U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 Soil and Water Management Research: St. Paul, MN
 close



    Research

                    Research Projects
                                    Publications
                                    Collaborations
                                    News
                                    Software
                People

                    Staff Listing
                                    CareersSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Midwest Area St. Paul, Minnesota Soil and Water Management Research Research Publications at this Location





- ARS National Programs
- Search for a scientific manuscript
- Search for a research project
- ARS Software
- Programs and Projects
- Collaborations
- Subjects of Investigation
- Publications

Title:   Author  item
                                            LABOSKI, CARRIEitem
                                            LAMB, J - UNIVERSITY OF MINNESOTAitem
                                            Dowdy, Robertitem
                                            Baker, Johnitem
                                            WRIGHT, JERRY - UNIVERSITY OF MINNESOTA
  Submitted to: Journal of Soil and Water Conservation
                                    Publication Type: Peer Reviewed Journal
                                    Publication Acceptance Date: 9/18/2000
                                    Publication  Date: N/A
                                    Citation: N/AInterpretive Summary: Improper irrigation scheduling can lead to over irrigation which in turn may cause agricultural chemical leaching to ground water. Currently, a checkbook type of accounting (plant available water equals incoming rain and irrigation, credits, minus crop water use, debits) is used by producers to schedule irrigations. This requires daily estimates of crop water use  (evapo-transpiration, ET) which vary from soil to soil and field to field. With the recent availability of low-cost, mobile time domain reflectometry (TDR) instrumentation, plant available water in the soil can be measured instantaneously and accurately. Our research showed that inherent errors in estimations of ET used in the checkbook approach for irrigation scheduling can be corrected (updated) by periodic measurement of plant available water with mobile TDR. These corrections allow farmers and consultants to more precisely irrigate each specific field when needed, reducing the potential  for over-irrigation (inefficient water use) with the associated probabilit of leaching agrichemicals into ground water by the application of excess water.
                                Technical Abstract: Time domain reflectomerty (TDR) has changed the way researchers measure soil water content. This technology can now be applied to practical field situations such as irrigation scheduling. Mobile TDR probes were inserted into the soil vertically and measured soil moisture in the upper 0.6 m of soil in two 0.3 m increments. Soil moisture measured by this method was  comparable to that measured by a TDR with waveguides permanently installed in a horizontal position (1:1 relationship, r=0.92). The mobile TDR was used to measure soil moisture in many locations in three crops (corn, soybean, wheat) on selected days for two growing seasons.  This information was used to update a checkbook method of irrigation scheduling and proved to be accurate and easy. Quick, mobile TDR measurements in several locations provided sound estimates of soil moisture throughout a field and allowed for enhanced water use efficiency and reduced leaching potential.


Return to top


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov