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ARS Home » Midwest Area » Ames, Iowa » National Laboratory for Agriculture and The Environment » Agroecosystems Management Research » Research » Research Project #449472

Research Project: Precipitation and Radiation Use Efficiency of Native Grasses in an Alley-cropping System

Location: Agroecosystems Management Research

Project Number: 5030-21600-002-009-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Jun 1, 2026
End Date: May 31, 2027

Objective:
Determine how precipitation and radiation use efficiency of a native grass mixture are affected within an integrated tree-crop-livestock (alley-cropping) system compared to a conventional pasture.

Approach:
The project involves comparison of the precipitation and radiation use efficiency of native grass forages grown in the alleys of widely-spaced tree (e.g., pecan, oak) rows and in a conventional pasture in Fayetteville, Arkansas. The research approach utilizes light interception and other biophysical sensors within the alley-cropping and open pasture to quantify differences in available radiation, evapotranspiration, and near-surface conditions between native grasses grown beneath rows of five tree species and in the open. Native grass height, biomass, and leaf area index will be measured multiple times throughout the season. Native grass biomass produced and cumulative precipitation received from the onset of growth or since the last grazing event will be used to calculate water use efficiency; similarly, radiation use efficiency will be calculated using the amount of photosynthetic active radiation captured between sample points.