Date of this Version
Conservation Tillage, Conservation Technology Information Center, 1992.
Estimating Percent Residue Cover Using the Line-Transect Method
The line-transect method is one of the easiest method to use in the field to determine the percent residue cover on the surface. Accurate measurement is necessary to determine if enough cover is present to comply with the conservation plan.
The following is a step-by-step procedure for using the line-transect method to measure the percentage of residue cover.
Use a 100-foot or 50-foot measuring tape for measuring residue cover. Other measuring length or even knotted ropes can be used if the appropriate multiplication factor is used to calculate the percentage.
Select an area that is representative of the whole field. Avoid end rows or small areas of the field that have been adversely affected by flooding, drought, weed or insect infestation, or other factors which have substantially reduced yields. The most accurate reading of residue cover can be obtained by taking an average from at least three different representative locations in the field. ·
Anchor one end of the tape and stretch it diagonally across the rows so that it crosses several passes of the farming implements used. Readings are more accurate when the tape is stretched diagonally across the rows than when taken in a windrow of residue left by the combine or in an area where residue amounts are less.
Measure the residue cover by counting the number of foot marks that are directly over a piece of residue as shown below. For the reading to be accurate,
• do not move the tape while counting
• look at the same side of the tape at each foot mark
• look straight down at the tape and the foot mark
• count only those foot marks that have residue directly under them