Rice Production Systems Research Articles

Kajian Penerapan Mekanisasi Pertanian Berbasis Usaha Pelayanan Jasa Alat dan Mesin Pertanian (UPJA) untuk Sistem Produksi Padi di Kabupaten Banyumas, Purbalingga dan Banjarnegara

<p><em>The use of agricultural equipment and machinery is one way to increase the productivity and efficiency of farming. In order to accelerate the adoption of agricultural equipment and machinery as part of the application of agricultural mechanization, one of which is through the agricultural equipment and machinery service business/usaha pelayanan jasa alat dan mesin pertanian (UPJA). This study aims to analyze the application of agricultural mechanization, especially related to the use of equipment and machinery by UPJA for the rice production system in Banyumas, Purbalingga and Banjarnegara Regencies. Data were obtained, including the ownership of the equipment and machinery, the extent of coverage carried out by the UPJA, the cost of renting the equipment and machinery determined by each UPJA, and the costs incurred for the operation of the equipment and machinery in each UPJA. The results of the calculation of the working capacity of the hand tractor obtained an average of 0.07 ha hour<sup>-1</sup>. The lack of ability of equipment and machinery operators as well as the topography of the area and soil conditions are factors that affect the working capacity of the hand tractor in this study. UPJA which has a coverage area of more than the Break Event Point (BEP) value means that the UPJA has met the minimum area that must be processed to break even. The results of the calculation of the B/C ratio are that 9 UPJAs are feasible because the B/C ratio > 1 and 10 UPJAs are not feasible because of the B/C ratio < 1. UPJA whose business is not feasible is expected to improve the managerial and performance of UPJA.</em></p>

Increasing sustainability for rice production systems

Rice (Oryza sativa L.) is the staple food for millions of people in Asia and the world; however, it is also the largest consumer of freshwater resources worldwide. More than 75% of the world's rice is grown under flooded conditions. However, the long-term sustainability of this flooded system is threatened by the rapid changes in climatic events causing erratic rainfall and abiotic stresses, looming water and energy crisis, low nitrogen use efficiency, increasing micronutrient deficienties, increasing labor costs and reduced labor availability, increased methane emissions, yield stagnation, and the negative effects of rice crops on post-rice crops. The narrow genetic background in rice has also slowed the pace of breeding rice cultivars tolerant to abiotic and biotic stresses which has resulted in yield stagnation. While direct-seeded rice has become popular in developed countries, saving water and labor resources and reducing methane emissions, developing countries in Asia struggle to disseminate direct seeding technologies due to the lack of government support and policy. Weed management in direct seeded rice is still a major bottle neck in wide scale adoption of this rice system in developing world. Mechanical transplanting of rice is gaining momentum in Asia, reducing labor requirements, ensuring timely transplantation, and saving water during initial growth. Nonetheless, government support and strong policy are needed to boost its uptake by providing subsidies to purchase mechanical transplanters and training farmers to use this technology. With deteriorating soil health due to continuous cultivation of rice with cereals in rotation, overuse of synthetic fertilizers, and increased co-occurrence of abiotic and biotic stresses in rice, there is a need to adopt integrated crop management techniques, and to identify genes of interest and quantitative trait loci (QTL) for their introgression into desired plants. These interventions will improve the improve biotic and abiotic stress tolerance in rice. There is also a need for extensive campaign and policy support from the government to force farmers to harvest their rice crops using specific rice harvesters that can save the yield losses that occur when using wheat combine harvesters—a common practice in many developing countries.

Comparative evaluation on calcium silicate and rice husk ash amendment for silicon-based fertilization of Malaysian rice (Oryza sativa L.) varieties

Rice (Oryza sativa L.) is the most important staple food in the South-east Asian region as a dominant portion of global rice supply is produced and consumed here. Rice plant is a high silicon (Si) accumulator. Constitutive deposition of Si in the form of “phytoliths” offers the plant resistance against various pests, pathogens and stresses, and enhances growth and development. In this study, two sources of Si namely calcium silicate (CaSiO3) and rice husk ash (RHA) were comparatively evaluated for their bio-fertilizing efficiencies on rice plants cultivated under a glasshouse condition. In addition, we added manganese (Mn), as a form of supplemental nutrient and tested it in combination with the two Si sources. A two-factorial pot experiment with Malaysian rice varieties (MR219 and MR253) and Si-based treatment combinations [NPK only (control), NPK + RHA, NPK + CaSiO3, NPK + RHA + manganese (Mn) and NPK + CaSiO3+Mn] indicated that soil amendment using both, a renewable and nonrenewable Si compound (with and without Mn) significantly improved the rice yield-related components and yield as compared to the control (Si-free treatment) at P < 0.05. At 100 day after planting (harvest stage), the grain yield per experimental pot (MR219 and MR253 rice varieties) treated with RHA (with and without Mn) showed no significant difference to the plants treated with CaSiO3 (with and without Mn). Our findings suggest that RHA, an excellent renewable source fetched from rice production system offers an environmentally sound solution for effective Si-based fertilization of rice plants (Malaysian varieties).

Strategies for rice self-sufficiency in Côte d'Ivoire

Côte d'Ivoire is a country which is not self-sufficient in rice despite its combined agricultural potential. It is timely to make an analysis of the problems encountered by the actors of the value chain to make concrete proposals to meet the challenge of self-sufficiency in rice in the country. Thus, documentary research and a survey were carried out on producers. It appeared that the actors in the rice production system (rice farmers, processors, traders) encountered some difficulties which do not allow for a match between local demand and local rice production. This situation results from the inability of suppliers to differentiate and qualify their products to meet the requirements of Ivorian rice consumers. Faced with such a situation of failure, the public authorities can help by supporting the organization of the actors in the rice production system through an association that enables them to mobilize and activate all local resources to serve their activities. Public actions are insufficient and centralized. Thus, there is a need for decentralized structures in Côte d'Ivoire, particularly around local authorities, to act in synergy and with the support of local private producers.

Estimating Nitrogen Flows and Nitrogen Footprint for Agro-Food System of Rwanda Over the Last Five Decades: Challenges and Measures

This study presents the first detailed estimate of Rwanda’s nitrogen (N) flows and N footprint for food (NFfood) from 1961 to 2018. Low N fertilizer inputs, substandard production techniques, and inefficient agricultural management practices are focal causes of low crop yields, environmental pollution, and food insecurity. We therefore assessed the N budget, N use efficiency (NUE), virtual N factors (VNFs), soil N mining factors (SNMFs), and N footprint for the agro-food systems of Rwanda with consideration of scenarios of fertilized and unfertilized farms. The total N input to croplands increased from 14.6 kg N ha−1 yr−1 (1960s) to 34.1 kg N ha−1 yr−1 (2010–2018), while the total crop N uptake increased from 18 kg N ha−1yr−1 (1960s) to 28.2 kg N ha−1yr−1 (2010–2018), reflecting a decline of NUE from 124% (1960s) to 85% (2010–2018). Gaseous N losses of NH3, N2O, and NO increased from 0.45 (NH3), 0.03 (N2O), and 0.00 (NO) Gg N yr−1 (1960s) to 6.98 (NH3), 0.58 (N2O), and 0.10 (NO) Gg N yr−1 (2010–2018). Due to the low N inputs, SNMFs were in the range of 0.00 and 2.99 and the rice production, cash-crop production, and livestock production systems have greater SNMFs in Rwanda. The weighted NFfood per capita that presents the actual situation of fertilized and unfertilized croplands increased from 4.0 kg N cap−1 yr−1 (1960s) to 6.3 kg N cap−1 yr−1 (2010–2018). The NFfood per capita would increase from 3.5 kg N cap−1 yr−1 to 4.8 kg N cap−1 yr−1 under a scenario of all croplands without N fertilizer application and increase from 6.0 to 8.7 kg N cap−1 yr−1 under the situation of all croplands receiving N fertilizer. The per capita agro-food production accounted for approximately 58% of the national NFfood. The present study indicates that Rwanda is currently suffering from low N inputs, high soil N depletion, food insecurity, and environmental N losses. Therefore, suggesting that the implementation of N management policies of increasing agricultural N inputs and rehabilitating the degraded soils with organic amendments of human and animal waste needs to be carefully considered in Rwanda.

Impacts of long-term composted manure and straw amendments on rice-associated weeds in a rice–wheat rotation system

AbstractAs part of a long-term experiment to determine the impacts of composted manure and straw amendments (replacing 50% of chemical fertilizer with composted pig manure, wheat straw return combined with chemical fertilizer, and setting no fertilizer and chemical fertilizer-only as controls) on rice-associated weeds in a rice (Oryza sativaL.)–wheat (Triticum aestivumL.) rotation system, species richness, abundance, density, and biomass of weeds were assessed during years 8 and 9. Fertilization decreased the species richness and total density of rice-associated weeds but increased their total biomass. The species richness and densities of broadleaf and sedge weeds decreased with fertilization, while species richness of grass weeds increased only with straw return and density was not significantly affected. The shoot biomass per square meter of grass and broadleaf weeds was significantly higher with fertilization treatments than with the no-fertilizer control, while that of sedge weeds declined with fertilizer application. With fertilization, the densities of monarch redstem (Ammannia bacciferaL.) and smallflower umbrella sedge (Cyperus difformisL.) decreased, that of Chinese sprangletop [Leptochloa chinensis(L.) Nees] increased, and those of barnyardgrass [Echinochloa crus-galli(L.) P. Beauv.] and monochoria [Monochoria vaginalis(Burm. f.) C. Presl ex Kunth] were not significantly affected.Ammannia bacciferawas the most abundant weed species in all treatments. Whereas composted pig manure plus fertilizer resulted in higher density ofA. bacciferaand lower shoot biomass per plant than chemical fertilizer only, wheat straw return plus chemical fertilizer caused lower density and shoot biomass ofA. baccifera. Therefore, it may be possible that fertilization strategies that suppress specific weeds could be used as improved weed management program components in rice production systems.

Adaptability Mechanisms of Japonica Rice Based on the Comparative Temperature Conditions of Harbin and Qiqihar, Heilongjiang Province of Northeast China

Japonica rice has been considerably impacted from climate change, mainly regarding temperature variations. Adjusting the crop management practices based on the assessment of adaptability mechanisms to take full advantage of climate resources during the growing season is an important technique for japonica rice adaptation to climate changed conditions. Research based on the adaptability mechanisms of japonica rice to temperature and other environmental variables has theoretical and practical significance to constitute a theoretical foundation for sustainable japonica rice production system. A contrived study was arranged with method of replacing time with space having four different japonica cultivars namely Longdao-18, Longdao-21, Longjing-21, and Suijing-18, and carried out in Harbin and Qiqihar during the years 2017–2019 to confer with the adaptability mechanisms in terms of growth, yield and quality. The formation of the grain-filling material for superior and inferior grains was mainly in the middle phase which shared nearly 60% of whole grain-filling process. Maximum yield was noticed in Longdao-18 at Harbin and Qiqihar which was 9500 and 13,250 kg/ha, respectively. The yield contributing components fertile tillers, number of grains per panicle, and 1000-grain weight were higher at Qiqihar; therefore, there was more potential to get higher yield. The data for grain-filling components demonstrated that the filling intensity and duration at Qiqihar was contributive to increase the grain yield, whereas the limiting agents to limit yield at Harbin were the dry weights of inferior grains. The varietal differences in duration and time of day of anthesis were small. Across all cultivars and both study sites, nearly 85% of the variation of the maximum time of anthesis could be justified with mean atmospheric temperature especially mean minimum temperature. Mean onset of anthesis was earliest in Longdao-21 at Harbin, whereas it was latest in Longdao-18 at Qiqihar. The maximum time to end anthesis and the longest duration of anthesis were taken by Longdao-18, i.e., 9.0 hasr and 4.2 h, respectively. Chalkiness and brown rice percentages were elevated at Qiqihar showing Harbin produced good quality rice. This study investigated the adaptability mechanisms of japonica rice under varying temperature conditions to distinguish the stress tolerance features for future sustainability and profitability in NEC. It was concluded that there is an adaptive value for anthesis especially regarding Tmin and, moreover, earlier transplantation may produce tall plants. The results demonstrated that high temperature at the onset of anthesis at the start of the day enhanced the escape from high temperature later during the day. Early transplantation is recommended in NEC because earlier anthesis during humid days rendered for potential escape from high ambient temperature later during that day. Temperature influenced japonica rice significantly and coherently, whereas the influence of growing season precipitation was not significant. Daily mean sunshine influenced the japonica rice significantly, but the impact was less spatially coherent. The results foregrounded the response of the japonica rice to external driving factors focusing climate, but ignored socioeconomic suggesting emphasis on both driving factors to target future research and render important insights into how japonica rice can adapt in mid-high-latitude regions.

Assessing the Social-ecological Resilience of Organic Farmers in Chiang Mai Province, Thailand

Since resilience is continuing to make its rise to the top of the sustainable development policies, monitoring resilience has become critical because it provides stakeholders with practical actions that can strengthen the state of adaptability to cope with all kinds of change. In this study, resilience, and social theories, such as grounded theory and technography, were integrated as a conceptual framework to produce a specific set of indicators, which yielded forty-seven indices, called social-ecological resilience indicators (SERIs). This study attempts to manage the temporal and spatial scales of resilience systems and to make such indicators suitable for organic rice production systems in four districts of Chiang Mai Province. A questionnaire was utilized to survey fifty-three organic farmers, and the results of the descriptive data analysis indicated that 0.54 (1.00 = the maximum) had been the respondents’ average score. Meanwhile, the highest and the lowest scores were serially 0.69 and 0.40. In addition, the findings revealed that Kendall’s Tau-b rank correlation’s numeric value came closer to +, which meant that the respondents had demonstrated an average tendency to be resilient. Generally, the highest score of resilience existed for those organic farmers, who had been outstanding in creating opportunities for self-organization, such as considerably relying on food and farm materials from the availability of local resources. Moreover, the majority of them were found to have a secondary on-farm profession that was not only subsidizing additional incomes but was also providing new knowledge and opportunities. This contrasted with the group with lowest score. The farmers, who exhibited unsatisfactory resilience, were centralized in dimensions, ranging from a having a lack of diverse water sources to having sufficient competency to exploit the benefits of Information and Communication Technology (ICT). They are, therefore, more prone to being affected by negative pressures. It is recommended that for building resilience, the ‘holy grail’ is boosting self-reliance. This capacity is key to reducing the risk of losing sustenance and enabling stakeholders to apply the appropriate strategies in times of change

Nutrient dynamics in water and soil under conventional rice cultivation in the Vietnamese Mekong Delta

Background The evaluation of nutrient variability plays a crucial role in accessing soil potentials and practical intervention responses in rice production systems. Synthetic fertilizer applications and cultivation practices are considered key factors affecting nutrient dynamics and availability. Here, we assessed the nutrient dynamics in surface, subsurface water and soil under local water management and conventional rice cultivation practices in the Vietnamese Mekong Delta. Methods We implemented a field experiment (200 m 2) in the 2018 wet season and the 2019 dry season in a triple rice-cropping field. Eight samples of surface water, subsurface water (30–45 cm), and topsoil (0–20 cm) were collected and analysed during the rice-growing seasons. Results The results showed that N-NH 4+, P-PO 43- and total P peaks were achieved after fertilizing. Irrespective of seasons, the nutrient content in surface water was always greater than that of subsurface water (P&lt;0.001), with the exception of N-NO 3-, which was insignificant (P&gt;0.05). When comparing the wet and dry seasons, nutrient concentrations exhibited minor differences (P&gt;0.05). Under conventional rice cultivation, the effects of synthetic fertilizer topdressing on the total N, soil organic matter (SOM), and total P were negligible in the soil. Higher rates of N fertilizer application did not significantly increase soil N-NH 4+, total N, yet larger P fertilizer amounts substantially enhanced soil total P (P&lt;0.001). Conclusions Under conventional rice cultivation, N-NH 4+, P-PO 43- and total P losses mainly occur through runoff rather than leaching. While N-NO 3- loss is similar in surface water and subsurface water. Notably, nutrient content in soil was high; whilst SOM was seen to be low-to-medium between seasons. Future work should consider the nutrient balance and dynamic simulation in the lowland soil of the Vietnamese Mekong Delta’s paddy fields.

Improving Nitrogen Use Efficiency—A Key for Sustainable Rice Production Systems

Fertilizer use and genetic improvement of cereal crops contributed to increased yields and greater food security in the last six decades. For rice, however, fertilizer use has outpaced improvement in yield. Excess application of nutrients beyond crop needs, especially nitrogen (N), is associated with losses to the environment. Environmental pollution can be mitigated by addressing fertilizer overuse, improving N use efficiency, while maintaining or improving rice productivity and farmers' income. A promising approach is the site-specific nutrient management (SSNM), developed in the 1990s to optimize supply to meet demand of nutrients, initially for rice, but now extended to other crops. The SSNM approach has been further refined with the development of digital decision support tools such as Rice Crop Manager, Nutrient Expert, and RiceAdvice. This enables more farmers to benefit from SSNM recommendations. In this mini-review, we show how SSNM can foster sustainability in rice production systems through improved rice yields, profit, and N use efficiency while reducing N losses. Farmer adoption of SSNM, however, remains low. National policies and incentives, financial investments, and strengthened extension systems are needed to enhance scaling of SSNM-based decision support tools.

Climate-resilient agricultural water management to alleviate negative impacts of global warming in rice production systems

Climate-resilient agricultural water management to alleviate negative impacts of global warming in rice production systems

Setting sustainability targets for irrigated rice production and application of the Sustainable Rice Platform performance indicators

Stakeholders have diverse purposes for analyzing economic, environmental and social sustainability indicators of rice production systems. Our aim was to show the added value of identifying external target values of the Sustainable Rice Platform’'s 12 performance indicators in addition to internal descriptive statistics values such as median and top decile performance for each indicator. Using household survey data from 1499 households in seven favorable rice production areas across seven countries in Asia, we identified baseline and target values appropriate to each indicator and illustrated their use for three purposes: assessing the outcomes of an extension program, comparing tradeoffs associated with two widely-used crop establishment methods, and providing individual feedback to a farmer about how to improve farm performance. We worked with our large survey data set and external reference values to calculate specific target values for each of the 12 indicators. These target values were used to evaluate the effectiveness of an extension program, showing that the extension program resulted in an improvement in scores for most indicators but did not achieve the target values for any of them. A comparison of wet-direct seeded rice (widely practice in irrigated regions of Vietnam, Thailand, and Sri Lanka) vs. puddled transplanted rice (China, Indonesia, Myanmar) indicated that there was a trade-off with wet-direct seeding having better labor productivity and greenhouse gas emission but worse pesticide use, and that both establishment methods had lower profitability than the target value. For the advice provided to an individual farmer, it was useful to be able to show both what the neighbors' average performance was and how far that was from the target values. Our illustrations demonstrate that using target values for indicators adds depth to the interpretation of indicator data.

MITIGATION YIELD SCALED METHANE EMISSION FROM RICE GROWN IN WATER STRESS CONDITIONS WITH BIOCHAR AND SILICATE AMENDMENTS

Climate change and water scarcity may badly affect existing rice production system in Bangladesh. With a view to sustain rice productivity and mitigate yield scaled CH4 emission in the changing climatic conditions, a pot experiment was conducted under different soil water contents, biochar and silicate amendments with inorganic fertilization (NPKS). In this regard, 12 treatments combinations of biochar, silicate and NPKS fertilizer along with continuous standing water (CSW), soil saturation water content and field capacity (100% and 50%) moisture levels were arranged into rice planted potted soils. Gas samples were collected from rice planted pots through Closed Chamber technique and analyzed by Gas Chromatograph. This study revealed that seasonal CH4 emissions were suppressed through integrated biochar and silicate amendments with NPKS fertilizer (50–75% of the recommended doze), while increased rice yield significantly at different soil water contents. Biochar and silicate amendments with NPKS fertilizer (50% of the recommended doze) increased rice grain yield by 10.9%, 18.1%, 13.0% and 14.2%, while decreased seasonal CH4 emissions by 22.8%, 20.9%, 23.3% and 24.3% at continuous standing water level (CSW) (T9), at saturated soil water content (T10), at 100% field capacity soil water content (T11) and at 50% field capacity soil water content (T12), respectively. Soil porosity, soil redox status, SOC and free iron oxide contents were improved with biochar and silicate amendments. Furthermore, rice root oxidation activity (ROA) was found more dominant in water stress condition compared to flooded and saturated soil water contents, which ultimately reduced seasonal CH4 emissions as well as yield scaled CH4 emission. Conclusively, soil amendments with biochar and silicate fertilizer may be a rational practice to reduce the demand for inorganic fertilization and mitigate CH4 emissions during rice cultivation under water stress drought conditions.

Diurnal Variation of Trace Gas Fluxes during the Vegetative Lag Phase in Furrow-Irrigated Rice Production

Studies on diurnal variations of greenhouse gas (GHG) fluxes in rice (<em>Oryza sativa L.</em>) production systems have been limited to flooded, or variations of flooded, soil conditions. This study aimed to quantify hourly CO₂, CH₄, and N₂O fluxes over a period of 20 hours and the effects of site position (up-, mid-, and down-slope) and tillage practice [conventional tillage (CT) and no-tillage (NT)] during the vegetative lag phase in a furrow-irrigated rice field on a silt-loam soil in eastern Arkansas.

Yield, Grain Quality, and Starch Physicochemical Properties of 2 Elite Thai Rice Cultivars Grown under Varying Production Systems and Soil Characteristics.

Rice production systems and soil characteristics play a crucial role in determining its yield and grain quality. Two elite Thai rice cultivars, namely, KDML105 and RD6, were cultivated in two production systems with distinct soil characteristics, including net-house pot production and open-field production. Under open-field system, KDML105 and RD6 had greater panicle number, total grain weight, 100-grain weight, grain size, and dimension than those grown in the net-house. The amounts of reducing sugar and long amylopectin branch chains (DP 25–36) of the RD6 grains along with the amounts of long branch chains (DP 25–36 and DP ≥ 37), C-type starch granules, and average chain length of the KDML105 were substantially enhanced by the open-field cultivation. Contrastingly, the relative crystallinity of RD6 starch and the amounts of short branch chains (DP 6–12 and DP 13–24), B- and A-type granules, and median granule size of KDML105 starch were significantly suppressed. Consequently, the open-field-grown RD6 starch displayed significant changes in its gelatinization and retrogradation properties, whereas, certain retrogradation parameters and peak viscosity (PV) of KDML105 starches were differentially affected by the distinct cultivating conditions. This study demonstrated the influences of production systems and soil characteristics on the physicochemical properties of rice starches.

Comparative analysis of the profitability of rice production systems in Kwara State, Nigeria

&#x0D; &#x0D; &#x0D; This study describes the socioeconomic characteristics of rice farmers, identifies the production system used by the farmers, compares the profitability of rice production systems, identifies the factors influencing the choice of production systems among the farmers as well as the constraints to rice production systems. A three-stage random sampling procedure was used to select 120 rice farmers on whom a set structured questionnaire was administered. Data was analysed using descriptive statistics and multinomial logistic regression model. Results show that 48.3%, 35% and 16.7% of the farmers cultivate rice using the upland, lowland and the combined production systems respectively. The findings also reveal variability in yield, profit and income across the rice production systems. The gross margins for lowland, upland and combined rice production systems were N65,735.73, N67,900.89 and N78,015.57 per hectare respectively. The factors that influenced the choice of upland production system relative to combined production system were age, household size, farming years and extension visits while the factors that influenced the choice for combined rice production system relative to lowland rice production system was income. Inadequate finance to purchase inputs, problem of pests and diseases, and unfavorable climatic conditions are the constraints faced by rice farmers in the upland, lowland and combined production systems. The combined production systems had the highest return per hectare. Therefore, the study recommends that farmers should be encouraged to choose the combined rice production system for optimum profitability of rice production.&#x0D; &#x0D; &#x0D;

Challenges and opportunities in productivity and sustainability of rice cultivation system: a critical review in Indian perspective.

Rice–wheat cropping system, intensively followed in Indo-Gangetic plains (IGP), played a prominent role in fulfilling the food grains demand of the increasing population of South Asia. In northern Indian plains, some practices such as intensive rice cultivation with traditional method for long-term have been associated with severe deterioration of natural resources, declining factor productivity, multiple nutrients deficiencies, depleting groundwater, labour scarcity and higher cost of cultivation, putting the agricultural sustainability in question. Varietal development, soil and water management, and adoption of resource conservation technologies in rice cultivation are the key interventions areas to address these challenges. The cultivation of lesser water requiring crops, replacing rice in light-textured soil and rainfed condition, should be encouraged through policy interventions. Direct seeding of short duration, high-yielding and stress tolerant rice varieties with water conservation technologies can be a successful approach to improve the input use efficiency in rice cultivation under medium–heavy-textured soils. Moreover, integrated approach of suitable cultivars for conservation agriculture, mechanized transplanting on zero-tilled/unpuddled field and need-based application of water, fertilizer and chemicals might be a successful approach for sustainable rice production system in the current scenario. In this review study, various challenges in productivity and sustainability of rice cultivation system and possible alternatives and solutions to overcome such challenges are discussed in details.Graphic abstract

QTL Validation and Development of SNP-Based High Throughput Molecular Markers Targeting a Genomic Region Conferring Narrow Root Cone Angle in Aerobic Rice Production Systems.

Aerobic rice production (AP) provides potential solutions to the global water crisis by consuming less water than traditional permanent water culture. Narrow root cone angle (RCA), development of deeper rooting and associated genomic regions are key for AP adaptation. However, their usefulness depends on validation across genetic backgrounds and development of linked markers. Using three F2 populations derived from IRAT109, qRCA4 was shown to be effective in multiple backgrounds, explaining 9.3–17.3% of the genotypic variation and introgression of the favourable allele resulted in 11.7–15.1° narrower RCA. Novel kompetitive allele specific PCR (KASP) markers were developed targeting narrow RCA and revealed robust quality metrics. Candidate genes related with plant response to abiotic stress and root development were identified along with 178 potential donors across rice subpopulations. This study validated qRCA4’s effect in multiple genetic backgrounds further strengthening its value in rice improvement for AP adaptation. Furthermore, the development of novel KASP markers ensured the opportunity for its seamless introgression across pertinent breeding programs. This work provides the tools and opportunity to accelerate development of genotypes with narrow RCA through marker assisted selection in breeding programs targeting AP, which may ultimately contribute to more sustainable rice production where water availability is limited.

Crayfish–rice integrated system of production: an agriculture success story in China. A review

Chinese agriculture is seeking a sustainable production increase in order to solve the food problem for its population. The traditional “high input, high pollution” agricultural production mode has led to a large burden on resources and on the environment. At present, China is promoting the transformation of its agricultural production modes in the direction of resource conservation and green development. In recent years, the crayfish–rice integrated system of production (CRISP) has been developed intensively in China due to its important economic benefits. Evaluating this new agricultural model comprehensively and guiding the related green sustainable development are urgent issues. Here, we used statistical data and literature to review the origin and development of CRISP in China and to compare the Chinese CRISP with similar models in other parts of the world. We reviewed studies on the ecological and social effects of CRISP for its objective evaluation and drew three main findings. First, although the crayfish initially introduced were sourced from the USA, the extensive application of CRISP led China to rapidly become the largest crayfish producer worldwide — accounting for over 90% of the crayfish production — and a leader in crayfish processing and catering industries. Second, the specific Chinese CRISP culture model promotes a green transformation towards a high-quality rice production system. Finally, CRISP affected positively soil quality, water and nutrient recycling, pest limitation, and biodiversity development in the paddy field system. CRISP reveals a good example of the effective application of green revolution in China’s agricultural production. We analyze for the first time the specific ecological foundation and management model for the sustainable development of CRISP. These observations provide a reference for the development of other agriculture–livestock integrated systems worldwide.

Crop Establishment Methods and Integrated Nutrient Management Improve: Part II. Nutrient Uptake and Use Efficiency and Soil Health in Rice (Oryza sativa L.) Field in the Lower Indo-Gangetic Plain, India

Rice, the predominant food crop in India, is being grown traditionally with improper plant nutrient management mostly under the flooded situation. Recent advancement in research on crop science focuses on water-saving rice technologies for maximization in crop and water productivity under the backdrop of a shrinking water resource base for ensuring environmental and agricultural sustainability. Under this situation, an experiment was conducted in two consecutive years in a split-plot design keeping rice cultivation methodologies, viz., aerobic culture, System of Rice Intensification (SRI), and conventional flooded culture in main plots and integrated plant nutrient management (INM) treatments in sub-plots. The experiment was aimed at understanding the effects of different rice production systems and INM on nutrient content, uptake, and use efficiency. The change in soil quality parameters was also studied to understand the impact of crop establishment methods (CEM) and INM options. Significant reduction (p ≤ 0.05) in nutrient uptake and use efficiency was observed under aerobic culture compared to SRI and flooded method, although aerobic culture showed the highest physiological nitrogen use efficiency. Post-harvest available Fe status was significantly lower in aerobic rice (mean 10.39 ppm) compared to other crop establishment technologies; however, Zn status was higher in aerobic rice over the flooded situation. Although available potassium was not affected due to rice cultivation methods, available nitrogen and phosphorus status were influenced remarkably. Soil microbial quality was improved in aerobic rice in comparison to flooded rice. SRI proved to be the most efficient rice establishment method for enhancement in nutrient uptake, use efficiency, and enrichment of soil chemical and microbiological quality. Irrespective of crop culture, integrated plant nutrition in rice improved the nutrient uptake, use efficiency, and soil quality parameters. The study revealed that, under the alluvial soils of the Indo-Gangetic Plains of Eastern India, SRI can be considered as a water-saving rice production method. The method can also improve nutrient uptake, efficiency, and soil quality parameters if proper INM is adopted.