R. L. Mahler

Bottled Water: United States Consumers and Their Perceptions of Water Quality

Consumption of bottled water is increasing worldwide. Prior research shows many consumers believe bottled water is convenient and has better taste than tap water, despite reports of a number of water quality incidents with bottled water. The authors explore the demographic and social factors associated with bottled water users in the U.S. and the relationship between bottled water use and perceptions of the quality of local water supply. They find that U.S. consumers are more likely to report bottled water as their primary drinking water source when they perceive that drinking water is not safe. Furthermore, those who give lower ratings to the quality of their ground water are more likely to regularly purchase bottle water for drinking and use bottle water as their primary drinking water source.

Evaluation of wood ash disposal on agricultural land. I. Potential as a soil additive and liming agent

Abstract This study evaluated wood ash as an agricultural fertilizer and liming material. Winter wheat (Triticwn aestivum) and poplar (Populus sp.) were grown in a greenhouse on six different Idaho soils amended with different ash concentrations. At ash levels equal to or lower than 2%, no detrimental plant growth effects were observed. In fact, the biomass of the wheat and the caliper and height of the poplar cuttings increased more at 2% ash (40 mt/ha) than with the control soil. These results suggest that wood ash could be used in agricultural applications as a low analysis fertilizer containing K and/or a liming agent. Land application of wood ash could be less expensive and more environmentally sound than present landfilling practices.

THE INFLUENCE OF TILLAGE METHODS, CROPPING SEQUENCE, AND N RATES ON THE ACIDIFICATION OF A NORTHERN IDAHO SOIL

Soils in northern Idaho are exhibiting a rapid decline in pH. In undertaking this study, we sought to determine the relative effects of common northern Idaho cultural practices—tillage methods, crop rotations, and N fertilizer rates—on the acidification of a northern Idaho soil. The plots were established north of Moscow, Idaho, in 1974 and evaluated no-till, minimum tillage, and conventional tillage treatments and three-crop rotation systems: (1) a 2-year winter wheat (Triticum aestivum L. cv. Nugaines)-spring pea (Pisum sativum cv. Alaska) rotation; (2) a 3-year winter wheat-spring wheat (Triticum aestivum L. cv. Fieldwin)-spring pea rotation; and (3) a 3-year winter wheat-alfalfa (Medicago sativa L. cv. Ladak) red clover (Trifolium pratense cv. Kenland) peaalfalfa red clover rotation. The plots were split by N application rates and sampled by depth. When sampled by 300-mm increments, depth was the only factor that affected soil pH. Soil pH increased with increasing depth. There was a statistically unique calcium chloride pH at each sampling depth down to 1500 mm. When the surface 300 mm was sampled by 75-mm increments, the interaction of crop rotation x tillage x N rate x depth was significant. It was apparent that N rates were the major influence on pH differences. Crop rotations influenced the amount of N fertilizer required for crop production and consequently affected the magnitude of the pH decline. Tillage influenced the placement of N fertilizer and consequently the location and depth of acidification in the soil profile. The greatest acidification under no-till management occurred in the surface 75 mm, under minimum tillage at the 75-to 150-mm depth, and under conventional tillage in the surface 250 mm. A significant decrease in pH was observed in all treatments over the 8-year period.

Hot water extraction of boron from soils using sealed plastic pouches

Abstract Logistically, the determination of available B in soils is one of the most difficult analysis routinely performed in soil testing laboratories. The purpose of this study was to examine the feasibility of using sealed plastic pouches in place of the traditional glass refluxing apparatus for the hot water extraction of B in soils. Seven northern Idaho soils were collected, spiked with B levels of 0.25, 0.5, 1.0, 1.5, 2.0, and 4.0 μg/g, and analyzed for extractable B using both types of vessels. When extraction time was five minutes, extraction of B from soil using glass refluxing apparatus yielded from 0.03 to 0.16 μg/g more extractable B than when sealed plastic pouches were used. This was true for all soils at all B levels. It was determined, however, that equivalent B values were obtained with both procedures when the boiling time with the plastic pouches was increased from 5 to 7 minutes. A procedure for B extraction is proposed using the sealed plastic pouches as extraction vessels. The plasti...

Wood ash as a soil additive and liming agent for wheat: Field studies

Abstract An industrial wood ash with a calcium carbonate equivalent (CCE) of 36 and a pH of 12.9 was applied to two field sites at 0, 0.56, 1.12, 1.68, 2.24, 4.48, and 8.96 Mg/ha and at 0, 0.56, 1.12, 2.24, 4.48, 8.96, 17.9, and 35.8 Mg/ha. Soil pH and available K increased with application rate, while growth of wheat and protein content on ash‐amended plots was unaffected. Cadmium, lead and zinc content in the wheat was comparable at 0 and 17.9 Mg/ha, which indicated no net accumulation of heavy metals. Based on this field study and other greenhouse studies described in the literature, wood ash can be recycled as a liming agent and soil amendment when applied at agronomic rates based on soil fertility needs and the chemical composition of the ash.

The influence of lime and phosphorus on crop production in northern Idaho

Abstract Soils in northern Idaho are rapidly becoming acidified as a consequence of heavy applications of ammonium‐based N fertilizers on cereal crops. The pH decline occurs primarily in the upper 30 cm of the soil profile. Liming with 4400 kg/ha resulted in 9 to 16% increase in cereal yields. A twenty percent increase in spring pea (Pisium sativum) yield was attributable to lime applications. Spring peas appeared to have a greater response to lime than cereals. This greater response may be due in part to increased numbers of Rhizobium leguminosarum found in the surface 15 cm of limed plots. Lime X P interactions were observed on spring pea and winter wheat yields (Triticum aestivum) in 1983 and 1984. The spring peas had a greater response to lime than wheat. Winter wheat, more tolerant to acid soil conditions, exhibited a greater response to P.

Newsprint pulp and paper sludge as a soil additive/ amendment for alfalfa and bluegrass: Greenhouse study

Abstract A newsprint, pulp and paper sludge was evaluated as a soil additive/amendment at 0, 8, 15, 31, 62, 123, and 246 Mgfta for growth of alfalfa (Medicago sativa) and bluegrass (Poa pratensis) under greenhouse conditions. Bluegrass biomass increased by 300%, and protein content increased by 27% at 246 Mg/ha compared to the unamended soil. Alfalfa biomass was unaffected by sludge application rate, but protein content increased by 12%. No net nitrogen (N) immobilization was observed. A comparison of single and double exponential N mineralization models showed that the two pool model more closely fit the N mineralization data obtained from a laboratory incubation study. The two pool model was then used to develop linear regression equations to estimate appropriate sludge application rates based on the rate of N mineralization.

Effects of plant residues and environmental factors on phosphorus availability in soils

Abstract Phosphorus availability is a major nutritional problem in several northern Idaho soils. Traditionally, fertilizers containing P have been applied to improve availability in soils; however, organic materials added to soils have the ability to provide large quantities of labile P via mineralization processes and to reduce sorption of P. Using this concept, plant residues applied to soils would increase P availability for future plant needs. This research evaluated the effect of plant residue, incorporated into a Northern Idaho soil, on P availability under controlled laboratory conditions. Alfalfa (Medicago sativa), pea (Pisum sativum) and wheat (Triticum aestivum) plant residues were incorporated into soil collected from the Ap horizon of a Latahco silt loam (fine‐silty, mixed, frigid Argiaquic Xeric Argialboll) at rates of 0, 1, 5 and 10% (w/w). The soils were incubated at soil water potentials of ‐0.05, ‐0.15 and ‐0.40 MPa, and temperatures of 10, 20 and 30°C over a 20 week period. Soils were sa...

Long-term sediment loading trends in the Paradise Creek watershed

The Northwest Wheat and Range Region is historically known for high soil erosion rates. During the 1920s and 1930s, erosion rates of 200 to 450 t ha−1 (90 to 200 tn ac−1) in a single winter season were observed. Improved soil conservation practices over the last 80 years have significantly reduced soil erosion rates, yet there is scarce evidence of significant reductions in sediment loading delivered by streams in the region. In this paper, detailed monitoring data collected in the Paradise Creek watershed, located in the high precipitation zone of the Northwest Wheat and Range Region in north central Idaho, provided an opportunity to assess the impacts of management practices on sediment loading at the watershed outlet. Both detailed event-based sampling over the last eight years and three day per week grab samples collected over the last 28 years indicate a statistically significant decreasing trend in overall sediment load. This decreasing sediment load can be attributed primarily to conversion from conventional tillage systems to minimum tillage and perennial grasses through the Conservation Reserve Program, practices initiated in the late 1970s and early 1980s. Over the last 10 years (1999 to 2009), management practices have targeted gully erosion and stream bank failures. Upstream and downstream sampling shows a larger than expected increase in sediment load through the urban areas of the watershed. Preliminary modeling results and empirical evidence indicate that delayed reduction in sediment load at the watershed outlet and the increased sediment load through the lower urban portion of the watershed may be caused by sediment storage in the stream channel.

Soil sampling fields that have received banded fertilizer applications

Abstract Banding of fertilizers below the seed at planting under reduced tillage conditions is becoming more commonplace. This technique however, can lead to difficulties in obtaining a representative soil sample for determining the status of mobile (N,S) and nonmobile (P,K) nutrients. This study was designed to evaluate three different soil sampling techniques. These techniques included: systematic (taking a series of soil cores perpendicular to band rows), controlled (random soil sampling avoiding the band row), and random soil sampling. All three sampling techniques adequately estimated the mobile nutrient status of soils; however, differences as a consequence of soil sampling techniques were observed for non‐mobile nutrients. The systematic sampling technique provided the highest non‐mobile nutrient values, while the controlled sampling procedure the lowest. Considering time, labor costs and the lack of availability of skilled labor the random sampling technique was the best for sampling fertilizer ba...