Hybrid rice generally showed higher grain yield than inbred rice, but its overall performance is largely affected by lodging and lower grain quality. Limited attention has been given to exploring genotypic variation and varietal traits for achieving high yield, superior quality, and strong lodging resistance simultaneously in both inbred and hybrid rice. To address this gap, field experiments with five representative rice varieties from each rice type were conducted in central China in 2020 and 2021. The results showed that the average yield of hybrid rice in 2020 and 2021 was 8.01 and 8.63 t ha-1, representing a significant increase of 10.3 and 13.4% compared to inbred rice, respectively. Importantly, hybrid rice showed comparable grain quality and lodging resistance to inbred rice. Substantial genotypic variation was observed among the varieties for yield, grain quality, and lodging-related traits. Efengsimiao (inbred) and Jinliangyou 534 (hybrid) showed the most balanced and superior agronomic performance within each variety type. Key traits associated with the integration of high yield, superior quality, and strong lodging resistance included high spikelets per unit area, low grain length-width ratio, and short basal internode. These findings highlighted the potential for selecting and breeding rice varieties that optimized multiple desirable traits, offering a promising strategy to meet growing food demands in both quantity and quality.
Pesticide poisoning is widely accepted as a major public health problem in low- and middle-income countries, especially in East Africa. However, a very high proportion of unintentional poisonings are either unreported or misreported. To help fill this knowledge gap, we investigated the scale of unintentional acute pesticide poisoning (UAPP) in cotton-growing communities in Tanzania by conducting a cross-sectional survey of 1074 cotton farmers or farm workers. The findings from this study revealed a high incidence of self-reported negative health effects following occupational pesticide exposure, with 48% of respondents experiencing symptoms of UAPP within the previous 12 months. Furthermore, the substantial proportion of UAPP incidents were associated with a few highly hazardous pesticides (HHPs), particularly profenofos, lambda cyhalothrin, and co-formulations with both chlorpyrifos and cypermethrin. Of those reporting UAPP, only 6% sought medical treatment in a formal healthcare setting. The findings from this study clearly indicates an urgent need for improved pesticide regulation, the scale up of community surveillance, and the promotion of less hazardous alternatives to the use of HHPs. We provide policy recommendations and identify alternatives to HHPs for cotton pest management.
Site-specific nutrient management (SSNM) for a rice ( Oryza sativa L.)-growing domain is typically developed by first using the nutrient omission plot technique (NOPT) to determine yield responses with added nitrogen (N), with added phosphorus (P), and with added potassium (K) and then conducting an evaluation experiment to verify an SSNM practice developed from the NOPT results. We hypothesized that an effective SSNM practice could be more rapidly developed through concurrent NOPT experiments and evaluation of a preliminary best-bet SSNM practice derived from experiences in other rice-growing domains. Our study domain was rainfed lowland rice in an Indonesian tidal swampland without past NOPT experiments and without a verified SSNM practice. Concurrent NOPT and evaluation experiments were conducted in the wet season (WS) and dry season across 20–25 farmers’ fields either directly or not directly influenced by tides. Rice yields and gross return above fertilizer cost for a preliminary SSNM practice were higher than for farmers’ fertilizer practice in both seasons and for two fertilizer practices based on soil tests in WS. The inherent ability of SSNM to adjust fertilizer rates for an attainable target yield and time fertilizer applications to match crop demand contributed to the superiority of SSNM. In NOPT experiments, relative yields without added N, without added P, and without added K respectively averaged 0.70, 0.89, and 0.88 across seasons and tidal locations. These relative yields enabled preliminary SSNM fertilizer rates to be further adjusted for the rice-growing domain. Rice growers in domains without a verified SSNM practice can benefit, before NOPT experiments are completed, by using generic SSNM guidelines for timing fertilizer applications and adjusting fertilizer rates for a target yield. After completion of NOPT experiments, the fertilizer rates can be further adjusted based on measured yield responses with added N, P, or K.
BACKGROUNDThe mechanisms that regulate multi-annual population dynamics of rodent pest species of cereal crops is often unknown. Better knowledge of such aspects can aid pest management and in turn improve food security and human health. The patterns and processes of the population dynamics of Rattus argentiventer, in rice fields of Indonesia, and Rattus tanezumi, in rice fields of the Philippines were assessed in this article. RESULTSThe meta-analysis of trapping data over 20 years in Indonesia, and 16 years in the Philippines indicated that rodent populations in rice fields did not show a regular multi-annual pattern. Rattus argentiventer populations in Indonesia responded to less rainfall from the current year. Rattus tanezumi populations in the Philippines responded positively to both rainfall and rainfall anomaly with a 1-year time lag. CONCLUSIONSOur study of long-term population data indicates that certain combinations of rainfall parameters could be useful to predict years when there is higher rodent abundance in rice fields. The key rodent pest species in rice fields in Indonesia (R. argentiventer) and the Philippines (R. tanezumi) differ, and the populations of each species respond differently to rainfall anomalies. Other factors such as crop cover and water availability may also be important and should be considered in future work. (c) 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Metal phosphides, particularly aluminium phosphide (AlP) and zinc phosphide (Zn3P2), are widely used in low- and middle-income countries (LMICs) as rodenticides in urban and domestic environments due to their low cost and high toxicity to rodent pests. However, they are also highly toxic to humans with no antidote available and have been associated with numerous fatal cases of intentional and accidental poisoning. This paper reviews alternatives to metal phosphide use for rodent pest management in urban and domestic environments, highlights case studies of effective alternative approaches, and provides recommendations for research and policy. This review identifies numerous alternative methods available for managing rodent pests in domestic/urban settings that can replace metal phosphides. These include chemical methods, i.e. rodenticides, and non-chemical methods, e.g. rodent-proofing, sanitation and trapping. However, because the majority of chemical rodenticides qualify as highly hazardous pesticides due to acute human health toxicity, environmental toxicity, and/or bioaccumulation, simply selecting substitute chemical rodenticides to replace metal phosphides are likely to replace one set of hazards with others. Thus, careful risk and hazard assessments are needed when considering substituting with other chemicals. Overall, we need to move away from current levels of rodenticide reliance towards more integrated and ecologically based approaches.
A small proportion of the thousands of pesticides on the market today are associated with a disproportionately high incidence of severe acute pesticide poisoning and suicide. Paraquat stands out as one of the most lethal pesticides in common use, frequently involved in fatal incidents due to suicides or accidental exposure. Even though paraquat has been banned in over 67 countries, it is still widely used in many others, particularly in Asia and Latin America. Based on a literature review and consultations, this paper identifies options for replacing paraquat and distils practical lessons from numerous successes around the world. Our aim is to support regulators, policymakers, agronomists and the supply chain sector with practical information related to phasing out paraquat. Production data consistently failed to show any negative effects of banning paraquat on agricultural productivity. A wide range of alternative approaches to weed management and crop defoliation are available, many of which do not rely on herbicides. Over 1.25 million farmers in low- and middle-income countries (LMICs) successfully produce a range of crops for private voluntary standards (PVS) in food and fiber supply chains which prohibit paraquat use. We conclude from the findings of this study that eliminating paraquat will save lives without reducing agricultural productivity. Less hazardous and more sustainable alternatives exist. To enhance successful adoption and uptake of these methods on a wide scale, farmers require training and support within an enabling policy environment.
How can we reach farmers with ecologically-based Integrated Pest Management (IPM) while creating a supportive context for adoption by farmers and relevant stakeholders? We assessed a new method – Adaptive Learning Networks – from reflections of varied stakeholders, farmer diaries and survey data procured in 2016 and 2019. This method is different from current IPM approaches, in that an explicit focus of learning was on engaging other stakeholders to enable adoption by farmers. For example, access to IPM products, providing new services and creating new policies were intrinsically part of the learning process, alongside learning on-farm IPM techniques. The main consideration is to ease farmers from being locked into the practice of pesticide reliance. The method facilitated multi-stakeholder learning that led to an adaptation of the IPM tools and techniques in the case examined. The priority of this new method was socio-technical learning, wherein varied stakeholders modify interactions, incentives and arrangements relating to pest management. Comparing 2016 and 2019 data, there was a significant reduction in insecticide, herbicide, and rodenticide applications. The observed outcomes indicate the potential to enable a wider spread of IPM technologies.
Context: Fertilizer recommendations for rice (Oryza sativa L.) in Asia often split a predetermined amount of N into several applications to match N supply with anticipated crop demand for N. Within-season deviations from anticipated N demand could necessitate mid-season adjustments in N applications to ensure closure of exploitable yield gaps.Objective: We hypothesized that application of additional fertilizer N to satisfy an underestimated crop demand for N could be delayed until two weeks after panicle initiation without a yield penalty. We additionally examined whether effects of mid-season N adjustments on rice differed between two plant spacings with different plant populations.Methods: Field experiments with irrigated, transplanted rice were conducted at two sites in two seasons in North Sumatra, Indonesia. The experimental design was a factorial combination of two rice cultivars, two plant spacings, and seven N treatments. Results: Rice growth and yield components sometimes differed between equally spaced rows (square planting) and alternating narrow and wide rows (legowo), but grain yield with legowo consistently matched and sometimes exceeded yield with square planting. Effects of N treatments - with varying rates and split applications of N - on yield were comparable across the two plant spacings and two cultivars. A predetermined fertilizer recommendation with three split applications of N underestimated the N needed for high yield in all experiments. Application of 30 kg ha-1 more N than the recommended 155 kg ha-1 in dry season (DS) and 125 kg ha-1 in wet season (WS) increased yield by up to 0.5 Mg ha-1 in DS and 0.7 Mg ha-1 in WS and consistently increased net income in both seasons. Additional N at tillering in DS increased vegetative biomass but not yield. Additional N in both seasons could be delayed until 12-14 days after panicle initiation for highest yield.Conclusions: Our study represented circumstances where a fertilizer recommendation provided to farmers before a growing season merited an upward mid-season adjustment in N rate to achieve higher yield. The upward midseason N adjustment of 30 kg ha-1 in our study could be delayed until two weeks after panicle initiation with no yield penalty in both seasons, for both cultivars, and for both equally spaced rows and alternating narrow and wide rows of transplanted rice. Implications: Farmers and advisory services using crop and/or weather monitoring to identify fields meriting additional mid-season N can delay the application of additional N until panicle initiation or two weeks after panicle initiation.
Rice production in the Central Plains of Thailand plays a key role in the country’s food security. However, the overuse of inputs coupled with the rising production costs are making it increasingly difficult for smallholder rice farming to remain economically and environmentally sustainable. Replicated production-scale field trials of Cost Reduction Operating Principles (CROP)—Thailand’s national package of best management practices for rice production—were established in tandem with laser land leveling (LLL), mechanical drum seeder, and the application of two biofertilizer products (i.e., PGPR II, that contains Azospirillum brasilense Sp. TS29 and Burkholderia vietnamiensis S45; and LDD #12, that contains Azotobacter tropicalis, Burkholderia unamae and Bacillus subtilis) and compared with farmer’s practices (FP). Performance indicators (PI) promoted by the Sustainable Rice Platform (SRP) were used to assess economic and environmental indicators. CROP + PGPR had significantly higher net income (79%) and nitrogen-use efficiency (57%) compared with FP. Pesticide use (28%), seed (60%), inorganic fertilizer N (41%) and total production costs (19%) were reduced in all CROP treatments compared with FP. These results demonstrate that the application of CROP, LLL, mechanical drum seeder, and biofertilizers can substantially improve the economic and environmental sustainability of rice production in the Central Plains of Thailand.
AbstractRice agriculture provides wetlands and complex habitats supporting biodiversity. Wetlands associated with rice agriculture since the 1960s have increased by 32% and now form nearly 12% of wetlands globally at a time when vast areas of natural wetlands are being lost. In this chapter, we set our sights beyond Sustainable Development Goal (SDG) 2 that focuses on ending hunger and achieving food security via the promotion of sustainable agriculture. Often, agricultural scientists are so motivated to achieve food security that they pay insufficient attention to the need to have a healthy and dynamic agroecosystem that promotes floral and faunal biodiversity, which may also provide ecosystem services including support for food security of smallholder families. Because of their aquatic, semi-aquatic, and terrestrial ecological phases, rice fields represent a changing mosaic of ecological niches and have the potential to sustain a broad diversity of wildlife. In addition, a multitude of studies have investigated how modifications to rice cultivation have the potential to support a greater diversity of species across biological scales while often maintaining or increasing yield. SDG 15 emphasizes the need to promote sustainable use of terrestrial ecosystems and halt biodiversity loss. Given the high losses in global biodiversity, especially in tropical zones where most of the world’s rice is grown, we set our sights on achieving both SDGs 2 and 15. We provide case studies on amphibians, bats, birds, and rodents living in and around irrigated rice-cropping systems. We report on transdisciplinary studies supported by CORIGAP that include agronomic, sociological, ecological, biochemical, environmental physiological, and genomic studies. Most of these studies identify potential positive ecosystem services provided by wildlife, which can lead to more sustainable and healthier rice production landscapes. We conclude that our current management of rice landscapes contributes to the biodiversity crisis. Rice production often overuses pesticides and fertilizers and applies unsustainable intensification practices and land modifications, which result in biodiversity loss. Finding a balance, where human population requirements for food are met without degrading the natural environment, is critical to the health of smallholder agricultural communities. We propose that future research and development projects need to: build capacity of countries to scale-up use of proven practices that reduce rice farming’s ecological footprint and conserve biodiversity, increase investment in biodiversity research in rice production landscapes, promote Green “Rice Value Chains” and “Agri-input Markets,” and monitor and evaluate the ecological benefits to biodiversity of broadscale promotion of sustainable rice production.
Rice is the dominant food staple and an important economic resource throughout Asia. Lowland rice production also provides important wetland habitats in support of biodiversity that may provide ecosystem services back to the rice agroecosystem. This review summarizes the literature on the ecosystem benefits that amphibians, birds, bats, and rodents support in the context of the Southeast Asia rice agroecosystem. The literature provides evidence that these taxonomic groups contribute to cultural, regulatory, and provisioning services in support of smallholder farmers and may allow for economic benefits through reduced use of chemical inputs into crops. We encourage a community-based participatory research approach to bring stakeholders together to provide structured and scalable education programs that will lead to improved human and agroecosystem health through the promotion of understanding the positive feedbacks from biodiversity in these important agricultural wetland habitats.
BACKGROUND:Trapping is a key method for monitoring small mammals and is also one of a number of methods recommended under an ecologically-based rodent management program to control rodent pest populations. Live-traps are widely used globally for studying small mammal populations. In Asia where rodents are major pests of rice, single capture traps typically provide low trap success. We compared the trap success between two types of live-traps in rice fields in Indonesia and the Philippines. RESULTS:Multiple-capture traps (MCTs) in conjunction with a linear trap barrier were significantly more effective in catching rodent pest species than single-capture traps (SCTs) in Indonesia and the Philippines. In Indonesia, MCTs captured more individuals with a mean (±SE) percent trap success rate of (15.54 ± 4.29) compared to SCTs (3.88 ± 1.58). In the Philippines, MCTs captured more species of rodents and had a significantly higher recapture rate (1.96 ± 0.79), than SCTs (0.58 ± 0.32). CONCLUSION:Multiple-capture traps with a linear trap-barrier were more effective for capturing Rattus argentiventer and Rattus tanezumi in rice field ecosystems compared to single-capture traps. MCTs captured more species of rodent pests in the Philippines and recaptured more individuals of each species. These results indicate that rodent populations can be more effectively monitored and controlled by using a multi-capture trap with barrier system than the use of single capture traps on their own. This is the first time these two trap types have been compared for use in rice ecosystems in Asia. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
CONTEXT: Recent studies on yield gap analysis for rice in Southeast Asia revealed different levels of intensification across the main 'rice bowls' in the region. Identifying the key crop management and biophysical drivers of rice yield gaps across different 'rice bowls' provides opportunities for comparative analyses, which are crucial to better understand the scope to narrow yield gaps and increase resource-use efficiencies across the region. OBJECTIVE: The objective of this study was to decompose rice yield gaps into their efficiency, resource, and technology components and to map the scope to sustainably increase rice production across four lowland irrigated rice areas in Southeast Asia through improved crop management.METHODS: A novel framework for yield gap decomposition accounting for the main genotype, management, and environmental factors explaining crop yield in intensive rice irrigated systems was developed. A combination of crop simulation modelling at field-level and stochastic frontier analysis was applied to household survey data to identify the drivers of yield variability and to disentangle efficiency, resource, and technology yield gaps, including decomposing the latter into its sowing date and genotype components.RESULTS AND CONCLUSION: The yield gap was greatest in Bago, Myanmar (75% of Yp), intermediate in Yogyakarta, Indonesia (57% of Yp) and in Nakhon Sawan, Thailand (47% of Yp), and lowest in Can Tho, Vietnam (44% of Yp). The yield gap in Myanmar was largely attributed to the resource yield gap, reflecting a large scope to sustainably intensify rice production through increases in fertilizer use and proper weed control (i.e., more output with more inputs). In Vietnam, the yield gap was mostly attributed to the technology yield gap and to resource and efficiency yield gaps in the dry season and wet season, respectively. Yet, sustainability aspects associated with inefficient use of fertilizer and low profitability from high input levels should also be considered alongside precision agriculture technologies for site-specific management (i.e., more output with the same or less inputs). The same is true in Thailand, where the yield gap was equally explained by the technology, resource, and efficiency yield gaps. The yield gap in Indonesia was mostly attributed to efficiency and technology yield gaps and yield response curves to N based on farmer field data in this site suggest it is possible to reduce its use while increasing rice yield (i.e., more output with less inputs).SIGNIFICANCE: This study provides a novel approach to decomposing rice yield gaps in Southeast Asia's main rice producing areas. By breaking down the yield gap into different components, context-specific opportunities to narrow yield gaps were identified to target sustainable intensification of rice production in the region.
Southeast Asia is a major rice-producing region with a high level of internal consumption and accounting for 40% of global rice exports. Limited land resources, climate change and yield stagnation during recent years have once again raised concerns about the capacity of the region to remain as a large net exporter. Here we use a modelling approach to map rice yield gaps and assess production potential and net exports by 2040. We find that the average yield gap represents 48% of the yield potential estimate for the region, but there are substantial differences among countries. Exploitable yield gaps are relatively large in Cambodia, Myanmar, Philippines and Thailand but comparably smaller in Indonesia and Vietnam. Continuation of current yield trends will not allow Indonesia and Philippines to meet their domestic rice demand. In contrast, closing the exploitable yield gap by half would drastically reduce the need for rice imports with an aggregated annual rice surplus of 54 million tons available for export. Our study provides insights for increasing regional production on existing cropland by narrowing existing yield gaps.
Overuse of seed and chemical inputs is a major constraint for sustainable rice production in Vietnam. In this study, two seasons of field trials were conducted to compare different crop establishment practices for rice production in the Mekong River Delta using environmental and economic sustainability performance indicators. The indicators including energy efficiency, agronomic use efficiency, net income, and greenhouse gas emissions (GHGEs) were quantified based on four treatments including manual broadcast-seeding, blower seeding, drum seeding, and mechanized transplanting. Across the four treatments, yields ranged from 7.3–7.5 Mg ha−1 and 6.2–6.8 Mg ha−1 in the Winter-Spring (WS) and Summer-Autumn (SA) seasons, respectively. In comparison with direct seeding methods, mechanized transplanting decreased the seed rate by 40%. It also led to a 30–40% reduction in pesticide use during the main crop season (WS). Mechanized transplanting required higher inputs, including machine depreciation and fuel consumption, but its net energy balance, net income and GHGE were at a similar level as the other non-mechanized planting practices. Mechanized transplanting is a technology package that should be promoted to improve the economic and environmental sustainability of lowland rice cultivation in the Mekong River Delta of Vietnam.
In rice ecosystems, seeding densities can be adjusted to compensate for lower nitrogen levels that reduce GHG emissions, or to increase farm profitability. However, density-induced changes to plant anatomy could affect herbivore-rice interactions, and alter arthropod community dynamics. We conducted an experiment that varied transplanting density (low or high), nitrogenous fertilizer (0, 60 or 150 kg added ha−1) and rice variety (resistant or susceptible to phloem-feeding insects) over two rice-growing seasons. Yields per plot increased with added nitrogen, but were not affected by variety or transplanting density. Planthopper and leafhopper densities were lower on resistant rice and in high-density field plots. Nitrogen was associated with higher densities of planthoppers, but lower densities of leafhoppers per plot. High planting densities and high nitrogen also increased rodent damage. The structure of arthropod herbivore communities was largely determined by season and transplanting density. Furthermore, two abundant planthoppers (Sogatella furcifera (Horváth) and Nilaparvata lugens (Stål)) segregated to low and high-density plots, respectively. The structure of decomposer communities was determined by season and fertilizer regime; total decomposer abundance increased in high-nitrogen plots during the dry season. Predator community structure was determined by season and total prey abundance (including decomposers) with several spider species dominating in plots with high prey abundance during the wet season. Our results indicate how rice plasticity and arthropod biodiversity promote stability and resilience in rice ecosystems. We recommend that conservation biological control, which includes a reduction or elimination of insecticides, could be promoted to attain sustainable rice production systems.
Abstract Future rice systems will need to produce more grain while minimizing the environmental impact. A key question is how to orient agricultural research & development (R&D) programs at national to global scales to maximize the return on investment. Here we assess yield gap and resource-use efficiency (including water, pesticides, nitrogen, labor, and energy) across 32 rice cropping systems, together accounting for 88% of global rice production. We show that achieving high yields and high resource-use efficiencies are not conflicting goals. Most cropping systems have room for increasing yield, resource-use efficiency, or both. In aggregate, current total rice production of these systems can be increased by 36%, and excess nitrogen almost eliminated, by focusing on a relatively small number of cropping systems with large yield gaps and/or poor resource-use efficiencies. This study provides essential strategic insight for prioritizing national and global agricultural R&D investments to ensure adequate rice supply while minimizing negative environmental impact in coming decades.
Rodents present a major problem for food security in Asia where smallholder farming families are particularly vulnerable. We review here recent developments in the biology and management of rodent pests in cereal cropping systems in Asia. The past decade has seen a strong focus on ecologically-based rodent management (EBRM), its adoption in field studies significantly increased rice yields (6-15%) and income (>15%) in seven Asian countries. EBRM principles have also been successfully applied to maize in China. We provide case studies on EBRM in Cambodia, on interactions between rodent pests and weeds, and on the importance of modified wetlands for biodiversity and rodent pest management. Knowledge on post-harvest impacts of rodents is increasing. One research gap is the assessment of human health impacts from a reduction of rodent densities in and around houses. We identify 10 challenges for the next decade. For example, the need for population modelling, a valuable tool missing from our toolbox to manage rodent pests in cereal systems. We also need to understand better the interactive effects of cropping intensification, conservation agriculture and climate change. Finally, new management approaches such as fertility control are on the horizon and need to be considered in the context of smallholder cereal farming systems and mitigating health risks from zoonotic diseases associated with rodents. (c) 2021 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Southeast Asia is a major rice-producing region, with high level of internal consumption and accounting for 40% of global rice exports. Limited land resources, climate change, and yield stagnation during recent years have once again raised concerns about the capacity of the region to meet the growing demand for rice and remain as a large net exporter. Here we use a modelling approach to map rice yield gaps and assess production potential and net exports by 2040. We find that the average yield gap represents 48% of the yield potential estimate for the region. Exploitable yield gaps are relatively large in Cambodia, Myanmar, Philippines, and Thailand, but comparably smaller in Indonesia and Vietnam. Continuation of current yield trends will not allow Indonesia and Philippines to meet their domestic rice demand. In contrast, closing the exploitable yield gap would allow all countries to achieve rice self-sufficiency, with an aggregated annual rice surplus of 100 million tons available for export. Our study provides insights for increasing regional production on existing cropland by narrowing existing yield gaps.
Future rice systems must produce more grain while minimizing the negative environmental impacts. A key question is how to orient agricultural research & development (R&D) programs at national to global scales to maximize the return on investment. Here we assess yield gap and resource-use efficiency (including water, pesticides, nitrogen, labor, energy, and associated global warming potential) across 32 rice cropping systems covering half of global rice harvested area. We show that achieving high yields and high resource-use efficiencies are not conflicting goals. Most cropping systems have room for increasing yield, resource-use efficiency, or both. In aggregate, current total rice production could be increased by 32%, and excess nitrogen almost eliminated, by focusing on a relatively small number of cropping systems with either large yield gaps or poor resource-use efficiencies. This study provides essential strategic insight on yield gap and resource-use efficiency for prioritizing national and global agricultural R&D investments to ensure adequate rice supply while minimizing negative environmental impact in coming decades.