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Full-Text Articles in Physical Sciences and Mathematics
Farm Nutrient Management, William O. Thom
Farm Nutrient Management, William O. Thom
Soil Science News and Views
Nutrient management is becoming a buzz word in today's vocabulary of crop and livestock production. In the past it was applied to efficient management of all nutrient sources used for crop production. More recently it is being used to account for all nutrients used for crop production that are brought onto the farm, removed from the farm in crop and animal products, and reallocated within the farm unit. Nitrogen, phosphorus, and potassium are the nutrients of concern with nitrogen and phosphorus being most important.
Managing Soil Content Of Nitrate Nitrogen, Kenneth L. Wells
Managing Soil Content Of Nitrate Nitrogen, Kenneth L. Wells
Soil Science News and Views
The concerns about leaching of fertilizer nitrogen (N} into groundwater which were raised in the late 1960's were largely silenced during the 1970's as our agricultural economy was massively expanded. But since the early 80's they have been raised again to the point that national legislation (the Clean Water Act) was put into place to bring purity of the nation's water supplies into compliance with EPA-established standards. Beyond the apprehension largely about nitrate (NO3) levels in groundwater, the groundwater issue today also includes concerns about pesticides. At the current time, the public is apprehensive about drinking water and …
The Kinetics Of Organic Matter Mineralization In Anoxic Marine Sediments, David J. Burdige
The Kinetics Of Organic Matter Mineralization In Anoxic Marine Sediments, David J. Burdige
OES Faculty Publications
The kinetics of sulfate reduction and inorganic nutrient production (ΣCO2, ammonium, and phosphate) were examined in the sediments at five sites in the southern Chesapeake Bay, using long term (> 200 d) sediment decomposition experiments. Average first order rate constants for these processes (at 25oC) decreased from 8.2 to 3.7 yr-1 in the surface sediments (0-2 cm), to 2.1 to 0.2 yr-1 at 12-14 cm. The C/N and C/P ratios of the organic matter undergoing decomposition also increased with depth at these sites. Taken together, these results indicate that the reactivity of the organic matter …