Earth Sciences Commons^™

Opportunities In Sustainability: Maize Seeders For The Developing World And Alternative Fertilizers In The United States, Rebecca Mattingly Harman

Masters Theses

Sustainable agricultural systems are needed for both large and small-scale farmers the world over. Central to the sustainability of these systems is the availability of cheap and effective seeders for smallholder farmers and effective utilization of less energy intensive nitrogen sources. In the first two chapters, this thesis considers maize seeders for smallholder use in a Conservation Agriculture system. To sustain the smallholder sector, soil fertility and soil erosion must be addressed and a Conservation Agriculture model seeks to improve soil conditions in agriculture. The technologies available to smallholder farmers, though, need to be tested in a no-till system before …

Extent Of Capillary Rise In Sands And Silts, Rachel Lynn Salim

Masters Theses

The values reported in literature for the height of capillary rise in fine sands, silts, and clays are contradictory. Most of the values were based on mathematical models, which used estimated rather than measured input data. This work measured capillary rise values in laboratory experiments in fine-grained sands and silts.

Two uniform sands with grains 0.35--0.7 mm in diameter and 0.3-0.6 mm in diameter, silt with an average grain size below 40 microns, and 0.35--0.7 mm sand coated with a water-repellant spray were carefully packed into two-inch diameter glass columns. These columns were placed into clear plastic tanks with water …