| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1989: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1988: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Research Abstract |
The studies were carried out to elucidate the ecological characteristics of crop community grown under the various intercropping systems, and effects of the intercropping arrangement of maize, sorghum, and soybean on crop yields were also investigated over a 3-year period.
1. In the intercroppings including maize, sorghum, and soybean, light was a factors which played a important role, because with the decrease of light available in the canopy of each component crop, net assimilation rates, and leaf area indices and consequently crop growth rates decreased at the flowering and ripening stages.
2. There was a negative correlation between light extinction coefficient (K) and leaf area indices at the mid flowering or ripening stages. K value increased commonly under the intercropping conditions in showing the deterioration in light intercepting characteristics, however dense cropping was supposed to bring the decrease of K value by making the leaves more upright.
3. Three types of inter-species competition were observed by comparing the yields of each component crop cultivated in the intercropping and sole cropping, that is, mutual cooperation, mutual inhibitation, and compensation.
4. Land equivalent ratios were used to compare the productivity of the intercropping and sole cropping, and they were considerably high, showing more than 1.10 in the intercropping. This means that the intercropping gave more yields than the sole cropping.
5. Some characters of soybean such as number of pods per plant and internode length were significantly reduced when soybean was intercropped with maize and sorghum. However, a less percentage of grains damaged by pod borer was found in the intercropping.
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