Intensive Rice Production Research Articles

Sheath Blight of rice: A review of host plant interaction and disease management

The devastating pathogen Rhizoctonia solani, which is responsible for significant quality and production losses worldwide, is discussed in this review article along with the symptoms, disease cycle, epidemiology which causes sheath blight disease in rice. R. solani Kuhn, poses a significant threat to tropical Asia's rice production, potentially reducing grain yield by 50%. The article also emphasises the numerous management techniques, such as cultural, biological, and chemical controls. It is a severe production bottleneck in high yielding rice varieties under intensive rice production techniques, monoculture methods, a dense canopy, and extensive nitrogen management. Disease propagation in fields is influenced by air temperature, moisture content, and leaf wetness, with 16-25 C temperature range and 90% humidity favoring growth. Vertical and horizontal spread are influenced by these factors. The article provides comprehensive insight on host plant interaction of pathogen R. solani.

Pathogenicity structure of the Xanthomonas oryzae pv. oryzae population causing rice bacterial blight in Vietnam

The rice bacterial blight caused by Xanthomonas oryzae pv. oryzae (Xoo) bacteria is rice’s most destructive disease. Due to the potential biomagnification caused by bactericides, deploying host resistance is the most effective method to protect the rice harvest. Studying the pathogenicity structure of the Xoo population helps propose the best breeding strategies to use the resistance gene pool. Among 12 resistance genes validated, xa5 and Xa21 maintained their efficacy against the Xoo population in Vietnam. Other genes, including Xa7 and xa13, remained effective in certain regions. The most destructive Xoo races distribute in the South, where intensive rice production was practiced. The same Xoo races found in different ecological regions illustrated the pathogen migration between adjacent areas. This manuscript proposed a designation system that converts the response of the differential set to each Xoo isolate into a binary, then into an octal system to name Xoo races appropriately.

Potential and limitations of crowdsourced data for high-resolution rice mapping in Madagascar: The importance of representation

Given the projected population growth and rice consumption in Madagascar, assessing its rice production potential is important. Existing spatial representations of rice are characterized by coarse resolutions and diverge widely. Mapping rice production based on remote sensing offers a potential solution to this problem but its application in Sub-Saharan Africa is hindered by scarce ground truth data and a complex array of cropping systems. While crowdsourcing initiatives provide data that could in principle be used to overcome this hurdle, their usefulness in rice mapping is hitherto underexplored. Here, we investigate the usefulness of crowdsourced data to enhance the mapping of rice production areas in the data-poor context of Madagascar. At present, dedicated crowdsourcing initiatives only limitedly cover rice but do provide sufficient information to build a dataset of data points characterizing a No-Rice class. On the other hand, geotagged pictures from social media, which do document rice production areas, predominantly represent 'scenic' fields appealing to social media contributors, i.e. irrigated, intensive rice production systems. The archetypal nature of these data leads to distinct feature signatures. Consequently, these data could be successfully used for rice mapping in the Lake Alaotra basin, which is characterized by the type of intensive rice cropping that is well-represented by the crowdsourced data. However, it was not possible to construct an accurate map of rice production in the greater Antananarivo region or at the national scale using crowdsourced data as they do not sufficiently represent the present variety in rice production systems. The value of crowdsourced data thus depends on the representativeness of the data, which in turn depends on the application and can be improved through applying a probabilistic sampling design. Our study also highlights the need for data representation checks prior to data augmentation or classification for future applications wanting to construct credible maps using crowdsourcing within their sampling design for which we present a multi-faceted evaluation framework.

A Dilemma between Flood and Drought Management: Case Study of the Upper Chao Phraya Flood-Prone Area in Thailand

Floods are the greatest natural disaster in Thailand, but they are an important part of recharging the water volume for groundwater resources. This paper focused on evaluating and discussing the relationship between flood magnitudes and flood management impacting groundwater storage in the Upper Chao Phraya River basin in Thailand, where the intensive rice production of the region is located. Based on satellite image data, there were annual flood inundations varying from 1950 to 10,470 km2 over the period 2005–2019. The evaluation shows those flooding events yielded floodwater recharge of approximately 0.5–5.9 km3. To lessen the flood damage, floodways with 2000 m3 s−1 of drainage capacity are proposed by the government. This measure aims to accelerate flood surplus out to the gulf of Thailand and to confine the flooding areas to a maximum value of 4650 km2. A reduction of approximately 3.4 km3 of groundwater storage is estimated if the floodways are implemented. Staple crops in the dry season, especially rice fields outside an irrigation project (rainfed area), cope with water stress. To sustain basin water demand in the dry season, approximately 1820 km2 should be allowed for an area flooded for a month where 0.9 km3 of water volume is harvested annually. Although flood control is important, potential impact on the reduction of groundwater recharge needs to be carefully considered. Therefore, a flood control policy shows the balance of available basin water occasionally supplied by the groundwater while rice water demand is being proposed.

Orderly Mechanical Seedling-Throwing: An Efficient and High Yielding Establishment Method for Rice Production

Developing an efficient and high-yielding mechanical rice establishment system is one of the most important approaches for intensive and large-scale rice production. Recently, an orderly mechanical rice seedling throwing system (OMST) was successfully developed; however, the performance of this system is unknown. In the present study, a two-year field experiment was carried out in a split-plot design with three establishment methods arranged in the main plots, and two elite rice cultivars arranged in the sub-plots. The grain yield and growth-related traits were then determined. The results showed that the grain yield of OMST was significantly higher than manual seedling throwing, and was equivalent to that of manual transplanting, which was mainly due to the variances in panicle number and total spikelet number. Further analysis suggested that the orderly mechanical seedling throwing takes advantage of higher biomass accumulation after heading, increased leaf area index and decreased leaf senescence rate against manual seedling throwing, and more tillers and biomass accumulation at vegetative growth stage as compared to manual transplanting. The present study showed that the OMST is an efficient and high-yielding rice establishment method that may be a promising option to replace traditional manual seedling throwing in rice production.

Assessing nutrient budget of ungauged catchment using intermittent water quality markers

This study is a preliminary spatial-temporal assessment method of the ungauged catchment to determine the variation in water quality (WQ) and the land use influence on river basins’ health. The intermittent WQ data, the principal component analysis, and the redundancy analysis were used to evaluate the (dis)similarity among the 10 ungauged streams and their significance in the entire catchment. These revealed some similarities/differences in nutrient pollution and latent land-use influence on the streams’ health. There were similarities between R6-R7, R9-R10, among R1 to R4 basins, while R5 and R8 had distinct variances in their WQ dynamics. The intensive vegetable and rice production in R5, R7, R8, R9, and R10 basins were the major sources of high nutrient concentrations. The unique variations, especially in R5 and R8 basins could be attributed to other different pollution sources. Hence, it’s of great significance to carry out comprehensive research in the above 5 river basins. That is the efficiency of management practices, identification of pollution sources, and the extent to which the elevated nutrients in the streams interact with biota within the river regime. This research offers a method to evaluate WQ dynamics in relation to human interferences in river basins of a catchment with limited data under similar climatic conditions.

Sub-soil Nitrogen Content as Influenced by Long-term Manuring and Its Relationship with Nitrogen Availability and Productivity of a Rice-rice Cropping System in Eastern India

Investigation was made to study the impact of long-term fertilizer and manure application on the sub-soil nitrogen (N) fertility of an acidic Inceptisol under continuous rice-rice cropping system. For this purpose, a long-term fertilizer experiment commenced from 2005-06, rabi season in the Central Farm of Odisha University of Agriculture and Technology (OUAT), Bhubaneswar under aegis of ICAR, New Delhi was used. The experiment had 12 manurial treatments whose impact on sub-soil N fertility up to 75 cm depth and its relation with surface soil N fertility was studied. N uptake and crop yield has been assessed after 20 cropping cycles. The initial soil was acidic (pH 5.8) with low soil organic carbon (4.3 g kg -1) and CEC of 3.75 cmol (p+) kg-1, mineralizable N of 187 kg ha-1 and total N of 1280 kg ha-1. After 20 cropping cycles, the soil organic carbon (SOC) content increased in all the fertilized treatments in the surface layer and with depth it decreased sharply from 15-30 cm to 30-45 cm layer. Treatments with balanced nutrition registered higher content of total N, organic N, mineralizable N and inorganic N both in surface soil and sub-soil. Not only the surface soil but also the sub-soil contents of total N, organic N and mineralizable N are significantly influenced by long-term use of fertilizer nutrients and manure under wet land intensive rice production system. Sub-soil contents of total N, organic N, mineralizable N, inorganic N, ammonium N and nitrate N have strong positive correlation with those of surface layer. SOC, total N, mineralizable N and inorganic N are strongly correlated with each other in the same layer. Correlation of organic N and total N with nitrate N was however, significant up to 30 cm depth and beyond that there was no correlation at 30-45 cm layer. From the results, it is concluded that application of nutrient in balanced and integrated manner (NPK + FYM) not only increased grain yield and sustainability of rice but also improved various pools of N in surface as well as sub-soil up to 75 cm depth of a wet land rice-rice production system under subtropical climatic situation.

Resilience of various innovative water management practices: The case of rice production in the Vietnamese Mekong Delta floodplains

The floodplains play an important role in agricultural development and rural livelihoods in the Vietnamese Mekong Delta. As an intensive rice production area of Vietnam, the floodplain has experienced significant changes in water management regime during the recent decades. Depending on specific locations and irrigation infrastructure investments, four main water management practices have been innovated, particularly a planting season of two crops per year (2C1Y), three crops per year (3C1Y), three years eight crops (3Y8C) and two years five crops (2Y5C). The 4R framework (Reform, Result, Resilience, and Return) was developed based on grounded theory approach for resilience assessment of various innovative water management practices. In terms of resilience, we found that each crop pattern involves pros and cons, and the intensive crop practices are less resilient systems, especially in social, environmental, and ecological aspects. The findings provide good lessons learned not only for Vietnam but also for the other rice-producing deltas implementing ecosystem resilience to adapt to global challenges such as flood, drought, and salinity intrusion.

Floods, soil and food – Interactions between water management and rice production within An Giang province, Vietnam

Rapid intensification of Vietnamese rice production has had a positive effect on the nation's food production and economy. However, the sustainability of intensive rice production is increasingly being questioned within Vietnam, particularly in major agricultural provinces such as An Giang. The construction of high dykes within this province, which allow for complete regulation of water onto rice fields, has enabled farmers to grow up to three rice crops per year. However, the profitability of producing three crops is rapidly decreasing as farmers increase their use of chemical fertilizer inputs and pesticides. Increased fertilizer inputs are partly used to replace natural flood-borne, nutrient-rich sediment inputs that have been inhibited by the dykes, but farmers believe that despite this, soil health within the dyke system is degrading. However, the effects of the dykes on soil properties have not been tested. Therefore, a sampling campaign was conducted to assess differences in soil properties caused by the construction of dykes. The results show that, under present fertilization practices, although dykes may inhibit flood-borne sediments, this does not lead to a systematic reduction in nutrients that typically limit rice growth within areas producing three crops per year. Concentrations of total nitrogen, available phosphorous, and both total and available potassium, and pH were higher in the surface layer of soils of three crop areas when compared to two crop areas. This suggests that yield declines may be caused by other factors related to the construction of dykes and the use of chemical inputs, and that care should be taken when attempting to maintain crop yields. Attempting to compensate for yield declines by increasing fertilizer inputs may ultimately have negative effects on yields.

Integrated weed management in transplanted rice: options for addressing labor constraints and improving farmers’ income in Bangladesh

AbstractIn Bangladesh, weeds in transplanted rice are largely controlled by labor-intensive and costly manual weeding, resulting in inadequate and untimely weed control. Labor scarcity coupled with intensive rice production has triggered increased use of herbicides. These factors warrant a cost-effective and strategic integrated weed management (IWM) approach. On-farm trials with transplanted rice were conducted during monsoon (‘Aman’) season in 2016 and 2017 and winter (‘Boro’) season in 2016 to 2017 in agroecological zones 11 and 12 with ten treatments—seven herbicide-based IWM options, one mechanical weed control-based option, and two checks (farmers’ current weed control practice and weed-free)—to assess effects on weed control, grain yield, labor use, and profitability. Compared to farmers’ practice, herbicide-based IWM options with mefenacet + bensulfuron-methyl as preemergence followed by (fb) either bispyribac-sodium or penoxsulam as postemergence fb one hand-weeding were the most profitable alternatives, with reductions in labor requirement by 11 to 25 person-days ha–1 and in total weed control cost by US$44 to 94 ha–1, resulting in net returns increases by US$54 to 77 ha–1 without compromising on grain yield. In contrast, IWM options with bispyrbac-sodium or penoxsulam as postemergence application fb one hand-weeding reduced yields by 12% to 13% and profits by US$71 to 190 ha–1. The nonchemical option with mechanical weeding fb one hand-weeding performed similarly to farmers’ practice on yield and profitability. We suggest additional research to develop feasible herbicide-free approaches to weed management in transplanted rice that can offer competitive advantages to current practices.

Intensive rice production systems in Europe

In the European Union rice is mainly grown in the Mediterranean countries with Italy and Spain being the top producers. Toward the end of 20th century, the number of farms dramatically decreased in all rice producing countries. For example, in Italy the total number of rice farms decreased to about one-half while the mean cultivating area per farm showed a proportional increase (from 20 to around 50 ha). Due to the high cost and shortage of human labor in Europe, rice crop in Europe is mostly cultivated under the intensive production system. In Italy, a single farm worker can manage from 40 to 60 ha of rice fields and many farmers are University graduates. Farm mechanization usually includes a number of equipment such as plows, scrapers, manure-spreaders, harrows, furrowers, combines and milling-machines. The major production and environmental challenges related to intensive rice production systems in Europe are presented.

Social Impacts of High Dyke Construction and Farmers’ Responses: Case of Agricultural Intensification in the Vietnamese Mekong Delta

Since Vietnam government adopted a comprehensive reform known as Doi Moi policy in 1986, agricultural sector, especially intensive rice production, has played a critical role in a substantial growth and contributed significantly to poverty reduction in the Mekong Delta. In promoting rice intensification and agricultural diversification, a series of high dyke systems and embankments have recently been installed in many inundation areas of the Mekong Delta to provide flood protection so that farmers could grow rice even during flooding seasons. Local government assumed that farmers in new flood-protected areas are able to diversify and intensify agriculture, particularly rice production, thereby improve local livelihoods. Innovations in artificial hydraulic management and changes in agricultural production, however, have not only generated a great impact on environment and ecology of the Mekong Delta, but also triggered a process of social differentiation, causing the appearance of marginalized groups who must struggle for access resources to maintain their survival. Studies on the aspects of social differentiation and local efforts to cope with such adverse impacts have been rare. This paper aims to investigate recent trends of human intervention to regulate floodwater flows for agricultural intensification in the Mekong Delta and to explore the diversity and dynamics of farmers in adapting with these changes by examining their livelihood strategies. The mixed method comprising participatory rural appraisal (PRA), field observations, in-depth interviews with key informants and household surveys was employed to collect necessary data. The analysis suggests that the local people’s livelihoods constitute dynamic, complex and diverse paths to respond to changing social, economic and environmental conditions after the appearance of the high dyke systems. Households and individual farmers differ in the degree of emphasis and choice of livelihood strategies, according to their own capacity in the broader socio-political and economic context and the structure of their internal size, composition and capital. However, the small-scale farmers and poor landless group have been seen at the losing end in the trade-off and thereby excluded from the development process.

Assessment of post-harvest losses and carbon footprint in intensive lowland rice production in Myanmar

This paper examines how a move from traditional post-harvest operations of smallholder rice farms in the Ayeyarwaddy delta, Myanmar, to improved post-harvest operations affected income, energy efficiency and greenhouse gas emissions (GHGE). Harvest and post-harvest losses were investigated in a field experiment with 5 replications per scenario. A comparative analysis on energy efficiency and cost-benefits was conducted for different practices of rice production from cultivation to milling. GHGE of different practices were also considered using a life-cycle assessment approach. The study demonstrates that the mechanized practices increased the net income by 30–50% compared with traditional practices. Despite using additional energy for machine manufacturing and fuel consumption, the mechanized practices significantly reduced postharvest losses and did not increase the total life-cycle enegy and GHGE. Combine harvesting helped to significantly reduce harvesting loss in a range of 3 to 7% (by weight of the rice product). Improved post-harvest management practices with a flatbed dryer and hermetic storage reduced the discoloration of rice grains by 3 to 4% and increased head-rice recovery by 20 to 30% (by weight of rice product). The research findings provide empirical evidence that improved post-harvest management of rice in the Ayeyarwaddy delta, compared to traditional post-harvest operations by smallholder farmers, reduce post-harvest losses and improve the quality of rice. The findings provide valuable information for policy makers involved in formulating evidence-based mechanization policies in South and Southeast Asia.

Underdeveloping the Mekong?

Over the past century, the Mekong River Delta of southern Vietnam has undergone a series of transformations. In the early twentieth century, its forests and marshes were cleared for extensive rice production under French colonial rule; rice production was then intensified along Green Revolution lines under the post-colonial regimes of the 1960s to 1990s, before a dramatic shift toward export-oriented shrimp aquaculture since 2000. Drawing on archival and secondary data, as well as theories of extraction and unequal exchange, this paper traces the development, expansion, intensification, and eventually crisis of rice cultivation in the Mekong Delta. After a brief literature review, the paper consists of three sections. The first examines the origins and drivers of export-oriented extraction in the French colonial period; the second, the shift toward intensive rice production in the developmental states of the postcolonial period; and the third, the return to extraction, in the form of shrimp aquaculture, in the 1990s and 2000s. Building on Bunker's notion of “extractive cycles,” I argue that the Mekong Delta's history of extraction has exposed the region to ecological and economic crises, as well as shaping the long-term trajectory of subsequent development toward the extractive cultivation of export-oriented commodities.

Impact of irrigation techniques on rice yield and dynamics of zinc in plants and soil

Zinc (Zn) insufficiency and water deficiency are primary challenges in intensive rice production systems. This study aims to examine the influence of two irrigation regimes, flood irrigation (FI) and water-saving irrigation (WSI), on rice grain yield and mobile Zn accumulation in soil and rice grains. Experiments were conducted in An Vien rice fields in the Tien Lu district, Hung Yen province, located in the middle of the Red River delta during four rice seasons from 2015 to 2016. The results showed that the WSI regime dramatically increased the grain yield and Zn concentrations in grain of rice. Grain yield was increased by 14.76% and grain Zn concentration by 17.93% when compared with the FI regime. The decrease in the mobile Zn concentration in soil was only 5.7% in the WSI technique, compared with 73.6% for FI techniques. Therefore, it can be concluded that WSI can be effective agricultural practice to elevate grain yield and increase Zn retention in soil and bioavailability in rice grains.

Prolonging seedling age does not reduce grain yields in machine‐transplanted early‐season rice under precision sowing

AbstractHigh seed sowing rates have shortened seedling age in conventional machine‐transplanted rice, which has become a challenge for intensive rice production in China. This study aimed to test our hypothesis that prolonging seedling age may not lead to reduced yield in machine‐transplanted early‐season rice under precision sowing. Field experiments were conducted with two cultivars in 2 years to determine the effect of prolonging seedling age on seedling traits, grain yield, and yield attributes in machine‐transplanted early‐season rice with printed sowing (a new precision sowing method). All tested seedling traits, including height, basal width, leaf and root number, and shoot and root biomass, were significantly increased when seedling age was prolonged from 20 days (a commonly recommended seedling age for conventional machine transplanting) to 30 days. The prolonged seedling age did not significantly affect grain yield, yield components, or biomass production and translocation. These results support our hypothesis and suggest that adopting precision sowing is a feasible way to prolong seedling age of machine‐transplanted early‐season rice.

Screening of Blast Resistance Genes from South Tapanuli Rice Cultivars, North Sumatra, Indonesia

Rice blast disease caused by a phytopathogenic fungus, Magnaporthe oryzae, has been considered as a major threat to global rice productivity, including Indonesia. South Tapanuli is a regency in North Sumatra, known for its intensive and significant rice production activities. A collection of 13 rice cultivars originating from the region, is claimed for its resistances against the rice blast disease based on the practices by the local farmers. Molecular screening of blast resistance (R) genes was initiated to the 13 accessions using the Polymerase Chain Reaction (PCR) targeting five blast resistance (R) genes, Pup1, Pi-37, Pi-d2, Pi-ta2, Pib and Pi-kh. Out of the 13 accessions, the Pi-d2, Pi-ta2 and Pib were detected in all cultivars, showing 100% of R gene frequency. The second dominant, Pup1 and Pi-37 gene frequencies were 76.9 and 61.5%, respectively while the least dominant, Pi-kh gene frequency was 15.4%. The number of R genes detected among cultivars was ranged between 3 to 6 genes. The genetic associations among thirteen germplasms were determined using unweighted pair group method with arithmetic mean (UPGMA) analysis. Cluster analysis revealed that the least blast-resistant cultivars: Putri Kembar, Silatian and Siganteng, were grouped into cluster 1, showing polymorphism for Pi-d2, Pi-ta2 and Pi-b. The high-resistant cultivars, Martabe-Sicondong and Sayuti, Sitolas, Pulo Raja, Pulo Pandan, Siporang and Pulo Manggis, were grouped into cluster 2 and 3, respectively. The medium blast-resistant cultivars, IR 64 and Sitampan were grouped into cluster 4, showing polymorphism for Pup1, Pi-d2, Pi-ta2 and Pi-b. These results indicated that the utilization of blast-resistant cultivars in North Tapanuli was supported by the presence of R genes.

Youths’ participation in agricultural intensification in Tanzania

Agricultural intensification is necessary in Tanzania to meet the demands of a rapid growing population, and to avoid dependence on agricultural imports. An overwhelming share of the Tanzanian population is young, and the issue of employment among youth is increasingly debated. Agriculture is perceived to play a key role in creating employment opportunities in Sub-Sahara African as urban employment possibilities are limited, and domestic demand for food is growing. Based on a mixed methods approach this article aims to explore youths' participation in agricultural intensification in Tanzania. Theoretically, we depart from the concept of 'opportunity space' and take a contextual approach to near and distant opportunity spaces for the young rural Tanzanians. Our findings suggest that youth are excluded in agricultural intensification in maize production, but play a central role in the more labour intensive rice production. Contrasting to previous research, a majority of the interviewed youth said they prefer to stay in the rural areas, and a combination of farming and business was aspired to by many respondents. Tools and machinery, capital for agricultural investment, and infrastructure and access to markets were identified by the youth as some of the main obstacles to intensify farming, limiting their opportunity space.

Effects of Vegetation Strips, Fertilizer Levels and Varietal Resistance on the Integrated Management of Arthropod Biodiversity in a Tropical Rice Ecosystem.

Integrated biodiversity management aims to conserve the beneficial species components of production ecosystems and reduce the impacts of pests. In 2011 and 2013, experiments were conducted at Los Baños, Laguna, Philippines, to compare arthropod communities in rice plots and on levees with and without vegetation strips. Vegetation strips included spontaneous weeds, sesame and okra (2011), or mung bean (2013). The plots were treated with one of three nitrogen levels and in one experiment were planted with planthopper-resistant (IR62) and susceptible (IR64) rice varieties. Parasitoids and predators of lepidopteran pests and of the ricebug, Leptocorisa oratorius, were more abundant in high-nitrogen rice plots where their prey/hosts also had highest densities. Planthoppers and leafhoppers were more abundant in low-nitrogen plots. Weedy and sesame/okra bunds provided habitat for a range of natural enemies including spiders, parasitoids and predatory bugs, but did not have higher pest numbers than cleared bunds. Higher abundances of the predator Cythorhinus lividipennis and higher parasitism of planthopper (Nilaparvata lugens) eggs by Anagrus sp. were associated with sesame/okra bunds in late season rice plots. Mung bean also provided habitat for key predators and parasitoids that spilled over to adjacent rice; however, mung bean was also associated with higher numbers of lepidopteran and grain-sucking pests in the adjacent rice, albeit without increased damage to the rice. For ricebug in particular, damage was probably reduced by higher parasitoid:pest ratios adjacent to the vegetation strips. Varietal resistance and mung bean strips had an additive effect in reducing abundance of the planthopper Sogatella furcifera and the leafhopper Nephotettix virescens. Reduced numbers of these latter pests close to vegetation strips were often compensated for by other plant-sucking bugs, thereby increasing the intensity of potentially stabilizing interspecific interactions such as competition. We highlight the benefits of diversifying rice landscapes and the need to optimize vegetation strips, e.g., by including lepidopteran trap-plants, for intensive rice production systems.

Eco-Efficiency Assessment of Intensive Rice Production in Japan: Joint Application of Life Cycle Assessment and Data Envelopment Analysis

To promote sustainable agriculture worldwide, it is important to understand what constitutes eco-efficiency for rice, a staple food in many countries. This study examined whether expanding the scale of rice farming contributed to the improved eco-efficiency of intensive rice production in Japan. Both life cycle assessment (LCA) and data envelopment analysis (DEA) were used to measure comprehensively the eco-efficiency of rice production. A DEA window analysis technique with two DEA inputs (global warming and eutrophication from the LCA results) and one DEA output (weight-based rice yield) was applied to the statistical data for 2005–2011 categorized by the size of rice farms. The results indicate that expanding the size of rice farms is an effective way of improving the eco-efficiency of intensive rice production in Japan. The important factors for improving eco-efficiency are the implementation of economies of scale, reduced outsourcing of farm work, and savings in chemical fertilizers and pesticides. Expansion of the size of rice farms through the recent abolition of the rice production adjustment program will also contribute to improving the eco-efficiency of Japanese rice production.