Effects of Rainfall Events on Soil in Orchard Field under Herbicide Treatment. 2. Characteristics of Runoff and Soil Erosion
2010
Chung, D.Y., Chungnam National University, Daejeon, Republic of Korea | Park, M.S., Chungnam National University, Daejeon, Republic of Korea | Lee, K.S., Chungnam National University, Daejeon, Republic of Korea | Lee, J.H., Chonbuk National University, Jeonju, Republic of Korea
Changes in runoff and soil erosion at slightly hilly erosive plots with pear trees over a three-year period were monitored under two distinct types of weed treatment by herbides : (1) pre-emergence herbicide with glyphosate; (2) post-emergence herbicide with paraquat. The numbers of rainfall events from June to Nov for three years of experimental periods were approximately 50 times in the plots having 5.5% to 10.2% slope at an altitude of 125 m. The steady-state infiltration rate was generally increased in the bare plot from which all weeds were removed while it was decreased in the herbicide treated plots and control. The runoffs from the control plot during the experimental periods were always less than those from plots of the herbicide-treated and the bare. The runoff under the same rainfall intensity was decreased in the order of bare, glyphosate, paraquat, and control. This results indicated that the removal time of weed by the different types of herbicides might influenced the runoff rate. For the first two years of the experimental periods, loss of fine fraction was much greater than that of coarse fraction while soil loss was correlated neither with total rainfall nor amount of runoff. The soil erosion rate under the same rainfall intensity was increased in the order of control, glyphosate, paraquat, and bare plot. However, there were not much differences in the soil loss for all plots under a relatively lower rainfall intensity less than 30 mm day-¹, resulting in rainfall intensity was important factor on soil erosion.
显示更多 [+] 显示较少 [-]