Production potential and profitability of some rice- based cropping sequences in a lowland ecosystem.

Thumbnail Image
Journal Title
Journal ISSN
Volume Title
Experiments were undertaken in 1997-98 to study various rice-based cropping systems for three seasons in a valley-bottom (lowland ecosystem) at Besease near Ejisu in the semi-deciduous forest belt. The objective of the study was to find out whether following rice (Oryza sativa L.) with vegetables or fallow or ratoon-rice will be more productive than continuous rice cropping. The effect of each system (pattern) on the soil fertility as well as the economics of production was studied. The systems (patterns) were: (1) Rice-Rice-Rice (2) Rice-Ratoon-Rice (3) Rice-Cowpea ( Vigna unguiculata L. WaIp.)-Rice (4) Rice-Okra (A belrnoschus esculentus L.)-Rice (5) Rice-Fallow-Rice In the first season, all plots were planted to rice. In the second season the following treatments were assigned to the plots: planted-rice, ratoon-rice, cowpea, okra, and fallow. In the third season all plots were again planted to rice. Soil fertility analyses were carried out before the first and third season plantings. Data were taken on the yield and yield components of the rice and other crops. Also economic analysis for all the crops and seasons was computed. The results indicated that continuous cropping of rice had detrimental effects on soil fertility especially P content which decreased drastically. In terms of rice production, the systems (patterns) ranked as follows: First was rice-ratoon-rice (6497.5t ha-1), followed by rice-fallow-rice (5643.7t ha-1), then rice-cowpea-rice (5 185 5t ha-1), then rice-okra-rice (4776 6t ha-1), and finally race-rice-rice (4l86.6t ha-1). In terms of overall productivity, the systems ranked as follows: First was rice-ratoon-rice (6497. 5 ha-1), followed by rice-fallow-rice (5643 7t ha 1), then rice-cowpea-rice (5584.Ot ha1), then rice-okra-rice (5201.6t ha-1), and finally rice-rice-rice (4186.6t ha-1). In terms of economics of production, the systems ranked as follows 1). Rice gross returns ranked in increasing order: rice-rice-rice ($907.6 or ¢42.16m.), rice-okra-rice ($ 1003.7 or ¢2.39m.), rice-cowpea-rice ($ 1078.0 or ¢42. 57m.), ricefallow-rice ($ 1188.9 or ¢42.83m.), and rice-ratoon-rice ($ 1373.2 or ¢3 .27m.). 2). The gross returns for all the crops together, had the ranking in decreasing order: rice-okra-rice(S 1423.4 or ¢43 .39m.), rice-ratoon-rice ($ 1373.2 or ¢3 .27m.), rice-cowpea-rice ($ 1335.9 or ¢3.18m.), rice-fallow-rice ($1 188.9 or ¢2.83m.), and rice-rice-rice ($907.6 or ¢2.16m.). It was concluded from the study that continuous cropping office in the valley bottoms (lowland ecosystem) should be avoided as much as possible.
A thesis submitted to the Board of Postgraduate Studies, Kwame Nkrumah University of Science and Technology, Kumasi, in partial fulfilment of the requirement for the award of the Degree of Master of Science in Agronomy, 1999