Rice unlike other crops that man grows is intimately involved in the culture of numerous world societies. In several regional languages the general terms for rice and food or rice and agriculture are synonymous. The rice grain forms an integral part of rituals in Hindu and Buddhist religions. Hence the interlinking of rice with humans is not just as a commodity but as a substance that goes deep into the cultural milieu of the human race. The much despised relation of rice and water began accidentally. In fact the first records of rice cultivation projects it as a dry seeded crop grown in ends of high land and forests cleared for shifting cultivation. It is in China that the process of puddling soil and transplanting seedlings began in river valleys and low lying areas with likelihood of flood and submergence of rice plants. As transplanting gives a head-start to rice seedlings in their fight with weeds, this method took an easy route of acceptance in other parts of the world, especially in South east Asia where originally rice is grown in dry land conditions. This historical perspective and the belief that rice would be better off if puddled and transplanted, has brought us to the present situation of excessive use of water for irrigating rice. A change of this attitude is going to be difficult and time consuming. But a change is all that is needed and the change is needed now!
Rice is the main grain that is consumed in India and other South Asian countries. A hectare of rice in conventional puddle cultivation uses 1300-1600 mm of water per season as per the literature. But in practice, farmers use a grater volume (up to 2000 mm) in many delta areas in India. The future of rice production which consumes a lion’s share of water (85%) used in irrigated agriculture will therefore depend heavily on developing and adopting technologies and practices which will use less water with highest use efficiency. Rice is cultivated usually in a puddled condition with large volumes of water and grown in standing water. The water productivity is hardly 0.15 kg/m³ water, which is very low. Even in SRI (Sustainable rice Initiative) method the total water use is 745-800 mm per ha though this method does away with standing water during the major crop phase. Similarly, productivity of rice is stagnant (Table.1) and how a change can be brought to this situation. A comprehensive package was tested that could reduce resource use and increase productivity in direct seeded rice which form 28% of the Indian rice cultivation. Jain Irrigation, the most highly water conscious Corporate in the country is working towards food security thru water and energy securities have now tested and released an innovative method for cultivating rice.
Precision farming is farming where 1) Timeliness of operations and 2) Precision in quantities of inputs and control measures are practiced. The different steps followed in precision farming varies from crop to crop and differences of these practises from conventional practises also varies from crop to crop. In Precision farming of rice we recommend the following steps: Planting on raised beds, adopting a plant spacing of 0.2 m x 0.15 m, irrigating with drip following an irrigation schedule and fertilizer thru fertigation scheduling and weed control by weedicide.
Based on the experience Jain Irrigation garnered over a number of field trials, the cultivation method and drip system for rice should have the following components:
- Adopt dry seeded aerobic method of rice cultivation.
- Disc plough the field twice; first East-West and second time North-South directions
- For rainy season crop, it is advisable to prepare broad bed and furrow (BBF) system that will take care of drainage during heavy rain. For rabi and summer crops even flat seed bed is appropriate.
- For BBF system for seeding; Bed width of 1 m, and height of 0.15 m and furrow width of 0.2-0.3 m.
- Sow rice in rows on a broad bed or on flat seed bed.
- Rotavate to break clods on the bed surface to achieve fine tilth.
- Sow seeds at 0.2 m x 0.15 m spacing; 5 rows per bed (in BBF).
- Install drip system.
- Mulch the seeded surface with rice husk.
Identification of varieties suitable for drip irrigation would take a large number of time consuming experimental trials. However, it is an intelligent assumption that all the varieties so far found suitable for dry seeded cultivation would also be suitable for drip. Varieities tested under drip irrigation and fertigation by Jain irrigation. More such varieties will be tested and recommended.
Varieties tested under drip fertigation
US 311, Arise 6129, SBH 999 (basmati), 25P25, 25P31, Try -R (2), BPT, Pusa sugandha (basmati), ADT -45, Pusa-2, WGL 32100
Traditional (Puddling) Cultivation Method
Rice fields are first flooded before tillage. Tillage of flooded field is referred to as puddling. In puddling, the top soil is subjected to repeated fine grinding with water. Besides saturating the top soil, an overlying water layer is created and maintained during the transplanting period. Apart from high water use the procedure of puddling has many disadvantages;
- Puddling destroys soil structure
- It reduces percolation rate
- It results in loss of water (Puddling accounts for 20-40% of total water use of rice culture).
- Most of the water used for puddling is lost by drainage.
- It induces high resistance to root penetration
- It causes low porosity and permeability
- It results in the formation of a soil plow pan
- All the above factors restrict root growth.
- It also causes emission of Methane gas. Thus it is suppose to be the creator of Green House Gases.
- The only known advantage of flooding for tillage (Puddling) seems to be the control on weed germination.
- Because of the demand on water modern technology high light dry sowing of paddy seeds into wet soil (no standing water). Drip irrigation makes the soil wetting easy and water use restricted to crop water requirement alone.
Drip Irrigation - The concept
Drip irrigation is the slow, even application of water at low pressure to the root –zone using a net work of plastic tubing placed above the rooting zone (surface drip) or buried among the root branches inside the rhizospherical soil at a certain depth from surface. (subsurface drip). In drip irrigation method, crops are irrigated daily to the precise volume of water equivalent to the evapo-transpiration (ET) of the crop. It is estimated from daily Evaporation data using crop and canopy coefficients, the latter two factors vary with the age of the crop and the size of its canopy. These are the two factors that affect the volume of transpiration of the plant/crop that changes with growth of the crop. Factoring in of these two coefficients is what makes the water requirement estimate unique to that particular crop at that particular stage of its growth.
Sowing and germination Irrigation
It is essential to pre irrigate and fully wet the broad bed before sowing the seeds. Keep the bed uniformly wet till germination and crop establishment.
One of the main issue in dry seeded and drip irrigated rice is the germination and growth of weeds. The standing water in the conventional flooded rice will suppress the weed germination. We recommend use of rice husk mulch on the beds after seeding. Mulch is applied 2-3 cm thick on the bed surface. Besides reducing weed growth it also helps reduce evaporation from the soil surface. However this is an optional recommendation.
Benefits of Jain Drip in Rice Cultivation
- Enhanced yield upto 50% .
- Higher and cleaner straw production.
- Conserving irrigation water up to 66%
- Conserving energy use for pumping up to 52%.
- Higher water and fertilizer use efficiency.
- Incidence of diseases and insects significantly low
- Early Maturity
- More Productive tillers
- Reduced chaffiness & shattering of grains
- No need for land leveling (prerequisite for flow irrigation).
- No need for labour use for trimming bunds and plugging breaches to contain water.
- Intercropping and rotation cropping is possible. Pulse rotation crop will be beneficial.
- When Direct Seeding (DSR), reduces seed cost.
- Soil structure is maintained (absence of puddling operation that destroys soil structure).
- Maintains aerobic condition in the soil.
- Prevents Nitrous oxide formation .
- Prevents Methane emission and protects environment as there is no standing water
- Absence of pollution from leached and washed Nitrate.
- Reduced humidity in micro climate .
- Lower mosquito population in the ecosystem as there is no standing water.
- Improves human health.
- More sustainable production of Rice.
Integrated Pest Management for Rice under drip irrigation
- Seed treatment with Pseudomonas fluorescens @ 10 gm/kg of seed
- Nursery – Application of Neem Seed Kernel extract (NSKE)@ 5% or neem oil 2 %
- Seedling dipping in Pseudomonas fluorescens @2.5 kg/ha
- Adoption of cultural practices
- a) Selection of Variety
- b.) Removal and burning of stubbles of previous crop.
- c) Spacing based on season, variety and location
- d) Leave Rogueing space of 30cm for every 2.5 mtr.
- Use of Pheromone traps for rice stem borer @ 4 per acre.
- Use of light traps for monitoring of pests.
- Release of bio control agents : Trichogramma japonicum for stem borer @ 5 card/ha at weekly interval for 3 times on 28 DAT onwards and Trichogramma chilonis for leaf folder @ 5 card/ha at weekly interval for three times on 42 DAT onwards.
Jain Irrigation Systems Ltd