| Author | Sarmah, Ajit Kumar |
| Call Number | AIT Thesis no. AE-88-06 |
| Subject(s) | Plants, Effect of soil compaction on
|
| Note | A thesis submitted in partial fulfillment of the requirement for the degree of Master of Engineering, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Abstract | Water losses through the borders of the irrigated paddy
fields have been assumed to be the main causes of high water
requirement of crop, in some South-East Asian countries. The
losses through the paddy borders are greatly influenced by the
soil and hydraulic conditions of the paddy field,
shrinkage/swelling behaviour and cracking of soil . The knowledge
and the magnitude of these losses, and how they are influenced by
the above factors, are very essential in order to improve the
water management in paddy field . An attempt has been made in this
study to find the effect of different compactive efforts,
shrinkage and cracking on border percolation. Studies were
conducted mainly in two parts, ยท as laboratory study and model
study and graphical relationships between various parameters have
been . established based on the laboratory and model studies.
It has been observed from the results that the minimum
hydraulic conductivity occured at or slightly greater than OMC
for all cases. For the least compactive effort Ccase1) the
hydraulic conductivity was 8. 40mm/day at moisture content
slightly greater than OMC C20. 9%). Shrinkage & swelling are found
to be the dominant characteristics governing border percolation
rate . For the least compactive effort Ccase1), the percolation
rate was f6und to reach a steady state of 20 mm/day/m length of
border, at a hydraulic head difference of 45cm and maximum
shrinkage of 33. 7% was observed. The crack development was
maximum where occurance of shrinkage was more and therefore the
percolation rate was also found much higher after cracking. |
| Year | 1988 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Agricultural and Food Engineering (AE) |
| Chairperson(s) | Mizutani, Masakazu |
| Examination Committee(s) | Murty, V.V.N ;Nielsen, Jens Moller
|
| Scholarship Donor(s) | The Royal Government of The Norway. |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1988 |