Somphob Jongruaysup, Vidhaya Trelo-ges, and Chindarat Chuenrung

pp. 191 - 197

Abstract

This research paper study on the comparison between no-tillage (NT) and conventional tillage (CT)
incorporated with 3 levels of nitrogen fertilizer application rate (0, 50 and 100 kg N/ha) on the fresh root
yield of cassava (var. Rayong 72). The field trial has been established since 2000 on the Satuk soil series
(fine loamy, silicious, Oxic Paleustults) Khon Kaen, Thailand. Under no-tillage practices, the physical soil
properties were improved compared to the conventional tillage system and the original soil properties at the
start of the trial. The soil structure parameters such as total porosity, soil saturated hydraulic conductivity
(K_sat) increased in NT plot, whilst soil bulk density (ρ_b) decreased compared to CT plot. Results indicated that
the higher yield of fresh root of cassava was observed in the NT plot (P<0.05) of the first year of the experiment. By contrast, the higher yield of the fresh root of cassava was observed in the conventional tillage of the
second year but the different yields were not statistically significantly different (P>0.05). For the nitrogen
application, the yield increased as nitrogen supply increased but the increment was not significant statistically (P>0.05).