In the dry season on the clay loam soil, 1,500 kg/ha of dry cowpea seeds were obtained with no-tillage. This yield was not' significantly different from the 1,460 kg/ha from tilled plots. No-tillage required less irrigation per kg of yield and hence had a better water use efficiency. In Guyana, on a heavy clay soil, no significant differences were obtained for three tillage regimes (Simpson and Gumbs, in press). The tillage systems were T1) disc-ploughing followed by one pass of a heavy harrow (reduced tillage), T2) T1 followed by one pass of a light harrow (conventional tillage) and, T3) T2 followed by chisel ploughing (conventional deep tillage). The results of this study are not dissimilar to those reported earlier by Lindsay and Osei-Yeboah (1982) on the Aquic eutropept in Trinidad for cowpea and maize. Moreover, there was no signifi- cant yield increase for these two crops grown on ridges compared to flat planting on this soil in Trinidad. These latter results are, however, contrary to the findings of Krantz et al. (1978) on Ver- tisols at ICRISAT. The tillage/soil management method which gives the best cost : benefit ratio should therefore be employed. In coastal Guyana there are two wet and two dry seasons per year. The mid-year rainy season is longer and more intense than the end of year (December-January) rainy season. With the prevailing climatic conditions, cowpea is found to be more suited to the less intense rainfall at the end of year planting season. Maize, however, is suited to both seasons, but is normally planted in the mid-year season because the rainfall is more reliable. Several systems are presently being tested which allow the cowpea/maize rotation to be tested with or without mulch and tillage in the rainy seasons. Some of the results (Table 3) of these studies indicate that major economic benefits can be gained by using a vegetative mulch for cowpea production in the end of year planting season. The benefits of mulching in the mid-year season appear to depend on the level of rainfall. When rainfall is high, particularly at planting, soil moisture under the mulch is excessive and this affects germination and growth of maize. Under more moderate rainfall conditions mulching can be beneficial to maize production. A comparison of no-tillage and conventional tillage for cowpea and maize production indicate comparable yields, particularly for cowpea in the end of year planting season. No-till maize is af- fected by excess moisture and the level of N-fertilization. It has, however, been shown that under moderate rainfall, and high N-fertilization of maize, it is possible to reduce or perhaps even eliminate tillage of the heavy frontland clays of Guyana for pro- ducing cowpea and maize. CONCLUSIONS AND RECOMMENDATIONS A survey of the soil and water management practices of small farmers in Trinidad and Guyana has shown that they lack basic information for optimizing yields. Although solutions to several of the problems are known and can be implemented, others re- quire national effort. There is, hence, an urgent need to disseminate available information and to demonstrate proven soil and water management practices to our farmers. In an attempt to mitigate some of the limitations highlighted in the survey, a research program has been initiated. Preliminary results have shown the potential of reduced tillage to give comparable yields to those obtained by conventional tillage. These findings hold much promise for maintaining or improving soil productivity and increasing crop yield in these areas. Selecting and growing crops at the time of year when the climatic conditions are suitable is also a recommended solution. There is also the need for long term studies over a wider soil and climatic zone, as well as the in- tegration of weed control, fertilizer use and water management for the benefit of regional agriculture. Acknowledgements The authors gratefully acknowledge the financial assistance of the Swedish Agency for Research Cooperation with Developing Countries (SAREC) and facilities provid- ed by the Ministries of Agriculture of Trinidad and Tobago and Guyana. They are also indebted to Dr. Dr. L. D. Wickham for presenting the paper in their absence. References 1. Johnson, C.E., R.L. Schafer, and C.B. Elkins. 1982. Prescribing tillage for clay soils. Trop. Agric. (Trin.) 59(2):76-81. 2. Krantz, B.A., J. Kampen, and S.M. Virmani. 1978. Soil and water conser- vation and utilization for increased food production in the semi-arid tropics. Publication prepared for the International Society of Soil Science, Edmonton, Canada, June 1978. 3. Lal, R. (Editor). 1979. Soil tillage and crop production. Proc. Ser. No. 2. Int. Inst. Trop. Agric., Ibadan, Nigeria. 361 pp. 4. Lindsay,J.I., and S. Osei-Yeboah. 1982. Summary of research in Trinidad: Workshop report on the management of clay soils. Trop Agric. (Trin.) 59(2):189-191. 5. Lindsay, J.I., S. Osei-Yeboah, and F.A. Gumbs. 1983. Effect of different tillage methods on maize growth on a tropical Inceptisol with impeded drainage. Soil and Tillage Research 3:185-196. 6. Simpson, L.A., and F.A. Gumbs. In Press. A comparison of three tillage methods for maize (Zea mays L.) and cowpea (Vigna unguiculata [L.] Walp.) pro- duction on a clay soil in Guyana. Trop. Agric. (Trin.). TABLE 3: Effect of tillage and mulch on the yields of cowpea/maize rotation on a heavy clay soil during four planting sea- sons (1981-1982) in Guyana. Crop/tillage treatment Seed yield kg ha1 Trial I Cowpea 1981 Till + mulch 545.0* (10 cm)a Till bare 444.3 Crop/tillage treatment Maize following cowpea No-till + previous mulch Till bare Till + mulch No-till + mulch (10 cm)a (10 cm) Yield kg ha-1 1595b 4226 2600 2175 LSD (0.05) 1623 Trial II Till bare 495.1 Till bare 974.3c 1982 Till + mulch 500.3 No-till + previous mulch 1650.7 (5 cm)a Till + mulch 660.9 No-till + previous mulch 1867.3 (10 cm) LSD (0.05) 50.4 J LSD (0.05)187.4 a Depth of mixed grass mulch b Cob yield 10% moisture c Seed yield 10% moisture Significant at 5% level of probability VOL. XX-PROCEEDINGS of the CARIBBEAN FOOD CROPS SOCIETY 197