Increase Rice Yield Research Articles

Fertilization effects on soil microbial composition and nutrient availability in integrated rice-livestock production systems

Integrated crop-livestock systems (ICLS) in paddies are an important strategy to reduce fertilizer requirements of rice (Oryza sativa). Legume crop rotations and fertilization increase soil carbon (C) and nitrogen (N) availability compared to rice monocropping. Our objectives were to evaluate the effects of fertilization, namely P and K, in no-till ICLS of continuously flooded rice and rice-soybean rotation in subtropical paddy fields on: (i) soil microbial community, (ii) labile C and N pools, (iii) microbial groups, and (iv) rice yield. Both ICLS were annual ryegrass pastures under beef cattle grazing during the winter season without tillage. Although flooded rice yield did not respond to P and K fertilization in either ICLS, P and K fertilization increased microbial biomass C and N content, and permanganate-oxidizable C (POxC) by 37%, 36%, and 42%, respectively, in both production systems, due to alleviation of nutrient limitation for microbial growth. ICLS under soybean-rice rotation had higher C availability and 22.4% higher rice yield than the rice monocropping. Positive relationships were observed between microbial biomass N and Gram-positive (G+; R2 = 0.61), Gram-negative (G-; R2 = 0.54) bacteria, and saprophytic fungi (R2 = 0.45). However, total fungi was almost 10 times lower than the PLFA of total bacteria on average of cropping systems. G+ bacteria were the only microbial group correlated with N availability under flooded rice. We conclude that P and K fertilization has a direct impact on the microbial community and biomass and consequently on the C and N availability, but does not increase rice yield under no-till ICLS. Soybean-rice rotation yields more than rice monocropping system under ICLS and soil bacteria are more sensitive than saprophytic fungi to changes in soil nutrient status during flooding period in paddy fields.

Deep placement of nitrogen fertilizer increases rice yield and energy production efficiency under different mechanical rice production systems

Increasing energy output and improving energy production efficiency is essential to ensure the long-term sustainability of rice production systems in China. Present study assessed the energy input/output and its production efficiency for manual transplanted rice with manual broadcasting fertilizer (TR-MBF), mechanical pot-seedling transplanted rice synchronized with deep fertilization (MPST-DF), and mechanical hill direct-seeding rice synchronized with deep fertilization (MHDS-DF) in a three-year field experiment. Two rice cultivars i.e., Yuxiangyouzhan (YXYZ, inbred rice) and Wufengyou615 (WFY615, hybrid rice) were used to determine the energy input/output and production efficiency of each system. Results depicted that the MHDS-DF and MPST-DF treatment substantially improved the grain yield by 20.9% and 32.3% for WFY615 and YXYZ owing to enhanced total above-ground biomass (TAB) and leaf area index (LAI), respectively. Means across years and cultivars for energy input in the TR-MBF, MPST-DF, and MHDS-DF were remained 31918.0, 35267.1 and 36036.7 MJ ha−1, respectively. The energy consumed by diesel and fertilizer for energy inputs in the production system exceeds 70% of the total energy input. Moreover, the three rice production systems were highly dependent on non-renewable energy. The highest output energy and net energy were obtained for MHDS-DF and MPST-DF treatments with 221517.2 and 185670.0 MJ ha-1, respectively. Among the three rice production systems, the highest energy use efficiency, energy productivity efficiency, energy profitability efficiency was found in MPST-DF, which was slightly higher than MHDS-DF. However, the human energy profitability efficiency of MHDS-DF treatment was significantly higher than other treatments. Therefore, MHDS-DF and MPST-DF could be best alternative technologies than conventional rice production systems with improved energy input and energy production efficiency in South China. Furthermore, both MHDS-DF and MPST-DF would also be suitable in the regions with lack of labor force for rice production.

Site-specific nutrient management in rice (Oryza sativa): Status and prospect–A review

Site-specific nutrient management (SSNM) plays a vital role in increasing crop profitability, maintaining soil health and reducing environmental pollution. Field experiments and demonstrations conducted across southeast (SE) Asia were conducted during 2020–21 at ICAR-Indian Agricultural Research Institute, New Delhi and observed that SSNM includes various nutrient management practices and each practice have a positive impact on fulfilling its vital role. After a thorough study, this review reflects that fertilizer recommendations based on targeted yield concept were more balanced, profitable and helpful in controlling soil nutrient mining and essential for sustainable crop production. Establishment of an attainable yield target, based on location, season, climate, rice cultivar and crop management ensures effective use of existing indigenous nutrients such as from soil, organic amendments, crop residue, manure and irrigation water and application of fertilizer to dynamically fill the deficit between crop needs and indigenous supply and to maintain soil fertility. Moreover, use of nitrification inhibitor, deep placement of nitrogen (N) and NPK fertilizers reduces the loss of N fertilizers up to 20% and increases rice yield up to 10%. The leaf colour charts (LCC), chlorophyll meter or SPAD are inexpensive need based tools for fertilizer N management that can reduce the excessive application of N (10–50%). Optical sensor-based nitrogen management is an alternative to LCC and SPAD that can quickly and reliably monitor N requirements of rice. On the other hand, the dissemination of SSNM through LCC, SPAD, QUEFT models, optical sensor etc., requires training of researchers, local extension workers, fertilizer retailers, and farmer leaders on techniques and guidelines for enabling rice farmers. Therefore, a simple nutrient decision support tool, Nutrient Expert® (NE) is useful to develop strategies to manage fertilizer N, P and K tailored to farmer’s field or growing environment. However, comparative evaluation of different SSNM approach is essential for location wise fertilizer prescription for increasing crop profitability, soil health and environmental safety.

The OsNAC23-Tre6P-SnRK1a feed-forward loop regulates sugar homeostasis and grain yield in rice

Tre6P (trehalose-6-phosphate) mediates sensing of carbon availability to maintain sugar homeostasis in plants, which underpins crop yield and resilience. However, how Tre6P responds to fluctuations in sugar levels and regulates the utilization of sugars for growth remains to be addressed. Here, we report that the sugar-inducible rice NAC transcription factor OsNAC23 directly represses the transcription of the Tre6P phosphatase gene TPP1 to simultaneously elevate Tre6P and repress trehalose levels, thus facilitating carbon partitioning from source to sink organs. Meanwhile, OsNAC23 and Tre6P suppress the transcription and enzyme activity of SnRK1a, a low-carbon sensor and antagonist of OsNAC23, to prevent the SnRK1a-mediated phosphorylation and degradation of OsNAC23. Thus, OsNAC23, Tre6P, and SnRK1a form a feed-forward loop to sense sugar and maintain sugar homeostasis by transporting sugars to sink organs. Importantly, plants over-expressing OsNAC23 exhibited an elevated photosynthetic rate, sugar transport, and sink organ size, which consistently increased rice yields by 13%–17% in three elite-variety backgrounds and two locations, suggesting that manipulation of OsNAC23 expression has great potential for rice improvement. Collectively, these findings enhance our understanding of Tre6P-mediated sugar signaling and homeostasis, and provide a new strategy for genetic improvement of rice and possibly also other crops.

Rice Yields and Soil Nutrients Response to Liming Method and Dosages in Field Cultivation

It is important to develop a new convenient and environmentally-friendly technology of liming for sustainable rice production on acidic soil area. Thus, an experiment was conducted to evaluate the effect of application methods and rate of lime on soil properties and rice yield. The results showed that a similar ameliorating effect on agricultural acidic soil were found between massive quicklime and powered hydrated lime. Interestingly, optimized application rate of lime significantly increases rice yield, while over-liming leads to an adverse effect to the rice production. The changes of soil nutrients affected by liming rates were related to organic matter content and soil texture, with elevated mineralization of organic matter were found in organic and sandy soil. Conclusively, massive quicklime method has been found to be optimal for rice cultivation on acidic soil conditions with rates of 1500-2250 kg/ha for clay soil and 2250-3000 kg/ha for sandy soil, respectively.

Effect of Seaweed Extract Supplement on Rice Rhizosphere Bacterial Community in Tillering and Heading Stages

Rhizosphere microbiota are conducive to soil nutrient cycling for plant growth. Long-term and excessive application of chemical fertilizer is harmful to agriculture. Seaweed extract is a good organic substitute for rhizosphere ecosystem and plant growth. We supplemented 5‰ seaweed extract powder to chemical fertilizer, and then studied its effect on rhizosphere bacteria of japonica rice (Oryza sativa L. subsp. japonica). In a short-term experiment, we compared the changes in rhizosphere bacteria among four treatments, i.e., no fertilizer (T1), chemical fertilizer only (T2), chemical fertilizer with 5‰ seaweed extract (T3), and less chemical fertilizer with 5‰ seaweed extract (80% of that of T3) (T4). Results show that seaweed extract supplement could affect the bacterial community in tillering and heading stages; the α-diversity of rhizosphere bacteria in the heading stage was obviously improved. In addition, seaweed extract supplement improved significantly the content of nitrate nitrogen (N), available phosphorus (P), and available potassium (K) in rhizosphere soil in the tillering stage, and, finally, increased the rice yield and quality mildly. Therefore, the seaweed extract supplement is shown to be a potential strategy to enrich the diversity of rhizosphere bacteria, which enhanced soil nutrient level, increased rice yield and quality, and also saved the use of chemical fertilizer.

Substitution or complementarity: why do rice farmers use a mix of biopesticides and chemical pesticides in China?

Although scholars have become increasingly concerned about finding ways to encourage more farmers to use biopesticides and fewer to use chemical pesticides, few studies have investigated the prevalence of Chinese rice farmers' mixed use of biopesticides and chemical pesticides for pest management. Based on a household survey in Hubei Province, China, this study found that 59.18% of the sample rice farmers used a mix of biopesticides and chemical pesticides. There is mainly a complementarity relationship between rice farmers' decision to use biopesticides and chemical pesticides. The pursuit of multiple production purposes is the main reason why farmers decide on the mixed-use of pesticides. Specifically, farmers generally tend to use biopesticides to ensure food safety for consumption, and chemical pesticides to reduce costs for profitability. The decision of farmers to mix pesticides has led to an increase of pesticide varieties and costs. However, it reduces the frequency of pesticide use, and does not result in a significant increase in rice yield and output value. While food safety should be emphasized in working towards greater use of biopesticides, rice farmers' mixed use of biopesticides and chemical pesticides will remain for a long time until the biotechnology is more developed. In fact, programs that investigate the effects of a combination of biopesticides and chemical pesticides should be implemented to achieve pesticide reduction, because biopesticides and chemical pesticides have specific disadvantages. © 2022 Society of Chemical Industry.

Mitigating greenhouse gas emissions from irrigated rice cultivation through improved fertilizer and water management

Greenhouse gas (GHG) emissions from agriculture sector play an important role for global warming and climate change. Thus, it is necessary to find out GHG emissions mitigation strategies from rice cultivation. The efficient management of nitrogen fertilizer using urea deep placement (UDP) and the use of the water-saving alternate wetting and drying (AWD) irrigation could mitigate greenhouse gas (GHG) emissions and reduce environmental pollution. However, there is a dearth of studies on the impacts of UDP and the integrated plant nutrient system (IPNS) which combines poultry manure and prilled urea (PU) with different irrigation regimes on GHG emissions, nitrogen use efficiency (NUE) and rice yields. We conducted field experiments during the dry seasons of 2018, 2019, and 2020 to compare the effects of four fertilizer treatments including control (no N), PU, UDP, and IPNS in combination with two irrigation systems— (AWD and continuous flooding, CF) on GHG emissions, NUE and rice yield. Fertilizer treatments had significant (p < 0.05) interaction effects with irrigation regimes on methane (CH4) and nitrous oxide (N2O) emissions. PU reduced CH4 and N2O emissions by 6% and 20% compared to IPNS treatment, respectively under AWD irrigation, but produced similar emissions under CF irrigation. Similarly, UDP reduced cumulative CH4 emissions by 9% and 15% under AWD irrigation, and 9% and 11% under CF condition compared to PU and IPNS treatments, respectively. Across the year and fertilizer treatments, AWD irrigation significantly (p < 0.05) reduced cumulative CH4 emissions and GHG intensity by 28%, and 26%, respectively without significant yield loss compared to CF condition. Although AWD irrigation increased cumulative N2O emissions by 73%, it reduced the total global warming potential by 27% compared to CF irrigation. The CH4 emission factor for AWD was lower (1.67 kg ha−1 day−1) compared to CF (2.33 kg ha−1 day−1). Across the irrigation regimes, UDP increased rice yield by 21% and N recovery efficiency by 58% compared to PU. These results suggest that both UDP and AWD irrigation might be considered as a carbon-friendly technology.

Model for Predicting Rice Yield from Reflectance Index and Weather Variables in Lowland Rice Fields

Smallholder rice farmers need a multi-purpose model to forecast yield and manage limited resources such as fertiliser, irrigation water supply in-season, thus optimising inputs and increasing rice yield. Active sensing tools like Canopeo and GreenSeeker-NDVI have provided the opportunity to monitor crop health and development at different growth stages. In this study, we assessed the effectiveness of in-season estimation of rice yield in lowland fields of northwest Cambodia using weather data and vegetation cover information measured with; (1) the mobile app-Canopeo, and (2) the conventional GreenSeeker hand-held device that measures the normalised difference vegetative index (NDVI). We collected data from a series of on-farm field experiments in the rice-growing regions in 2018 and 2019. Average temperature and cumulative rainfall were calculated at panicle initiation and pre-heading stages when the crop cover index was measured. A generalised additive model (GAM) was generated using log-transformed data for grain yield, with the combined predictors of canopy cover and weather data during panicle initiation and pre-heading stages. The pre-heading stage was the best stage for grain yield prediction with the Canopeo-derived vegetation index and weather data. Overall, the Canopeo index model explained 65% of the variability in rice yield and Canopeo index, average temperature and cumulative rainfall explained 5, 65 and 56% of the yield variability in rice yield, respectively, at the pre-heading stage. The model (Canopeo index and weather data) evaluation for the training set between the observed and the predicted yield indicated an R2 value of 0.53 and root mean square error (RMSE) was 0.116 kg ha−1 at the pre-heading stage. When the model was tested on a validation set, the R2 value was 0.51 (RMSE = 925.533 kg ha−1) between the observed and the predicted yield. The NDVI-weather model explained 62% of the variability in yield, NDVI, average temperature and cumulative rainfall explained 3, 62 and 54%, respectively, of the variability in yield for the training set. The NDVI-weather model evaluation for the training set showed a slightly lower fit with R2 value of 0.51 (RMSE = 0.119 kg ha−1) between the observed and the predicted yield at pre-heading stage. The accuracy performance of the model indicated an R2 value of 0.46 (RMSE = 979.283 kg ha−1) at the same growth stage for validation set. The vegetation-derived information from Canopeo index-weather data increasingly correlated with rice yield than NDVI-weather data. Therefore, the Canopeo index-weather model is a flexible and effective tool for the prediction of rice yield in smallholder fields and can potentially be used to identify and manage fertiliser and water supply to maximise productivity in rice production systems. Data availability from more field experiments are needed to test the model’s accuracy and improve its robustness.

Response of Rice Harvest Index to Different Water and Nitrogen Management Modes in the Black Soil Region of Northeast China

Understanding the methods leading to rice yield increase is vital for sustainable agricultural development. Improving the harvest index (HI) is an important way to increase rice yield. To explore the effects of different water and nitrogen management modes on the rice HI in the black soil region of Northeast China, a field experiment was conducted in 2019 (Y1) and 2020 (Y2). Two irrigation methods, conventional flooding irrigation (FI) and controlled irrigation (CI), were established in the experiment, and four nitrogen application levels (0 kg/ha, 85 kg/ha, 110 kg/ha, and 135 kg/ha) were set during the entire growth period, named N0, N1, N2, and N3. The dry matter weight and the rice yield at the maturity stage were determined, and the HI was then calculated. The results showed that different irrigation modes and nitrogen application levels had significant effects on the rice HI. Under different irrigation modes with the same nitrogen application level during the two years, the comparison regular of HI was consistent. In Y1 and Y2, the HI of FN0 was 3.36% and 5.02% higher than that of CN0 (p &lt; 0.05), and the HI of CN1 was 0.31% and 2.43% higher than that of FN1 (p &gt; 0.05). The HI under CI was significantly higher than that under FI under N2 and N3 (p &lt; 0.05), the HI of CN2 was 4.21% and 4.97% higher than that of FN2, and the HI of FN3 was 13.12% and 20.34% higher than that of CN3. In addition, during the two-year experiment, the HI first increased and then decreased with an increase in the nitrogen application rate under FI and CI. Under the FI treatments, the HI of N1 was the highest, and that of N2 was the highest under the CI treatments. A variance analysis showed that the irrigation pattern and nitrogen application level had significant interactions on the rice HI (p &lt; 0.01), and the appropriate water and N management mode could increase rice the HI by 26.89%. The experimental results showed that the HI of the 110 kg/ha nitrogen application rate under CI was the highest, reaching 0.574 and 0.572, respectively, in two years. This study provides a data reference and theoretical support for realizing water savings, nitrogen reduction, and sustainable agricultural development in the black soil region of Northeast China.

Impacts of Slow-Release Nitrogen Fertilizer Rates on the Morpho-Physiological Traits, Yield, and Nitrogen Use Efficiency of Rice under Different Water Regimes

The efficient use of water and fertilizer is vital for optimizing plant growth and yield in rice production. To achieve sustainable rice production and resource management, the ways in which applied water and nitrogen affect the root and shoot morpho-physiology, as well as yield, must be understood. In this study, a pot experiment was conducted to investigate the effects of slow-release nitrogen fertilizer (sulfur-coated urea) application at three levels (light nitrogen (NL), medium nitrogen (NM), and heavy nitrogen (NH)) on the growth, yield, and nitrogen use efficiency (NUE) of rice grown under three water regimes (wetting and soil saturation (WSS), wetting and moderate drying (WMD) and wetting and severe drying (WSD)). The results revealed that differences in water regimes and fertilizer rates led to significant differences in the roots, shoots, yield, and NUE of rice. Increasing the N dosage by 5% enhanced the root and biomass production by 16% in comparison with that of the other groups. The NH×WSS treatment produced the greatest root length, weight, density, active absorption, and oxidation. However, the integration of WSS × NL generated the maximum value of nitrogen apparent recovery efficiency (63.1% to 67.6%) and the greatest value of nitrogen partial factor productivity (39.9 g g−1 to 41.13 g g−1). Transmission electron microscopy (TEM) images showed that plants grown under high and medium nitrogen fertilizer rates with WSS had improved leaf mesophyll structure with normal starch grains, clear cell walls, and well-developed chloroplasts with tidy and well-arranged thylakoids. These results show that TEM images are useful for characterizing the nitrogen and water status of leaves in the sub-micrometer range and providing specific information regarding the leaf microstructure. The findings of this study suggest that the application of NH×WSS can produce improvements in growth traits and increase rice yield; however, the NL×WSS treatment led to greater NUE, and the authors recommend its usage in rice agriculture.

Genetic diversity reveals synergistic interaction between yield components could improve the sink size and yield in rice

AbstractIntensive breeding programs have increased rice yields, strongly contributing to increasing global food security during the post‐green revolution period. However, rice productivity has reached a yield barrier where further yield improvement is restricted by inadequate information on the association of yield components, and morphological and physiological traits with yield. We conducted a field experiment to evaluate (i) the contribution of morphological and physiological traits to yield and (ii) quantify the trade‐off effect between the yield components in rice, using a mini‐core collection of 362 rice genotypes comprising geographically distinct landraces and breeding lines. Our data point towards multiscale coordination of physiological and morphological traits associated with yield and biomass. Considerable trait variations across the genotypes in yield ranging from 0.5 to 78.5 g hill−1and harvest index ranging from 0.7% to 60.7% highlight enormous diversity in rice across the globe. The natural elimination of trade‐off between yield components revealed the possibility to enhance rice yield in modern cultivars. Furthermore, our study demonstrated that genotypes with larger sink sizes could fix more carbon to achieve a higher yield. We propose that the knowledge thus generated in this study can be helpful for (a) trait‐based modeling and pyramiding alleles in rice‐breeding programs and (b) assisting breeders and physiologists in their efforts to improve crop productivity under a changing climate, thus harnessing the potential for sustainable productivity gains.

Biochar increases rice yield by improving root morphological and root physiological functions in heavily saline-sodic paddy soil of Northeast China

Saline-sodic soil is one of the major threats to crop growth, production, and quality. Biochar amendment could alleviate the adverse impacts of saline-sodic stress in crops. However, the effect of biochar on root morphological, root physiological functions, and rice yield in saline-sodic paddy soil has not been studied. Here, the underlying mechanisms of positive effects in morphological characteristics and physiological functions of rice roots under heavily saline-sodic paddy soil amended with biochar were evaluated. The soil was amended with biochar at zero-biochar (CK), 15g kg-1 soil (T1), 30 g kg-1 soil (T2), or 45 g kg-1 soil (T3). Biochar addition significantly increased root length, root volume, root dry weight, and root-shoot ratio at all growth stages. The root absorption vigor and root oxidization capacity were enhanced and increased significantly by decreasing Na+/K+ ratio, MDA content, and increasing K+ concentration in rice root after biochar amendment. The root bleeding rate of biochar treatments at different growth stage were 11.01% to 67.73% greater than these of CK. The yield of rice was increased significantly under saline-sodic paddy soil after biochar amendment. It was concluded that biochar had positive effect on the morphological characteristics and physiological functions in rice roots in saline-sodic paddy soil.

Phosphorus management strategies to increase lowland rice yields in sub-Saharan Africa: A review

Phosphorus (P) deficiency is one of the major yield-limiting factors for lowland rice production in sub-Saharan Africa (SSA). Therefore, improved P management could be an effective strategy to increase lowland rice yields in SSA. The study reviews on historical and recent efforts for improving P management for lowland rice production in SSA together with their limitations and prospects for future research. Special focuses are on following three aspects: (1) suitable soil tests to assess the indigenous soil P supply and the yield response to P application in lowlands; (2) organic inputs and localized P application to the nursery bed (nursery P) and to the seedling roots at transplanting (P-dipping); (3) the interaction between P application and climate-induced stresses via its impact on phenological development. For the first aspect, we demonstrate the importance of considering the P adsorption and desorption kinetics in SSA soils, where large amounts of insoluble P complexes are bound to iron and aluminum oxides while these insoluble P pools are solubilized under submerged soil culture. We propose using the oxalate-extractable P, which extracts insoluble P pools bound to amorphous iron-oxide minerals, as a reliable test for measuring the indigenous soil P supply for lowland rice production. With respect to the second aspect, the efficient use of organic inputs—an important nutrient resource for smallholder farmers in SSA—can be reconsidered not only as a source of P but also as a substance to accelerate the chemical reaction and P solubilization in soils for lowland rice production. Several studies have demonstrated significant effects of nursery P and P-dipping to increase rice yields and agronomic P use efficiency (AE P ) as the yield gain per unit of P applied. Excess yield gains with a micro-dosing nursery P may have a risk of P mining from soils. The P-dipping retains the P input-output balance and achieves a consistently high AE P at 74–152 kg kg −1 . The third aspect has received little attention in the previous studies, although recent observations indicate that P management affects rice yields via its impact on phenological development. The time to heading under P deficiency can extend beyond three weeks, which allows plants to accumulate more biomass production while increasing the risk of biotic and abiotic stresses at the reproductive and ripening stages. Further attention should be paid to changes in phenological development and their interactions with climate-induced stress to develop improved P management practices in SSA. • Improved P management strategies can increase rice yield in sub-Saharan Africa. • Organic amendment increases effectively available P in soils and rice growth. • Localized P at nursery and transplanting stages increases rice yields with high AE P . • Improved P management should take into account the effect of P on rice phenology.

Characterization and fine mapping of a semi-rolled leaf mutant srl3 in rice

Moderate leaf rolling can maintain leaf erectness, improve light transmittance in the population, and improve light energy utilization, thereby increasing rice yield. This study used ethyl methanesulfonate (EMS) to treat Yunjing 17 (YJ17) and obtained a semi-rolled leaf mutant that was named semi-rolledleaf3 (srl3). We found that the rolled-leaf phenotype was due to the aberrant development of bulliform cells and the loss of sclerenchymatous cells. In addition, the shoot and root length of srl3 seedlings differed from the wild type. The srl3 mutant had significantly lower plant height and seed-setting rate but notably greater tiller number, panicle length, and primary branch number per panicle than the wild type. Genetic analysis showed that a single recessive nuclear gene defined the srl3 mutant, and it was precisely located in a 144-kb region between two insertion-deletion (InDel) markers, M8 and M19, on chromosome 2. In this region, no leaf-rolling-related genes have been reported previously. Thus, the study indicated that SRL3 is a novel leaf-rolling-related gene, and the results laid the foundation for the cloning and functional analysis of the SRL3 gene.

EXPLORING FARMERS’ ATTITUDES TOWARDS YIELD GAP MINIMIZATION OF RICE: A CASE FROM MYMENSINGH DISTRICT, BANGLADESH

Farmers’ understanding of yield gap is necessary to increase rice yield and meet the rising demand for rice in Bangladesh. An investigation was conducted to explore the farmers’ attitudes towards yield gap minimization of rice in Muktagachha sub-district, Mymensingh District, Bangladesh. From February to April 2019, data was collected utilizing a structured interview schedule from 100 randomly selected rice growers. Descriptive statistics, rank order, coefficient of correlation, and multiple linear regression were used to examine the data. The findings revealed that almost all of the rice farmers had moderately (62.22%) to highly (37.78%) favourable attitudes towards yield gap minimization of rice in the investigation region. Among twenty attitudinal statements, ‘measurement of yield gap of rice is very easy for the farmers’ was identified as the most important one. The least ranked statement was ‘political problems act as a barrier to minimize rice yield gap’. According to the results of the correlation analysis, participation in organization, extension media interaction, training received, knowledge of adoption of HYV, and innovativeness were positively and significantly related with farmers’ attitudes towards yield gap minimization of rice. Results of regression analysis showed that organizational participation, extension media interaction, training received, knowledge of adoption of HYV, and innovativeness made significant contributions to favourable attitudes of the farmers towards yield gap minimization of rice. Expanding research, monitoring transfer of technology, providing simple access to extension agents, and developing farmers’ knowledge and skills through effective training could all help to close the rice yield gap.

Rotation with Green Manure Increased Rice Yield and Soil Carbon in Paddies from Yangtze River Valley, China

Rotation with Green Manure Increased Rice Yield and Soil Carbon in Paddies from Yangtze River Valley, China

Winter Crops Rotation Intensification to Increase Rice Yield, Soil Carbon and Microbial Diversity

Winter Crops Rotation Intensification to Increase Rice Yield, Soil Carbon and Microbial Diversity

Using ENSO conditions to optimize rice yield for Nepal’s Terai

The direct application of forecasts from seasonal prediction systems (SPSs) in agriculture is limited by their skill, and SPSs are more skilled at El Niño-Southern Oscillation (ENSO) prediction than precipitation prediction. An alternative to the direct application of forecasts from SPSs could be to link the forecast of ENSO conditions with dynamic crop models to evaluate alternate crop management options prior to the start of the actual planting. Although potential benefits of this approach have been tested in many areas of the world, so far limited evidence exists regarding its application in Nepal’s Terai region. The overall goal of this study was to determine the potential relationship between ENSO and summer monsoon precipitation over Nepal’s Terai and ascertain SPSs’ skill in predicting ENSO. This analysis included disentangling the relative contribution of precipitation to interannual variability in rice yield from other factors using a cropping system model, namely, the Crop Environment Resource Synthesis-Rice (CSM-CERES-Rice). The crop model was also employed to explore options for increasing rice yield and minimizing risk by adjusting crop management. This study found that precipitation was the main variable affecting interannual variability in rice yield, that SPSs are good at predicting ENSO, and that the ENSO signal can be used to predict seasonal precipitation anomalies in the study area in all years except ENSO neutral years. Prior knowledge of seasonal precipitation anomalies can then be used to optimize rice yield using a crop model, and ultimately to assist farmers with decision making.

The impact of cultivar development and cultural practices on Louisiana rice yield

AbstractThis analysis investigates the impact of cultivar development and cultural practices on Louisiana rice (Oryza sativa L.) yield growth using the Chow test (Chow, 1960) in combination with regression analysis. The analysis examines the 1895–2019 period, and uses four scenarios in which one, two, three, and four subperiods show varying rates of rice yield growth in Louisiana. There has been a significant increase in Louisiana rice yields over time. However, the growth in yields for some of the subperiods is greater than for others. Our results of significant rice yield increase over time correspond with events such as the establishment of Louisiana's Foundation Seed Program, the release of the Magnolia rice cultivar, and increased mechanization.