ผลของชนิดและอัตราของปูนต่อมันสำปะหลังที่ปลูกบนดินยโสธร

Abstract

Two years experiment was conducted in farmer field at Ban Kud Muang, Takhian subdistrict, Dan Khun Thot district, Nakhon Ratchasima province from April 2009 to May 2011 to investigate the response to type and rate of limes by cassava grown on Yasothon soil (Typic Paleustult). Randomized Complete Block design was employed with four replications. There were seven treatments comprising no application of lime as a control (NL), applications of grinded limestone (GL1, GL2 and GL3) and applications of dolomite lime (DL1, L2 and DL3) with both limes being applied at the rates of 100, 200 and 300 kg/rai in respective treatment. Limes were applied before planting repeatedly in the first and second year of the study. All treatments received equally split application of complete fertilizer (15-15-15) at the rate of 100 kg/rai at two- and four-month after planting. Young mature leaves (the fifth fully expanded leaf from the tip) were sampled at four months of age for the analysis of major nutrients concentration. Cassava was harvested at ten months old. Fresh tuber yield, starch yield and aboveground biomass in the second year were higher than that in the first year in all treatments. In the first year, application of dolomite lime at the rate of 300 kg/rai tended to give the highest fresh tuber yield of 2.67 ton/rai while at the rate of 100 kg/rai giving a slightly lower yield of 2.13 ton/rai. In the second year, use of grinded limestone at the rate of 300 kg rai-1 gave the highest fresh tuber yield of 4.28 ton/rai. It was slightly higher than the yield obtained from the treatment applied with dolomite lime at the same rate (4.11 ton/rai). These yields retrieved were very significantly higher than that gained from the control treatment without lime added. The application of grinded lime at the rate of 300 kg/rai also gave the highest starch yield of 1.32 ton/rai, which was also significantly greater than the yield retrieved from the control. The trend of aboveground biomass among treatments was similar to leaf and branch and closely related to given fresh tuber yield. These limes had no effect on a difference in major nutrients concentration in cassava leaf but P and K concentrations seemingly indicated inadequate amounts of both nutrients taken up by the plant.