Water management in paddy cultivation is vital to making substantial progress in agriculture because the lion’s share of irrigation water is being sanctioned for paddy cultivation in India. This deprives other lands of sufficient irrigation water leading to loss of productivity. Due to excessive irrigation in paddy cultivation, sources of surface water, as well as groundwater aquifers, are being depleted fast instead of being used in a sustainable and judicious manner. For every kilogram of paddy, we are using 5,000 – 10,000 L of irrigation water. Do we really have to use such large quantities of water for irrigation of paddy as we are using now?
In the past, a small number of landowners owned large tracts of land. These few wealthy men employed field labourers to work their lands and still had a dearth of workforce. Therefore, to optimize their work, they made a habit of cultivating paddy only in areas where water was freely available in large quantities. They did this to avoid weeds that arise when paddy crops are not waterlogged. Farmers who worked under these wealthy landowners soon adopted this technique and over a period, it has come to be the ‘standard’ practice in paddy cultivation to waterlog all paddy fields.
However, it has been observed that paddy gave higher yields of harvest in situations where the aaru-tadulu intermittent irrigation (I-I Technique) was implemented, whether through wells, bore wells, or canals, and regardless of whether electricity was or was not available for pumping water. For instance, in the Rabi season of 2016-17, the government recommended farmers to sow pigeon peas, black gram, black-eyed peas, and sesame instead of paddy, giving water supply once every 8 days.
Being accustomed to paddy cultivation, however, farmers sowed paddy again! Having invested in paddy cultivation heavily in the initial stage, they did not want to move away from paddy. Farmers used the intermittent water supply from the government and the paddy crop sometimes had to wait for 15 days for irrigation. In contrast to what was expected, India saw the largest paddy harvest of the Rabi season since Independence, 64 Lakh metric tons! We should scientifically observe the reasons for this unprecedented harvest and determine the value of the I-I technique in paddy cultivation.
For example, in the I-I technique, the lower part of the paddy crop is periodically exposed to air and sunlight instead of being submerged in water. This results in thickening of the main stem, which improves plant health and productivity. Any living being can live without food for a few days and without water for several hours, but without air for only a few minutes. Through this, we can see how important air is to all living beings. Farmers who have been cultivating paddy for many decades should also recognize the significance of air for plants. Root respiration is important for paddy crops, which are being choked due to waterlogging.
In the I-I technique, the roots of the paddy crop reach deep into the soil owing to the porosity created in the gap between irrigation periods. This enables the plants to obtain both, nutrition and strength. In contrast, waterlogged paddy crops have shallow roots that spread on the surface. The I-I technique enables sufficient aeration of the soil in the gap between irrigation periods. This facilitates the growth of healthy microorganisms, mycorrhizae, and soil fauna (such as earthworms) which process and prepare the soil nutrients, making them more easily available to the plants. Deep soil is not as beneficial to the plants as the surface level soil, because it does not receive sufficient aeration and lacks the rich and active bio-diversity of surface soil. Even soil that has turned black due to waterlogging can be revived using this technique.
As a side benefit, the space between paddy plants in the I-I technique gives shelter to the bio-diversity around, such as frogs, mice, snakes, songbirds, cats, and mongooses. Farmers who benefited greatly through the no-till cultivation approach easily understand this concept.
Paddy crops that are waterlogged to avoid weeds often show signs of root damage due to waterlogging. In contrast, paddy crops irrigated with the I-I technique give greater harvest with increase in the gap between watering periods. This is the most important aspect of the I-I technique; that even in drought conditions, the paddy is able to survive depending on the deep root system that it has developed. It is also observed that waterlogged paddy crops develop a shallow root system parallel to the ground. This increases the risk of a failed crop in instances where water is unavailable for some time and the heat dries the shallow roots, killing the paddy crop as it stands. This has further embedded the faulty thought that paddy crops must be grown waterlogged with constant irrigation, leading to soil erosion among other problems.
The energy from sunlight falls equally on all crops, but waterlogged paddy struggles to survive using that energy, barely creating enough grain mass, whereas paddy irrigated with the I-I technique converts the energy into a bounty harvest. Due to constant waterlogging, 70% of the roots are damaged due to rot in paddy crops that are waterlogged, and the remaining 30% cannot give sufficient nutrition and strength to the crop, which resultantly fails to develop full grain in the ears and gives rise to many empty husks. Other serious disadvantages of excess water and constant waterlogging are the growth of unwanted pests such as mosquitoes, unavailability of zinc due to cold water, and affliction of diseases on the crop.
We have also observed that paddy crops cultivated with the I-I technique withstand extreme weather and are more drought-tolerant. The healthy plant matter remaining after harvest, including thick stem stalks and deep root systems, acts as a natural source of organic nutrition for the next crop once it is incorporated into the soil mass over time. (Alternatively, it could be fed to cattle as an organic feed, devoid of chemical residues of pesticides and insecticides.) There would be no need to invest in buying artificial, chemical, or organic fertilizers from outside.
Considering these above facts, we should widely broadcast the benefits of the I-I technique to farmers across the nation. They could inspire neighbouring farmers to adopt this technique as well! Imagine the amount of water we could save by adopting this method, would it not be more than the size of the Nagarjuna Sagar dam! We would be able to restore health to the soil biodiversity, soil chemistry, and the underground water aquifers! The regional ecosystem would also be enlivened through this technique. Farmers will be able to save expenses on irrigation and get a fair price for their produce. Since this technique avoids the methane generation that is characteristic of waterlogged paddy crops, it is also good for the environment!
The I-I technique is clearly most suitable for paddy crop at all times of its cultivation, as proven by the record harvest of the Rabi season, 2016-17. There is no need for further research or confirmation on this fact! We have to protect the elements of our environment by revolutionizing paddy cultivation with the I-I technique and using natural agricultural practices. Moreover, this could be the most valuable message for farmers for this century!
Yours,
Kalaga Mattapalli Narasimha Murthy
Mattampalli gramam & mandalam,
Suryapet zilla, Telangana
Cell No.: 9701823838