Researchers from IUPUI investigate drought effects on legumes

CEES researchers (and IUPUI Department of Earth Sciences faculty) Dr. Lixin Wang and Dr. Pierre-Andre Jacinthe and postdoctoral researcher Dr. Stefani Daryanto published a new paper this month, “Global synthesis of drought effects on food legume production,” in the journal PLOS ONE. Wang et al.’s focus on legumes is of particular importance due to these protein rich (and tasty) Fabaceae family members being major players for food security for the developing world as well as gaining popularity from increasing healthy-eating-style dieting trends.

Unfortunately, legumes have growing limitations.  A particular concern the researchers evaluated was what effect drought has on legume productivity.  The researchers conducted a meta-analysis – a comprehensive analysis of published studies from 1980 to 2014  – to bring clarity to how variables including agroclimatic region, legume species, soil texture, and timing of the drought affect legume yield responses.

One of the major findings of the study was that legume yields are more negatively affected when drought occurs during the reproductive stage versus their vegetative stage.  It was very interesting that the researchers also found that legumes grown in soil with medium texture exhibited greater yield reduction compared to those planted in soil of either coarse or fine texture. This is surprising, considering production potential of medium textured soils is usually high. Inevitably, as Wang states, “This study provides useful information that could inform agricultural planning and management to minimize drought-induced yield loss.”

The researchers’ efforts do not stop here. Jacinthe and Wang and their colleagues  – Dr. Lin Li, Dr. Pamela Martin, Dr. Juan Sesmero (Purdue University), and Dr. Dev Niyogi (Indiana State Climatologist) –  are interested in understanding the effect of various tillage practices on agricultural yields and water quality under changing climate. Climate models show hydro-climatic alterations that may further affect current water quality issues and nutrient export.  This team’s newly funded USDA supported project is addressing the role of no-till farming methods play in helping water quality sustainability currently and for future scenarios.

Jacinthe, Wang and colleagues are exploring drought impacts on no-till and conventional till plots and the variables assessed will be crop yield, efficiency of nutrient usage, and potential of nutrient leaching. Collaborative research with Dr. Li is using spectral analysis of vegetation canopy and root-zone soil moisture obtained through satellite-based monitoring to analyze drought impacts on crop yields under differing tillage practices. Concurrently, Purdue economist Sesmero and graduate students are assessing producer awareness towards connectivity of climatic information and how their decision-making process will be carried out.

The ongoing research is being conducted within the Eagle Creek watershed of Indiana and the results are aligned with the USDA’s mission of research, education, and economics: “water conservation efforts with a focus on socio-economic research and extension to increase adoption of appropriate practices and technologies to achieve increased water conservation at the farm/landscape/watershed scale.”