Soybean yield response to biostimulant seed treatments in Brazil and the United States: A review

Developing successful strategies to ensure future increases in crop yield depends, in part, on a better understanding of the basis for past increases. To this end, I compared historical yield trends of two dissimilar crops—corn (Zea mays L.), a high yielding C4 grass, and soybean [Glycine max (L.) Merr.], a moderate yielding C3 legume—in high (Iowa, Illinois, Indiana) and low (Kentucky, Missouri, Tennessee) yield environments. Average state corn yield changed very little from 1866 to 1930, an era of low‐input agriculture, but it increased rapidly from 1950 to 2005 in all states as the low‐input system gave way to a high‐input system that utilized commercial hybrids, manufactured N fertilizer, herbicides, and higher plant populations. Soybean yield, first available in 1924, increased steadily from the beginning until 2005. Corn yield increased faster than soybean yield in the early decades of the high‐input era (mean growth rates of corn were 3.3 vs. 1.5% per year for soybean with a slight advantage for both crops in high yield states) in all six states, but for the rest of the era (up to 40 yr), corn and soybean yields grew at nearly the same rate (1.8% per year for corn, 1.4% per year for soybean with a slight advantage for the low‐yield states). Thus, the efforts to improve the plant (plant breeding) and production environment (better management practices) had essentially the same affect on these two very dissimilar crops.

A high-density, well-distributed, and consistent historical weather data series is of major importance for agricultural planning and climatic risk evaluation. A possible option for regions where weather station network is irregular is the use of gridded weather data (GWD), which can be downloaded online from different sources. Based on that, the aim of this study was to assess the suitability of two GWD, AgMERRA and XAVIER, by comparing them with measured weather data (MWD) for estimating soybean yield in Brazil. The GWD and MWD were obtained for 24 locations across Brazil, considering the period between 1980 and 2010. These data were used to estimate soybean yield with DSSAT-CROPGRO-Soybean model. The comparison of MWD with GWD resulted in a good agreement between climate variables, except for solar radiation. The crop simulations with GWD and MWD resulted in a good agreement for vegetative and reproductive phases. Soybean potential yield (Yp) simulated with AgMERRA and XAVIER had a high correlation (r > 0.88) when compared to the estimates with MWD, with the RMSE of about 400 kg ha−1. For attainable yield (Ya), estimates with XAVIER resulted in a RMSE of 700 kg ha−1 against 864 kg ha−1 from AgMERRA, both compared to the simulations using MWD. Even with these differences in Ya simulations, both GWD can be considered suitable for simulating soybean growth, development, and yield in Brazil; however, with XAVIER GWD presenting a better performance for weather and crop variables assessed.

Narrow row spacing (<76 cm) could improve crop competitiveness, suppress weeds and might provide yield advantage. Many studies have been conducted to evaluate the impact of narrow row spacing; however, no quantitative synthesis of these studies exists. The objectives of this meta-analysis were to (1) quantify the overall effect of narrow row spacing (<76 cm) on weed density, biomass, control, weed seed production, and yield in corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] compared with 76-cm row spacing, and (2) assess the influence of agronomic management decisions (tillage type, weed management, herbicide application frequency and time) on effect of narrow row spacing on weed suppression and corn and soybean yield. We compiled 1,904 pair-wise observations from 35 studies conducted in 12 states in the United States during 1961 to 2018. Averaged across individual observations, narrow row spacing suppressed weed density by 34%, weed biomass by 55%, and weed seed production by 45%, while it improved weed control by 32% and crop yield by 11% compared with 76-cm row spacing. Narrow row spacing in soybean suppressed weed density by 42%, weed biomass by 71%, and increased crop yield by 12% compared with 76-cm row spacing. Although narrow row spacing had a nonsignificant effect on response variables in corn, the number of studies (n = 1 to 6) and observations (n = 1 to 59) addressing each response variable were limited. Tillage type (conventional and reduced) did not influence the response of weed density, control, and seed production in narrow row spacing; however, weed biomass and weed seed production were more greatly reduced with the sequential application of herbicides compared with a single application. Thus, narrow row spacing in soybean can be integrated with other options for management of herbicide-resistant weeds.

As the cost of corn (Zea mays L.) production increases, some farmers find continuous soybean [Glycine max (L.) Merr.] to be more profitable than corn–soybean rotation. However, a grass cover crop could help diversify the cropping system. The study objectives were to evaluate planting date and termination timing of a rye (Secale cereale L.)/oat (Avena sativa L.) cover crop mix on cover crop biomass and soybean disease, insects, slugs, and grain yield within a 2‐yr soybean production system. Field trials were conducted in 2018 and 2019 at two locations in Ohio (northwestern and western). The main plot factor was cover crop planting date (September through October) and the subplot factor was cover crop termination timing (2 and 4 wk prior to soybean planting). Cover crop planting date and termination timing had little influence on soybean diseases and insects. Soybean grain yield was influenced by cover crop termination timing at the northwestern location. In 2018, soybean yield was 4% greater when the preceding cover crop was terminated late and in the control (no cover crop) compared to early cover crop termination. The following year, soybean yield was 8% greater when the cover crop was terminated late compared to early termination and the control. At the western location, there was no impact of cover crop termination timing on yield. Late‐terminated cover crops had a positive effect or no effect on yield of the following soybean crop.

The number of hectares dedicated to winter wheat (Triticum aestivum L.) in the southern United States has been trending downward for almost a decade, presenting an opportunity for producers to utilize alternatives in their soybean [Glycine max (L.) Merr.] rotations, such as winter cover crops. A study was established to compare the cover crops to traditional cropping systems by determining the effect each had on a successive soybean crop and to examine partial economic returns. Cropping systems implemented were winter fallow, winter wheat, and seven cover crop treatments, including cereal rye (Secale cereale L.), black‐seeded oat (Avena sativa L.), barley (Hordeum vulgare L.), Austrian winter pea (Pisum sativum L.), blue lupin (Lupinus angustifolius L.), Blend 1 (cereal rye, crimson clover [Trifolium incarnatum L.], seven‐top turnip [Brassica rapa L.]). and Blend 2 (black‐seeded oats and Austrian winter pea). The winter cropping system did not affect the soybean plant population (p = 0.32). Soybean grain yield varied among the different winter cropping systems (p < 0.01) with yields ranging from 3346 to 3906 kg ha−1. The soybean double‐crop system ($1383.02 ha−1) and soybean following winter cover crops ($1239–1380 ha−1) produced similar partial returns but both were greater than soybean following winter fallow ($1217.81 ha−1) (p < 0.01). Soybean yields and partial returns were the highest when following Blend 2. Results of this study showed that winter cover crops can provide an adequate alternative to both winter fallow and traditional winter wheat soybean double‐crop systems in the mid‐southern United States.

<p>Climate change is projected to affect the atmospheric variables that control crop production in the Eastern United States (US). Given that changes in these variables over the next decades are currently unavoidable, crop production will need to adapt to the expected changes in order to prevent or reduce yield losses. The main objectives of this study were: 1) to evaluate the effects of climate change on yields in rainfed corn (Zea mays L.)-soybean (Glycine max (L.) Merr.) rotation systems in the Eastern US and 2) to test two soil conservation practices—no tillage and winter cover cropping with rye (Secale cereale L.)—for their effectiveness as climate change adaptations in these systems. We used the Agricultural Policy/Environmental eXtender (APEX) model to simulate corn-soybean rotation systems in the future (2041‒2070) at nine land grant university research farms located throughout the Eastern US corn-soybean production belt from New York to Georgia. The simulated effects of climate change on yields varied depending on the climate model used, ranging from decreases to increases. Mean corn yields experienced decreases of 15‒51% and increases of 14‒85% while mean soybean yields experienced decreases of 7.6‒13% and increases of 22‒170%. Yield decreases were most common under the climate model predicting the highest increase in temperature and a reduction in precipitation, whereas yield increases were most common in the climate models predicting either a relatively small increase in temperature or a relatively large increase in precipitation. In many cases, the effects of climate change on yields worsened with time within the 30-year future period. The effects of climate change differed between the northern, central, and southern regions of the Eastern US, generally improving with latitude. Climate change generally affected corn yields more negatively or less positively than it did soybean yields. No tillage and rye cover cropping did not serve as effective climate change adaptations in regards to corn or soybean yields. In fact, planting rye after corn and soybeans reduced mean corn yields by 3.1‒28% relative to the control (no cover crop). We speculate that this yield decrease occurred because the rye cover crop reduced the amount of soil water available to the following corn crop.</p>

One of the major constraints to profitable soybean [Glycine max (L.) Merr.] production is yield losses caused by disease. The mid‐southern region of the United States typically experiences environmental conditions that are conducive to disease development, particularly during later reproductive growth stages. It is common for producers in this region to apply fungicides at the beginning of pod development (R3 growth stage; development of pods 3/16 inches long). Producers often question if establishing crops in different row patterns would alter the yield response to prophylactic fungicide applications. Producers also seek answers regarding the yield and grain quality responses to fungicide applications across different row patterns. However, limited data exist to determine if fungicide applications influence the responses of soybean's yield and grain quality between different row spacings. The objective of this research was to evaluate soybean's growth, development, yield, and grain quality across various row spacings, planting dates, and prophylactic fungicide application programs in the absence of disease. These data support that early‐planted soybean had greater yield than later‐planted soybean. No interactions were observed among row spacing, planting date, and fungicide product with respect to yield. Independently, no yield differences were observed regardless of the row spacing or the fungicide product. Regarding quality, soybean planted later resulted in fewer total damaged soybean kernels. These data suggest that row spacing and planting date may not influence soybean's yield response to prophylactic fungicide. Furthermore, these data also suggest that prophylactic fungicide during pod development may not influence the subsequent grain quality.

Equidistant plant arrangements have shown positive impacts, in the United States over the last century, on soybean (Glycine max L.) yield and seed quality by reducing intraspecific plant competition and enhancing early canopy cover. This study aims to (i) assess the effects of equidistant versus non‐equidistant plant arrangements on soybean yield and seed quality across different regions in the United States; (ii) explore the effect of modified soybean plant canopy resulting from different plant arrangements on yield and seed quality. In 2021 and 2022, 13 trials were conducted in Kansas, Mississippi, and South Dakota. The treatments consisted of three equidistant plant arrangements of 13 cm × 13 cm, 15 cm × 15 cm, and 20 cm × 20 cm (620,000, 430,000, 242,363 seeds ha−1, respectively), and a non‐equidistant with 38 cm of row space (321,236 seeds ha−1). Soybean yield and yield components were collected, and canopy coverage (%) was monitored throughout the growing season. Overall, there is no evidence of any advantage of equidistant over non‐equidistant arrangements in soybeans. Yield differences related to spatial arrangement were observed in only three trials: the non‐equidistant increased yield compared to the 20 cm × 20 cm equidistant arrangement (lowest density) in two trials, while the 13 × 13 and 15 × 15 patterns (highest density) showed higher yield compared to the 20 cm × 20 cm arrangement in one trial. Furthermore, seed quality remained constant across spatial arrangements in the 13 trials. In contrast to prior research, our study found no correlation between canopy coverage development and yield improvement. The tested equidistant arrangement while promising did not provide substantial evidence of yield improvement relative to the non‐equidistant.

The Southeastern region of the United States (SE-US) is agroecologically diverse, economically agriculture reliant, and distinct from the twentieth-century warming trend. Considering the inextricable link between climate and agricultural production, it is necessary to quantify future environmental implications on economically important crops of cotton ( Gossypium hirsutum L.) and soybean [ Glycine max (L.) Merr.] in the SE-US. The current study used the fixed-effect model (panel data approach) for climate and yield studies, to assess the impact of climatic variables from 1980 to 2020 such as daily maximum temperature (T max ), minimum temperatures (T min ), and rainfall on cotton and soybean yields. The data from 11 states were averaged per growing season and results revealed significant variability in temperature and rainfall during the last four decades. The T max , T min , and rainfall shifted in the range of 0.46–0.50 °C, 1.30–1.45 °C, and 3.74–3.95 cm, respectively, during the cotton growing season (CGS) and soybean growing seasons (SGS). However, the annual rate of change in T max , T min , and rainfall from 1980 to 2020 was in the range of 0.011–0.012 °C, 0.031–0.034 °C, and 0.089–0.094 cm, respectively, during the CGS and SGS. Rainfall had no significant effect on cotton and soybean yields. A 1 °C rise in T min increased cotton yield by 20.8% while decreasing soybean yield by 31.6%. Alternatively, a 1 °C rise in T max decreased cotton and soybean yield by 10.3% and 25.6%, respectively. • The nocturnal temperature explained the overall heating trend for both Soybean and Cotton over the 41-years. • Rainfall had a positive effect on cotton yield but a non-significant negative effect on soybean yield. • The 1 °C incremental T min boosted the cotton yield while reducing the soybean yield. • The 1 °C rise in the T max decreased the cotton yield and reduced the soybean yield.

Winter cover crops effect on soil moisture and soybean growth and yield under different tillage systems

Generics first appeared in the United States in the 1960’s, and they are medications which, by and large, are less expensive than the innovative ones. This is why they have an important role in controlling and reducing medication prices. The lower prices are due to the savings with development and clinical tests, since these investments have already been made by the innovative medication proprietor. In 1999, with the promulgation of Law 9.787, a Generic Medication policy was instituted in Brazil. The new Legislation introduced a series of production innovations and demands, product quality and bioequivalence tests, as well as medication prescriptions, dispensations and pricing practices. Initial contrary reactions and problems occurred, forcing the Government to make corrective regulatory measures. This research project aims at analyzing both the conditions that lead to such measures being taken and their efficacy. The proposal herein is to analyze the changes made to the generic medication Legislation in Brazil between 1999 and 2002, keeping the Brazilian pharmaceutical market characteristics and market reactions as a backdrop and also relying on articles published in the major newspapers and on interviews made with members of both the regulation agency and of the pharmaceutical industry. The Brazilian Legislation will also be analyzed from the angle of the World Health Organization’s recommendations in order to provide qualitative parameters to evaluate its quality and, finally, to analyze media and political influence in the results the generic medications reached. Legislation manipulation revealed to be an interesting device to assist in the generic implanting process in Brazil and helped in reaching the positive results obtained in such process.

Different tillage methods can have varying effects on soil properties and crop quality. Therefore, field experiments were conducted at the Teaching and Research Farm of Landmark University, located in Omu‐Aran, Kwara State. The objectives were to investigate the impacts of various tillage methods on soil characteristics and the growth, yield, mineral and proximate content of soybean (Glycine max (L.) Merr.). Based on these objectives, it was hypothesized that soil properties, growth, yield, mineral and proximate contents of soybean would react differently to different tillage methods. Consequently, experiments were conducted to validate this hypothesis. The treatments were four tillage methods: manual clearing (MC), ploughing (P), ploughing plus harrowing (P + H) and manual ridging (MR), replicated three times in a randomized complete block design. Data on the initial soil properties (bulk density, particle size, pH, organic matter, N, P, K, Ca and Mg), along with the chemical properties of the soil on a per‐plot basis at the end of the experiment, were collected. Additionally, data on soil bulk density, porosity, moisture content and temperature were collected during the vegetative growth of the soybean. Soybean plant height and the number of branches were recorded at the midflowering stage, while grain yield and the number of pods were recorded at harvest. Soybean seeds were later analysed for their mineral and proximate contents using standard methods. P + H resulted in lower soil bulk density than other tillage methods and led to higher growth, yield, proximate and mineral contents of soybean. In MC, bulk density, soil moisture content, soil organic matter, N, P, K, Ca and Mg were significantly higher and temperature lower than in other tillage methods; yet, these advantages did not translate into increased yield and quality due to the higher bulk density. The growth, yield and quality of soybean were significantly influenced by soil bulk density rather than by soil chemical properties. Using the mean of the two sites, relative to MC, P and MR, P + H increased the grain yield of soybean by 41.3%, 24.4% and 13.7%, respectively. These findings underscore the importance of appropriate tillage practices for successful soybean cultivation in similar agroecological zones. For small‐scale operations, MR is suggested, while P + H is recommended for large‐scale soybean production in the studied area. Future studies could include additional variables, such as economic analysis, long‐term soil health impacts or the effects of tillage methods under varying climate conditions.

Field studies were conducted in 1997 and 1998 to evaluate weed control and soybean (Glycine max) yield with cloransulam and diclosulam. Cloransulam at 35 g/ha applied preplant incorporated (PPI) and preemergence (PRE) controlled at least 91% of hyssop spurge (Euphorbia hyssopifolia) and prickly sida (Sida spinosa) and at least 82% of entireleaf morningglory (Ipomoea hederacea var. integriuscula) and pitted morningglory (Ipomoea lacunosa) at 7 wk after planting. Control of these species with cloransulam was not affected by method of soil application. Control of prickly sida with cloransulam PPI or PRE was better than with cloransulam postemergence (POST) at 18 g/ha. Soybean yields were similar with cloransulam PPI (2,880 kg/ha) or PRE (3,110 kg/ha) and were comparable to imazaquin PRE at 140 g/ha (3,080 kg/ha). Weed control and soybean yields with cloransulam POST were similar to that with chlorimuron POST at 11 g/ha. SAN 582 plus cloransulam PRE followed by cloransulam POST provided the highest soybean yield (3,450 kg/ha). Diclosulam PPI or PRE provided similar levels of control of hyssop spurge, Ipomoea morningglories, and prickly sida. Overall, control of these species with diclosulam PPI or PRE was similar to that obtained with sulfentrazone plus chlorimuron PRE. Soybean yields (≥ 3,290 kg/ha) were similar regardless of method of diclosulam application, and yields were equivalent to that of sulfentrazone plus chlorimuron PRE (3,270 kg/ha).Nomenclature: Chlorimuron, ethyl 2-[[[[4-chloro-6-methoxy-2-pyrimidinyl)amino]carbonyl]amino]sulfonyl]benzoate; cloransulam, 3-chloro-2-[[(5-ethoxy-7-fluoro[1,2,4]triazolo[1,5-c]pyrimidin-2yl)sulfonyl]amino]benzoic acid, methyl ester; diclosulam, N-(2,6-dichlorophenyl)-5-ethoxy-7-fluoro[1,2,4]triazolo-[1,5-c]pyrimidine-2-sulfonamide; SAN 582 (proposed common name, dimethenamid), 2-chloro-N-[(1-methyl-2-methoxy)ethyl]-N-(2,4-dimethyl-thien-3-yl)acetamide; imazaquin, 2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imadazol-2-yl]-3-quinolinecarboxylic acid; sulfentrazone, N-[2,4-dichloro-5-[4-(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazol-1-yl]-phenyl]methanesulfonamide; entireleaf morningglory, Ipomoea hederacea var. integriuscula Gray #3 IPOHG; hyssop spurge, Euphorbia hyssopifolia L. # EPHHS; pitted morningglory, Ipomoea lacunosa L. # IPOLA; prickly sida, Sida spinosa L. # SIDSP; soybean, Glycine max (L.) Merr. ‘DP 3588.’Additional index words: Metolachlor, SAN 582, EPHHS, IPOHG, IPOLA, PANRA, SIDSP.Abbreviations: fb, followed by; POST, postemergence; PPI, preplant incorporated; PRE, preemergence; WAP, weeks after planting.

Crop rotations involving corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] are well‐known production systems across the Midwestern United States, but the addition of wheat (Triticum aestivum L.) in the rotation has received less attention. Additionally, the interactive effect of crop rotation with nitrogen (N) fertilizer and foliar fungicide application on yields for these three crops is not yet well understood. Data were collected in Wisconsin from a long‐term crop rotation experiment during 2013 to 2015 to measure corn (grain and silage), soybean, and wheat yield response to crop rotation frequency (seven rotations involving corn, soybean, and wheat), six levels of N, and foliar fungicide use. During the 3 yr of the experiment, minimal interactive effects were detected, which suggested that the examined management decisions can remain separate for growers in Wisconsin. Yearly crop rotation of corn and soybean increased corn grain yields in 2014 by 15 to 18% and soybean yields by 24 to 31% in 2015 compared with continuous cropping. No other crop rotation effect was observed. Fungicide use at the V5 growth stage for corn, at R3 for soybean, and at GS9 for wheat, increased wheat (7.4–16.8%) and soybean yield (3.6–5.4%) but not corn grain or silage yields. Nitrogen application was more beneficial for corn compared with wheat and soybean. The effect of N on soybean was similar across all rotations, and grain yields increased when N rate was higher than 100 kg ha−1. The data suggest that N rate recommendations should be based on crop needs, regardless the rotation system.

Reviewed by: Imitation Nation: Red, White, and Blackface in Early and Antebellum US Literature by Jason Richards Jonathan Daigle (bio) Imitation Nation: Red, White, and Blackface in Early and Antebellum US Literature jason richards Charlottesville: University of Virginia Press, 2017 256 pp. For decades, scholars have been expanding the geographic and temporal lenses through which they study "American" identities, cultures, and texts. The logic of this reconsideration is simple and sound: the notion of an autochthonous, independent US literature and culture is inaccurate and, at bottom, in bad faith. What this project lacks in freshness, it makes up for in continued relevance. Decades after the transnational shift began, American exceptionalism and its tangle of assumptions persist. Indeed, the remapping of identities and relationships is a vast imaginative effort, one of several generations, in the very least. This long revaluation requires textured analysis and new conceptual frameworks. In Imitation Nation: Red, White, and Blackface in Early and Antebellum US Literature, Jason Richards offers both. Triangulating modes of inquiry, Richards studies hiding-in-plain-sight relationships among white Americans, African Americans, Native Americans, and white Europeans. For example, Richards combines insights from scholarship on blackface minstrelsy with those gleaned from settler postcolonial theory to bring Natty Bumppo's native and African American mimesis into sharp focus. This approach to James Fenimore Cooper's The Pioneers (1823) reveals the dependence of American whiteness on Native American, African American, and British Anglo-Saxon identities. Exploring new relationships among established schools of thought, Richards provides a model for redressing the insularity that has long shaped conceptions of US history, literature, and culture. Richards borrows from nineteenth-century social theorist Gabriel Tarde, who viewed imitation, not essence, as the basis of identity. Tarde's [End Page 537] notion that identity is contingent on one's response to others is particularly suggestive in the early American and antebellum contexts. As Richards notes, the theater's rapid growth in the early Republic reflected a longing for national culture keyed to an implicit understanding that Americanness would be achieved through imitation, specifically, through embodying and absorbing Native American, African American, and European identities. Engaging the work of Philip J. Deloria, Eric Lott, and Robert S. Levine, Richards delineates mutually constitutive relationships among diverse acts of cross-racial, cross-Atlantic mimesis. Imitation Nation makes an important contribution to the scholarship of blackface minstrelsy. But because mimesis took place offstage, too, Richards conceptualizes redface and blackface broadly to cover a range of cross-racial imitations. While mimesis occurs wherever contact happens, it assumed particularly robust form in a new republic defined by remarkable diversity and dominated by descendants of white Europe who faced the unusual problem of defining themselves as, at once, white and not European. A unique postcolonial settler society, the early United States sought the temporal depth and legitimacy associated with aboriginal Indian identity, but it also imitated Britain's imperial dominance over nonwhite groups. Imitation Nation makes a compelling case that American identity emerged in the complex interplay of western and Atlantic frontiers. Literature helped shape national identity in this push-pull fashion: European models distinguished the white United States from its Native American and African American inhabitants, and these Others helped distinguish American literature and identity from European antecedents. This dynamic set at odds preoccupations with racial purity and American distinctiveness. That is, a distinctive white national identity required absorbing and excluding racial and cultural Others at the same time. Citing Homi K. Bhabha's idea of mimicry from The Location of Culture, Richards opens a space for nonwhite agency in the production of national identity. Through mimicry, the disenfranchised, colonized, and enslaved exploit the slippage between the identities hegemonic regimes enforce and those same identities as performed by the oppressed. Mimicry and cross-cultural imitation, more broadly, energize what Richards calls "hybridity, the inevitable offspring of mimesis" (31). Imitation Nation sets the reality of hybridity against the fiction of white purity, as Richards argues: "If the colonial apparatus stabilized itself through a fiction of racial [End Page 538] purity, the fact of hybridity cut through the homogenous myth, opening the door to a more democratic postcolonial future" (31). A robust conception of hybridity leads Richards to...