Tuesday, July 7, 2015

Monday, July 6, 2015



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..

Note: The elongation is triggered when the plant is submerged through a mechanism involvingethylene gas. Ethylene is normally produced by plants and diffused into the air but when floating rice is submerged in water this process is disrupted as the gas moves more slowly into water. This leads to a buildup of ethylene in the plant. This triggers the production of a hormone called gibberellin which causes the rapid growth in the plant. When the plant reaches the surface the ethylene gas can escape as normal and the rapid growth stops. Research continues to enhance the ability to cope with increasing water depth. (Ref: https://en.wikipedia.org/wiki/Deepwater_rice)