults took significantly more time (e.g., delay) to complete cycles of head rotation in both pitch and yaw compared to younger participants across all GSE. Such delay was further increased during yaw head rotation while fixating gaze of the 1 m target. The average peak velocity (APV) and average angular displacement (AAD), however, were equivalent between groups in all GSE. Conclusion: Aging leads to the maintenance of head rotation APV and AAD at the expense of delayed cycles of head rotation, suggesting an age-dependent prioritization strategy (e.g., adapt duration first, range second) during continuous head movements. The distance of the visual target and head movement direction influenced elderly performance and should be considered when prescribing GSE to older populations.

Crop Establishment, Residue Retention and Nutrient Management Influence the Phenology-mediated Greenhouse Gases Emission in an Intensive Rice-wheat System

The impact of management practices (i.e. crop establishment, tillage, residue addition etc.) on the global warming potential (GWP) and greenhouse gas intensity (GHGI) in rice-wheat cropping system accounting the economic viability is sparsely documented. A field experiment was established in 2020 to gain insight crop phonology mediated greenhouse gas emission into GWP, GHGI and economic viability on crop seasonal scale over three cycles (2020, 2021 and 2022) of rice-wheat rotations under subtropical climatic condition. Treatments were three planting techniques viz., System of rice intensification (SRI) followed by conventional wheat without residues (SRI-CW), Puddle Transplanted rice (TPR) followed by CW with 30% rice residue incorporation (TPR-CWRi) and zero-till direct sowing of rice (ZT-DSR) followed by ZT wheat with 30% rice residue retention (ZTDSR-ZTWRr) and four different nutrient management practices viz., 100% NPK (as per recommended dose) through mineral fertiliser (100% NPKi), 75% NPK through mineral fertiliser with 25% N trough organics (75% NPKi + 25%NOrg.), 50% NPK through mineral fertiliser with 50% N trough organics (50% NPKi + 50% NOrg.) was followed in both rice and wheat crop and 100% NPK through mineral fertiliser (100% NPKi) along with mung bean (Vigna radiata) green manure in rice and 100% NPK through mineral fertiliser in wheat (100% NPKi + GM). All treatments were established in a split-plot design and repeated three times; where three planting techniques were arranged in main plots and four different nutrient management practices were arranged in sub-plots. The highest system productivity was obtained under ZTDSR-ZTWRr treatment. Moreover, this system reduced the CH4 and N2O emission by 62.7 and 48% respectively over TPR-CWRi, hence, the Global Warming Potential (GWP), as well as gaseous intensity (GHGI), were reduced by 2.0-2.18 and 2.13-2.20 times, respectively than the traditional technique of cultivation. Green manure behaves differently by increasing the system productivity by 4.27% was and reducing the GHGI 4.56% over 100% NPKi. Thus, ZTDSR-ZTWRr along with 100% NPKi and green manuring in rice could be an economically viable opportunity for maintaining future yield standard of the system with lower emission scenario.