Introduction This experiment was designed to discover whether or not acid rain stunts the growth of the fast plant brassica rappa. When pollution from various sources combines with moisture in the atmosphere, it falls back to earth as acid rain. Acid rain pollutes lakes, damages trees and wildlife, and washes nutrients out of the soil. Data collected from the early 1960's from New Hampshire's H...

salicylic acid is an important organic acid in plants rhizosphere soil exuded in the phosphorus (p) deficiency condition. to study the sorption behavior of p in the presence of salicylic acid, a batch experiment was conducted with different concentrations of salicylic acid (0, 2, 5 and 10mm) and p (0- 45 mg p/l) in a calcareous soil. the results showed that application salicylic acid decreased ...

Soil amino acids are often an important source of nitrogen (N) for plants, and anticipated global changes, including climate warming and rising atmospheric CO2 levels, have the potential to alter plant and microbial production and consumption of this N source in soils. We determined soil amino acid composition over a 1-year period at diurnal and seasonal time scales in a multi-factor global cha...

Recent work (Kojima, 1947 a; Bremner, 1949) has shown that a considerable fraction of the organic nitrogen of soil is in the form of protein, about onethird of it being liberated as Oc-amino nitrogen by acid or alkaline hydrolysis. No method of separating this protein material from other soil constituents has yet been found and information about its amino-acid composition is scattered and incom...

zero tillage practices have a direct effect on soil microbial communities modifying soil productivity and sustainability. the crop sequences used can change the aforementioned properties, too. in this study, we evaluated the effect of crop sequences under zero tillage management on soil biological and chemical properties including vertical distribution of soil organic carbon, soil basal respira...

Young children with their hand-to-mouth activity may be exposed to contaminated soils. However few studies assessing exposure of organic compounds sequestrated in soil were realized. The present study explores the impact of different organic matters on retention of NDL-PCBs during digestive processes using commercial humic substances in a close digestive model of children: the piglet. Six artif...

The minerals from which a soil is formed partly determine whether it is acid or alkaline. Soils formed from acidic rocks have a lower pH than those formed from basic rocks or alkaline parent material. Rainfall affects soil acidity development by leaching basic elements such as calcium, magnesium, potassium, and sodium from the soil profile, leaving the acidic elements: hydrogen, aluminum and ma...

Soil is an important compartment in the environmental cycling of trichloroacetic acid (TCA), but soil TCA concentration is a methodologically defined quantity; analytical methods either quantify TCA in an aqueous extract of the soil, or thermally decarboxylate TCA to chloroform in the whole soil sample. The former may underestimate the total soil TCA, whereas the latter may overestimate TCA if ...

There is increasing recognition of the importance of niche optima in the shift of plant-plant interactions along environmental stress gradients. Here, we investigate whether deviation from niche optima would affect the outcome of plant-plant interactions along a soil acidity gradient (pH = 3.1, 4.1, 5.5 and 6.1) in a pot experiment. We used the acid-tolerant species Lespedeza formosa Koehne as ...

For 5 yr we monitored the fertility of a volcanic-ash derived Inceptisol at a site in the humid tropics of Costa Rica. After forest felling and burning, we established four treatments in a randomized block design with six blocks: a sequence of monocultures (two crops of maize [Zea mays] followed by cassava [Manihot esculenta], then the tree species Cordia alliodora), successional vegetation, a ...