,Irrigation Residue Removal Study for Greenhouse gas Reduction through Agricultural Carbon Enhancement network and Resilient Economic Agricultural Practices in Lincoln, Nebraska USDA-ARS REAP Study (Ithaca, NE) - NEMEIRR Sustainable intensification of high-yielding production systems may help meet increasing demands for food, fuel, and fiber worldwide. Specifically, corn stover is being removed by producers for livestock purposes, and stover is also targeted as a primary 2nd generation biofuel feedstock. The NEMEIRR experimental objectives are to quantify how stover removal (no removal, moderate removal, high removal) and tillage management (no-till, disk) affect crop yields, soil organic carbon, soil greenhouse gas emissions, and other soil responses (microbial community structure, function; soil health). This experiment is conducted in a fully irrigated continuous corn system in the western Corn Belt, and soil and plant measurements have been taken since study establishment in 2001. By: V.L. Jin (1 Sep 2016). (41 9 43.3 N. 96 14 41.4 W; 349 m asl). Thc soil is Tomck silt loam (a fine, smectitic. mesic Pachic Argiudoll) and Filbert silt loam (a fine, smectitie. mesie Verne Argialboll). Long-term (1981-2010) mean annual precipitation is 74 cm and tempera¬ture is 9.8°C The study has been in continuous corn since 2000. Thc experimental design is a randomized complete block with factorial treatments arranged in split plots. The whole-plot factor is tillage treatment (NT or CT) and the subplot factor is none (0%). medium (•35%). and high (40%) stover removal calcu¬lated on a mass basis. Nitrogen fertilizer was applied at 202 kg N ha-I yr I in 2001. 2002. 2004. 2007. 2008. 2009, and 2010.190 kg N hi t yr-I in 2003. and 168 kg N ha 1 yr- I in 2005 and 2006. Treatments (tillage) and subplot treatments (residue re¬moval levels) were randomly assigned in a factorial arrangement to whole-plot experimental units (9 by 45.6 m) and subplots within the whole plots (9 by 15.2 m) in six blocks. The previous crop for the entire area in 2000 was corn under rainfcd conditions. Before 2000. the study site was historically cropped with corn, soybean [Glycinc max (L.) Merr.). oat (Arena JoIliM L.), and alfalfa (Maid-ago saliva L). In the spring of 2001, residue was removed from the medium and high stover removal treatments using a flail chopper. The entire study was then disked to remove ridges formed during the previous crop year. In each successive year of the study, only the disk treatment area was tilled to a depth of 15 to 20 cm. usually in the spring before plant¬ing. Irrigation was conducted with a solid set sprinkler system in 2001, then supplemental water applications from 2002 to 2010 were made using a linear-move irrigation system. Irrigation treat¬ments were applied when deemed necessary, with annual rates averaging 12.5 ± 7.0 cm from 2001-2010 (Table I). Glyphosatc-tolerant corn hybrids adapted to eastern Nebraska have been used throughout the study. Corn was plant¬ed with a six-row planter in 76-cm rows at a rate *174.000 viable seeds ha 1, typically during the first week of May. Weed control was accomplished using glyphosate EN-(phosphonomethyl)gly¬eine] and atrazine (6.chloro-N-ethyl-AP-(1-methylethyl)-1.3.5- triazine-2.4-diamine) applications along with in-season cultiva.,

,Long-term Crop Rotation Study for Greenhouse gas Reduction through Agricultural Carbon Enhancement network in Lincoln, Nebraska Lincoln NE Long-term Crop Rotation Project Overview of NEMLTCRS: Long-term Crop Rotation Study (Ithaca, NE) Crop rotation and fertilizer N management are common practices that affect productivity and input use efficiency. Evaluating these practices in a long-term setting provides the opportunity to assess their influence across a wide range of growing conditions and to determine their effect on yield stability (performance across a wide range of environmental conditions). Previous publications from this experiment have evaluated the response of corn, soybean, and sorghum production to these treatments under conventional tillage during an earlier time period (e.g., Peterson and Varvel, 1989a,b,c; Varvel, 2000), concluding that diversified crop rotations generally enhance grain production. Following conversion to no-till, yield trends from 2007 to 2013 indicate that: • Diversified 2- and 4-yr crop rotations increased corn and grain sorghum yields. • Corn and grain sorghum grain yields in 2- and 4-yr rotations were more resilient to variable growing conditions.• Soybean was less sensitive than corn and grain sorghum to crop rotation. Excerpted from: Sindelar et al., 2016 (Agron. J. 108: 1592-1602) viewed as an unfassirable management practice in soybean because it can inhibit nodular:ion (Salvagiotti et aL. 2008). However. responses to early-season fertilizer N are inconsistent. For example. Varvd and Peterson (1992) reported a decrease with fertilizer N input. yet Osborne and Riedell (2006) reported a grain yield increase with fertilizer N addition. Therefore. additional work is needed to clarify this particular response of soybean to early-season N fenilization. Crop rotation and fertilizer N management arc common practices that affect productivity and input use efficiency. Evaluating these practices in a long-term setting provides the opportunity to assess their influence across a wide range of growing conditions and to determine their effect on yield stability (performance across a wide range of environmental conditions). Previous publications from this experiment have evaluated the response acorn. soybean. and sorghum produc-tion to these treatments under conventional tillage during an earlier time period (e.g.. Peterson and VarveL 1989a.b.c: Varvel. 2000). concluding that diversified crop rotations gener-ally enhance grain production. Information has not yet been reported from this study naluacing the treatments under no-till (2007-2013). To our knowledge. no studies have simul-taneously evaluated the stability of continuous and diversified rotations of corn. grain sorghum. and soybean. The objective of this study was to evaluate long-term yield performance. yield stability. and fertilizer N of corn. grain sorghum. and soybean as affected by crop rotation and fertilizer N under no-till in the western Corn Belt. MATERIALS AND METHODS A field experiment was established in 1972 on a Yuan silty clay loam-Tomek salt barn compkx (fine-silty. mired. supaac-tire. mesic Mollie Hapkidalfs and fine. smecutic. mimic Pachic Argiudolls. resik.l.didy) near Ithaca. NE (31•10'N. 96'25'W). Elevation of the site is 366 rn. and mean annual temperature and precipitation arc 10.5*C and 765 mm. respectively. In-season air temperature. soil temperature. precipitation. and open pan evaporation measured on-site during this time period arc shown in Tabk I. The experiment was a randomized complete block design in a split plot arrangement with five replications. Crop rotation was the main ploc, and fertilizer N rate was the split plot. Crop rotations included continuous crops (continuous corn (CC). continuous grain sorghum IGGI. and continuous soybean (SS]). 2-yr (CS and OS) and 4-yr crop rotations (corn-soybean-grain sorghum-ad/clover vocation ((:5C01 and corn-cut/clover - grain sorghum-soybean rotation (COGS]). Continuous

,Long-term tillage and cropping system experiment for Greenhouse gas Reduction through Agricultural Carbon Enhancement network and Nutrient Use and Outcome Network in Lincoln, Nebraska Lincoln NE Long-term Tillage Project Overview of NELITCSE: Long-term Tillage and Cropping System Experiment (Lincoln, NE) The objectives of this experiment is to evaluate the agronomic and environmental impacts of long-term tillage and crop rotation practices in a rainfed agroecosystem. This experiment was initiated in 1981 with continuous corn only under six tillage practices (chisel, tandem disk, moldboard plow, no-till, ridge-tillage, and subsoil tillage). In 1985, the experimental design was modified to include 3 crop rotation systems (continuous corn, corn-soybean, and continuous soybean) under 6 tillage practices. Each year, both the corn phase and soybean phase of the two-year rotation system are present. In 2015, all tillage practices were converted to no-till to evaluate the magnitude, direction, and rate of agronomic and soil changes to this management shift. In addition, the continuous soybean system was converted to continuous corn with a 3-species winter cover crop (hairy vetch, purple-topped radish, and cereal rye). Prepared 13 Sep 2016 (V. Jin),

,REAP Study for Resilient Economic Agricultural Practices in West Lafayette, Indiana Corn stover is an important livestock feed and will probably be a major source of renewable bioenergy, especially in the U.S. Corn Belt. Overly aggressive removal of stover, however, could lead to greater soil erosion and hurt producer yields in the long-run. Good residue management practices could help prevent erosion of valuable topsoil by wind and water while still providing a revenue source for producers, either as livestock feed or for use in renewable bioenergy. Plant residues also contribute to soil structure, nutrient cycling, and help sustain the soil microbiota. Good residue management could also help control the loss of greenhouse gases from agricultural soils that could add to already increasing levels of atmospheric greenhouse gases contributing to global climate change. Cumulative GHG emissions varied widely across locations, by management, and from year-to-year. Despite this high variability, maximum stover removal averaged across all sites, years, and management resulted in lower total emissions of CO2 (-12 ± 11%) and N2O (-13 ± 28%) compared to no stover removal. Decreases in total CO2 and N2O emissions in stover removal treatments were attributed to decreased availability of stover-derived C and N inputs into soils, as well as possible microclimatic differences. Soils at all sites were CH4 neutral or small CH4 sinks. Exceptions to these trends occurred for all GHGs, highlighting the importance of site-specific management and environmental conditions on GHG fluxes in agricultural soils.,

,Alternative Rotation Study for Greenhouse gas Reduction through Agricultural Carbon Enhancement network in Brookings, South Dakota Greenhouse gas fluxes and ancillary data are being measured in a 2-yr corn-soybean rotation (business as usual) and a 4- yr corn-pea-winter wheat-soybean rotation (more sustainable).,

,SMT Study for Greenhouse gas Reduction through Agricultural Carbon Enhancement network in St. Paul, Minnesota Carbon and Nitrogen Storage are Greater under Biennial Tillage in a Minnesota Corn-Soybean Rotation. Venterea, Rodney T., Baker, John M., Dolan, Michael S., Spokas, Kurt A., Soil Science Society of America Journal; Madison. http://search.proquest.com/assets/r20171.4.0.302.1590/core/spacer.gif70.5http://search.proquest.com/assets/r20171.4.0.302.1590/core/spacer.gif (Sep/Oct 2006): 1752-1762. Few studies have examined the impacts of rotational tillage regimes on soil carbon (C) and nitrogen (N). We measured the C and N content of soils managed under corn (Zea mays L.)-soybean (Glycine max L.) rotation following 10 and 15 yr of treatments. A conventional tillage (CT) regime employing moldboard and chisel plowing in alternate years was compared with both continuous no-till (NT) and biennial tillage (BT), which employed chisel plowing before soybean only. While masses of C and N in the upper 0.3 m under both BT and NT were higher than CT, only the BT treatment differed from CT when the entire sampled depth (0.6 m) was considered. Decreased C inputs, as indicated by reduced grain yields, may have limited C storage in the NT system. Thus, while more C was apparently retained under NT per unit of C input, some tillage appears necessary in this climate and cropping system to maximize C storage. Soil carbon dioxide (CO2) fluxes under NT were greater than CT during a drier than normal year, suggesting that C storage may also be partly constrained under NT due to wetter conditions that promote increased soil respiration. Increased temperature sensitivity of soil respiration with increasing soil moisture was also observed. These findings indicate that long-term biennial chisel plowing for corn-soybean in the upper mid-west USA can enhance C storage, reduce tillage-related fuel costs, and maintain yields compared with more intensive annual tillage. Urea Decreases Nitrous Oxide Emissions Compared with Anhydrous Ammonia in a Minnesota Corn Cropping System. Venterea, Rodney T; Dolan, Michael S; Ochsner, Tyson E. http://search.proquest.com/assets/r20171.4.0.302.1590/core/spacer.gif. Soil Science Society of AmericanJournal; Madison http://search.proquest.com/assets/r20171.4.0.302.1590/core/spacer.gif74.2http://search.proquest.com/assets/r20171.4.0.302.1590/core/spacer.gif (Mar/Apr 2010): 407-418. Quantifying N2O emissions from corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] fields under different fertilizer regimes is essential to developing national inventories of greenhouse gas emissions. The objective of this study was to compare N2O emissions in plots managed for more than 15 yr under continuous corn (C/C) vs. a corn-soybean (C/S) rotation that were fertilized during the corn phase with either anhydrous NH 3 (AA) or urea (U). During three growing seasons, N2O emissions from corn following corn were nearly identical to corn following soybean. In both systems, however, N2O emissions with AA were twice the emissions with U. After accounting for N2O emissions during the soybean phase, it was estimated that a shift from C/S to C/C would result in an increase in annual emissions of 0.78 kg N ha-1 (equivalent to 0.11 Mg CO2-C ha-1) when AA was used, compared with only 0.21 kg N ha-1 (0.03 Mg CO2-C ha-1) with U. In light of trends toward increased use of U, these results suggest that fertilizer-induced soil N2O emissions may decline in the future, at least per unit of applied N, although further study is needed in different soils and cropping systems. While soil CO2 emissions were 20% higher under C/C, crop residue from the prior year did not affect soil inorganic N or dissolved organic C during the subsequent season. We also compared different flux-calculation schemes, including a new method for correcting chamber-induced errors, and found that selection of a calculation method altered N2O emissions estimates by as much as 35%.,

,TPAC Study for Greenhouse gas Reduction through Agricultural Carbon Enhancement network in West Lafayette, Indiana Recent efforts have attempted to establish emission estimates for greenhouse gases (GHG) from agricultural soils in the United States. This research project was conducted to assess the influence of cropping system management on non-carbon dioxide (non-CO2) GHG emissions from an eastern cornbelt alfisol. Corn (Zea mays L.) and soybean (Glycine max (L.) Merr.) rotation plots were established, as were plots in continuous management of native grasses or Sorghum/Sudan grass. GHG fluxes were monitored throughout each growing season from 2004 through 2007. Fluxes of N2O were significantly correlated with soil temperature (P < 0.001), and thus a Q10 correction was made (3.48 for N2O). Nitrous oxide emissions from corn were lowest from the precision tillage treatment (2.4 kg N ha-1 yr-1), significantly lower than the conventional tillage (4.9 kg N ha-1 yr-1) or cover crop corn treatments (5.0 kg N ha-1 yr-1). Corn-soybean and biomass-based cropping systems resulted in significantly greater N2O emissions than native grasses. There was a positive correlation between N fertilization rate and N2O emissions when comparing all treatments in this study. These soils were typically a sink for atmospheric CH4 for these cropping systems, and thus N2O is the primary non-CO2 GHG of concern. When evaluating the entire cropping system, native grasses resulted in the lowest N2O emissions, while corn-soybean rotation planted with precision tillage resulted in similar N2O emissions as bare soil and were significantly lower than emissions from the other cropping systems assessed.,

,NWISRL South Farm Study for Greenhouse gas Reduction through Agricultural Carbon Enhancement network in Kimberly, Idaho We report N2O emissions along with CO2 and CH4 from a silage corn (2013)–barley (2014)–alfalfa (2015) rotation under conventional tillage and sprinkler irrigation. The main study objectives were to evaluate the effectiveness of an enhanced-efficiency fertilizer (SuperU; stabilized granular urea with urease and nitrification inhibitors) to reduce N2O emissions when compared to granular urea, and determine GHG emissions from fall-applied dairy manure or composted dairy manure and spring-applied dairy manure. Nitrogen treatments were only applied during the first two years of the study. Compared to urea, SuperU plots emitted 53% less N2O during the monitoring period with corn, while no N2O emission reductions occurred in 2014 with barley. The N2O-N emission losses as a percentage of total N applied were 0.21% and 0.04% for urea and SuperU in 2013, respectively, with losses of 0.05% from both urea fertilizers in 2014. On average, N2O fluxes from fall and spring manure were statistically similar and greater than the other N treatments in 2014, and there was a lasting manure treatment effect on emissions when under alfalfa. Carbon dioxide fluxes, on average, were greatest from fall- and spring-applied manure during the first two years of study. Methane fluxes were negative on average, indicating microbial oxidation, and no differences occurred among the N treatments. Silage corn, barley grain, and alfalfa yields were statistically similar among all N treatments. This work demonstrates that SuperU can potentially reduce N2O emissions from irrigated cropping systems in the semiarid western United States while not affecting crop yields.,

,The increase in corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] production in rainfed cropping systems of the northern Great Plains has altered the delivery of ecosystem services from agricultural land. A study was conducted to quantify carbon balance of a spring wheat (Triticum aestivum L.)-corn-soybean rotation under no-till management using eddy covariance techniques over a 3-yr period. Paired field sites with the same soil type near Mandan, ND USA were used for the study. Data from the study included fluxes of carbon dioxide and water vapor, precipitation, air temperature, relative humidity, photosynthetically active radiation, soil temperature, soil water content, vegetation phenology, green chromatic coordinate, aboveground biomass, leaf area index, and grain yield. Data were used to generate estimates of net ecosystem exchange, ecosystem respiration, gross ecosystem production, net ecosystem carbon balance, evapotranspiration, vapor pressure deficit, relative greenness of vegetation, and carbon-, water-, and light-use efficiencies. Data are generally applicable to rainfed conditions under a semiarid Continental climate for Temvik-Wilton silt loams (fine silty, mixed, superactive, frigid Typic and Pachic Haplustolls) and related soil types (i.e., Grassna, Linton, Mandan, and Williams).,

,The ‘Management Strategies for Soil Quality’ study was established in 1993 by Dr. Don Tanaka (USDA-ARS-NGPRL) to evaluate long-term impacts of minimum and no-till cropping systems on crop yield, precipitation use, and soil properties. The study was designed with six crop sequences (whole plot) each split by tillage type (split plot). All phases of each crop sequence are present every year, and treatments are replicated three times.,See record in the GeoData catalog at https://geodata.nal.usda.gov/geonetwork/srv/eng/catalog.search#/metadata/dda43934-b75f-46da-b48e-81be1317b79b for more information and links to the data resources.,