Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network

Open Access. Powered by Scholars. Published by Universities.®

PDF

Iowa State University

Plant Sciences

Graduate Theses and Dissertations

Phosphorus

Publication Year

Articles 1 - 5 of 5

Full-Text Articles in Entire DC Network

Physiology Of Genotype X Soil Fertility Effects On Yield And Accumulation Of Iron And Zinc In The Common Bean (Phaseolus Vulgaris L.) Seed, Gerald Sebuwufu Jan 2013

Physiology Of Genotype X Soil Fertility Effects On Yield And Accumulation Of Iron And Zinc In The Common Bean (Phaseolus Vulgaris L.) Seed, Gerald Sebuwufu

Graduate Theses and Dissertations

This thesis research focused on evaluating improved common bean (Phaseolus vulgaris L.) germplasm under intensified fertility regimes, and assessing how assimilate partitioning to the seed impacts seed mineral concentration. In Chapter 2, the agronomic performance of four improved varieties was evaluated on small-landholder farms using locally available manure and typical farming practices. Only one of the improved varieties, K131, yielded significantly more than the local check, Kanyebwa. Use of locally available manure significantly increased yields, but they remained less than 50% of the potential yield of improved varieties as demonstrated by the experiment station. Among resource limited farmers, options for ...


Effects Of Phosphorus And Potassium Fertilization Rate And Placement Method On Soybean (Glycine Max L.) Seed Quality And Long-Term Storability, Keaton Krueger Jan 2011

Effects Of Phosphorus And Potassium Fertilization Rate And Placement Method On Soybean (Glycine Max L.) Seed Quality And Long-Term Storability, Keaton Krueger

Graduate Theses and Dissertations

The fertilization rate and placement methods of phosphorus and potassium fertilizers can positively affect soybean [Glycine max L. (Merr.)] seed composition and yield in some environments, but not in others. Soybean seed production costs and chemically-treated seed disposal costs have increased, coinciding with farmers' adoption of planting chemically-treated soybean seeds. Seeds are treated with fungicides and sometimes with insecticides to provide protection from pathogens and insects before seed emergence. These changes in production costs have renewed seed industry's interest in identifying agronomic practices that enhance soybean quality, composition, and storability. Soybean seeds do not store well and seed quality ...


Mineral Evaluation And Quantitative Trait Loci Mapping In A Soybean (Glycine Max (L.) Merr.) Population Developed For Iron Deficiency Chlorosis Resistance, Keith E. King Jan 2011

Mineral Evaluation And Quantitative Trait Loci Mapping In A Soybean (Glycine Max (L.) Merr.) Population Developed For Iron Deficiency Chlorosis Resistance, Keith E. King

Graduate Theses and Dissertations

The identification of the causal gene(s) of disease resistance is paramount in plant breeding. Nutrient analysis in plant tissues can lead to the identification of these gene(s). The objectives of this research were 1) to map quantitative trait loci (QTL) for seed and leaf iron and zinc concentration in the soybean population Anoka x A7, 2) to determine if QTL for iron and zinc accumulation co-localized to the same regions of the genome, 3) to determine if any of newly identified QTL for Fe and/or Zn concentration correlate with QTL previously identified for Fe efficiency, 4) to ...


Phosphorus Sorption-Desorption Of Soils And Sediments In The Rathbun Lake Watershed, Najphak Hongthanat Jan 2010

Phosphorus Sorption-Desorption Of Soils And Sediments In The Rathbun Lake Watershed, Najphak Hongthanat

Graduate Theses and Dissertations

Livestock grazing in pastures has been identified as a possible factor controlling sediment and phosphorus (P) delivery to Rathbun Lake and associated water bodies in the watershed. The risk of P loss from soils in this watershed was estimated by Mehlich-3 (M3) extractable P, P sorption indices (Smax and k), degree of P saturation (DPS) and P desorption indices (equilibrium phosphorus concentration (EPC) and phosphorus equilibrium buffering capacity (PEBC)) for seven representative soil samples. Most of selected soils had low risk of P loss as indicated by PM3 and DPS. However, EPC values indicated that some soils could ...


Phosphorus Loss With Surface Runoff As Affected By Bioenergy-Based Residue And Nutrient Managment Systems For An Iowa Loam Soil, Aaron Alan Andrews Jan 2009

Phosphorus Loss With Surface Runoff As Affected By Bioenergy-Based Residue And Nutrient Managment Systems For An Iowa Loam Soil, Aaron Alan Andrews

Graduate Theses and Dissertations

Growing interest in biofuel generation with cellulosic biomass from row crop residues necessitates research to investigate biomass and nutrient management systems impacts water quality. The objective of this research was to evaluate the impact of a range of cropping and corn biomass harvest systems on P loss with surface runoff as affected by N–P management based on inorganic fertilizers or liquid swine manure. A 2–year rainfall simulation study was conducted on established field plots with Clarion loam soil (mixed, superactive, Typic Hapludolls). Eight treatments, each replicated three times, were set up in a completely randomized block design using ...