Floatigation is growing plants on water bodies using floats and growing media such as biochar. The plants need not be watered as they take nutrient enriched water through capillary action - rich in nitrates, phosphates and other nutrients. The biochar and the plants together clean the water by this method.
Floating gardens would improve cleanliness of water, increase fish densities, habitat for birds, etc. In this method there is also scope for growing submergent, floating, emergent and terrestrial plants. The algal boom and eutrophication of the water bodies is prevented in this method.
Considering all other values floatigation we could use already water bodies, canals and reservoirs for growing crops. The effective microorganisms, biochar and the plants help in treatment of the water bodies too. The advantages are:
FLOATIGATION ON RESERVOIRS, IRRIGATION CANALS AND DRAINAGE CHANNELS
Floatigation on the standing water in lakes, reservoirs and canals
Typical irrigation systems has a dam / bund / anicut / barrage which stops the flowing water to channelise or control through the sluice gates. The standing water in the reservoirs cannot be used immediately say during the rainy season / rainy days. It is dormant water not usable by the farmers used only when required. There would be evaporation losses of water apart from large area under submergence. Similarly the canal systems are either empty or just cesspools without much purpose when water is not flowing through them. During lean periods, sometimes for 6 months or more they are idle without any use.
These surface water bodies could be used for biomass / crops production through floatigation without compromising the purpose of irrigation water supply to the farmers. For any plant the transpiration is proportional to the production of biomass. Evaporation is a direct loss and has nothing to do with crop production. Moreover in all irrigation systems there are many ways water is lost: Irrigating the soil rather crop - water is lost as seepage into the ground; as run off it is lost into the drainage system; evaporated directly; etc.
In many irrigated areas paddy is the basic crop cultivated. Paddy can grows well in the water logged condition. Through floatigation, using biochar one could grow paddy crop on these water bodies, which also prevent evaporation of the water and improve the fish production through the presence of plants. There is no need to provide nutrients as there would be enough nutrients in the water, especially the Nitrates and Phosphates. Also prevents the eutrophication of the water bodies. Especially in the drainage channels there would be high concentrations of nitrates and phosphates.
For the floatigation, polystyrene / thermocol, plastic buoys, synthetic buoys can be used. The biochar would be used as a media for the plants, the roots will be in contact with the water grows well in the aerobic conditions of the water. The aerobic condition is more close to the surface of any water body due to wave action.
The methane emissions and Carbon dioxide emissions from these floating paddy fields would be least. The farmers would gain additional area through floatigation for cultivation of crops apart from paddy other short duration crops like - fodder grass, vegetables, etc..