4.2. Economic benefit evaluation of water spinach floating bed
The traditional terrestrial cultivation method involves construction of greenhouses, which occupies large amount of lands, and labors cost. However, the aquatic cultivation method could solve these problems. Water spinach is perennial in warm climates, while an annual under cooler growing conditions. It can be harvested many times every year. Water spinach floating bed could take full advantage of land, increase economic income of farmers and reduce the risk of single cultivation method. Besides, the input–output ratio was calculated for both terrestrial cultivation method and aquatic cultivation method. Our results showed that the input–output ratio for terrestrial cultivation method was 1.78; however ,the input–output ratio for aquatic cultivation method was 1.80,which is a little higher than that of terrestrial cultivation method. During experimentation in present work, 11,907 kg water spinach had been harvested, which could earn 37,628¥ after deducting the input.