Physical Sciences and Mathematics Commons^™

The Effect Of Organic Matter On Maximum Compactability Of Soil, Grant W. Thomas, Gerald R. Haszler, Robert L. Blevins

Soil Science News and Views

Bulk density is the weight of a given volume of soil expressed by soil scientists as grams per cubic centimeter (g/cm3). The higher the bulk density, the lower the volume of soil occupied by pore space, that volume of soil in which air and water reside. Because of this, there is much interest on the degree to which soil can be compacted.

The Proctor test is a means of determining the maximum bulk density that can be attained in a soil sample. This "maximum compactibility" is widely used on highways and building foundations but has had little use in agricultural …

Effects Of Tillage And Grass Filter Strips On Surface Runoff Of Water, Nitrate, Sediment, And Atrazine, C. E. Madison, Robert L. Blevins, Wilbur Frye

Soil Science News and Views

The contamination of streams and other natural bodies of water through agricultural runoff has become a very important environmental issue. Surface water runoff can contain heavy loads of sediment and/or agricultural chemicals, such as nitrogen and atrazine. Conservation tillage methods with vegetative filter strips downslope from cropped fields help· to combat this problem. Conservation tillage has proven effective in decreasing erosion by decreasing exposure of the soil surface to rainfall. Vegetative filter strips provide an area where sediment and agricultural chemicals from cropland can be deposited before the runoff reaches a body of water.

Basic Fertilizer Facts, Monroe Rasnake

Soil Science News and Views

The "foods" used by green plants for growth and life functions are referred to as nutrients or fertilizer elements. There are 16 nutrients required for plant growth and development (See Table l). Although carbon, hydrogen, and oxygen are found in plants in the greatest quantities. they are obtained by plants from air (carbon dioxide) and water rather than from fertilizers or the soil. Of the nutrients provided by the soil or from fertilizers. those required in large amounts are called PRIMARY nutrients. Those required in smaller amounts are called SECONDARY nutrients, while those needed in very small amounts are called …

Plant Available Water And Plant Water Stress, Ronald E. Phillips

Soil Science News and Views

The 1983 growing season in Kentucky was a vivid reminder that water is essential for good plant growth. And the water used by plants is taken from the reserve or water stored in soil.

Sewage Sludge For Land Application, William O. Thom

Soil Science News and Views

Sewage sludge is a product of waste water treatment plants that function as environmentally acceptable pollution control facilities. In past years most of the sludge had been landfilled, dumped at sea or buried. But environmental and economic considerations have resulted in greater interest in its application on cropland.