Complex Rotation Research Articles

Regulation of wheat yield by soil multifunctionality and metagenomic-based microbial degradation potentials under crop rotations

Crop rotation benefits soil fertility and crop yield by providing organic components including cellulose, lignin, chitin, and glucans that are mainly degraded by soil microbial carbohydrate-active enzymes (CAZymes). However, the impacts of crop rotation on soil microbial CAZyme genes are not well understood. Hence, CAZyme genes and families involved in the degradation of differentially originated organic components were investigated using metagenomics among distinct crop rotations. Crop rotation had a more significant effect on soil nitrogen than on carbon fractions with higher content in the complex rotation referring to alfalfa (Medicago sativa L.; 4 year)-potato (Solanum tuberosum L.; 1 year)-winter wheat (3 year; A4PoW3). The composition of soil microbial CAZyme genes related to the degradation of fungi-derived components was more affected by crop rotation compared with the degradation of plant- and bacteria-derived components. The total abundance of CAZyme genes and families was significantly higher in the complex rotation. Notably, CAZyme genes belonging to glycoside hydrolase and glycosyl transferase families had more connections in their network. Moreover, key genes including CE4, GH20, and GH23 assembled toward the middle of the network, and were significantly regulated by dominant soil nitrogen fractions including soil potential nitrogen mineralization and microbial biomass nitrogen. Soil multifunctionality was mostly explained by the composition and total abundance of CAZyme genes, but wheat grain yield was profoundly regulated by fungi-derived components degradation genes under effects of dominant nitrogen fractions. Overall, the findings provide deep insight into the degradation potentials of soil microbial CAZyme genes for developing sustainable crop rotational agroecosystems.

Modeling soil organic matter changes under crop diversification strategies and climate change scenarios in the Brazilian Cerrado

In Brazil, land conversion and agricultural management have historically accounted for the largest share of the country's greenhouse gas (GHG) emissions, with the Cerrado region being one of the most affected areas. Although cropping diversification has been proposed as a potential strategy to mitigate GHG emissions through soil organic carbon (SOC) sequestration, the long-term effects of these systems in the Cerrado are unknown. The DayCent model was used to simulate the impact of crop diversification and tillage on SOC dynamics until 2070 (∼50 years), including common crop succession systems and crop rotations associated with cover crops under climate change scenarios. First, we calibrated and evaluated the DayCent model using plant and soil observations from three sites in the region, where Pearson coefficients (r values) ranged from 0.50 to 0.94 (calibration sites) and 0.53–0.99 (validation site) for crop yields, SOC, and nitrogen. We then used the model to investigate how cropping systems and climate interact to control SOC levels. Results indicate that SOC stocks would decrease under the long-term (∼50 years) soybean-cotton succession, regardless of soil management (-0.04 to −0.17 Mg C ha−1 year−1). Crop diversification with crop rotation and cover crops (i.e., millet, ruzigrass, sunn hemp) had the highest SOC accrual potential (∼0.71 Mg C ha−1 year−1), resulting in SOC stocks of up to 130 Mg C ha−1 by 2070. Ruzigrass, either single or intercropped with maize on crop succession systems, showed substantial potential for SOC sequestration (∼0.55 Mg C ha−1 year−1) and could be a viable strategy if implementing more complex rotations is not feasible. The SSP2 – 4.5 and SSP5 – 8.5 climate change scenarios increased SOC stocks by 6.3 and 8.2 % in SOC across treatments by 2070, respectively. Results suggest that diversified cropping systems are a promising strategy for increasing SOC sequestration, and they offer valuable guidance for enhancing current management practices in the region.

A Robust Switching Control Strategy for Three-Phase Voltage Source Converters with Uncertain Circuit Parameters

This study proposes a novel double closed-loop robust control strategy based on a power switching affine model of three-phase voltage source converters (VSCs). The aim is to overcome the challenges posed by inaccurate mathematical models, complex controller configurations, indirect switching control, and performance degradation under circuit parameters uncertainty or load variation in conventional methods. These conventional methods rely on linearization models, duty ratio regulation, and pulse width modulation (PWM) technologies. The contributions of work are the following: (1) A two-dimensional (2D) power switching affine model is constructed without any approximation or averaging. (2) The proposed approach achieves direct switching control of three-phase VSCs, eliminating the need for complex rotation coordinate transformation, PWM, and phase locking loop (PLL), which are utilized in traditional control methods. (3) The rigor of the system stability analysis is enhanced based on the 2D power switching model compared to the existing three-dimensional (3D) current switching model. (4) A simple control structure with only two control parameters is employed to address circuit parameter uncertainties. The effectiveness and superiority of the proposed method is validated through simulation and experimental comparison results.

The motion of three-dimensional fractal aggregates in homogeneous shear flow

A model for the motion of aggregates in low Reynolds number flow has been established by utilizing the Stokesian dynamics and applying the quaternion as global attitude parameter. The model has been validated by the theorical solution of sphere doublet in shear flow, the simple helical aggregates, and the experiment on the settling of some specific objects in still water. The motion of fractal aggregates has been further studied, aiming to get better understanding of the dynamic behavior of fine-grained sediment flocs in shear flow. The fractal aggregates have been generated using the diffusion-limited aggregation model, which has similar fractal dimension as natural flocs. The results illustrate that fractal aggregates undergo a complex rotation in shear flow, which exhibit a bi-periodic characteristic. The motion of a particle within the fractal aggregate shows three-dimensional trajectory in a simple shear flow, affected by its initial orientation. The major rotation period is approximately 4π/γ̇, which corresponds to the rotation period of a sphere with shear strength γ̇. The deviation decreases with the increase in the size of the fractal aggregate.

Investigation of the doubly excited [formula omitted] resonance series in C[formula omitted] ion

We investigate in the present paper the doubly excited 1Po states in the C4+ ion. We report highly accurate results of their energy positions in the energy spectrum, their lifetimes and the x-ray photon energies required to populate them and observe their autoionization. The results were obtained by using our B-spline based spectral approach combined with the complex rotation method that has proven its effectiveness in the detection of the doubly excited states in the O6+[1] and Li+[2] ions. We also report in the paper the first results on the characterization and identification of the states that share similar angular correlation pattern, which allows their classification into distinct resonance series.

Generalized spin σ-SCF method.

We introduce a generalization of the σ-SCF method to approximate noncollinear spin ground and excited single-reference electronic states by minimizing the Hamiltonian variance. The new method is based on the σ-SCF method, originally proposed by Ye et al. [J. Chem. Phys. 147, 214104 (2017)], and provides a prescription to determine ground and excited noncollinear spin states on an equal footing. Our implementation was carried out utilizing an initial simulated annealing stage followed by a mean-field iterative self-consistent approach to simplify the cumbersome search introduced by generalizing the spin degrees of freedom. The simulated annealing stage ensures a broad exploration of the Hilbert space spanned by the generalized spin single-reference states with random complex element-wise rotations of the generalized density matrix elements in the simulated annealing stage. The mean-field iterative self-consistent stage employs an effective Fockian derived from the variance, which is utilized to converge tightly to the solutions. This process helps us to easily find complex spin structures, avoiding manipulating the initial guess. As proof-of-concept tests, we present results for Hn (n = 3-7) planar rings and polyhedral clusters with geometrical spin frustration. We show that most of these systems have noncollinear spin excited states that can be interpreted in terms of geometric spin frustration. These states are not directly targeted by energy minimization methods, which are meant to converge to the ground state. This stresses the capability of the σ-SCF methodology to find approximate noncollinear spin structures as mean-field excited states.

Fitting the Light Curve of 1I/‘Oumuamua with a Nonprincipal Axis Rotational Model and Outgassing Torques

In this paper, we investigate the nonprincipal axis (NPA) rotational state of 1I/‘Oumuamua—the first interstellar object discovered traversing the inner solar system—from its photometric light curve. Building upon Mashchenko, we develop a model which incorporates NPA rotation and Sun-induced, time-varying outgassing torques to generate synthetic light curves of the object. The model neglects tidal forces, which are negligible compared to outgassing torques over the distances at which ‘Oumuamua was observed. We implement an optimization scheme that incorporates the NPA rotation model to calculate the initial rotation state of the object. We find that an NPA rotation state with an average period of 〈P〉 ≃ 7.34 hr best reproduces the photometric data. The discrepancy between this period and previous estimates is due to continuous period modulation induced by outgassing torques in the rotational model, as well as different periods being used. The best fit to the 2017 October data does not reproduce the 2017 November data (although the later measurements are too sparse to fit). The light curve is consistent with there being no secular evolution of the angular momentum, which is somewhat in tension with the empirical correlations between nuclear spin-up and cometary outgassing. The complex rotation of ‘Oumuamua may be the result of primordial rotation about the smallest principal axis if (i) the object experienced hypervolatile outgassing and (ii) our idealized outgassing model is accurate.

Using Time Series Sentinel Images for Object-Oriented Crop Extraction of Planting Structure in the Google Earth Engine

Timely and accurate extraction of crop planting structure information is of great importance for food security and sustainable agricultural development. However, long time series data with high spatial resolution have a much larger data volume, which seriously limits the quality and efficiency of the application of remote sensing to agriculture in complex crop rotation areas. To address this problem, this paper takes Lujiang County, a typical complex crop rotation region in the middle and lower reaches of the Yangtze River in China as an example, and proposes utilizing the Google Earth Engine (GEE) platform to extract the Normalized Difference Vegetation Index (NDVI), Normalized Difference Yellowness Index (NDYI) and Vertical-Horizontal Polarization (VH) time series sets of the whole planting year, and combining the Simple Non-Iterative Clustering (SNIC) multi-scale segmentation with the Support Vector Machine (SVM) and Random Forest (RF) algorithms to realize the fast and high-quality planting information of the main crop rotation patterns in the complex rotation region. The results show that by combining time series and object-oriented methods, SVM leads to better improvement than RF, with its overall accuracy and Kappa coefficient increasing by 4.44% and 0.0612, respectively, but RF is more suitable for extracting the planting structure in complex crop rotation areas. The RF algorithm combined with time series object-oriented extraction (OB + T + RF) achieved the highest accuracy, with an overall accuracy and Kappa coefficient of 98.93% and 0.9854, respectively. When compared to the pixel-oriented approach combined with the Support Vector Machine algorithm based on multi-temporal data (PB + M + SVM), the proposed method effectively reduces the presence of salt-and-pepper noise in the results, resulting in an improvement of 6.14% in overall accuracy and 0.0846 in Kappa coefficient. The research results can provide a new idea and a reliable reference method for obtaining crop planting structure information efficiently and accurately in complex crop rotation areas.

Ag sputter coating of PLLA nonwovens

Abstract Physical vapor deposition (PVD) sputtering is a promising technique for the generation of electrically conductive coatings on complex structured biomaterials, such as nonwovens, that can be used in implants. The ultra-thin coatings can fulfil a variety of purposes, such as drug depot or biosensor. The aim of our studies was to determine the feasibility of generating thin silver (Ag) coatings on complex structured poly-L-lactide (PLLA) nonwovens by sputtering and their morphological characterization. PVD sputter process was performed using a customized plasma chamber and a complex rotation of the tender electrospun PLLA nonwovens. Morphological analysis revealed a promising homogenous Ag coating, representing the structure of the nonwovens.

Membrane anatomy-based splenic hilar lymph node dissection for gastric cancer

There is a consensus that selectively perform splenic lymph node dissection is necessary for high-risk patients with proximal gastric cancer to achieve radical treatment. However, there are still some outstanding issues that need to be solved during the practice of splenic lymph node dissection. These include poorly defined boundaries, technical difficulties, and blurred boundaries in No. 10 and No. 11 lymph nodes, etc. Membrane anatomy has achieved successful applications in the field of gastric and colorectal surgery in recent years. The study of membrane anatomy in the splenic hilum region is controversial due to the special location of the splenic hilum, which involves multiple organs and affiliated mesentery undergoing complex rotation, folding, and fusion during embryonic development. In this manuscript, we summarize the following points based on existing research and personal experience regarding membrane anatomy. 1. There is a membrane anatomical structure that can be used for lymph node dissection in the splenic hilum region. 2. The membrane structure in the splenic hilum region can be divided into two layers: the superficial layer is composed of the dorsal mesogastrium, and the deep layer is composed of Gerota fascia, the tail of the pancreas, and the mesentery of the transverse colon (from head to tail). 3. There is a loose space between the two layers that can be used for separation during surgery. The resection of the dorsal mesogastrium belongs to D2 dissection. The No. 10 lymph node in the deeper layer belongs to the duodenal mesentery, and the resection of the No.10 lymph node exceeds D2 dissection. The complete excision of the gastric dorsal mesentery is consistent with the D2+CME surgical mode proposed by Gong Jianping's group.

Conversion of THz refractive index variation to detectable voltage change realized by a graphene-based Brewster angle device.

The Brewster effect has been previously reported as an essential mechanism for terahertz (THz) wave sensing application. However, generally in a sensing application, a complex rotation apparatus is required for detecting the slight change in Brewster angle. Here, we propose a graphene-based Brewster angle device operating at a specific terahertz frequency capable of sensing the refractive index at a fixed incident angle. In other words, our sensing device could avoid the impact of Brewster angle shift and eliminate the need for high-precision rotating equipment, which is usually required in traditional sensing applications. The conversion from the refractive index to a Volt-level detectable voltage roots from the tunability of graphene's Fermi level in the external electrical field. A linear correlation between the output voltage and the background refractive index is observed and theocratically analyzed. Furthermore, we present the improvement of our device in terms of sensing range and sensitivity by adjusting the permittivity of the dielectric substrate. As a demonstration of our proposed device, a detection range of 1.1-2.4 and a sensitivity of 20.06 V/RIU for refractive index is achieved on a high-resistance silicon substrate operating at 0.3 THz.

Linking soil phosphorus fractions to associated microbial functional profiles under crop rotation on the Loess Plateau of China

Crop rotation plays an essential role in maintaining soil fertility and is meaningful to soil health and sustainable agricultural management. However, the impact of crop rotational regimes on the soil phosphorus (P) fractions and associated phosphorus cycling (P-cycling) profiles driven by microbial communities are not well elucidated. Hence, we used metagenomics to comprehensively investigate the variations in soil microbial P-cycling functional genes and representative processes, as well their regulations for soil P fractions among distinct crop rotational regimes and complexity. Most soil properties, particularly P fractions, were significantly greater in corn rotations than other crop rotations. The composition of P-cycling functional genes and microbial communities was also distinctly clustered in accordance with crop rotational regimes to varying degrees. The potential of representative P-cycling processes was all significantly higher in the complex rotation. Notably, the key functional genes including phoD, ppx, pstB, ugpA were differently screened from each P-cycling process and assembled toward the middle of their networks. Furthermore, soil potential carbon mineralization as a dominant property regulated several P-cycling processes and was intimately associated with the key P-cycling functional genes. Crop rotational complexity and the P-uptake and transport process had profoundly total effects on soil P fractions. Overall, this study provides a deep insight into soil microbial P-cycling functional profiles for developing sustainable soil P management practices at crop rotational agroecosystems.

Complex crop rotations improve organic nitrogen cycling

Nitrogen (N) availability in agroecosystems is often poorly coupled to plant N uptake, leading to inefficient fertilizer use and environmental losses. Building soil organic N pools and enhancing internal recycling of N with crop rotations while reducing synthetic inputs may help improve N use efficiency. The organic N pool could be a valuable source of N that could help farmers reduce reliance on large inorganic N inputs if controls on its availability were better understood. While we know that the breakdown of high-molecular weight organic N compounds is the rate-limiting step to accessing bioavailable N from organic sources in natural ecosystems, there has been little work in agroecosystems to identify how management influences this inflection point in the N cycle. To provide insight into how growers can manage the organic N pool to reduce fertilizer input, we examined gross protein depolymerization rates within an agricultural context. Specifically, we investigated 1) how crop rotations affect organic N pools and alter the rate of organic N cycling, and 2) whether inorganic N fertilization enhances, has no effect, or suppresses soil N cycling responses to crop rotation. To test this, we measured gross rates of protein depolymerization, amino acid consumption, mineralization, and ammonium consumption using 15N isotope pool dilution assays on soils collected from a long-term crop complexity experiment near Mead, NE, USA. Treatments sampled included both 0 kg and 180 kg N ha−1 fertilization levels in continuous corn, corn-soybean, and corn-soybean-sorghum-oat/clover rotations. We found that higher cropping complexity coupled with zero fertilization increased gross depolymerization and amino acid consumption rates by 193% and 93%, respectively, relative to fertilized, monocrop plots. Gross mineralization was 2.7 and 3.9x higher in complex rotations than corn-soybean and continuous corn rotations, respectively, while ammonium consumption was 4x higher in fertilized plots than unfertilized plots across all cropping regimes. We show that within our study system internal N cycling is stimulated by cropping system complexity; however, N fertilization suppresses some of the benefits of temporal crop diversification. Balancing reduced mineral fertilizer application rates with increased cropping complexity has the potential to promote internal N cycling while minimizing N losses in agroecosystems.

Complex case treatment: Is there a limit for surgery-first approach?

Are there any limits for Surgery-first approach? the article strives to identify the tenets of effective management of complex cases, such as facial asymmetry, with surgery-first approach. The main purpose of the article is in attempting to itemize prerequisites or determining factors, through various degrees of facial asymmetry severity, for the successful management of facial asymmetry cases. The key factors such as (1) assessment of chin deviation, (2) quantification or discernment of transverse occlusal plane canting, (3) spatial orientation evaluation of differential anterior and posterior region transverse occlusal canting, and (4) contemplations of six degrees of freedom (6DoF) (translation movements combined with rotation axis - pitch, roll and yaw) are evaluated. Furthermore, dental alignment, severity of mandibular and maxillary occlusal (anterior and posterior) plane canting, critical cephalometric parameters, such as, incisor mandibular plane angle, and other vital sub- components of facial asymmetry are analysed, in detail. Subsequently, these are coherently synchronized with the maxillomandibular complex (MMC) rotation surgery during planning for the successful execution of facial asymmetry correction. Additionally, the article describes the (1) usage of orthodontic arch wires, (2) selection criteria of specific surgical osteotomies, and (3) coordination of maxillary and mandibular dentition to establish a transitional or treatable malocclusion. In conclusion, a thorough evaluation of the determining factors, as described in the article, for the correction of facial asymmetry with surgery-first, aid in categorising facial asymmetry cases that require minimal pre-surgical orthodontics or without pre-surgical orthodontic treatment, thereby defining the limits of surgery-first.

Y-type quadrotor radar cross-section analysis

PurposeThe purpose of his paper is to study the radar stealth performance of a Y-type quadrotor with coaxial rotors and parallel rotors.Design/methodology/approachThis Y-type quadrotor is designed as an aerodynamic layout with parallel twin rotors at the front and coaxial twin rotors at the rear. The multi-rotor scattering (MRS) method based on multi-rotor dynamic simulation (MRDS) and electromagnetic scattering module (ESM) is presented. MRDS is used to simulate the complex rotation of parallel rotors and coaxial rotors. ESM is used to calculate the instantaneous radar cross-section (RCS) of the quadrotor.FindingsFor a single rotor, the minimum period of the RCS curve at a given azimuth is equal to the basic passage time of the blade, where increasing the speed can shorten this minimum period. When the elevation angle increases, the forward RCS fluctuation of the quadrotor increases, while the average RCS decreases. The change of the roll angle will affect both the mean and the maximum difference of the RCS–time curve at the given lateral azimuth. The increase of the pitch angle will enhance the dynamic amplitude of the RCS–time curve under the forward azimuth.Practical implicationsThe research in this article can provide reference for the stealth design of the Y-type quadcopter in the future.Originality/valueThe originality is the establishment of the MRS method. This method could provide value for dealing with the electromagnetic scattering problem of coaxial rotors and parallel rotors.

What Is Unusual About the Third Largest Geomagnetic Storm of Solar Cycle 24?

AbstractWe report on the solar and interplanetary (IP) causes of the third largest geomagnetic storm (26 August 2018) in solar cycle 24. The underlying coronal mass ejection (CME) originating from a quiescent filament region becomes a 440 km/s magnetic cloud (MC) at 1 au after ∼5 days. The prolonged CME acceleration (for ∼24 hr) coincides with the time profiles of the post‐eruption arcade intensity and reconnected flux. Chen et al. (2019, https://doi.org/10.3847/1538-4357/ab3f36) obtain a lower speed since they assumed that the CME does not accelerate after ∼12 hr. The presence of multiple coronal holes near the filament channel and the high‐speed wind from them seem to have the combined effect of producing complex rotation in the corona and IP medium resulting in a high‐inclination MC. The Dst time profile in the main phase steepens significantly (rapid increase in storm intensity) coincident with the density increase (prominence material) in the second half of the MC. Simulations using the Comprehensive Inner Magnetosphere‐Ionosphere model show that a higher ring current energy results from larger dynamic pressure (density) in MCs. Furthermore, the Dst index is highly correlated with the main‐phase time integral of the ring current injection that includes density, consistent with the simulations. A complex temporal structure develops in the storm main phase if the underlying MC has a complex density structure during intervals of southward IP magnetic field. We conclude that the high intensity of the storm results from the prolonged CME acceleration, complex rotation of the CME flux rope, and the high density in the 1‐au MC.

Management zone‐based estimation of positive and negative nitrous oxide flux in organic corn fields

AbstractAccurate estimation of field‐scale nitrous oxide (N2O) fluxes is hindered by their considerable variability and the fact that soils can be both sources and sinks for N2O. This is particularly challenging for organic systems that have complex rotations and inputs. This study used digital soil mapping and survey datasets to explore spatial controls of N2O “hot moments” induced by precipitation with strategic sampling designed to identify covariates that influence N2O emission patterns. Soil N2O fluxes after rain events were measured within three management zones (MZs, “High,” “Medium,” “Low”) delineated by crop productivity, soil fertility, and hydrological features in eight organic fields during the 2018 and 2019 corn (Zea mays L.) growing seasons. Hot moments typically occurring 1 d after rain events included both positive and negative N2O fluxes. The MZ‐based design identified regions with different patterns in positive and negative flux, with hotspots for both being co‐located with areas of poorer drainage and higher soil fertility. Covariates that best explained hot moments included corn growth stage, soil moisture, slope, texture, and soil organic matter. Negative fluxes were large enough to offset positive fluxes so that averaged net N2O fluxes were only significantly different between the “High” and “Low” MZs. Had negative fluxes been omitted, averaged N2O fluxes would have increased estimates by 37%. Processes that lead to N2O consumptions must be better quantified to improve the estimation of management‐associated net N2O flux. Use of strategic sampling can efficiently capture needed information, but spatial and temporal weighting is needed to scale up results.

Robust image similarity metric method for SAR images

Synthetic aperture radar (SAR) image similarity metric is at the core of SAR image interpretation techniques, however, it is still a challenging task due to complex nonlinear intensity, scale, and rotation differences between SAR images and other remote sensing images. This letter addresses this problem by proposing a novel similarity metric method for SAR images using structure and shape properties. The magnitude and orientation representation of the phase congruency model is first built based on the local phase of images. Then a new scale and rotation-invariant local binary pattern (SRI-LBP) descriptor is proposed using local structure and shape information. Finally, a similarity metric is defined using the symmetry Kullback Leibler divergence (SKLD) of the SRI-LBP descriptors. Numerical experiment results verify its robustness in terms of nonlinear intensity, scale, and rotation differences.

Spontaneous radiative dissociation of the second bound state of positronium hydride

The spontaneous radiative dissociation spectrum of the second bound state of positronium hydride (PsH) located just below the $\mathrm{H}(2p)+\mathrm{Ps}(2p)$ threshold energy is investigated by the variational and complex coordinate rotation methods. Convergence of the transition rates is examined in both length and velocity gauges. The spectrum indicates that the primary channel of radiative dissociation is the transition into the continuum of $\mathrm{H}(1s)+\mathrm{Ps}(2p)$, and the secondary one is that into the $\mathrm{H}(2p)+\mathrm{Ps}(1s)$ continuum. Radiative transition to the resonance state located close to the second bound state is found to exist. The total rate of the radiative dissociation is found to be $9.1(2)\ifmmode\times\else\texttimes\fi{}{10}^{8}\phantom{\rule{4pt}{0ex}}{\mathrm{s}}^{\ensuremath{-}1}$.

Crop rotational complexity affects plant-soil nitrogen cycling during water deficit

One of the biggest environmental challenges facing agriculture is how to both supply and retain nitrogen (N), especially as precipitation becomes more variable with climate change. We used a greenhouse experiment to assess how contrasting histories of crop rotational complexity affect plant-soil-microbe interactions that govern N processes, including during water stress. With higher levels of carbon and N cycling hydrolytic enzymes, higher mineral-associated organic matter N concentrations, and an altered microbial community, soils from the most complex rotation enabled 80% more corn N uptake under two moisture regimes, compared to soil from monoculture corn. Higher levels of plant N likely drove the changes in corn leaf gas exchange, particularly increasing intrinsic water use efficiency by 9% in the most complex rotation. The water deficit increased the standing pool of nitrate 44-fold in soils with a history of complex crop rotations, compared to an 11-fold increase in soils from the corn monoculture. The implications of this difference must be considered in a whole cropping systems and field context. Cycling of 15N-labeled fresh clover residue into soil N pools did not depend on the water regime or rotation history, with 2-fold higher recovery in the mineral vs. particulate organic N pool. In contrast, the water deficit reduced recovery of clover 15N in corn shoots by 37%, showing greater impacts of water deficit on plant N uptake compared to organic N cycling in soil. This study provides direct experimental evidence that long-term crop rotational complexity influences microbial N cycling and availability with feedbacks to plant physiology. Collectively, these results could help explain general observations of higher yields in more complex crop rotations, including specifically during dry conditions.