Dr. Schroeder’s primary focus is teaching the newly developed undergraduate Agroecology courses, CS 230: Introduction to Agroecology (3 credit hours) and CS 430: Advanced Agroecology (4 credit hours). The Introduction to Agroecology course will be offered for the first time in Fall 2004 (CS 495) and the Advanced Agroecology course (CS 430) will be offered for the first time in Spring 2005.

Students working on organic farm at the Center for Environmental Farming Systems (CEFS)

The study of Agroecology provides an interdisciplinary perspective to studying the ecological interactions within agroecosystems and the environmental, social, and economic impacts of agricultural practices. These new courses (CS 230 and CS 430) are part of a newly established Agroecology concentration within the Crop Science Department and development of a new minor in Agroecology within the College of Agriculture and Life Sciences (CALS).

Dr. Schroeder is also part of the teaching faculty for the student Summer Internship Program in Sustainable Agriculture at the Center for Environmental Farming Systems (CEFS).

RESEARCH

Internal colonization of arbuscular mycorrhizas in corn roots.

Dr. Schroeder’s research is centered on examining the functioning of arbuscular mycorrhizas and the plant responses to competition and nutrient availability. Arbuscular mycorrhizas are a mutualistic association between Glomeromycotan fungi and the majority of plant roots. Mycorrhizas colonize roots internally where they receive carbon from host plants.

Arbuscular mycorrhizas can greatly benefit plants by exploring the soil through extension of extraradical hyphae and increasing absorptive surface area for poorly mobile nutrients, primarily phosphorus. In areas where phosphorus is limiting, such as many tropical soils, arbuscular mycorrhizas are vital for growth and survival of many plants, including many crop species.

Extradical mycorrhiza hyphae stained with trypan blue external to root.

RECENT PUBLICATIONS

Schroeder, M.S. and D.P. Janos. 2004. Phosphorus and intraspecific density alter plant responses to arbuscular mycorrhizas. Plant and Soil. (Accepted for publication).

Janos, D.P., M. Schroeder, B. Schaffer, and J. Crane. 2001. Arbuscular mycorrhizas stimulate the growth of air-layered Litchi chinensis Sonn. trees. Plant and Soil. 233:85-94.

Carpenter, L.F., S. Palacios-Mayorga, E. Gonzalez-Quintero, and M. Schroeder. 2001. Land use and erosion of a Costa Rican ultisol affect soil chemistry, mycorrhizal fungi and early regeneration. Forest Ecology and Management. 144:1-17.