Wheel Traffic Placement Effects on Corn Response under No-Tillage and Conventional Tillage

Although previous studies on the Del-Mar-Va peninsula have indicated that vehicular wheel traffic from small scale farm equipment (<5 tons/axle) does not result in soil conditions considered detrimental to plant growth under no-tillage (NT) and conventional tillage (CT) management, farmers are still concerned that decreased plant response and reduced crop yields may result. A study was conducted from 1988 to 1991 to evaluate the effects of wheel traffic placement on corn (Zea mays L.) growth, nutrient uptake, and yield response under NT and CT. The soil was a Bertie silt loam (fine, loamy, mixed, mesic Aquic Hapludult) and was somewhat poorly drained. Replicated field plots were established for NT and CT corn in which rows of corn were subjected to different wheel traffic patterns. The patterns were: wheel traffic on neither side of the row (NS), wheel traffic on one side of the row (1S), wheel traffic on both sides of the row (2S), and wheel traffic on both sides and in the center of the row (IR). Corn plant emergence, biomass production, nutrient uptake, and yield were evaluated. The results generally indicated that NT had higher emergence rates than CT each year of the study. The NT plots also generally exhibited higher N and P levels for all growth components than the CT. In the grain tissue, NT plots had higher K levels than CT. Wheel traffic had significant effects on plant emergence 3 out of 4 yr. Wheel traffic did not have significant effects on biomass production and yield in 1988 or 1989, but did in 1990 and 1991. The IR treatment consistently exhibited reduced plant growth and yield response. It is felt that the concerns commonly expressed by farmers on the detrimental effects of wheel traffic activity may be due to plant responses observed in the end rows on the field boundaries. These end rows are exposed to wheel traffic directly in the row during planting operations. As long as small scale farm equipment is used and the soil is worked at proper moisture contents, there does not seem to be strong justification for regular deep-tillage of Del-Mar-Va's coastal plain soils to overcome perceived problems related to vehicular wheel traffic activity on continuous NT and CT fields. Research QuestionAlthough previous studies on the Del-Mar-Va peninsula have indicated that vehicular wheel traffic from small scale farm equipment (<5 tons/axle) does not result in soil conditions considered detrimental to plant growth, farmers are still concerned that decreased plant response and reduced crop yields may result. This study examines wheel traffic placement effects on corn plant emergence, biomass production, nutrient uptake, and crop yields for a coastal plain soil under conventional and no-tillage management systems. Literature SummaryPrevious studies have demonstrated that corn plant and grain yield response have generally decreased with an increase in wheel traffic activity. Typically, these studies have been performed on Corn Belt soils using heavier equipment than commonly used in the northeastern USA. It has been suggested that crop damage can be reduced by timely management of wheel traffic and limiting the number of passes. Recent studies on the Del-Mar-Va peninsula have indicated that neither wheel traffic placement nor long term continuous tillage results in detrimental soil conditions for corn plant growth as long as small scale farm equipment is used at appropriate soil moisture conditions. Farmers on the Del-Mar-Va peninsula still express concerns based on their visual observations that wheel traffic is causing reductions in corn plant growth and yield response. Study DescriptionThis study was conducted from 1988 to 1991 at the University of Maryland Wye Research and Education Center located near Wye Mills, MD, on a Bertie silt loam soil. The objective was to evaluate the effects of vehicular wheel traffic placement on corn growth, nutrient uptake, and yield response under no tillage (NT) and conventional tillage (0 plots. Replicated field plots were established for NT and CT corn in which rows of corn were subjected to different wheel traffic patterns. The patterns were: no wheel traffic on either side of the row (NS), wheel traffic on one side of the row (1S), wheel traffic on both sides of the tow (2S), and wheel traffic on both sides and in the center of the row (IR). Corn plant emergence, biomass production, nutrient uptake, and yield were evaluated. Applied QuestionsWhat effect did wheel traffic placement have on corn growth, nutrient uptake, and yield response under NT and CT management? Results generally indicated that NT had higher plant emergence rates than CT for each year of the study. The NT plots also generally exhibited higher N and P levels for all growth components than the CT. In the grain tissue, NT plots had higher K levels than CT. Wheel traffic had significant effects on plant emergence 3 out of 4 yr. Wheel traffic did not have significant effects on biomass production and yield in 1988 or 1989, but did in 1990 and 1991. The IR treatment consistently exhibited reduced plant growth and yield response. The results indicate that the detrimental effects of wheel traffic activity reported by farmers may be due to plant responses observed in the end rows on the field boundaries. As long as small scale farm equipment (<5 tons/axle) is used, there does not seem to be strong justification for regular deep-tillage of Del-Mar-Va coastal plain soils to overcome perceived problems related to vehicular wheel traffic on continuous NT and CT fields.