| no-choice preference of cerotoma trifurcata (coleoptera: chrysomelidae) to potential host plants of bean pod mottle virus (comoviridae) in iowa. | to better understand the naturally occurring host range of bean pod mottle virus (family comoviridae, genus comovirus, bpmv) and its principal vector cerotoma trifurcata (förster) (coleoptera: chrysomelidae), 18 field-collected perennial plant species were tested for the presence of bpmv. by using no-choice assays, we determined the preference of these plants by bean leaf beetle, by measuring their level of herbivory relative to soybean, glycine max (l.). new food hosts for adult bean leaf beetl ... | 2007 | 17598542 |
| estimated historical and current nitrogen balances for illinois. | the midwest has large riverine exports of nitrogen (n), with the largest flux per unit area to the mississippi river system coming from iowa and illinois. we used historic and current data to estimate n inputs, outputs, and transformations for illinois where human activity (principally agriculture and associated landscape drainage) have had a dominant impact. presently, approximately 800,000 mg of n is added each year as fertilizer and another 420,000 mg is biologically fixed, primarily by soybe ... | 2001 | 12805881 |
| seasonal population dynamics of thrips (thysanoptera) in wisconsin and iowa soybean fields. | with the discovery of neohydatothrips variabilis (beach) as a vector of soybean vein necrosis virus (family bunyaviridae genus tospovirus), a relatively new pathogen of soybean, a multiyear study was initiated in wisconsin (2013 and 2014) and iowa (2014 and 2015) to determine the phenology and species composition of thrips in soybean fields. yellow sticky card traps were used to sample thrips at regular intervals in five counties within each state's primary soybean-growing region. the assemblage ... | 2017 | 28011679 |
| residual soil nitrate content and profitability of five cropping systems in northwest iowa. | many communities in the midwestern united states obtain their drinking water from shallow alluvial wells that are vulnerable to contamination by no3-n from the surrounding agricultural landscape. the objective of this research was to assess cropping systems with the potential to produce a reasonable return for farmers while simultaneously reducing the risk of no3-n movement into these shallow aquifers. from 2009 to 2013 we conducted a field experiment in northwest iowa in which we evaluated five ... | 2017 | 28248976 |
| effect of liquid swine manure rate, incorporation, and timing of rainfall on phosphorus loss with surface runoff. | excessive manure phosphorus (p) application increases risk of p loss from fields. this study assessed total runoff p (tpr), bioavailable p (bap), and dissolved reactive p (drp) concentrations and loads in surface runoff after liquid swine (sus scrofa domesticus) manure application with or without incorporation into soil and different timing of rainfall. four replicated manure p treatments were applied in 2002 and in 2003 to two iowa soils testing low in p managed with corn (zea mays l.)-soybean ... | 2008 | 18178885 |
| perennial filter strips reduce nitrate levels in soil and shallow groundwater after grassland-to-cropland conversion. | many croplands planted to perennial grasses under the conservation reserve program are being returned to crop production, and with potential consequences for water quality. the objective of this study was to quantify the impact of grassland-to-cropland conversion on nitrate-nitrogen (no3-n) concentrations in soil and shallow groundwater and to assess the potential for perennial filter strips (pfs) to mitigate increases in no3-n levels. the study, conducted at the neal smith national wildlife ref ... | 2013 | 21284298 |
| root parameters show how management alters resource distribution and soil quality in conventional and low-input cropping systems in central iowa. | plant-soil relations may explain why low-external input (lei) diversified cropping systems are more efficient than their conventional counterparts. this work sought to identify links between management practices, soil quality changes, and root responses in a long-term cropping systems experiment in iowa where grain yields of 3-year and 4-year lei rotations have matched or exceeded yield achieved by a 2-year maize (zea mays l.) and soybean (glycine max l.) rotation. the 2-year system was conventi ... | 2016 | 27792744 |
| effect of nitrogen fertilizer application on growing season soil carbon dioxide emission in a corn-soybean rotation. | nitrogen application can have a significant effect on soil carbon (c) pools, plant biomass production, and microbial biomass c processing. the focus of this study was to investigate the short-term effect of n fertilization on soil co(2) emission and microbial biomass c. the study was conducted from 2001 to 2003 at four field sites in iowa representing major soil associations and with a corn (zea mays l.)-soybean (glycine max l. merr.) rotation. the experimental design was a randomized complete b ... | 2013 | 18268294 |
| maximum soil organic carbon storage in midwest u.s. cropping systems when crops are optimally nitrogen-fertilized. | nitrogen fertilization is critical to optimize short-term crop yield, but its long-term effect on soil organic c (soc) is uncertain. here, we clarify the impact of n fertilization on soc in typical maize-based (zea mays l.) midwest u.s. cropping systems by accounting for site-to-site variability in maize yield response to n fertilization. within continuous maize and maize-soybean [glycine max (l.) merr.] systems at four iowa locations, we evaluated changes in surface soc over 14 to 16 years acro ... | 2017 | 28249014 |
| nitrous oxide emissions from corn-soybean systems in the midwest. | soil n2o emissions from three corn (zea mays l.)-soybean [glycine max (l.) merr.] systems in central iowa were measured from the spring of 2003 through february 2005. the three managements systems evaluated were full-width tillage (fall chisel plow, spring disk), no-till, and no-till with a rye (secale cereale l. 'rymin') winter cover crop. four replicate plots of each treatment were established within each crop of the rotation and both crops were present in each of the two growing seasons. nitr ... | 2013 | 16825470 |
| sources of nitrate yields in the mississippi river basin. | riverine nitrate n in the mississippi river leads to hypoxia in the gulf of mexico. several recent modeling studies estimated major n inputs and suggested source areas that could be targeted for conservation programs. we conducted a similar analysis with more recent and extensive data that demonstrates the importance of hydrology in controlling the percentage of net n inputs (nni) exported by rivers. the average fraction of annual riverine nitrate n export/nni ranged from 0.05 for the lower miss ... | 2010 | 21043271 |
| is preventative, concurrent management of the soybean aphid (hemiptera: aphididae) and bean leaf beetle (coleoptera: chrysomelidae) possible? | in iowa, the management of insect pests in soybean, glycine max (l.) merr., has been complicated by the arrival of the invasive species soybean aphid, aphis glycines matsumura (hemiptera: aphididae), and occasional outbreaks of bean leaf beetle, cerotoma trifurcata (förster) (coleoptera: chrysomelidae), populations leading to economic losses. several insecticide programs designed to reduce abundance of the overwintered and first generation c. trifurcata and the incidence of bean pod mottle virus ... | 2008 | 18613581 |
| epic modeling of soil organic carbon sequestration in croplands of iowa. | depending on management, soil organic carbon (soc) is a potential source or sink for atmospheric co(2). we used the epic model to study impacts of soil and crop management on soc in corn (zea mays l.) and soybean (glycine max l. merr.) croplands of iowa. the national agricultural statistics service crops classification maps were used to identify corn-soybean areas. soil properties were obtained from a combination of ssurgo and statsgo databases. daily weather variables were obtained from first o ... | 2008 | 18574164 |
| survey of soybean insect pollinators: community identification and sampling method analysis. | soybean, glycine max (l.) merrill, flowers can be a source of nectar and pollen for honey bees, apis mellifera l. (hymenoptera: apidae), wild social and solitary bees (hymenoptera: apoidea), and flower-visiting flies (diptera). our objectives were to describe the pollinator community in soybean fields, determine which sampling method is most appropriate for characterizing their abundance and diversity, and gain insight into which pollinator taxa may contact soybean pollen. we compared modified p ... | 2015 | 26313954 |
| nitrogen fertilizer effects on soil carbon balances in midwestern u.s. agricultural systems. | a single ecosystem dominates the midwestern united states, occupying 26 million hectares in five states alone: the corn-soybean agroecosystem [zea mays l.-glycine max (l.) merr.]. nitrogen (n) fertilization could influence the soil carbon (c) balance in this system because the corn phase is fertilized in 97-100% of farms, at an average rate of 135 kg n x ha(-1) x yr(-1). we evaluated the impacts on two major processes that determine the soil c balance, the rates of organic-carbon (oc) inputs and ... | 2009 | 19688919 |
| the impact of prairie strips on aphidophagous predator abundance and soybean aphid predation in agricultural catchments. | reconstructing prairie vegetation in row crop-dominated agricultural landscapes may contribute to several ecosystem services, including the biological control of insect pests, such as the soybean aphid aphis glycines matsumura. the influence of the amount and configuration of reconstructed prairie vegetation on the delivery of ecosystem services was investigated in several small catchments at neal smith national wildlife refuge in iowa. treatments include catchments entirely in row crops under a ... | 2014 | 25199149 |
| population dynamics of a western corn rootworm (coleoptera: chrysomelidae) variant in east central illinois commercial maize and soybean fields. | three on-farm sites in iroquois county, il, each containing an adjacent 16.2-ha commercial production maize, zea mays l., and soybean, glycine max (l.) merr., field, were monitored for western corn rootworm, diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae), adults from june through september 1999-2001. mean captures of d. v. virgifera adults as measured with pherocon am yellow sticky traps were significantly greater in maize than in soybean. overall mean numbers of d. v. virgif ... | 2007 | 17849858 |
| abundance and distribution of western and northern corn rootworm (diabrotica spp.) and prevalence of rotation resistance in eastern iowa. | the western corn rootworm diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae) and the northern corn rootworm diabrotica barberi smith & lawrence (coleoptera: chrysomelidae) are major pests of corn (zea mays l.). historically, crop rotation has been an effective management strategy, but both species have adapted to crop rotation in the midwest. for both species in eastern iowa, we measured abundance and prevalence of rotation resistance using sticky traps and emergence cages in fie ... | 2013 | 23448029 |
| defining the insect pollinator community found in iowa corn and soybean fields: implications for pollinator conservation. | although corn (zea mays l.) and soybeans (glycine max l.) do not require pollination, they offer floral resources used by insect pollinators. we asked if a similar community of insect pollinators visits these crops in central iowa, a landscape dominated by corn and soybean production. we used modified pan traps (i.e., bee bowls) in both corn and soybean fields during anthesis and used nonmetric multidimensional scaling (nms) to compare the communities found in the two crops. summed across both c ... | 2016 | 27516433 |