Track topics on Twitter Track topics that are important to you
Excessive nutrient loading from small agricultural headwaters can substantially degrade downstream water quality and ecological conditions. But, our understanding of the scales and locations to implement nutrient attenuation tools within these catchments is poor. To help inform farm- and catchment-scale management, we quantified nitrate export in nine one-kilometre-long lowland agricultural headwaters fed by tile and open tributary drains in a region with high groundwater nitrate (<1 to >15 mg L NO-N) over four years. Across-catchment differences in upstream spring water nitrate concentrations predicted differences in annual nitrate loads at catchment outlets (range <1-72 megagrams NO-N 365 d), and nitrate loads were higher in wet seasons and wet years, reflecting strong groundwater influences. Partitioning the sources of variability in catchment nitrate fluxes revealed that ~60% of variation was accounted for by a combination of fluxes from up-stream springs and contributions from tile and open tributary drains (46% and 15%, respectively), with ~40% of unexplained residual variation likely due to groundwater upwellings. Although tile and open tributary drains contributed comparatively less to catchment loads (tile drains: <0.01 and up to 50 kg NO-N d; open drains: <5 kg and up to 100 kg NO-N d), mitigation targeted at these localised, farm-scale sources will contribute to decreasing downstream nitrate fluxes. However, high nitrate loads from groundwater mean current NO-N waterway management and rehabilitation practices targeting waterway stock exclusion by fencing alone will be insufficient to reduce annual NO-N export. Moreover, managing catchment nutrient fluxes will need to acknowledge contributions from groundwater as well as farm-scale losses from land. Overall, our results highlight how nutrient fluxes in spring-fed waterways can be highly dynamic, dominated more by groundwater than local run-off, and point to the scales and locations where nitrate attenuation tools should be implemented.
This article was published in the following journal.
Name: The Science of the total environment
In the present study, water quality of 16 springs, located along National Highway-58 from Rishikesh to Badrinath in India, was assessed by determining various physicochemical and microbiological param...
In many temperate forested watersheds, hydrologic nitrogen export has declined substantially in recent decades, and many of these watersheds show enduring effects from historic acid deposition. A wate...
.Instream biogeochemical process measurements are often short term and localised. Here we use in-situ sensors to quantify the net effects of biogeochemical processes on seasonal patterns in baseflow n...
The mRNA molecule roams through the nucleus on its way out to the cytoplasm. mRNA encounters and is bound by many protein factors, from the moment it begins to emerge from RNA polymerase II and during...
As the concentrated discharge outlet of an aquifer or groundwater system, a karst spring is partly independent from the aquifer, due to its formation of a pool or lake after outcropping onto the surfa...
The standard treatment for skin abscesses in drainage followed by packing to prevent premature closure and reaccumulation of pus. Studies from the 1950s and later conducted outside of the...
This study investigates the effect of dietary inorganic nitrate supplementation on 1) large elastic artery stiffness and hemodynamics and 2) cerebrovascular function in middle-aged and old...
The purpose of this study is to examine the effect of different vegetables on cardiovascular function in subjects with moderately increased blood pressure. Specifically we are comparing th...
This study evaluates the addition of inorganic dietary nitrate to the optimal treatment of patients diagnosed with heart failure with reduced ejection fraction. Some vegetables contain lar...
This study investigates the influence of dietary nitrate supplementation on cardiovascular health and physical and cognitive performance in older adults. Participants will receive both a n...
An NAD-dependent enzyme that catalyzes the oxidation of nitrite to nitrate. It is a FLAVOPROTEIN that contains IRON and MOLYBDENUM and is involved in the first step of nitrate assimilation in PLANTS; FUNGI; and BACTERIA. It was formerly classified as EC 126.96.36.199.
An iron-sulfur and MOLYBDENUM containing FLAVOPROTEIN that catalyzes the oxidation of nitrite to nitrate. This enzyme can use either NAD or NADP as cofactors. It is a key enzyme that is involved in the first step of nitrate assimilation in PLANTS; FUNGI; and BACTERIA. This enzyme was formerly classified as EC 188.8.131.52.
An enzyme that catalyzes the oxidation of nitrite to nitrate in the presence of NADP+. It is a FLAVOPROTEIN that contains IRON and MOLYBDENUM. This enzyme was formerly classified as EC 184.108.40.206 and should not be confused with the enzyme NITRATE REDUCTASE (NAD(P)H).
An enzyme that catalyzes the oxidation of nitrite to nitrate. It is a cytochrome protein that contains IRON and MOLYBDENUM.
Habitat of hot water naturally heated by underlying geologic processes. Surface hot springs have been used for BALNEOLOGY.