An Analysis of the Role of Tile-Drained Farmland Under Alternative Nitrogen Abatement Policies

Agricultural nitrogen is a major contributor to Gulf of Mexico hypoxia, and research has shown that agricultural subsurface tile drainage is a major carrier of nitrogen from croplands to streams and rivers. This study compares the results of abating nitrogen under a retired-land minimization policy with those of a new revenue-maximizing policy, paying particular attention to the role of tile-drained land. Findings reveal the retirement-minimizing policy resulted in more tile-drained land being retired and less being fertilizer-managed than was optimal under the net-return maximizing policy. Also, it led to a greater economic burden being shouldered by tile-drained land. Under both cases, tile drainage dominated the abatement process.abatement, ADAPT, drainage, hypoxia, nitrogen, Crop Production/Industries, Land Economics/Use,

1,1′-Binaphthyl-2,2′-diyl benzyl­phos­phoramidate

In the title compound, C27H20NO3P, the P atom exhibits a somewhat distorted PNO3 tetra­hedral geometry, with the O—P—O angle for the binaphthyl fragment being 102.82 (6)°. The dihedral angle between the naphthyl ring systems is 59.00 (2)°. In the crystal, inversion dimers linked by pairs of N—H⋯O hydrogen bonds generate R 2 2(8) loops

Targeting Agricultural Drainage to Reduce Nitrogen Losses in a Minnesota Watershed

Agricultural nitrogen losses are the major contributor to nitrogen loads in the Mississippi River, and consequently, to the existence of a hypoxic, or dead, zone in the Gulf of Mexico. Focusing on two small agricultural watersheds in southeast Minnesota, simulation results from the Agricultural Drainage And Pesticide Management (ADAPT) model were combined with a linear-optimization model to evaluate the environmental and economic impact of alternative land-use policies for reducing nitrogen losses. Of particular importance was the studys explicit focus on agricultural subsurface (tile) drainage, which has been identified as the major pathway for agricultural nitrogen losses in the upper Midwest, and the use of drainage-focused abatement policies. Results indicate that tile-drained land plays a key role in nitrogen abatement, and that a combined policy of nutrient management on tile-drained land and retirement of non-drained land is a cost-effective means of achieving a 20- or 30-percent nitrogen-abatement goal. Results also indicate that although it is cost-effective to abate on tile-drained land, it is not cost-effective to undertake policies that plug or remove tile drains from the landscape, regardless of whether the land would be retired or kept in production. Therefore, results imply that although tile-drained land is a major source of nitrogen lost to waterways, it is not cost-effective to remove the land from production or to remove the drainage from the land. Because of its value to agricultural production, it is better to keep tile-drained land in production under nutrient management and focus retirement policies on relatively less-productive, non-drained acres.Environmental Economics and Policy, Land Economics/Use,

The CEOS Data Cube Portal: A User-Friendly, Open Source Software Solution for the Distribution, Exploration, Analysis, and Visualization of Analysis Ready Data

There is an urgent need to increase the capacity of developing countries to take part in the study and monitoring of their environments through remote sensing and space-based Earth observation technologies. The Open Data Cube (ODC) provides a mechanism for efficient storage and a powerful framework for processing and analyzing satellite data. While this is ideal for scientific research, the expansive feature space can also be daunting for end-users and decision-makers who simply require a solution which provides easy exploration, analysis, and visualization of Analysis Ready Data (ARD). Utilizing innovative web-design and a modular architecture, the Committee on Earth Observation Satellites (CEOS) has created a web-based user interface (UI) which harnesses the power of the ODC yet provides a simple and familiar user experience: the CEOS Data Cube (CDC). This paper presents an overview of the CDC architecture and the salient features of the UI. In order to provide adaptability, flexibility, scalability, and robustness, we leverage widely-adopted and well-supported technologies such as the Django web framework and the AWS Cloud platform. The fully-customizable source code of the UI is available at our public repository. Interested parties can download the source and build their own UIs. The UI empowers users by providing features that assist with streamlining data preparation, data processing, data visualization, and sub-setting ARD products in order to achieve a wide variety of Earth imaging objectives through an easy to use web interface

Performance of Distributed CFAR Test Under Various Clutter Amplitudes

We evaluate the performances of several distributed constant false-alarm rate (CFAR) tests operating in different background clutter conditions. The analysis considers the detection of Rayleigh target in various clutters with the possibility of differing clutter power levels in the test cells of distributed radars. Numerical results studied for a two-radar system show how the false-alarm rate of the maximum order statistic (MOS) test changes with differences in the clutter power levels of the test cells. The analysis for the detection of Rayleigh target in Rayleigh clutter indicates that, with the power levels of differing test cells, the OR fusion rule can be quite competitive with the new normalized test statistic (NTS). However, for the detection of Rayleigh target in Weibull or K-distributed clutter, the results show that NTS outperforms both the OR and the AND rules under the condition of large signal-to-clutter power ratio and moderate shape parameter values

Robustness of Decentralized Tests with ε-Contamination Prior

We consider a decentralized detection problem where the prior density is not completely known, but is assumed to belong to an ε-contamination class. The expressions for the infimum and the supremum of the posterior probability that the parameter under question is in a given region, as the prior varies over the ε-contamination class, are derived. Numerical results are obtained for a specific case of an exponentially distributed observation and an exponentially distributed nominal prior. Asymptotic (as number of sensors tends to a large value) results are also obtained. The results illustrate the degree of robustness achieved with quantized observations as compared to unquantized observations

Monitoring of Pesticide Residues in Farmgate Samples of Vegetables in Karnataka, India

Fifty Vegetable samples in Ramanagara district of Karnataka, India were analysed for 20 pesticide residues. Vegetable samples were extracted with acetonitrle and the pesticides are partitioned into petroleum ether and evaluated by gas liquid chromatography equipped with ECD and FTD. Recovery studies were performed at 0.1, 0.5 and 1.0 mg kg -1 fortification levels of each compound and the recoveries obtained ranged from 80.5% to 96.2% with relative standard deviations lower than 7%. The method showed good linearity over the range assessed 0.05-1.5mg kg -1 with correlation coefficient> 0.998 and the detection and quantification limits for the pesticides studied varied from 0.0001 to 0.044 mg kg -1 and 0.0005 to 0.0155 mg kg -1 , respectively. All the samples were found to be contaminated; the organo chlorines (83.5%) dominated followed by organophosphates (67%) and pyrethroids (55%). However, 34% of the samples were found to contain the residues of organophosphate insecticides above their respective maximum residue limits (MRL). It is therefore proposed to perform extensive monitoring studies covering all the vegetable crops from different agro-climatic regions of the state to know the exact status of pesticide contamination

p-Tolyl­methanaminium cyclo­hexane-1,2-diyl phosphate

In the title mol­ecular salt, C8H12N+·C6H10O4P−, the cation and anion are connected by N—H⋯O hydrogen bonds. The C atoms of the cyclo­hexane ring are disordered over two sets of sites in a 0.51 (4):0.49 (4) occupancy ratio to generate two superimposed chair conformations. One of the terminal phosphate O atoms is also disordered in a 0.62 (2):0.38 (2) ratio