Modelling draft requirement of secondary tillage tools in vertisol

Abstract

A study was undertaken to develop a draft prediction model for sweep and reversible type tyne in vertisol. Draft requirements of these tillage tools were measured in soil bin at four levels of depth and four levels of speed of operation in three different soil compaction levels at average soil moisture content of 14-16% (db). Experimental design was based on the factorial RBD. An appropriate ANOVA model was selected for analysis of variance using the SAS statistical software package. All the variables under study significantly affected draft (P < 0.001). The draft of tillage tools increased with cone index, depth and speed of operation. The effect of depth was found to be more significant on the draft. Rate of increase of draft with respect to depth was higher as compared to that with respect to speed of operation and cone index for all the tools tested. Draft values predicted by ASABE model were compared with those obtained from soil bin tests at three compaction levels separately. A simple equation similar to the ASABE model incorporating cone index was developed using stepwise regression analyses to model the draft of tillage implements for the range of soil and operating condition tested. The high value of R2 of the model (0.93 and 0.96) for the draft data obtained from soil bin tests indicated that the experimental data fit the regression very well.