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Abstract : |
Oxic Paleustults soil required the additional amounts of both dolomite and chemical fertilisers annually from crop to crop due to high rate of leaching and some amounts of nutrients have been taken up by roots of the soybean plants. An increase in N levels consistently increased total shoot dry weights, stem plus petiole dry weights, leaf dry weights, and pod dry weights of the soybean plants but the differences were relatively small and not statistically significance. Potassium increased top growth, seed yields and seed sizes only up to the second level and then a decline. The levels of K were relatively too high for N to encounter. The differences between the fertiliser treated plants and the untreated plants were large and statistically significance. Oxic Paleustults soil requires the lowest rates of both N and K fertilisers but higher K levels should be adjusted to attain N:K ratio of 1:1.5. Nitrogen is needed for soybean plants even though rhizobium Japonicum is available in soil from the previous soybean experiments. Seed yields of soybean plants increased with an increase in N levels but slightly depressed by higher K levels. Seed sizes of the soybean plants increased by the second level of K and higher K levels depressed it. There were some significant relationships between seed yields and total shoot dry weights, seed yields and leaf areas, seed yields and leaf area indices and a slightly positive relationships between seed yields and levels of N but with lesser extent with higher K levels., |
