Leopold Center for Sustainable Agriculture

Completed Competitive Grant

Soil moisture dynamics and plant transpiration under contrasting annual-perennial cover types

Project ID: E2008-17

Abstract

Soil moisture dynamics are influenced by land cover, thus different land covers would be expected to have different soil moisture behavior. This project tested various land covers and crops to see whether and how moisture was retained or depleted.

Key Question: How does a range in vegetation types influence soil moisture dynamics?

Findings: These results show that diversified LEI systems can produce yields and profits that match or exceed those obtained from conventionally managed corn-soybean systems.  Additionally, we learned that ecological processes such as weed seed consumption by rodents and insects can promote effective weed control in LEI systems, while allowing substantial reductions in herbicide use. Weed seed losses to rodents and insects can be enhanced by delaying tillage operations to leave seeds on the soil surface for as long as possible.

Lead investigator: Matt Helmers, ISU Agricultural and Biosystems Engineering

Co-Investigator(s):

Amy Kaleita, Agricultural and Biosystems Engineering; Heidi Asbjornsen, formerly ISU Natural Resource Ecology and Management, currently University of New Hampshire Natural Resources & Environment

Year of grant completion: 2012

This competitive grant project was part of the Leopold Center's Ecology Initiative.

Topics: Corn-soybean cropping systems, Cover crops, double crops, strip cropping, Soils and agronomy, Water quality, quantity and management