Factors affecting nitrate reduction by leaf discs of cotton (Gossypium hirsutum L.) were investigated. When incubated in 30 mm nitrate, discs reduced nitrate much more slowly under air or O(2) than under N(2). Inhibition by O(2) did not occur at nitrate levels of 100 mm or greater. Treatment with arsenate had little effect under N(2) but stimulated nitrate reduction under air. Similarly, ammoni...

conclusions it was shown that the removal efficiency of nitrate was directly proportional to the amount of chaff, temperature, and contact time but inversely to the ph. this study showed that nitrate removal by chaff is a promising technique. results the result of this study revealed that chaff as an absorbent could remove nitrate from solutions, and the efficiency of adsorption increased as co...

Peat forming Sphagnum mosses are able to prevent the dominance of vascular plants under ombrotrophic conditions by efficiently scavenging atmospherically deposited nitrogen (N). N-uptake kinetics of these mosses are therefore expected to play a key role in differential N availability, plant competition, and carbon sequestration in Sphagnum peatlands. The interacting effects of rain N concentrat...

The present study investigated the significance of apical transport proteins for ruminal acetate absorption and their interaction with different anions. In anion competition experiments in the washed reticulorumen, chloride disappearance rate (initial concentration, 28 mM) was inhibited by the presence of a short-chain fatty acid mixture (15 or 30 mM of each acetate, propionate, and butyrate). ...

Although nutrient availability and oceanographic context can influence top-down processes in intertidal communities, the reciprocal effects of consumers on bottom-up processes, such as nitrogen uptake by macroalgae, are less well-documented. We used a combination of field observations, mesocosm experiments, and laboratory nitrate-uptake measurements to evaluate the interaction between the kelp ...

Observed phenotypic variation in the lateral root branching density (LRBD) in maize (Zea mays) is large (1-41 cm(-1) major axis [i.e. brace, crown, seminal, and primary roots]), suggesting that LRBD has varying utility and tradeoffs in specific environments. Using the functional-structural plant model SimRoot, we simulated the three-dimensional development of maize root architectures with varyi...

Week-old wheat seedlings absorbed at least 40% NO3from NaNO3 when preloaded with K+ than when preloaded with Na+ or Ca2". Cultures of Tnticum vulgare L. cv. Arthur were grown for 5 days on 0.2 ,M CaSO4, pretreated for 48 hours with either 1 mM CaSO4, K2SO4, or Na2SO4, and then transferred to 1 mM NaNO3. All solutions contained 0.2 mM CaSO4. Shoots of K+-preloaded plants accumulated three times ...