Why Such Wide Spacing? Why Reduce Plant Numbers So Radically?
When rice plants are crowded together, within hills of 3-6 plants packed together in a clump, with little space between hills, this reduces the amount of sunlight that can reach the lower leaves. Measurements made in 2003 by Dr. Anischan Gani at the Indonesian Rice Research Institute at Sukamandi found that with typical close spacing of rice plants, not enough illumination reaches the lower leaves in the canopy to support photosynthesis. This means that these leaves, instead of contributing to the plants pool of energy, are taking energy from it, parasitically. Moreover, we know that rice roots rely mostly on the plants lower leaves for their energy supply, to support their metabolism (Tanaka, 1958). So crowding plants together impedes whole-plant photosynthesis and undermines the growth and functioning of root systems. When there are fewer plants per square meter, all rice plant leaves are active in photosynthesis, and root systems are well-nourished by the lower leaves, which makes a
