What grows—or won’t grow—in the soil, and why, is at the
heart of natural resource and environmental management (NREM). Travis Idol,
associate professor in NREM, focuses on nutrient cycling, conservation
agriculture, and sustainable intensification, making him the ideal advisor for
Aliza Pradhan in her research into the increasing problem of low crop yield due
to poor soil fertility and erosion in the rain-fed uplands of her native
Odisha, India.
Dr. Pradhan, who earned her PhD in May 2015 and has returned
to India to continue her research, theorized that more sustainable conservation
agriculture production systems (CAPS) would help to maintain soil quality,
improving crop production as well as farmers’ livelihood. However, since the
benefits of conservation agriculture may take a decade to fully manifest, she
needed to identify shorter-term indicators to show whether the system was
improving.
Many Odisha farmers grow maize in single-crop systems using
conventional tillage—repeatedly weeding, hoeing, and otherwise disturbing the
soil. But recent research shows when soil is left as undisturbed as possible,
erosion is reduced and soil nutrients conserved. Reduced tillage is an
important CAPS practice, as is intercropping—growing compatible plants together
instead of a single crop—and cover cropping, growing plants between crop cycles
that enrich the soil and keep it from washing away.
Dr. Pradhan adapted CAPS practices to traditional Indian
systems at a research station in Odisha over three years. She assessed the
soil’s physical, chemical, and biological properties and processes, showing
that reduced tillage, cowpea–maize intercropping, and cover-cropping with
mustard—also an important Indian seasoning—not only improved soil quality; it
increased system productivity by 124% and net benefits to farmers by 204% over
traditional systems. And the longer the new systems continued, the greater
their benefits.
Because the yield and income improvements were so striking,
and because Dr. Pradhan used variations on familiar crops and technologies, she
believes such CAPS should be acceptable and attractive for smallholder farmers
in the area. Not only that, but using these systems creates a better soil
environment for agricultural sustainability, allowing them to sustainably
intensify crop production to meet increased future household income and
nutritional needs.
The research was funded by USAID and Feed the Future
Innovation Lab for Collaborative Research on Sustainable Agriculture and
Natural Resource Management (SANREM) through a University of Hawai‘i and Orissa
University of Agriculture & Technology collaborative project, Sustainable
Management of Agro-Ecological Resources for Tribal Societies (SMARTS).