Sieglinde S Snapp

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Root architectural plasticity might be an important factor in the acquisition by plants of immobile nutrients such as phosphorus (P). In this study, we examined the effect of P availability on the orientation of basal roots with respect to gravity, and thereby on the growth angle of these roots of common bean (Phaseolus vulgaris L.). In one set of studies(More)
The Asian green revolution trebled grain yields through agrochemical intensification of monocultures. Associated environmental costs have subsequently emerged. A rapidly changing world necessitates sustainability principles be developed to reinvent these technologies and test them at scale. The need is particularly urgent in Africa, where ecosystems are(More)
Iron and zinc are essential micronutrients for human health often found in insuffi cient quantities in the diet. Biofortifi cation of seed crops has been undertaken to reduce micronutrient malnutrition. The objectives of this study were to identify variability for seed Fe, Zn, P, and phytic acid levels in an F5:7 recombinant inbred line (RIL) population(More)
D espite doubling of yields of major grain crops since the 1950s, more than one in seven people suffer from malnutrition ( 1). Global population is growing; demand for food, especially meat, is increasing; much land most suitable for annual crops is already in use; and production of nonfood goods (e.g., biofuels) increasingly competes with food production(More)
Phosphorus (P) uptake from patches was investigated in high-P and low-P common bean (Phaseolus vulgaris L.) plants using a split-root system. A P-patch was developed by exposing a small sub-section of the root system to localized P enrichment. A soil-based media was used to provide realistically low, buffered levels of P. In addition, nutrient solution(More)
The relay cropping of sesbania (Sesbania sesban) — a N2-fixing legume — with maize (Zea mays) has been proposed as a strategy to increase soil fertility and food production in densely populated areas in southern Africa. We determined the production of relay-cropped maize and sesbania at three landscape positions under researcher-designed and farmer-managed(More)
In Rwanda, farmers’ traditional farming systems based on intercropping and varietal mixtures are designed to meet a variety of livelihood objectives and withstand risks associated with fluctuation in market and agro-climatic conditions. However, these mixed systems have been disappearing since 2008 when government mandated intensification strategies. In(More)
Farm typologies are a useful tool to assist in unpacking and understanding the wide diversity among smallholder farms to improve targeting of crop production intensification strategies. Sustainable crop production intensification will require the development of an array of nutrient management strategies tailored to farm-specific conditions, rather than(More)
The prospect of biofuel production on a large scale has focused attention on energy efficiencies associated with different agricultural systems and production goals. We used 17 years of detailed data on agricultural practices and yields to calculate an energy balance for different cropping systems under both food and fuel scenarios. We compared four grain(More)