Summaries of papers of a workshop which was organized with the objective of reviewing and comparing experiences in the application of computerized decision support tools to improve the performance of water management in irrigation systems of Sri Lanka.

The research activity described in this working paper is a joint effort undertaken by the International Irrigation Management Institute (IIMI) and the Irrigation Department of Sri Lanka. Two of the authors, S. Mohanrajah (Resident Engineer, Irrigation Department) and M. H. Junaid (Additional Engineer, Irrigation Department), were responsible for the management of the Right Bank Main Canal (RBMC) in Kirindi Oya during the season, maha 1991/92.

This chapter reviews relevant Vertisol properties, experimental results and the overall experience of the project on this subject. There are several types of drainage problems in Vertisols whose magnitude may vary from site to site. Drainage improvement is discussed in relation with camber beds, broadbeds and furrows, field depressions, perched watertable, open ditches, height of beds, soil erosion and supplemental irrigation. The need for water shed development projects is also examined.

The purpose of this literature review is to identify the lessons learnt from the implementation of these projects based on available literature, and the gaps that need to be filled by additional research. It brings out clearly a number of lessons learned, some of which have been incorporated in recent projects, and some not. Many of these lessons are applicable not only to Sri Lanka but more widely.

Fourty eight mature Ethiopian Menz ewes were used to investigate the effect on nutrition on oestrous and ovarian activity in tropical sheeA control group was fed on hay alone and a high nutrition group received an additional 400g per ewe per d of a concentrate feed providing 263 g crude protein/kg dry matter and 10.5 MJ metabolisable energy/kg dry matter. Half the ewes in each group interacted with harnessed vasectomized rams to detect oestrous, which was also verfied by weekly plasma progesterone assays. Ram presence did not depress feed intake or liveweight gain.