Management of Excess Rainwater for Sustainable Productivity

1. WELCOME

2. Management of Excess Rainwater for Sustainable Productivity Presented By: Dr. S.K. Pyasi Professor Department of Soil & Water Engineering College of Agricultural Engineering J.N.K.V.V. Jabalpur (M.P)

3. Key to Manage Excess Rain water/Runoff Water in Watershed • If rainwater is running, make it walk. • If rainwater is walking, make it stand. • If rainwater is standing, make it sit. • If rainwater is sitting , make it sleep.

4. Thumb Rule for Calculating the Quantum of Excess Rainwater Available on a Microwatershed - Let the area of the field = 20m × 10m = 200 meter square Let average rainfall of the area = 1000mm = 100cm = 1m Hence, Volume of water = 1m × 200 meter square = 200 cubic meter According to review about 30-40% of total volume of rainwater is converted into rainfall excess/ runoff water. Therefore, excess rainfall water available = 40% of 200 cubic meter for conservation in the field itself. = 80 cubic meter Then the hydraulics of earthen tank at downstream end of field may be calculated and a single drop of water will not go out of field.

5. iz/kkuea=h d`f"k flapkbZ ;kstuk mn~ns’; & gj [ksr dks ikuhtyxzg.k {ks= esa % gj [ksr dks ikuh rc] [ksr dk ikuh [ksr esa tc A • Water availability to each field in command area. • Increasing water productivity by adopting advanced methods of irrigation. • Restricting and strengthening the canal network system and reducing the conveyance losses. • iii. Adopting rotational water supply system, so that water can be made available at every field of the tail end.

6. Pradhanmantri Krishi Sinchayi Yojana(PMKYSU)Motto- Har Khet Ko PaniꞌHar Khet Ko Pani Tab, Khet Ka Pani Khet Mein Jabꞌ • Water availability to each field in command area. • Increasing water productivity by adopting advanced methods of irrigation. • Restricting and strengthening the canal network system and reducing the conveyance losses. • iii. Adopting rotational water supply system, so that water can be made available at every field of the tail end.

7. iv. Provisions for canal operation during dry spells of kharif season to sustain rice productivity. v. Management of excess water in the fields of the command area which receives huge amount of seepage water through reservoir or main canal and becomes unproductive for rabi crops due to water logging condition. vi. Management of excess rain water in every field of the command area.

8. 2. Water availability to each field in watershed area. • Renovation of existing traditional water resources system. • Management of excess rain water at micro-watershed level that is in the individual farmer’s field it self after quantifying the rain fall excess amount. • Construction of large diameter wells in series for excess rain water storage.

9. (iv) Recharging of exist open wells and tube wells in the watershed area to secure water availability. (v) Construction of Check dams in nearby nala/natural streams (vi) Construction of Percolation tanks in upper reaches of watershed and diversion trenches/drains in peripheral of hill foothills

10. National policies should aim at encouraging the efficient use of rain water in situ. Management of rain water is the key to success in agriculture. The management of rain water can increase agricultural productivity many times, reduces the flood hazard and alleviate the misery of droughts. According to estimates in India out of 370 million ha meters of rain water which falls on 329 million ha of land in 2 to 4 months in a year, 170 million ha meter water as runoff in rivers and streams and hardly 86 million ha meter seems to entering the soil system. 120 million ha meter exhaust in evaporation. It is only a friction of runoff water which is being used for irrigation. How can we change this distribution and improve, rain fed agriculture by providing supplemental irrigation is the main question. In India about 45% of cultivated area is under irrigation

11. 4. No doubt, irrigation is given the highest priority in our national planning and country hopes to extend irrigation as much as 50% of the total cultivated area. But even after this extension half of the cultivated area in country will still remain dependent on rainfall for farming. Thus, the key to equitable agricultural development and the solution to the problem of poverty lies in the rain fed agriculture. 5. More or less same situation of rain water management exists in Madhya Pradesh too. Here lies the scope to increase productivity of the state by management of excess rain water in the fields itself for providing supplemental irrigation.

12. Existing Strategies for Rain Water Management: The first effort is to retain as much rain water in the soil on which it falls, so as to provide favorable moisture regimes to the crop by construction of percolation tanks, farm ponds etc. Harvesting and storing of run off water in small tanks nearby, when the rain exceeds the storage capacity of soil. Adoption of suitable cropping pattern on the basis of past record of monsoon season and its duration.

13. Efficient & Farmerꞌs Friendly Ways to Manage Excess Rainwater/Runoff Water: Technology for assured rice crop- According to current estimates, out of the 142million hectares of agricultural land in India, only about 45% has arrangement for irrigation. The rest of the agricultural land is dependent only on rainfall for its need and comes under rainfed agriculture/dry land agriculture. A delay in rainfall or long dry spells creates uncertainty even for rice crop leaving farmers in pity. Due to lack of sources for irrigation water the general tendency of the farmers is to store maximum rainwater in the cropped field that is also called HAVELI SYSTEM to avoid moisture deficiency during dry spells. Excessive rainfall sometimes leads to submergence of rice crop whose degree and

14. duration is stochastic . Due to this submergence, a damage to crop and yields take place. On the other hand, long dry spells at critical stages of crop growth causes moisture deficiency and leads to crop failure. • Hence, need of the hour is to optimize bund height for optimum storage of water in the rice field itself and every drop of excess water can be managed at the point itself by adopting following technology. The following technology for management of excess rain water in rain fed areas for rice fields has been recommended as a scientific finding in a project of NATP. They recommended • Construction of pheripheral bunds with optimum dimensions around cultivated rice • field under different soil and slope conditions for conservation of rainwater, • sediments and nutrients

15. Construction of earthen trapezoidal tank at down stream side/all around the • selected rice field for collection of excess runoff water • Construction of farm ponds and suitable water harvesting structures at suitable • locations in the watershed area • Construction of large diameter open wells for harvesting/storage of rain/runoff • water at suitable locations in watershed area • Construction of check dams in series at existing nalas/rivers in the watershed • area.

16. To develop suitable technology for removing excess rain water accumulation in low lands with special reference to surface and sub-surface drainage to increase rice productivity and making the land reclaimed for agricultural production

17. Either excess or deficit amount of water adversely effects the crop productivity. Hence, design of graded bund around the cultivated rice field is one of the most economical methods for excess rain water management in the field itself in view of conserving soil moisture in case of long dry spells for sure and sustainable rice production. • The earthen ( excavated) structure preferably trapezoidal in shape may be constructed at down stream end of each bunded field. Its internal capacity will be approximately equal to the expected runoff that would the collected from the bunded area and will be calculated by using Rational formula or any other suitable method applicable as per availability of hydrological data. The dimension of proposed earthen tank will depend on the expected runoff produced from the bunded fields.

18. Water Management for Low Lands/ Waterlogging Situations: 1. Water logging occurs, when there is too much water in the plants root zone, which results in the roots not being able to access enough oxygen for respiration. Water logging, when it occurs is a major constraint to production. Plant growth is effected and under certain conditions will even lead to premature plant growth. 2. Drainage is usually the best way of reducing water logging. If the environment of low land is favorable for channelizing confined water fully or partly by engineering methods, leading to reclamation of water logged area and increase of cropping intensity. Suitable agronomic practices can increase productivity in low lands. In case the confined water cannot be channelized then further help in fish culture, which can add to sustainable income of farmers.

19. Case 1- Photographs showing Excess Rain water Management techniques in Rice Fields in one past experiment conducted at WTC, Bhubaneswar in the year 1997

23. Case 2: Some Photographs showing Excess Rain water Management techniques in Farmer’s Rice Fields in one experiment conducted at Birsa Agricultural University, Ranchi Under the Funding of NATP,ICAR during 1998-2004

33. THANK YOU