Life Sciences Commons^™

Dust Deposition Changes Production, Chlorophyll-A And Community Composition In Mountain Lakes, Jiahao Wen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Increasing quantities of dust emitted from semi-arid soils, agricultural soils, and urban regions are blown to remote mountain lakes in the American West. Remote mountain lakes lacking local nutrient inputs and presenting simple food webs that are easily affected by climate changes. Dust can carry nutrients (e.g., nitrogen and phosphorus) to mountain lakes and potentially enhance algae growth and change algal communities. However, experimental tests of this hypothesis are lacking. Using in situ experiments, we investigated the effects of dust enrichment on the production, biomass, and primary algal species in three mountain lakes in the American West. We found that …

Soil Health, Phosphorus And Carbon Dynamics In Response To A One-Time Compost Application And Cover Crops In Organic Dryland Winter Wheat, Idowu Ademola Atoloye

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Organic dryland winter wheat (Triticum aestivum) growers in the U.S. are faced with high interannual variability in yields. This is related to the low annual precipitation and low soil fertility on the cultivated soils. Improving soil health is the key to increasing and maintaining crop yields. In this study, we compared the effects of different rates (0, 12.5, 25 and 50 Mg DW ha^-1 compost and 2 Mg ha manure^-1) of large quantities of steer manure compost and the inclusion of cover crops versus fallow on soil health and on carbon and phosphorus dynamics in …

Effects Of Phosphorus On No-Till, Minimum-Till, And Conventional Till Irrigated Field Corn, John A. Mckay

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This investigation involved three tillage treatments, fall plowed (conventional) (moldboard IS-centimeter depth), fall chiseled (ripped) (25-centimeter depth), and no-tillage (zero tillage) replicated four times on an established alfalfa field. Rye was planted in the fall and harvested prior to planting the corn. Soil samples contained an average of 5.9 ppm phosphorus in the 0-30 centimeter soil layer, indicating the need for additional phosphorus. Within each tillage treatment, six rows received 11 kilograms/hectare phosphorus with the seed and 34 kilograms/hectare phosphorus side-dressed. Six rows received 45 kilograms/hectare phosphorus side-dressed, and four rows received 0 phosphorus. All 16 rows received 64 kilograms/hectare …

Influence Of Phosphorus And Water Management On Mycorrhiza And Rhizobia In Symbiosis With Legumes, David C. Ianson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Mycorrhizal associations are very important to plant growth. This is mainly due to the hyphal stands that are able to utilize concentrations of nutrients that would normally be considered unavailable for plant growth, especially phosphorus. These associations are of great importance in soils that have been disturbed by mineral extraction and are consequently low in available nutrients. The ability of mycorrhizal fungi to form associations on disturbed sites may be dictated by a number of factors: moisture, soil pH, soil fertility (including heavy metal ions), salinity, and plant response.

Two factorial experiments were conducted with the legume Hedysarum boreale cv …