Various soil texture schemes are in current use. These differ in the size ranges of their particle fractions. There is a need to establish simple methods to correlate these conventional schemes. Therefore I have defined closed-form exponential and power law functions to fit models to cumulative particle-size distribution data. I have tested the functions for their suitability (i) to represent c...

In recent years agricultural practices in New England have undergone dramatic changes. Traditional dryland crops such as potatoes and silage corn have been replaced by irrigated “landscape” crops; specifically turf and nursery crops. For example, commercial sod production in Rhode Island has risen from 200 acres in 1972 to over 2,500 acres in 1986, while potato acreage has shown a similm declin...

The objectives of this study were to count and culture Azotobacter spp. in sampled soils, to determine the nitrogen (N) fixing capacity byAzotobacter spp. in pure culture and different soils, and to explore the relationships between N fixation capacity of Azotobacter spp. and microbiological properties of soils in Northern Anatolia, Turkey. Statistically significant relationships were found bet...

712 Soil physical conditions can aff ect diff usion, environmental fate, and effi cacy of fumigants in soil disinfestation treatments. Water seals (applying water using sprinklers to soil following fumigation) can eff ectively reduce fumigant emissions from sandy loam soils. Soil column studies compared the eff ectiveness of water seals in reducing cis-1,3-dichloropropene (1,3-D) emissions from...

Contarinia nasturtii (Kieffer) (Diptera: Cecidomyiidae), a common insect pest in Europe and a new invasive pest in North America, causes severe damage to cruciferous crops. Currently, many counties in Canada and the United States in which C. nasturtii has not been previously reported are at risk of being infested by C. nasturtii. Effectiveness of chemical control is limited, especially under hi...

Excess crude protein (CP) in dairy cow diets is excreted mostly as urea nitrogen (N), which increases ammonia (NH) emissions from dairy farms and heightens human health and environmental concerns. Feeding less CP and more tannin to dairy cows may enhance feed N use and milk production, abate NH emissions, and conserve the fertilizer N value of manure. Lab-scale ventilated chambers were used to ...

Global models projected that, precipitation in Great Plains of the United States will decrease in summer and increase in spring and winter. However, few studies had carefully examined ecosystem responses to this intra-annual redistribution of precipitation. Here we used a process-based model, Terrestrial ECOsystem (TECO) Model, to evaluate responses of ecosystem carbon processes (including net ...