A novel system for leaching of reconstituted cores of soils taken from horizons of <I>Calluna</I> moorland podzol profiles derived from granites has been used to see if absolute, or at least, relative, weathering rates assessed by simple leaching techniques and by using the PROFILE model agreed. Initial base cations are first removed by leaching with ammonium acetate. Agreement was reasonable, but the results highlighted problems posed by mineralization effects in column-based procedures. A successful attempt was made to develop a procedure to overcome this problem, based upon pre-oxidation with H₂O₂. This procedure was tested on a selection of B and C horizon soils from podzol profiles, and shown to give weathering rates which correlated well with those derived using the PROFILE model. The equilibrated soil cores remaining at the end of the study were then used for testing the effect of acidification of infiltrating water upon weathering rates of base cations. Weathering rate did not increase regularly to combat the acid input. Intact soil core microcosms, fitted with rhizon samplers at three depths and subjected to appropriate simulated precipitation, have been used to elucidate how land use influences the mobility of copper and zinc. Three land uses were considered, improved pasture, semi-improved pasture, and <I>Calluna</I> moorland. Copper and zinc concentrations were also measured in river water samples collected at 59 points from throughout the River Dee network under diverse flow conditions, with a view to elucidating catchment factors influencing the mobilisation of these two elements into river water. The results demonstrated large inputs of copper arising as a consequence of arable land use, and suggested that TOC in drainage water from moorland soils mobilises copper from mineral sediments in the river network. Both zinc and copper concentrations were increased under high discharge conditions.

Yield and chemical changes of second-cutting alfalfa hay treated with artificial rain were determined in a 2 x 3 x 2 factorial experiment. Factors were 2 stages of maturity (1 late vegetative; 2 early bloom), 3 levels of artificial rain applied (1 =no rain; 2 =low or approximately 5 mm; 3 =high or approximately 20 mm), and 2 times of applying artificial rain (1 = when drying forage was 40-60% dry matter; 2 =when drying forage was 60-75% dry matter). Thirty samples of alfalfa were collected at the 2 stages of maturity when the alfalfa was fresh cut, pre-sprinkled, pre-baled and prefeeding. Alfalfa samples were analyzed for dry matter, nitrogen, ash, plant cell walls, cellulose, hemicellulose, lignin, total lipids and acid insoluble ash. Available carbohydrates and soluble ash were calculated. Yield of dry matter increased with advancing maturity. Plant cell content fraction was lowered but plant cell wall constituents were increased with advancing stage of growth. Artificial rain significantly affected chemical composition of alfalfa hay. Available carbohydrates, soluble ash and ash decreased due to the effect of leaching. Total lipids was slightly reduced by leaching, while protein content was not changed. Cellulose, lignin and cell wall fractions of alfalfa hay increased consistently under the effect of artificial rain. Sprinkling and processing time did significantly change the chemical composition of alfalfa hay. DM and AlA content increased in relation to process. Interactions among treatment factors were generally nonsignificant. The only significant interactions were maturity-by-artificial rain level effect on available carbohydrate, lipids, cellulose and cell wall. In general, alfalfa hay treated with artificial rain had a lower nutritive and economic value than when it is not affected by any rain.