Issues & Opportunities
Issues associated with DSR and potential opportunities for DSRC to contribute in realizing the full potential of DSR technology in Asia
Crop establishment risk: Risk of poor and uneven crop stand if field get inundation during early germination/emergence phase due to rain or poor leveling.
Risk management: To evaluate the performance of anaerobic germination tolerant rice (developed by IRRI) in reducing the risk of seedling mortality due to early field inundation caused by rain or due to poor leveling of fields.
High seed rate: Most farmers establish DSR by broadcasting method using high seed rate ranging from 100-300 kg/ha. Farmers mostly use their own saved seeds in DSR. Current use of high seed rate is one of the bottlenecks in the investment of good quality seeds and hence the adoption of quality seeds of inbred or hybrid is low in DSR.
Mechanized and precise planting using low seed rate: To develop robust mechanized DSR with low seeding rate to enable farmers to use quality inbreds and hybrids in DSR. Also opportunities to optimize and refine technologies such as precise planting, land leveling and seed treatment to adapt to local conditions. Results from India, China, and Cambodia on mechanized dry DSR and wet-DSR suggest that high yields can be achieved with low seed rate (20-25 kg/ha).
Weed management: Many weed-related issues have emerged in DSR including higher weed infestation leading to the risk of higher yield losses, evolution of herbicide resistance in weeds, a shift in weed flora towards difficult-to-control weeds such as weedy rice, Leptochloa chinensis, and Ischaemum rugosum, and poor efficacy of herbicides because of poor application technologies.
Integrated weed management: To develop, refine and catalyze dissemination of IWM practices including (1) identifying innovative solutions for weedy rice and other emerging weed problems (e.g. herbicide resistance); (2) decision tools for accurate recommendation, (3) identifying new herbicides for broad-spectrum weed control, (4) exploiting the potential of anaerobic germination tolerant rice for weed suppression, (5) integrating mechanical tools, and (6) precision application methods and safe handling to improve herbicide efficacy and human safety.
Water management: DSR is an establishment method and water saving will depend on irrigation scheduling criteria and methods. Significant work has been done on irrigation scheduling in PTR but not much in DSR.
Precision water management: To develop irrigation scheduling decision tool for DSR based systems. Also to evaluate and refine microirrigation (e.g. sprinkler or drip) and fertigation management.
Nutrient management: Key issues in fertilizer management include inefficient fertilizer application method, low fertilizer use efficiencies, and higher micronutrient deficiencies (Fe and Zn) and emission of N2O- a greenhouse gas, especially in dry-DSR.
Precision nutrient management: Improving efficiencies of fertilizer use by applying SSNM principles, using more efficient fertilizer formulations (e.g. slow/controlled release fertilizers) and precise application methods, developing solutions for emerging micronutrient deficiencies, and developing effective water and nutrient management strategies to reduce emission of both methane and N2O from DSR to minimize the negative impact on environment.
Cultivars: cultivars used in DSR are mainly bred for transplanted conditions. To realize the full potential of DSR, cultivars which are better adapted to DSR need to be identified.
Appropriate cultivars: Testing of existing and new superior rice cultivars (inbreds or hybrids) to identify cultivars which are more adapted to DSR. Breeding for DSR (development of new cultivars) is not within the scope of DSRC. Some of the desirable traits for DSR include anaerobic germination tolerance, early vigor with quick and uniform emergence, weed competitive, shorter duration with high yield potential and lodging resistant.
Access to services: Majority of farmers in Asia are small and poor, therefore access to new mechanized and precision agriculture technology is limited as these are capital intensive and farmers cannot afford.
Strengthening service economy: supporting and strengthening the service economy of scale-appropriate mechanization and precision agriculture technologies to provide cost-effective access to capital-intensive machinery and technologies.