Studies on the Improvement of Soil-Overturning Performance by Rotary Tillage

Research Project

Project/Area Number	02660248
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	農業機械
Research Institution	Ibaraki University
Principal Investigator	MORIIZUMI Shoji Ibaraki University, Faculty of Agriculture, Associate Professor, 農学部, 助教授 (80007682)
Co-Investigator(Kenkyū-buntansha)	HAYASHI Naotaka Ibaraki University, Faculty of Agriculture, Professor, 農学部, 教授 (10007669)
Project Period (FY)	1990 – 1991
Project Status	Completed (Fiscal Year 1991)
Budget Amount *help	¥1,600,000 (Direct Cost: ¥1,600,000) Fiscal Year 1991: ¥700,000 (Direct Cost: ¥700,000) Fiscal Year 1990: ¥900,000 (Direct Cost: ¥900,000)
Keywords	Tillage / Rotary Tiller / Measuring Method of Soil Displacement / Soil-Overturning / Application of Electrical Conductivity
Research Abstract	In this study, the authors adopted electrical conductivity method used the mixture soil of KCl for the estimation of displacement ratio of soils tilled by rotary tillage. The main results were as follows. 1. From the comparison of electrical conductivity before tillage with one after tillage, the soil displacement in the backward and forward by rotary tillage was confirmed. It is assumed that the soil-overturning performance of up-cut rotary tillage is better than one of down-cut rotary tillage. Moreover the soil-overturning by down-cut rotary deteriorated with the increase of tilling pitch. 2. The soil under 7 mm with index number of Yamanaka soil hardness meter showed tendency to decrease the soil-overturning, but the soils above its hardness did not show the difference of soil overturning. 3. In the tilling pitch of 42.4 mm, the soil-overturning performance by a traditional blade was better than a wide blade with gentle curve. On the other hand, the obvious difference for soil-overturning between both blades was not almost observed on the condition of tilling pitch 63.1 mm. 4. Comparing the experimental results of sand with one of clay loam, soil-overturning of sand seems to be excellent than clay loam. However, we can not definitely conclude this, as the experimental condition differs between the two soils. 5. In order to simplify furthermore the above method used mixture soil of KCl, we conducted a fundamental experiment of new method spraying the solution of KCl. The variation of application rate was within 4.1 %. Measuring the electrical conductivity of soil which solution of KCl percolated, the variation of 5.5 % in the swath width was recognized. However, From the various results, we think that this method is hopeful as the method to discriminate soil-overturning.