The overall research focus of the lab is understanding the genetic, physiological, and ecological basis of plant adaptation to infertile soils. Since most soils on earth suffer from one or more nutritional problems, this subject is of considerable importance for two of the great challenges confronting humanity: how to sustainably support over 7 billion people, and how to deal with global environmental change.

The first 'Green Revolution' in the 1960s was based on dwarf varieties of wheat and rice that were capable of responding to fertilizer without lodging. The 'Second Green Revolution' will consist of crop genotypes with superior yield at low soil fertility. The UN estimates that over 1 billion people are undernourished, and the number of malnourished people is actually growing. Agricultural production in developing nations is primarily limited by drought and low soil fertility. Fertilizer use in these regions is low and is not likely to increase substantially in the foreseeable future because of the rising costs of fuel and therefore N fertilizer, as well as limited reserves of high-grade P ore deposits. Prospects for increased irrigation is limited by decreasing availability of clean water, and climate models predict increased crop water demand in the future. The development of crops with better growth under limited water and nutrient availability therefore has great promise to alleviate human suffering.

Our work with this topic includes crop adaptation to low phosphorus availability, low nitrogen availability, drought, manganese toxicity, and salinity. Of these phosphorus has been a principal focus as this element is a major limitation to life on earth. We have identified several novel plant traits that enhance soil exploration and phosphorus acquisition. Root architectural traits are important for phosphorus acquisition and we have discovered several novel architectural traits that have been useful in crop breeding. More recently we have extended this work into increasing the efficiency of nitrogen and water acquisition by maize, an issue of substantial importance to agriculture and the global environment. Our work in this area includes physiological characterization of the adaptive value of specific traits, their genetic control, and their agroecological impacts in the third world. In collaboration with plant breeders, this work has resulted in the generation of new genotypes of bean and soybean with substantially better yield in low phosphorus soils of Africa, Asia, and Latin America. We currently have projects with colleagues in Mozambique, Malawi, South Africa, China, Ecuador, Honduras, Nicaragua, and Colombia.

We are also interested in how global climate change may affect ecosystems in low nutrient soils, which include most terrestrial ecosystems on earth. Very little is understood about the interaction of nutrients and other plant stress factors that may result from changing temperature, light, ozone, UV, precipitation, etc. On this topic we have ongoing research on how Mn toxicity may interact with global change variables to determine the health and composition of the Eastern forest of North America. We have discovered that Mn toxicity creates oxidative stress in tree species of the eastern forest, which means that it should change the sensitivity of these species to light, temperature, UV radiation, and ozone. Our work on this topic includes analysis of molecular, biochemical, and physiological processes in tree leaves in the forest canopy and in saplings in controlled conditions.

We welcome prospective graduate students and collaborators interested in novel, multidisciplinary research that addresses real world issues.

Our work involves a number of students and colleagues at Penn State, and collaborators from other institutions. Dr. Kathleen Brown and Dr. Jonathan Lynch are close collaborators on virtually all aspects of the research.

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