Conventional Grain Research Articles

The new early-ripening grain sorghum variety “Derzhavnoe”

Grain sorghum is the most important feed and food agricultural crop with a number of advantages. The purpose of the current study was to develop the feed sorghum variety being early-ripening, productive, low height, adaptable, resistant to the main diseases for the arid conditions of the Middle Povolzhie and the Urals. The variety has been developed by the method of individual selection from a hybrid population, which was based on a complex stage hybridization, which included the varieties “Slavyanka”, “Zersta97”, “Perspektivny1”. The current paper has presented the results of the study conducted in 2016–2018 on the plots of the Povolzhsky RIISS. There have been presented the traits and properties of a new grain sorghum variety “Derzhavnoe” sent to the State Variety Testing and intended for cultivation in the Middle Povolzhie and Ural regions. The advantage of the variety is its low height, large productivity, good adaptability, resistance to lodging, to brittle stems and panicles and grain shedding. Grain productivity in the Competitive Variety Testing has averaged 3.55 t/ha, which is higher on 0.73 t/ha than that of the standard variety “Slavyanka” (2.82 t/ha). The grain of the new variety contains 10.6–12.2% of raw protein, 62.8–76.8% of starch and 3.4–3.6% of oil.100 kgof grain contains 128 u. The variety is productive both in wet and dry weather conditions when sown in mid-May by continuous sowing method. The variety is suitable for mechanized harvesting with conventional grain combines both separately and directly.

Melt Conditioned Direct Chill (MC-DC) Casting and Extrusion of AA5754 Aluminium Alloy Formulated from Recycled Taint Tabor Scrap.

The melt conditioned direct chill (MC-DC) casting process has been used to produce billets and extruded planks of AA5754 alloy formulated from 100% recycled Taint Tabor scrap aluminum. The billets were homogenized and then extruded into flat planks. Optical metallography of the MC-DC cast billets showed equiaxed refined grains in comparison to conventional direct chill (DC) cast and direct chill grain refined (DC-GR) cast billets formulated from the same Taint Tabor scrap. Microstructural evaluation of the extruded planks showed extensive peripheral coarse grain (PCG) for the DC, DC-GR and MC-DC cast planks. The 2 mm and 1 mm MC-DC cast planks produced after cold rolling and heat treatment showed a fully recrystallized microstructure at 380 °C and 300 °C for 10 min respectively with an improvement in mechanical properties over DC-GR cast and similarly processed planks. The as-extruded MC-DC cast planks tensile tested in the transverse direction showed 34% elongation and 213 MPa ultimate tensile strength. These tensile results showed 5.8% higher elongation and 1.2% higher ultimate tensile strength compared with the DC-GR planks after applying high shear melt conditioning.

Research on an electric energy‐saving grain drying system with internal circulation of the drying medium

AbstractIn this study, we designed a 5HLN‐R‐50 electric grain dryer with internal circulation of the drying medium based on the analysis of drying medium enthalpy and humidity status variation diagrams. We aimed to reduce the dryer energy consumption and exhaust gas emission. Using clean electric energy instead of a conventional dryer heat source, the drying system can cyclically dry high‐moisture grain with zero emissions. The experimental results indicate that the condensation effect is suitable when the ratio of the cool and hot air flows is 6:1 at a heat transfer coefficient of the condenser of 79.5 W/(m2.K) and a specific heat consumption of 3,916 kJ/kgH2O when compared with the Chinese standard of 7,500 kJ/kgH2O, that is, a maximum energy savings of 48%. This paper proposes a novel technological method and idea, studies the differences in energy efficiency, emissions reduction and clean production, and provides a reference for replacing the conventional grain dryer heat source of coal with electricity.Practical applicationsThis drying system is applied in circular grain drying; a corn drying experiment indicates that compared with the specific energy consumption stipulated by the national standards of China, the highest energy savings is 48%, and zero release nonpollution is shown. The state parameters of the dried material and drying medium are displayed graphically in real time, and the operating parameters of the drying process are intuitively tracked in real time and automatically adjusted.

New SAPO-34-SPEEK composite coatings for adsorption heat pumps: Adsorption performance and thermodynamic analysis

In this paper, a new adsorbent composite coating by using SAPO-34 filler in a sulfonate polyether ether ketone matrix is proposed for thermally efficient adsorption heat pumps. Composite SAPO-34 zeolite based coatings with 80–95 wt% SAPO-34 content were realized. Preliminary morphological analysis, by scanning electron microscopy, highlighted that the coating microstructure is homogeneous and permeable to water vapor diffusion. Water vapor adsorption isobars were measured at equilibrium for all samples in the temperature range 30–120 °C. The results showed the typical S-shaped trend, which is suitable for adsorption heat pump applications. The highest adsorption value was observed for the coating with highest zeolite filler amount, 95 wt%. This batch exhibited a maximum water uptake of about 29.0 wt%, demonstrating that the S-PEEK matrix does not hinder the SAPO-34 adsorption performance. Finally, starting from obtained experimental data of composite materials adsorption capacities the, a simple energy balance based thermodynamic analysis was performed for air conditioning application by using an aluminum finned-flat tube heat exchanger, as reference. Results highlight that this composite coating technology allows cooling COP up to over 5% higher than that of the conventional loose adsorbent grains configuration, indicating the proposed technology promising for practical application in adsorption heat pumps.

Kinetic Monte Carlo simulations of structural evolution during anneal of additively manufactured materials

POur experiments indicated that upon a post-processing anneal, an additively manufactured 316L stainless steel exhibits cubic grains rather than the conventional equiaxed grains. Here, we have used kinetic Monte Carlo simulations to explore the origin of these cubic grains. First, we implemented a new kinetic Monte Carlo model in parallel code SPPARKS to simulate grain growth and recrystallization under a residual energy distribution. Our model incorporates physical properties and real-time, as opposed to generic properties and relative time. We further validated that our SPPARKS simulations reproduced the expected kinetic behavior of single-grain evolution. We then used the validated approach to simulate the anneal of an additively manufactured material under the same conditions used in our experiments. We found that the cubic grains can origin from a periodically varying residual energy that may be present in additively manufactured materials.

Hierarchical nanotwins in single-crystal-like nickel with high strength and corrosion resistance produced via a hybrid technique.

High-density growth nanotwins enable high-strength and good ductility in metallic materials. However, twinning propensity is greatly reduced in metals with high stacking fault energy. Here we adopted a hybrid technique coupled with template-directed heteroepitaxial growth method to fabricate single-crystal-like, nanotwinned (nt) Ni. The nt Ni primarily contains hierarchical twin structures that consist of coherent and incoherent twin boundary segments with few conventional grain boundaries. In situ compression studies show the nt Ni has a high flow strength of ∼2 GPa and good deformability. Moreover, the nt Ni has superb corrosion behavior due to the unique twin structure in comparison to coarse grained and nanocrystalline counterparts. The hybrid technique opens the door for the fabrication of a wide variety of single-crystal-like nt metals with unique mechanical and chemical properties.

Canopy reflectance, stalk sugar and juice yields in specialty corn hybrids as affected by nitrogen management strategies.

The newly developed sugarcorn is conceived for dual-purpose use as a potential biofuel feedstock and a high-energy silage crop. Its agronomic traits are, however, not fully appraised under the umbrella of nitrogen (N) management and with canopy reflectance indicator. A 3-year field study was conducted to examine the responses of silage biomass, stalk sugar concentration, sugar and juice yields to various N applications; and determine the quantitative relationships between canopy reflectance, expressed as the normalized difference vegetation index (NDVI), and stalk sucrose or other sugar measures in a dual-purpose sugarcorn (cv. 'CO384xC103'), in comparison with a commercial leafy silage-specific hybrid (cv. 'Pride A5892G3 EDF'). The moderate N rate, 125 kg ha-1 , produced similar stalk sucrose, silage and grain yields, compared to the high rate (250 kg N ha-1 ), regardless of application methods. The NDVI signatures measured at the V8-V10 stage exhibited significant (P< 0.01) and exponential relationships with stalk sucrose concentrations, sucrose and juice yields at the R3 stage, and with silage yield at approximately 65% whole-plant moisture, the optimum silage-harvest window. The results indicate that the moderate N rate, 125 kg ha-1 , which is recommended for conventional grain corn production in the region, was likely close to the economic optimum N rate for leafy silage-specific and sugarcorn. Canopy reflectance, measured at the early growth stages, can be used as a potential indicator of sugar and silage production, and this quantitative relationship necessitates further evaluation with more genotypes and under wide environmental conditions. © 2019 Her Majesty the Queen in Right of Canada Journal of The Science of Food and Agriculture © 2019 Society of Chemical Industry.

PSVIII-5 Determination of true digestibility and the endogenous outputs of magnesium in corn for growing pigs by using the regression analysis technique

Abstract Dietary magnesium (Mg) is essential to bone mineralization. Supplemental Mg is typically not considered in commercial swine diets by assuming high bioavailability of Mg from bulky feed ingredients such as corn grain. The objectives of this study were to determine true ileal and fecal digestibility and the endogenous losses of Mg associated with corn in growing pigs by the regression analysis technique. A total of 48 barrows, with an average initial body weight (BW) 32 kg, were randomly assigned to 6 grower pig diets and were fed close to ad libitum for 10 d, with 8-d adaptation and 2-d collection fecal and the terminal ileal digesta samples, according to a randomized complete block design. Six cornstarch-based diets, containing 6 levels of Mg at 0.22, 0.32, 0.38, 0.51, 0.71 and 0.79 g/kg dry matter intake (DMI) of diets, were formulated from corn. There were linear relationships (P &amp;lt; 0.05), expressed as g/kg DMI, between the ileal and fecal outputs of Mg and the total intake of dietary Mg, suggesting that true ileal and fecal Mg indigestibility values (94.8±12.5 vs. 89.2±17.7%); and the ileal and fecal endogenous Mg outputs (0.16±0.02 vs. 0.21±0.11, g/kg DMI of diets) associated with corn could be estimated by the regression analysis. Our results have shown that Mg associated with conventional corn grain was very poorly digested and the gastrointestinal endogenous fecal loss of Mg was significant in the grower pig. Thus, Mg bioavailability in feeds for pigs should be assessed and supplemental of Mg may be warranted in swine diet formulation.

Achieving good tensile properties in ultrafine grained nickel by spark plasma sintering

In this work, the tensile properties of ultrafine grain Ni samples processed by spark plasma sintering are investigated. To this aim, a high purity Ni powder was nanostructured by ball milling using different processing conditions, and consolidation of the powder was performed by spark plasma sintering. Milling parameters were varied to produce samples with different microstructures. Each sample was characterised in terms of grain size and grain boundary character distribution to study the influence of milling parameters on the microstructure. Results show that suitable ball milling and subsequent sintering can be employed to obtain specimens with grain sizes in the ultrafine grain range with a high fraction of Σ3 grain boundaries. All samples exhibit a low internal stress state, which is evaluated in terms of grain orientation spread computed from electron backscatter diffraction and dislocation observation by transmission electron microscopy. Uniaxial tensile testing shows an increase in yield strength with grain refinement with a pronounced deviation from the Hall-Petch relation, for samples with grain sizes below 1.2 μm. Heterogeneity in deformation at yielding seems responsible for the deviation due to differences in the strain hardening behaviour between ultrafine grains and conventional coarse grains. All samples display high ductility with values of elongation to fracture above 35% as well as good toughness. The combination of ball milling with spark plasma sintering is therefore a promising tool to produce ultrafine grain Ni with good mechanical properties.

Organic acids as antibrowning agents in parboiling: Effects on the technological properties and cooking quality

AbstractBackground and ObjectivesThe conventional rice parboiling process improves the physical quality of the grains; however, the browning is a factor that reduces the acceptance of the product. The aims of this study were to evaluate the effect of the addition of tartaric, citric, and lactic acids in soaking at concentrations of 0.0%, 0.2%, 0.4%, 0.6%, and 0.8%, followed by autoclaving at 110°C.FindingsAt all concentrations used, there was an increase in the head rice yield (HRY) and gelatinization degree, regardless of the acid type. Tartaric and lactic acid treatment led to minimal changes in color, while parboiled rice subjected to citric acid treatment exhibited lighter coloring. At the highest concentration of the acids, a reduction in cooking time was observed. The addition of organic acids in parboiling promotes whiter grains when compared to conventional grains, and at high concentrations reduces cooking time.ConclusionsThe addition of lactic, citric, and tartaric acids to the soaking water of the parboiling process led to an increase in the HRY and gelatinization degree of parboiled rice, with the majority of the rice grains exhibiting 75%–100% gelatinized/vitreous area.Significance and noveltyThese results are important because they provide an alternative for quality improvement of parboiled rice. Among the studied acids, citric acid yielded the best technological properties and cooking quality of parboiled rice, implying greater economic gain for rice industries and good consumer.

The effect of anisotropic microstructure on the crack growth and fatigue overload behaviour of ultrafine-grained nickel

Changes in crack growth rate associated with overload events during fatigue are poorly understood, especially for materials with anisotropic microstructures. Here overload fatigue tests are reported for compact tension samples cut in two different orientations from high pressure torsion disc samples. During growth the crack planes reoriented either slightly, or significantly, to align with the elongated grain structure leading to low, and high, levels of mixed mode fatigue loading respectively. In both cases the ultrafine grained microstructure led to macroscopically flat crack faces. The fatigue crack growth rate was around 2.4 times slower for the case with the high mode II component than for the low. A 100% overload was then introduced and synchrotron X-ray diffraction and digital image correlation (DIC) were applied in-situ to map the bulk crack-tip elastic strain field (plane strain) and surface displacement field (plane stress) respectively prior to, during and after overload. The high mode II case displayed a larger degree of retardation after overload. Residual stress and plasticity-induced crack closure were found to be the primary causes for the retardation as the crack grows into the overload plastic zone. Significant crack face contact was observed for the high mode II case along with significant levels of compressive stress transferred across the crack faces at minimum load. Compared with conventional (coarse) grain Ni, the ultrafine grained Ni is less retarded by overload, because of its relatively flatter crack path and higher yield stress and thus less plasticity and residual stress induced closure.

SOME FEATURES OF BARLEY AND OATS PROCESSING

It is proved the high effectiveness of using naked oats varieties Salomon and Samuel and hull-less barley variety Achilles as raw material for production new groats products with high biological value. Researched modes of pearling, water heat treatment and its impact on yield of pearled and flaked groats. The technological scheme of processing hull less barley and naked oats for producing groats, flakes, mixtures of groats and flakes were developed. Technology includes grain cleaning stage, grain water heat treatment, pearling, sorting of pearling products, pearled groat water heat treatment, mixing, flaking, drying, and control of end products. Studied hull-less barley characterized by high protein content 14,615,8 % and β-glucans – 6,8-7,4 %, has same to conventional dehulled grain mass fraction of lipids 2,1-3,8 % and starch – 57,6-60,5 %, low ash content 2,3-2,7%. Naked oats grain traditionally characterized by high mass fraction of lipids – 6,0-6,3 %,high mass fraction of protein - 14,9-15,4% and βglucans - 6,4-6,9% close to conventional dehulled grain mass fraction of starch – 59,3-61,6 % and ash – 2,1-2,3 %. It was found that the technologically expedient moisture content of hull-less barley and naked oats before pearling is 12-13 %. In the pearling the grain with this humidity depending on the duration of pearling yield of groat estimated to range between 6796 %. Increasing moisture content of grain before pearling to 14.0% does not significantly change the limits of yield values, and pearling grain with low moisture content of 10.5% leads to excessive grinding and formation of a significant amount of by-products and waste in the form of fine particles and husking bran.Technologically expedient moisture content of naked oats pearled groat before steaming stage are 15 % and the vapor pressure in steamer of 0.10 MPa. For the pearled barley groat most appropriate moisture content of before steaming is 20 % and the vapor pressure in steamer of 0.10 MPa.Steaming in this mode allows to obtain flaked groats with yield at 84 to 93%

Mechanical property study on C90300 copper composites reinforced with rare earth oxide

The copper alloys with conventional grain structure and size are soft materials with relatively low yield strength. The strength of copper based CMCs increases with the reinforcement addition. In the present experiment we have gone with Tin bronze as the matrix, an alloy of copper since it has got superior properties compared to copper due to the incorporation of Tin. The experiment revolves around the development of composite of Tin bronze with Rare Earth Oxide addition. Addition of Rare Earth Metal results in grain refinement and thus helps in increasing the mechanical properties of the material. The Tin Bronze C90300 with 1%, 2%, 3%, 4% and 5% cerium oxide weight percentage were cast. The composites were characterized by X-ray diffraction, Optical microscopy and Scanning Electron Microscopy. The composites were also sent for chemical analysis to adjudge its chemical composition. The effect of rare earth oxide addition on the mechanical properties were investigated by Rockwell hardness test and tensile test. The results showed that addition of cerium resulted in the microstructure refinement and formation of intermetallic phases, which causes pinning effect at the boundaries and increases the hardness and tensile strength of the cast sample.

Cost Analysis of Chaff Harvesting Concepts in Germany

This work assesses the costs of exploiting the biomass feedstock chaff. Chaff is a harvest residue generated during the conventional grain harvesting process and usually remains on the field. In this paper, the costs of collecting and supplying chaff to the end user with different harvesting methods and supply chains are analyzed. The costs are estimated for a base case defining a set of general assumptions. The impact of these assumptions is analyzed in a sensitivity analysis by means of tornado diagrams. A full costing method based on the VDI guideline 2067 part 1 is applied for the cost estimation. The cost analysis reveals that ceasing the fractioning of grain, straw and chaff during harvesting and transporting them as a mixture reduces the harvesting costs significantly. The costs are decreased due to a reduction in agricultural operations and processing large amounts of material. The lowest total costs originate from the production of chaff-straw bales. Harvesting chaff as a single fraction leads to the highest costs with the investigated supply chains. Comparing the costs of chaff supply to potential revenues shows that an exploitation of the harvest residue can be economically feasible.

Atomistic investigation of the deformation mechanisms in nanocrystalline Cu with amorphous intergranular films

Grain boundaries in nanocrystalline (NC) materials are important as they control the microstructural evolution and act as both sinks and sources for dislocation activities. In order to enhance the absorption of dislocations and restrict the crack nucleation and growth, the conventional grain boundaries can be substituted with amorphous intergranular films (AIFs). In the present atomistic study, we investigated the deformation mechanism of bicrystals and NC Cu specimens with AIF under dynamic and static loading conditions with a particular focus on the influence of grain sizes (3 nm–17 nm) and AIF thicknesses (0.5 nm–1.5 nm). We found that the presence of AIF homogenized the interfacial energy irrespective of the grain orientations and decreased its overall value, which posed a strong effect on the strength of the metallic system. In addition, we observed a shift of the deformation mechanism from that dominated by dislocations to interfacial activities due to the presence of AIF as the grain size or AIF thickness changed. Finally, results from high-temperature creep deformation showed that the NC Cu with AIF had excellent thermal stability despite its small grain size.

The Role of Spatial Density and Technological Investment on Optimal Pricing Strategies in the Grain Handling Industry

Shuttle-loading elevators represent an investment that may lower marginal grain-handling costs. Some portion of those savings could be passed on to farmers in the form of higher cash prices. We model the pass-through decision and exploit a natural, historical difference in Kansas and Montana wheat markets to test several pass-through hypotheses empirically. Using cross-sectional, temporal, and spatial variation in weekly wheat prices in 2005–2013, we find that—relative to conventional grain elevators in Kansas—shuttle-loading facilities offer a $0.13 per bushel premium. In Montana—where there is less spatial competition among elevators—the pass-through is only $0.04 per bushel.

Crystalline Liquid-like Behavior: Surface-Induced Secondary Grain Growth of Photovoltaic Perovskite Thin Film

Surface effects usually become negligible on the micrometer or sub-micrometer scale due to lower surface-to-bulk ratio compared to nanomaterials. In lead halide perovskites, however, their "soft" nature renders them highly responsive to the external field, allowing for extended depth scale affected by the surface. Herein, by taking advantage of this unique feature of perovskites we demonstrate a methodology for property manipulation of perovskite thin films based on secondary grain growth, where tuning of the surface induces the internal property evolution of the entire perovskite film. While in conventional microelectronic techniques secondary grain growth generally involves harsh conditions such as high temperature and straining, it is easily triggered in a perovskite thin film by a simple surface post-treatment, producing enlarged grain sizes of up to 4 μm. The resulting photovoltaic devices exhibit significantly enhanced power conversion efficiency and operational stability over a course of 1000 h and an ambient shelf stability of over 4000 h while maintaining over 90% of its original efficiency.

367 Organic versus conventional grain on placental factors in caprine

Abstract Organic products are increasing in popularity due to consumer interest and animal products are no exception. Trends towards organic livestock diets have increased yet many questions exist regarding potential health benefits or negative increased cost from the organic product. Organic livestock diets could impact reproductive health yet research into organic feedstuffs is lacking. Previous research examined impacts of diet on placental factors and indicated nutrient transfer from dams to fetus. Impacts of organic practices on livestock reproduction has not been explored, as studies linking nutrition and reproductive abilities have been limited to conventional diets, despite increases in organic practices. The objective of the current study observed differences in placental factors between Nubian dams fed organic and conventional diets. Placental factors were defined as placental weight and cotyledon factors. Six (n = 3) pregnant Nubian dams were separated into an organic group and conventional group based on BW and BCS. The organic group was fed a certified organic concentrate and organic supplement, which had equivalent nutrients to conventional concentrate and supplement. Dams were fed 0.907kg/d/45.4kg of BW of concentrate and 0.012kg/d/45.4kg of BW in individual feeding stocks at 0630 and 1730 for the last six wks of gestation and three wks post-parturition. Upon expulsion of the placenta, the placenta was weighed, cotyledons were counted, and three cotyledons were measured for height, length, width, and volume. Differences in placental weight and cotyledon factors were analyzed by a two-tailed independent T-Test at P &lt; 0.05. No differences were observed for any of the placental aspects (P = 0.486, 0.987, 0.997, 0.468, 0.448, and 0.809, respectively). Placental aspects, such as number and height, may have been influenced by the number of offspring each dam produced, but was not consistent between groups. Based upon the current study, increased cost of organic livestock production may not be justifiable for most goat producers.

Observation of dendrite growth velocity and microstructure transition in highly undercooled single phase alloys

Dendrite growth velocity as a function of initial bulk undercooling was systematically studied in situ using high speed thermal imaging of highly undercooled Ni90Cu10 and Ni95Cu5 single phase alloy melts. For these two non-dilute concentrated alloys, the dendrite growth velocity first increased continuously at small and mediate undercooling regimes and then discontinuously to a maximum value at the high undercooling range. A clear plateau appeared in the growth velocity-undercooling curve revealed a gradual transition from mainly solute-controlled growth to mainly thermal-controlled growth, which was very similar to the solidification characteristics of a dilute alloy. The discontinuity appeared in the growth velocity-undercooling relationship was suggested to be induced by the finite solute diffusion speed in the bulk melt ahead of the advancing solid-liquid interface. Microstructure, substructure and microtexture of the two undercooled alloys were characterized using EBSD technique, and the fundamental mechanism behind “spontaneous grain refinement” is elucidated. The microstructure evolution indicated two kinds of grain refinements: one was dendrite remelting induced grain refinement and the other was recrystallization induced grain refinement. It was found that the texture of the as-solidified microstructure was getting more and more random as the initial bulk undercooling increased, which was due to the increased stress and recrystallization in the as-solidified microstructure. New evidence of grain refinement was found in the as-solidified samples. We found that the samples undercooled beyond the critical undercooling had a grain refined microstructure and that this corresponded with a clear discontinuity in the dendrite growth velocity-undercooling curve. Microstructural data suggested that in Ni-Cu alloys grain refinement at a high undercooling was a consequence of a recrystallization process, which contrasted with conventional grain refined alloys where grain refinement appeared to be the result of remelting-induced dendritic fragmentation.

Dryland Organic Farming Partially Offsets Negative Effects of Highly Simplified Agricultural Landscapes on Forbs, Bees, and Bee-Flower Networks.

Industrialized farming practices result in simplified agricultural landscapes, reduced biodiversity, and degraded species-interaction networks. Thus far, most research assessing the combined effects of farming systems and landscape complexity on beneficial insects has been conducted in relatively diversified and mesic systems and may not represent the large-scale, monoculture-based dryland agriculture that dominates many regions worldwide. Specifically, the effects of farming systems on forbs, bees, and their interactions are poorly understood in highly simplified dryland landscapes such as those in the Northern Great Plains, United States, an area globally important for conventional and organic small grain, pulse, forage, and oilseed production. During a 3-yr (2013-2015) study, we assessed 1) the effects of dryland no-till conventional and tilled organic farming on forbs, bees, and bee-flower networks and 2) the relationship between natural habitat and bee abundance. Flower density and richness were greater in tilled organic fields than in no-till conventional fields, and forb community composition differed between farming systems. We observed high bee diversity (109 taxa) in this highly simplified landscape, and bee abundance, richness, and community composition were similar between systems. Compared with tilled organic fields, bee-flower interactions in no-till conventional fields were poorly connected, suggesting these systems maintain relatively impoverished plant-pollinator networks. Natural habitat (11% of the landscape) did not affect small-bodied bee abundance in either farming system but positively affected large-bodied bees within 2,000 m of crop-field centers. In highly simplified agricultural landscapes, dryland organic farming and no-till conventional farming together support relatively high bee diversity, presumably because dryland organic farming enhances floral resources and bee-flower networks, and no-till management in conventional farming provides undisturbed ground-nesting habitats for wild bees (Hymenoptera: Apoidea).