Surface Waters: Ammonium is Not Ammonia – Part 3

Two previous ICM News articles outlined the difference between ammonium and ammonia, the relationship between the two nitrogen forms, and the implication of a combined (ammonium-N plus ammonia-N) analysis related to water quality criteria for aquatic life and chlorination treatment for drinking water.This article focuses on the potential sourcing of ammonium and ammonia in surface waters. Ammonium and ammonia in surface water systems can originate from many sources, and are naturally occurring forms of nitrogen. Predominant sources will vary on a watershed or sub-watershed basis. Also, sources and concentrations are greatly influenced by hydrology, including timing and volume of water runoff

Nitrate loss in subsurface drainage as affected by nitrogen application rate and timing under a cornsoybean rotation system

Subsurface agricultural drainage has allowed for enhanced crop production in many areas of the world including the upper Midwest, United States. However, the presence of nitrate-nitrogen (nitrate-N) in subsurface tile drainage water is a topic of intense scrutiny due to several water quality issues. Many studies have been conducted looking at ways to reduce nitrate-N in tile drainage (Baker et al., 1975; Baker and Johnson, 1981; Hanway and Laflen, 1974; Kanwar et al., 1988).With the growing concern for the health of the Gulf of Mexico (Mitsch et al., 2001; Rabalais et al., 1996) and local water quality concerns, there is a need to understand how recommended nitrogen management practices, such as through nitrogen rate and timing, impact nitrate-N concentrations from subsurface drainage systems. The objective of this paper is to summarize results of studies from within Iowa and nearby states that have documented the impact of nitrogen application rate and timing on tile drainage nitrate loss

Impact of 4R Management on Crop Production and Nitrate-Nitrogen Loss in Tile Drainage

Corn Belt corn and soybean producers are increasingly challenged to maximize crop production while addressing the contributions farm practices make to Gulf hypoxia. Based on the need for nitrate-N reductions to meet water quality goals, new management practices are needed to reduce nitrate-N losses at minimal cost and maximum economic benefits. This three-year field research and demonstration project is evaluating various promising N management methods and technologies by documenting the nitrate-N export and crop yield from various systems

Deterministic quantum state transfer of atoms in a random magnetic field

We propose a method for transferring atoms to a target quantum state for a multilevel quantum system with sequentially increasing, but otherwise unknown, energy splitting. This is achieved with a feedback algorithm that processes off-resonant optical measurements of state populations during adiabatic rapid passage in real-time. Specifically, we reliably perform the transfer $|F=2,m_F=2\rangle \rightarrow |1,1\rangle \rightarrow |2,1\rangle$ for a sample of ultracold $^{87}$Rb in the presence of a random external magnetic field

Do Active Canopy Sensors Measure Biomass or Chlorophyll in Corn?

Vegetative indices from canopy sensors are currently being used as a tool to measure N deficiency in corn (Zea Mays L.). Symptoms of N deficiency include stunted growth (reduced biomass) and yellowing (reduced chlorophyll). It is unclear which sensor index is most useful. The objective was to determine if canopy sensor indices (NDVI and CHL) measure plant biomass or plant chlorophyll

Impact of Swine Manure Application on Water Quality

Nonpoint source nutrient pollution related to land application of manures is recognized as an important environmental and social issue for several reasons. First,swine manure application to land can impact water quality. Second, several states are in the process of creating laws and/or regulations to reduce nitrogen and phosphorus loadings from manure to soil and water resources. Third, the quality of water resources will help set parameters for developing public policies on management of manure

Genomic Organization and Molecular Phylogenies of the Beta (β) Keratin Multigene Family in the Chicken (\u3cem\u3eGallus gallus\u3c/em\u3e) and Zebra Finch (\u3cem\u3eTaeniopygia guttata\u3c/em\u3e): Implications for Feather Evolution

Background: The epidermal appendages of reptiles and birds are constructed of beta (β) keratins. The molecularphylogeny of these keratins is important to understanding the evolutionary origin of these appendages, especially feathers. Knowing that the crocodilian β-keratin genes are closely related to those of birds, the published genomes ofthe chicken and zebra finch provide an opportunity not only to compare the genomic organization of their β- keratins,but to study their molecular evolution in archosaurians. Results: The subfamilies (claw, feather, feather-like, and scale) of β-keratin genes are clustered in the same 5\u27 to 3\u27 orderon microchromosome 25 in chicken and zebra finch, although the number of claw and feather genes differs between the species. Molecular phylogenies show that the monophyletic scale genes are the basal group within birds and thatthe monophyletic avian claw genes form the basal group to all feather and feather-like genes. Both species have a number of feather clades on microchromosome 27 that form monophyletic groups. An additional monophyleticcluster of feather genes exist on macrochromosome 2 for each species. Expression sequence tag analysis for thechicken demonstrates that all feather β-keratin clades are expressed. Conclusions: Similarity in the overall genomic organization of β-keratins in Galliformes and Passeriformes suggestssimilar organization in all Neognathae birds, and perhaps in the ancestral lineages leading to modern birds, such as theparavian Anchiornis huxleyi. Phylogenetic analyses demonstrate that evolution of archosaurian epidermal appendagesin the lineage leading to birds was accompanied by duplication and divergence of an ancestral β-keratin gene cluster.As morphological diversification of epidermal appendages occurred and the β-keratin multigene family expanded,novel β-keratin genes were selected for novel functions within appendages such as feathers

Genomic organization and molecular phylogenies of the beta (β) keratin multigene family in the chicken (Gallus gallus) and zebra finch (Taeniopygia guttata): implications for feather evolution

Abstract Background The epidermal appendages of reptiles and birds are constructed of beta (β) keratins. The molecular phylogeny of these keratins is important to understanding the evolutionary origin of these appendages, especially feathers. Knowing that the crocodilian β-keratin genes are closely related to those of birds, the published genomes of the chicken and zebra finch provide an opportunity not only to compare the genomic organization of their β-keratins, but to study their molecular evolution in archosaurians. Results The subfamilies (claw, feather, feather-like, and scale) of β-keratin genes are clustered in the same 5' to 3' order on microchromosome 25 in chicken and zebra finch, although the number of claw and feather genes differs between the species. Molecular phylogenies show that the monophyletic scale genes are the basal group within birds and that the monophyletic avian claw genes form the basal group to all feather and feather-like genes. Both species have a number of feather clades on microchromosome 27 that form monophyletic groups. An additional monophyletic cluster of feather genes exist on macrochromosome 2 for each species. Expression sequence tag analysis for the chicken demonstrates that all feather β-keratin clades are expressed. Conclusions Similarity in the overall genomic organization of β-keratins in Galliformes and Passeriformes suggests similar organization in all Neognathae birds, and perhaps in the ancestral lineages leading to modern birds, such as the paravian Anchiornis huxleyi. Phylogenetic analyses demonstrate that evolution of archosaurian epidermal appendages in the lineage leading to birds was accompanied by duplication and divergence of an ancestral β-keratin gene cluster. As morphological diversification of epidermal appendages occurred and the β-keratin multigene family expanded, novel β-keratin genes were selected for novel functions within appendages such as feathers.</p

Corn Era Hybrid Nutrient Concentration and Accumulation of Secondary and Micronutrients

Studies are limited that focus on change in concentration and accumulation of secondary and micronutrients in corn (Zea mays L.) plant fractions and across corn hybrid development periods. This research was conducted in 2007 and 2008 to evaluate the partitioning of secondary and micronutrients across vegetative and reproductive stages at the plant-fraction level for 1960- and 2000-era hybrids. Two popular hybrids for each era were grown, with measurement of nutrient concentration and content in several plant and grain fractions. Secondary and micronutrient concentrations in plant fractions were lower in 2000- than 1960-era hybrids with most nutrients, except ear shoots and tassels for certain nutrients. However, nutrient content was consistently greater in 2000- compared to 1960-era hybrids in the whole plant and fractions at most development stages, except tassels and ear shoots. In tassels, nutrient content was mostly smaller in 2000-era hybrids, but in ear shoots content was similar. The accumulation rates of most nutrients per growing degree day (GDD) were greater in the reproductive period for 2000-era hybrids, but similar among eras in the vegetative period. Remobilized nutrients from vegetative to reproductive components were similar between era hybrids, except Ca and Fe, and positive except Fe, Mn, and B. It is apparent that greater nutrient content in newer hybrids was driven mainly by associated nutrient uptake rates and greater dry matter (DM). Despite the greater nutrient content with the modern hybrids, removal with grain or stover harvest would still be small for S and micronutrients

Nitrogen, carbon, and phosphorus balances in Iowa cropping systems: Sustaining the soil resource

The Corn Belt’s exceptional productivity depends on high soil organic carbon and nutrient stocks (that is, the amount of carbon and nutrients stored in the soil). However, there is growing concern among scientists and farmers that soil carbon, nitrogen, and phosphorus stocks in corn-based cropping systems may be declining as a result of outputs that exceed inputs. The lack of certainty about the status of soil carbon and nutrient stocks is largely due to the extreme difficulty associated with measurement of inputs, outputs, and stocks of soil organic carbon and nutrients