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Northeastern USA (northeastern + usa)

Distribution by Scientific Domains

Earth and Environmental Science	66%

Selected Abstracts

Nitrogen, Phosphorus, Potassium, Magnesium and Calcium Removal by Brown Midrib Sorghum Sudangrass in the Northeastern USA

JOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 6 2006
Q. M. Ketterings
Abstract For the long-term sustainability of the dairy industry in the Northeastern USA, manure nutrient application rates should not exceed crop nutrient removal once above-optimum soil fertility levels are reached. Dairy producers have shown a growing interest in brown midrib (BMR) forage sorghum (Sorghum bicolor (L.) Moench.) × sudangrass (Sorghum sudanense Piper) hybrids (S × S) as a more environmentally sound alternative to maize (Zea mays L.) but data on S × S nutrient removal rates are scant. Our objectives were to determine N, P, K, Ca and Mg removal with harvest as impacted by N application rate, using six N rate studies in New York. One of the six sites had a recent manure history. Although site-to-site differences existed, N application tended to decrease P and K and increase N, Ca and Mg concentrations in BMR S × S forage. Nutrient removal and yield were highly correlated for all sites except one location that showed a K deficiency. The crop removed large amounts of P and K in the manured site, suggesting that BMR S × S is an excellent scavenger of these nutrients. If manure is applied mid-season, forage K levels are likely too high for feeding to non-lactating cows. [source]

Anomalous seaward dip of the lithosphere,asthenosphere boundary beneath northeastern USA detected using differential-array measurements of Rayleigh waves

GEOPHYSICAL JOURNAL INTERNATIONAL, Issue 2 2002
William Menke
Summary Rayleigh wave phase velocities and azimuth anomalies in the period range of 30,100 s are measured for a set of four triangular arrays of broad-band seismometers in coastal northeastern USA. This is a region in which a strong upper mantle slow shear velocity anomaly (a ,New England Anomaly'), crosses the continental margin. Earthquakes from a wide range of directions are used to detect the variation of parameters with azimuth, ,, of propagation. No lateral heterogeneity in phase velocity is detected at these periods between stations at the centre and the edge of the Anomaly. However, large (10,20; per cent) azimuthal variations occur, and have a cos(1,) dependence, which is indicative of a dipping structure in the upper mantle. Corresponding azimuth variations, with a magnitude of ±5°, are also detected. This behaviour is consistent with a southeasterly (N150°E) dip of the lithosphere,asthenosphere boundary beneath New England. This dip is associated with the shoaling of the New England Anomaly beneath the Adirondack mountains, west of the array. It is opposite to the dip associated with lithospheric thickening toward the interior of the craton. [source]

Incorporating variable source area hydrology into a curve-number-based watershed model

HYDROLOGICAL PROCESSES, Issue 25 2007
Elliot M. Schneiderman
Abstract Many water quality models use some form of the curve number (CN) equation developed by the Soil Conservation Service (SCS; U.S. Depart of Agriculture) to predict storm runoff from watersheds based on an infiltration-excess response to rainfall. However, in humid, well-vegetated areas with shallow soils, such as in the northeastern USA, the predominant runoff generating mechanism is saturation-excess on variable source areas (VSAs). We reconceptualized the SCS,CN equation for VSAs, and incorporated it into the General Watershed Loading Function (GWLF) model. The new version of GWLF, named the Variable Source Loading Function (VSLF) model, simulates the watershed runoff response to rainfall using the standard SCS,CN equation, but spatially distributes the runoff response according to a soil wetness index. We spatially validated VSLF runoff predictions and compared VSLF to GWLF for a subwatershed of the New York City Water Supply System. The spatial distribution of runoff from VSLF is more physically realistic than the estimates from GWLF. This has important consequences for water quality modeling, and for the use of models to evaluate and guide watershed management, because correctly predicting the coincidence of runoff generation and pollutant sources is critical to simulating non-point source (NPS) pollution transported by runoff. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Changes in the timing of spring and autumn migration in North American migrant passerines during a period of global warming

IBIS, Issue 2 2005
ALEXANDER M. MILLS
Butler (2003) used first arrival dates (FADs) of 103 migrant birds in northeastern USA and found that both long-distance migrants (LDMs; wintering south of the USA) and short-distance migrants (SDMs; wintering in the southern USA) arrived earlier in the second half of the 20th century than they had in the first, consistent with scenarios of global warming; the trend was stronger in SDMs. Using FADs to characterize migration systems can be problematic because they are data from one tail of a distribution, they comprise a mostly male population and they may not correlate well with the balance of the migration period. FADs also provide no information about autumn migration. This paper uses a banding dataset from Long Point Bird Observatory, Ontario, for 14 passerines for a period of global warming (1975,2000), taking these issues into account. The data were filtered to minimize effects of unequal netting effort (147 491 resulting records), and the passage dates then calculated in each season of each year for the 1st, 2nd and 3rd quartiles for regression analysis. Only two of 13 species analysed in the spring showed significantly earlier passage times, although the overall trend was towards earlier spring migration, especially among SDMs. Autumn responses were more prevalent, however, and in some cases more dramatic with six of 13 species showing delayed migration (four SDMs, two LDMs). Two LDMs exhibited earlier autumn migration. Where earlier spring migration occurred, both sexes appeared to contribute to the change. Where delayed migration occurred in autumn, both sexes and both adults and hatch-year birds appeared to contribute in at least some cases. The spring FAD results are consistent with those of Butler, but when the whole migration is considered, change is far from universal in spring and is in fact more substantial and complex in autumn. [source]