EFFECT OF SRI AND AWD TECHNOLOGY IN COMPARISON TO TRADITIONAL METHODS ON YIELD CONTRIBUTING CHARACTERS OF RICE ( ORYZA SATIVA )

ABSTRACT


INTRODUCTION
Rice (Oryza sativa) is a starchy cereal grain and belongs to the family Poaceae (Britannica, 2022).It is a notified crop of Bangladesh.It is a dominant staple food crop not only for this country but also for the world.More than 3.5 billion people eat rice as main food (CGIAR, 2016).Huge amount of water is needed for its production where 97% of water is needed for irrigation purpose.Cultivation of rice is well-suited to regions and countries with high rainfall, as it requires ample water.Globally rice production has enlarged from 605 million ton(s) in 2004 to 696 million ton(s) in 2010, wherever 90% of rice is produced & consumed in Asia continent (FASTAT, 2010).Rice is the staple food for more than half of the world's population (Gowda et al., 2003).It contributes nearly 20 percent of the gross domestic product (GDP) and providing about one-sixth of the national income of Bangladesh.Over 90% of the world's rice is produced and consumed in the Asian region with 6 countries viz.China, India, Indonesia, and Bangladesh accounted for 80% in the world's production and consumption (USDA, 2016;Abdullah et al., 2015).
Bangladesh is an agro-based country where agricultural productions contribute about 20% of Gross Domestic Product (BBS, 2010).Among the agricultural products only rice is contributing to about 71% of total agro based production in Bangladesh (Sahid, 2011).Rice is not only the staple food for the entire population of Bangladesh but also one of the main sources of economic engagement of the rural people.About 75 percent of agricultural land is used for rice production in Bangladesh.The seasons of rice cultivation in Bangladesh are summer (Aus), monsoon (Aman) and winter (Boro).In winter season the major rice crop Boro (about 55.2% of the total annual rice production in Bangladesh (BBS, 2019), is transplanted and in summer season at its reproductive stage it faces high temperature.in future rice crop will be more affected with amplified temperature (Karim et al., 2012).The demand of food is increasing as because of increasing the population in the world.Thus, food production needs to be increased about 70% to meet up the global food demand by 2050 (Muthaya et al., 2014).
Rice production is increased every year but the annual increases have generally been modest.Rice production exceeded 15 million tons for the first time in FY 1986.In the mid-1980s, Bangladesh was the fourth largest rice producer in the world, but its productivity was low compared with other Asian countries, such as Malaysia and Indonesia (FAO, 2015).High yielding varieties of seed, application of fertilizer, and irrigation have increased yields, although these inputs also raise the cost of production and chiefly benefit the richer cultivators.About 3000-4000 liter of water is needed to produce one kg of rice as an aquatic plant (Hoekstra, 2008).Out of total water utilization 97% of water is used for irrigation purpose and our irrigation coverage is about 46% of total land.In Bangladesh 78% irrigation is dependent on ground water (GW) resources though surface water is most sweated for crop production.Due to unavailability of surface water more than 70% of irrigation is dependent on ground water (GW) (Sattar et al., 2009).The presence of essential nutrients for plants and organic matter are leaching out through this irrigation water.
Soil health is extensively suffered due to excessive irrigation.
Contamination of arsenic in Ground Water is an effect of excess withdrawal of ground water.On the other hand, every year a huge quantity of water is extracted for irrigation by different means i.e.Deep Tube well (borehole) DTW, Shallow Tubewell (STW), and Low Lift Pump (LLP) etc.Moreover, recurrent invention of new high yielding varieties is creating an adverse effect in the environment because sometimes highly intensive care (e.g., irrigation, fertilization, pesticide applications) is needed for cultivation of these varieties.In the long run environmental imbalance will appear.Considering the mentioned problems above utilization of ground water in irrigation could be minimized by adopting the improved technologies to reduce the production cost with increased yield, savings of national power, and conservation of soil health as well as the protection of environmental degradation.Over the past years, much more public and political attention has been given to current and future water-related problems.
Concerning Agriculture, efficient use of water in irrigation system is the important issue not only in Bangladesh but also over the globe.The vast challenges ahead concerning water and food necessitate exploring water saving rice technology in our country.The System of Rice Intensification (SRI) technique is a system of rice production.In this way, certain management operations is involved in providing better growing condition for rice plants, specifically in the root zone.The SRI technique becomes apparent to have potential in irrigated rice to defeat the scarcity of water.SRI is maintained by following some steps like 8-12 days old seedlings are transplanted carefully, wider spacing (e.g. 25 cm X 25 cm), alternate wetting & dry method rather than flood irrigation.Potential is stored in seedlings in case of tillering and rooting ability.
Alternate wetting and drying (AWD) skill is a pioneering water (irrigation) saving system which consents producers to sustain rice grain yields and handsome economic returns.AWD technique is a modern farming method of rice which prevents the depletion of water assets, irrigation cost and protects the soil from degradation.AWD technique is a necessity for modern farming of rice as it is profitable over the continuous flooding irrigation system which prevents the wastage of scarce and vital water resources, irrigation cost and protects the environment from degradation (Subedia and Poudel, 2021).Rice and other crop cultivation pattern and management practices may need to be adjusted with the present practices i.e.Alternate Wetting & Drying (AWD) method; Raised bed farming and System of Rice Intensification (SRI) etc. (Paliset et al., 2014;Lampayan et al., 2014;Rejesus et al., 2013;Uphoff, 2001;Laulanie, 1993).
Under the above circumstances, now it's a burning question how to save our ground water, natural resources, input cost and to increase yield with existing variety.Application of some improved technology for cultivation can help to increase yield, reduce production cost, proper utilization of national resources and save ground water to maximum level.Rural Development Academy, Bogura had taken a project on rice for the best utilization of ground water in irrigation & adopting the improve technologies to reduce the production cost with increased yield.

Location of The Experiment
The project was conducted in 5 Upazillas (3 in Mowlovibazar and 2 in Sylhet district) of Sylhet division of Bangladesh.

Time Duration of Rabi Season
Mid November to 30 April in the year of 2017-18 and 2018-19

Technology Used.
Two different types of modern technology were used where only two namely SRI (Less water, fewer plants and more rice) system and AWD (Alternate wetting and drying) system were implemented in two districts of Sylhet division.Rice varieties BRRI dhan 28 and BRRI dhan 29 are well recognized cultivar in Bangladesh.

System of Rice Intensification (SRI)
The system of Rice intensification (SRI) was established to invent sustainable agricultural practices.It can make possible higher productivity, best use of capital labor, low input cost and a reduced amount of necessity of water (Toungos, 2018).The System of Rice Intensification (SRI) is started in Madagascar in the early 1980s.In SRI, rice plants are transplanted early, after just 8-12 days old in an un-flooded nursery, and they are planted singly, rather than in clumps.In case of boro rice, 20-25 days old seedlings are used.Planting is done in a square pattern (25x25 cm) or relatively wide spacing (25-30 cm) between plants in good quality soil (Plate 1).This increases the sunlight each receives and gives roots more room to grow.Fields are ideally kept damp rather than completely flooded, creating a more aerated environment, which promotes root development and diversity of soil organisms.SRI seedlings are planted in a square grid, weeding along and across the rows is possible, also giving better soil aeration.This practice boosted plant vigour, eliminating competition from weeds and encouraging the infiltration of moisture and nutrients into the root zone.
Plate 1: SRI Management Practices

Alternate Wetting and Drying (AWD)
In this process, lowland rice fields are prepared for the transplantation of seedlings by soaking, ploughing, and puddling (Pearson et al., 2018).Following this process, the rice field is flooded with irrigated water for 4-5 days.Before re-irrigation the rice crop field is allowed 3-4 days for drying.14-21 days old seedlings are transplanted into puddle soil in this system and are kept a standup water layer (5 cm) in the rice growing ground.A poly venial chloride (PVC) pipe is fixed having length (40 cm) and diameter (20 cm) with 5-6 mm diameter holes spaced at 2 cm.Ground water levels is monitored after transplanting.After 10 days of transplanting, AWD method is being started and is being waited until the rice field is dried out.When the groundwater is 16-20 cm beneath the soil apparent the field is re-inundated to a vertical water layer of 4-5 cm.standing water layer (5 cm) is kept for 1 week at flowering stage.This process is continued (AWD cycles) after flowering until harvest (Plate 2).

RESULTS AND DISCUSSIONS
Two technologies namely SRI (System of Rice Intensification (Less water, fewer plants, more rice) and Traditional were compared for production of rice in two districts of Sylhet division (Table 1).It was observed that technology SRI has excellent effect on plant height, no. of tiller and no. of effective tiller which were higher than that of traditional method used.20-50% rice yields can be increased by following SRI method and lessen the uses of irrigation water by 25-50% (Anonymous, 2012).Underground and surface water resources are lessening which is a warning factor in rice production (Farooq et al., 2009).In comparison to other cereal crops in flooded soils traditional rice cultivation demands an elevated amount of water (Pimentel et al., 2004).To save irrigation water use in the rice field, a water management technique was developed by IRRI which is called alternate wetting and drying (AWD) (Bouman and Tuong 2001).
Agriculture is the main stay in Bangladesh and more than 100 different crops are grown in the country.Of the total cropped areas, rice alone occupies 72.5% (Fakir and Karim, 1999).In Mowlovibazar district, average plant height, no. of tiller and no. of effective tiller were 99.92 cm, 31.72 and 30.36, respectively which were much higher that traditional method (94.22 cm, 23.80 and 21.46, respectively) used.The same trend was followed in case of Sylhet district which were 93.25 cm, 34.75 and 32.95, respectively using SRI technology and 85.60 cm, 16.60and 15.05, respectively using traditional method.If we compare between these two methods, SRI technology yielded 6.57 cm (96.96-90.39)higher plant height, 12.47 (33.07-20.60)more tiller and 12.90 (31.51-18.61)more effective tiller than that of traditional method in Sylhet Division (Table 1).The cost-returns analysis exposed that the total return of total cost was higher in SRI method than in conventional method (Haldar et al., 2012).2).These results were also sustained by where they found higher number of effective tillers in SRI than CM (Vijayakumar et al., 2006;Krishna et al., 2008;Udaykumar, 2005).A group researchers observed similar results in SRI technique over conventional method (CM) of transplanting rice where 250.04% higher tillers found in SRI than conventional methods (Mondol et al., 2017).Similar research findings were also reported by (Mondol et al., 2017;Biswas et al., 2013;Thakur et al., 2011;Latif et al., 2005).They clarified that longer panicle of SRI might be due to higher dry matter accumulation, higher photosynthetic rate and better utilization of nutrients.A group of researchers observed a higher number of grains per panicle (Ali et al., 2013).Similar results on grain per panicle were also observed (Mondol et al., 2017;Thakur et al., 2011).A group researcher reported 15.65% higher grain yield in SRI over traditional method.
Considering irrigated water used in two technologies, it was observed that traditional method need comparatively more water than that of SRI technology (Figure 1).
In Mowlovibazar district, 409,000 liters (2678000-2269000) more water was used by traditional method where it was 636,250 liter (2688750-2052500) in Sylhet district for cultivation of rice.In Sylhet division, 509,999.98 liter (2682777.78-2172777.80)more irrigated water was used for rice production in Rabi/2017-18 (Table 3).Rice is an aquatic plant and 97% of water is used for irrigation purposes.Utilization of ground water in irrigation could be minimized by adopting improved technologies to reduce the production cost with increased yield and saving of national power.From our study, we observed that SRI technology not only increased yield but also saved irrigated water over traditional methods.Similar results were also found (Narayanamoorthy and Jothi, 2019).They reported that about 40% irrigation water were saved by SRI method and reduced 23% cultivation cost over traditional method.Similar research findings were also reported in different countries where 40% in Indonesia, 67% in Philippines and 25% in Sri lanka over traditional methods used for rice cultivation (Nemoto et al., 1995;Lazora, 2004;Sato, 2006).
In Rabi/2018-19, technology AWD (Alternate Wetting and Drying) and Traditional were used as comparison for rice cultivation in two districts of Sylhet division (Table 4).It was observed that technology AWD increased plant height, no. of tiller and no. of effective tiller than that of traditional method.In Mowlovibazar district, average plant height, no. of tiller and no. of effective tiller were 101.24 cm, 29.80 and 26.40, respectively which were much higher than traditional method (95.80 cm, 20.20 and 17.48, respectively) used.The same trend was found in the case of Sylhet district which were 95.68 cm, 31.00 and 27.55, respectively using AWD technology and 91.85 cm, 20.75 and 17.85, respectively using traditional method.If we compare between these two methods, SRI technology yielded 4.73 cm (98.77-94.04)higher plant height, 9.89 (30.33-20.44)more tiller and 9.27 (26.91-17.64)more effective tiller that were significantly higher than that of traditional method in Sylhet Division (Table 4).The results are supported (Rahman and Bulbul, 2014;LaHue et al., 2016;Oo et al., 2018).gm and 18.30 monds per bigha, respectively.In the case of Sylhet district, AWD showed same trend in all parameters compare to traditional method (Table 5).From the result it was revealed that AWD gave significantly better response in all the parameters than that of traditional methods for both varieties in two districts of Sylhet division.
AWD technology enhanced 3.24 cm (27.13-23.89) panicle length, 24.69 (168.69-144.00) no. of grain per panicle, 1.31 gm (26.28-24.97)1000 grains wt. and 2.21 monds (20.32-18.11)higher yield than that of traditional method (Table 5).The results are supported by many researchers (Oo et al., 2018;LaHue et al., 2016;Thakur et al., 2011).Rahman and Bulbul (2014) observed that a higher number of effective tillers and higher grain yield of rice were found in AWD than continuous submergences at BRRI, Gazipur.Higher yields were also found by AWD over conventional method used reported (Zhao et al., 2009).Regarding irrigated water used in two technologies, more water was used in traditional method than that of AWD technology (Figure 2).AWD technology could save irrigated water in rice production.In Mowlovibazar district, 360,000 liter (2496000-2136000) more water was used as irrigated water by traditional method where it was 260,000 liter (2977500-2717500) in Sylhet district for cultivation of rice.In Sylhet division, 315556 liter (2710000-2394444) more irrigated was used for rice production in Rabi/2018-19 (Table 6).The results were supported by who reported that 22.4 to 34.6% water could be saved by AWD technology (Linquist et al., 2015;Prince et al., 2013).A group researchers reported that AWD was a promising method of water management compared with the conventional system of rice cultivation (Awio et al., 2015).
Modern farming technologies viz.SRI and AWD increased yield over use of traditional technology (Table 7).In Mowlovibazar district 8.05% more yield were obtained from using of SRI technology over traditional method and 14.69% more yield in Sylhet district.On average 11.52% higher yield was obtained in Rabi/2017-18 in Sylhet division over the use of traditional method.The similar trend was also followed by using of AWD technology during Rabi/2018-19 where 14.43% more yield was obtained in Mowlovibazar district and 9.34% in Sylhet district and on an average 12.20% higher yield was obtained over use of traditional technology during Rabi/2017-19.

Figure 1 :
Figure 1: Irrigated water used for rice cultivation using two different technologies in two districts of Sylhet division.

Figure 2 :
Figure 2: Irrigated water used for rice cultivation using two different technologies in two districts of Sylhet division during Rabi/2018-19

Table 1 :
Effect of SRI and Traditional Technology on Growth Contributing Characters of Rice in Sylhet Division during Rabi/2017-18

Table 2 :
Effect of SRI and Traditional Technology on Yield Contributing Characters of Rice in Sylhet Division during Rabi/2017-18

Table 3 :
Effect of SRI and Traditional Technology on Usages of Irrigated Water to Produce Rice in Sylhet Division during Rabi/2017-18

Table 4 :
Effect of AWD and Traditional Technology on Growth Contributing Characters of Rice in Sylhet Division during Rabi/2018-19Regarding yield contributing characters, AWD technology has good effect that increased panicle length, no. of grain per panicle, 1000 grains weight and yield compared to traditional method.In case of Mowlovibazar district, average panicle length, no. of grain per panicle 1000 grain weight and yield were 28.60 cm, 170.40, 26.40 gm and 20.94 monds per bigha, respectively and in traditional method, these were 24.68 cm, 146.60, 25.74

Table 5 :
Effect of AWD and traditional technology on yield contributing characters of rice in Sylhet division during Rabi/2018-19

Table 6 :
Effect of AWD and traditional technology on usages of irrigated water to produce rice in Sylhet division during Rabi/2018-19