HERBICIDE MOVEMENT IN RELATION TO TILLAGE AND CONTROLLED TRAFFIC ON TYPICAL PIEDMONT SOILS OF NC
OBJECTIVES: The objectives are to: (1) to evaluate the effects of tillage, and wheel-trafficcompaction in a no-till system, on the dynamics of soil phosphorous and nitrogen; (2) to evaluate the effects of tillage, and wheel-traffic compaction in a no-till system, on soil physical properties and crop growth; and (3) to evaluate the performance of erosion and water quality models under several soil management practices.
APPROACH: The experiment approach will be a randomized complete block with 4 replications.There will be four tillage treatments, namely conventional tillage, strip tillage, no-tillage with controlled wheel-traffic and no-tillage with randomized traffic. There will be sixteen experimental plots each with dimension of 10 m long and 3.7 m wide. Each equipped with a multislot divisor which will retain 1/9 of the runoff from the plots. Runoff volume and the sediment will be collected from each tank. Nutrient analyzer will be made on samples collected using standard procedure. Soil physical properties will be determined including bulk density, infiltration, hydraulic conductivity, soil porosity, pore size distribution, soil water content, pore size distribution and aggregate stability. Crop growth parameters will also be measured. Finally, evaluation of water quality models will be made.
PROGRESS: 1999/01 TO 1999/12
In the southeast Piedmont, considerable research has been conducted showing the benefits of conservation tillage over conventional tillage. Most evaluations have mainly focused on the benefits of conservation tillage with respect to rainfall capture and retention, but few have directly evaluated runoff, soil loss and the fate of agricultural chemicals. The objectives of this study were to evaluate the effects of tillage and wheel traffic compaction in no-till on runoff, soil loss, herbicide loss, soil physical properties, and crop productivity. Corn was planted in 1995, 1996, and 1999, and soybean in 1997 and 1998. Treatments were: (i) no-tillage with tractor traffic control, (ii) no-tillage with traffic compaction, (iii) strip tillage, and (iv) conventional tillage. Herbicide data collected from 1995 through 1999 is in the final stages of processing and interpretation. In 1996 and 1999, traffic compaction reduced corn growth and decreased grain yield by 44%. Grain yield for corn was also greater in no-tillage compared to conventional tillage (6.5 Mg/ha vs 3.7 Mg/ha). With soybeans, a slight reduction in yield was obtained due to traffic compaction in no-tillage. No differences in yield were observed between tillage treatments. Total runoff increased by as much as 45% as result of traffic compaction in no-tillage and was generally slightly higher in conventional tillage compared to no-tillage with controlled traffic. The largest differences in soil loss were obtained in 1997 where a four-fold increase was observed as a result of wheel-traffic compaction in no-tillage. The greatest soil loss was also observed in 1997 where a loss of 254.6 tons/ha was observed in conventional tillage. Soil loss in no-tillage in 1997 was only 4.8 tons/ha.
PUBLICATIONS: 1999/01 TO 1999/12
No publications reported this period
PROJ NO: NCX-115-5-92-130-1 AGENCY: CSRS NC.X
PROJ TYPE: EVANS-ALLEN PROJ. STATUS: EXTENDED
START: 01 OCT 1996 TERM: 30 SEP 2000 FY: 1999INVESTIGATOR: Gayle, G.; Reyes, M.; Raczkowski, C. W.
PERFORMING INSTITUTION:
NATURAL RESOURCES & ENVIRONMENTAL DESIGN
NORTH CAROLINA A&T STATE UNIV
GREENSBORO, NORTH CAROLINA 27411