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Full-Text Articles in Animal Sciences
Predicting Maize Yield, Nutrient Concentration And Uptake In P And K Fertilized Soils: Pressurized Hot Water And Other Alternatives To Mehlich I Extraction In Guatemala Soils, Heather Mae Hunsaker
Predicting Maize Yield, Nutrient Concentration And Uptake In P And K Fertilized Soils: Pressurized Hot Water And Other Alternatives To Mehlich I Extraction In Guatemala Soils, Heather Mae Hunsaker
Theses and Dissertations
The inaccessibility and cost of soil testing reduce effectiveness of fertilizer use on small-scale subsistence farms, and inadequate funding promotes adoption of soil tests in developing countries with minimal validation. For example, Mehlich-I extraction of phosphorus (P) currently used extensively in Guatemala may not be suitable for its broad range of soils. At least four alternatives are available but are relatively untested [Bray 1, Mehlich III, Olsen and pressurized hot water (PHW)]. Pressurized hot water is relatively simple and inexpensive, but is not yet tested against other extraction methods under variable P or potassium (K) fertilization levels. To determine whether …
Soil Stable Carbon Isoptope Analysis Of Landscape Features At Aguateca, Guatemala, David R. Wright
Soil Stable Carbon Isoptope Analysis Of Landscape Features At Aguateca, Guatemala, David R. Wright
Theses and Dissertations
The ancient Maya of the Classic period (1700-1050 B.P.) relied on maize agriculture to support their populations. The agricultural systems they employed to produce that maize varied in form and degree of intensity, with more productive forms of agriculture needed in the Late Classic period (1350-1050 B.P.) to sustain the peaking population. It is likely that the ancient systems of production agriculture contributed to environmental degradation that in turn contributed to the pressures that culminated in the collapse of the civilization. In this study, stable carbon isotope ratios contained in the soil organic matter were used to further investigate ancient …