It is estimated that more than half of the ice-free land surface on Earth is directly modified by humans, and of this, over two-thirds is occupied by cropland and pastures . In order to preserve remaining natural landscapes and to meet the needs of a growing human population, human-altered land must be optimized, not expanded. This requires enhancing the efficiency of agriculture in both fertile and marginal lands, and rehabilitating lands that provide little functional value (e.g. contaminated sites, urban lawns) to states that contribute to ecological and human wellbeing.
Pushing the limits of plant productivity
For most of the 20th century, traditional plant breeding has led to substantial gains in crop production. In contrast, the plant-associated microbiome is a genetic reservoir that has barely been tapped. Although we have long known that microorganisms impact plant growth and health, the genomic tools needed to comprehensively survey complex microbiomes have only become widely available in the past 5-10 years. An explosion in the genomic investigation of microbiomes now allows us to ask questions about how groups of microorganisms influence the growth and function of plants across agricultural and ecological landscapes, and how this might be altered.
In our lab, we are interested in the effects of modifying plant-associated microbiomes on plant productivity. How might altered microbiomes impact plant growth? Below are some known and suspected mechanisms:
Engineering the rest of the agricultural ecosystem
Intensive farming relies on the engineering of multiple biotic components of the agricultural ecosystem. Plants are bred for desired traits, soil is modified to optimize yield, and the abundance of pest species may be heavily controlled. Although the plant-associated microbiome is likely to be indirectly affected by these activities, it has not been directly targeted for engineering, with the exception of a small number of select pathogens and known growth-promoting microbes. To what extent do crop-microbiome relationships mirror those found in natural landscapes, and can we further improve agricultural productivity by reintroducing microbiomes found in nature, or breeding for microbiome states that better conform to agricultural objectives?
Using high-throughput sequencing and other approaches from molecular biology, ecology, soil science, and plant science, our lab aims to better understand and optimize plant-associated microbiomes in human-disturbed environments. Projects address at least one of three main areas:
1 - Hooke and Martín-Duque. 2012. Land transformation by humans: a review. GSA Today 22: 4-10.
○ 100 PA Soils
○ Is there a role for microbial management in organic agriculture?
○ Interactions between soil microbiomes and soil surface consortia
○ In-soil persistence of genetically modified bacterial strains
○ Root-centric microbiome analysis
○ Resilient switchgrass cultivars for marginal lands
○ Pennsylvania Soybean On-Farm Network