Effects and Interactions of Nitrogen and Soil Moisture Status Under a High Yield Irrigated Corn Environment

A two-part study was conducted during the 1979 and 1980 growing seasons on irrigated lands adjoining the Missouri River in central South Dakota. Empirical [sic] models were developed to describe the response of irrigated corn (Zea mays L.) to soil water status and nitrogen fertilization at a location recently developed for sprinkler irrigation. Nitrogen fertilizer rates of 0, 100, 200, and 400 kg of N/ha were used under water treatments consisting of a 2.5 cm irrigation when soil water matric potential at a depth of 40 cm decreased to -35, -50, and -75 kPa. Yield differences due to soil water matric potential levels were more pronounced under the hot, dry conditions that existed during the 1980 growing season than under the cooler conditions present in 1979. Maximum treatment yields of 13,500 kg/ha and 12,000 kg/ha were obtained in 1979 and 1980 using 200 kg of fertilizer nitrogen/ha with a soil water matric potential of -35 kPa. Yields were 7 and 14% less in 1979 and 8 and 25% less in 1980 at the -50 and -75 kPa matric potential levels where 200 kg of fertilizer N/ha was used. The highest rate of nitrogen did not improve yield under the -35 kPa water treatment but did increase yields from 1 to 5% under the other water treatments. The zero fertilizer nitrogen treatments produced only 50 to 60% of maximum grain yield. Plant tissue nitrogen levels increased with both nitrogen additions and water stress. The relationship between leaf and grain nitrogen contents and percent attainment of maximum yield varied with water stress. Where water stress was limited, lower grain nitrogen contents were associated with adequate nitrogen nutrition than when water stress was more severe. These effects were not as pronounced, over the range tested, for the leaf nitrogen content relationship. The empirical [sic] models calibrated at the newly developed site were tested on nitrogen response data gathered under farmer managed center-pivot systems. These fields reflected diverse past management and irrigation histories. This process revealed that preseason soil nitrate nitrogen levels accurately predicted response to fertilizer N additions. Differences due to past management and nitrogen mineralization were less than the variability found in assessing nitrate-N. The available organic nitrogen as measured by sodium bicarbonate extraction techniques appeared to increase with the number of years these soils were irrigated and fertilized

Best Management Practices for Corn Production in South Dakota: Tillage, Crop Rotations, and Cover Crops

Historically, tillage and cultivation were used to manage residue, diseases, insects, weeds, and soil compaction. Tillage equipment that has been used includes molderboard plows, discs, cultivators, rippers, and chisel plows. Conservation practices and innovations in production tools (i.e., planters, herbicides, and genetically modified crops) provide farmers with the opportunity to minimize losses

Measurement of the inclusive isolated-photon cross section in pp collisions at √s = 13 TeV using 36 fb−1 of ATLAS data

The differential cross section for isolated-photon production in pp collisions is measured at a centre-of-mass energy of 13 TeV with the ATLAS detector at the LHC using an integrated luminosity of 36.1 fb. The differential cross section is presented as a function of the photon transverse energy in different regions of photon pseudorapidity. The differential cross section as a function of the absolute value of the photon pseudorapidity is also presented in different regions of photon transverse energy. Next-to-leading-order QCD calculations from Jetphox and Sherpa as well as next-to-next-to-leading-order QCD calculations from Nnlojet are compared with the measurement, using several parameterisations of the proton parton distribution functions. The predictions provide a good description of the data within the experimental and theoretical uncertainties. [Figure not available: see fulltext.

31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival

Nitrogen and Water Stress Impacts Hard Red Spring Wheat (Triticum aestivum) Canopy Reflectance

Remote sensing has been proposed as a method for implementing an inseason spring wheat (Triticum aestivum) nitrogen (N) fertilization program. However, in fields where yields are influenced by both water and N stress, accurate N recommendations require that that the N and water stress signals be separated from each other. The objective of this study was to determine the impact of water and N stress on canopy reflectance and the ability of vegetation (NDVI, GNDVI, and BNDVI), and chlorophyll (CGreen and CRedEdge) indices to separate water and N stress. A split-plot experiment containing four blocks was conducted in 2002, 2003, and 2005 at Aurora South Dakota. The treatments were two soil moisture regimes and four N rates. Canopy reflectance was measured with a handheld multispectral radiometer at Haun 2, 4-4.5, 6, and 10-10.2. Canopy reflectance was measured in 16 different bands. Remote sensing-based prediction models for yield, yield loss due to N stress, yield loss for water stress, and protein were developed. Yield loss due to N stress decreased with increasing N, while yield loss to water stress had the opposite relationship. Protein concentration generally increased with N. The remote sensing models for protein and yield loss due to N stress explained more of the variability than the yield model at Haun 4-4.5 and Haun 6. These data suggest that canopy reflectance can be used to separate N and water stress signals in hard red spring wheat

Nitrogen and Water Stress Affect Winter Wheat Yield and Dough Quality

Nitrogen recommendations designed to increase wheat (Triticum aestivum L.) yields may diminish wheat quality. By understanding fertility management impacts on quality, it may be possible to optimize N recommendations to sites and climates. The objective of this study was to quantify the combined and individual impacts of N and water stress on winter wheat grain yield, grain protein, dough quality, and water and N use efficiency. A field experiment using five N rates (ranging from 0 to 1.5 times the current university recommendation) and two water levels (adequate and deficient) was conducted in South Dakota in 2007 and 2008. Dough characteristics were measured using a farinograph. In 2007, soil N mineralization was high (192 kg N ha−1), supplemental water increased grain yield and grain N use efficiency (GNUE) by 25% and reduced yield loss due to N stress from 1141 to 480 kg ha−1, whereas relative to 0 N, the recommended N rate increased water use efficiency by 21% and reduced yield loss due to water stress from 737 to 481 kg ha−1. These benefits were achieved without a loss of dough quality. In 2008, N mineralization was low (99 kg N ha−1), water did not impact GNUE, and the adequate water treatment had lower grain protein (12.5 vs. 13.1 g kg−1) and arrival (3.3 vs. 4.3 min) and peak times (6.1 vs. 7.8 min) than the deficient water treatment. These findings suggest that the implementation of strategically applied N fertilizer may require improved estimates of N mineralization