Paddy Rice Cultivation Research Articles

Impact of dairy wastewater on paddy rice cultivation, leachate microbes, and soil health under alternate wetting and drying irrigation

Impact of dairy wastewater on paddy rice cultivation, leachate microbes, and soil health under alternate wetting and drying irrigation

METODE PENYULUHAN KELOMPOK DALAM BUDIDAYA PADI SAWAH DI DESA LEBO JAYA KECAMATAN KONDA KABUPATEN KONAWE SELATAN

The implementation of extension activities is confronted with a multitude of challenges and difficulties. It is therefore imperative for extension workers to possess a comprehensive understanding of the most appropriate and productive extension methods in the context of agricultural extension activities. The objective of this study was to ascertain the efficacy of group extension methods in paddy rice cultivation and to elucidate the relationship between the two. The study population consisted of all rice paddy farmers in Lebo Jaya Village, Konda Subdistrict, with a total of 104 farmers. The sample size was determined using the Slovin formula, with a degree of error or margin of error of 15%, resulting in a research sample of 31 respondents. The sampling technique employed was simple random sampling. The data were collected via survey, interview, and document analysis, using various media in the form of questionnaires. The research employed a quantitative approach. The research variables were twofold, comprising group extension methods and paddy rice cultivation activities. The data were subjected to quantitative descriptive analysis, employing the class interval formula and the Spearman rank correlation equation. The findings indicated that the implementation of group extension methods in paddy rice cultivation in Lebo Jaya Village was classified as "good." The aforementioned activities, which pertain to paddy rice cultivation specifically, land preparation, seed selection, irrigation, fertilization, pest and disease control have been classified as "good." The level of application of group counseling methods is found to be significantly and positively related to the cultivation of wet rice in Lebo Jaya Village. The correlation value is 0.542, and the significance of 0.002 is less than 0.05. The strength of the relationship between group extension methods and paddy rice cultivation activities is moderately strong. This indicates that an improvement in the method of agricultural counseling will result in an improvement in rice paddy farming activities in Lebo Jaya Village, Konda Subdistrict, South Konawe District.

Greenhouse gases emission trade-offs for benefits gain - An analysis from paddy rice and upland crops cultivation in Hau Giang province, Viet Nam

Agriculture activities require energy for operation and emit greenhouse gases (GHGs) into the atmosphere. However, agriculture provides essential nutrients with carbon sources through its main and by-products. This study used the life cycle assessment methodology to evaluate the carbon balance in agricultural systems of paddy rice (PR), corn, mung bean (MB), and black sesame (BS) in the summer-autumn growing season in the Vietnamese Mekong Delta. The results showed that PR and upland crops produced a net carbon source of 1,280.9–18,915 kg-C ha–1. Corn cultivation achieved the best value in carbon index analyses. To have one calorie from grain, selected crops must trade off 115.19–501.81 mg-CO2e. This study concluded that four selected crop cultivations achieved carbon analysis benefits. However, corn is a suitable recommendation for adapting to the agricultural conversion from PR farming to better upland crop cultivation.

Evaluating Flood Damage to Paddy Rice Fields Using PlanetScope and Sentinel-1 Data in North-Western Nigeria: Towards Potential Climate Adaptation Strategies

Floods are significant global disasters, but their impact in developing countries is greater due to the lower shock tolerance, many subsistence farmers, land fragmentation, poor adaptation strategies, and low technical capacity, which worsen food security and livelihoods. Therefore, accurate and timely monitoring of flooded crop areas is crucial for both disaster impact assessments and adaptation strategies. However, most existing methods for monitoring flooded crops using remote sensing focus solely on estimating the flood damage, neglecting the need for adaptation decisions. To address these issues, we have developed an approach to mapping flooded rice fields using Earth observation and machine learning. This approach integrates high-resolution multispectral satellite images with Sentinel-1 data. We have demonstrated the reliability and applicability of this approach by using a manually labelled dataset related to a devastating flood event in north-western Nigeria. Additionally, we have developed a land suitability model to evaluate potential areas for paddy rice cultivation. Our crop extent and land use/land cover classifications achieved an overall accuracy of between 93% and 95%, while our flood mapping achieved an overall accuracy of 99%. Our findings indicate that the flood event caused damage to almost 60% of the paddy rice fields. Based on the land suitability assessment, our results indicate that more land is suitable for cultivation during natural floods than is currently being used. We propose several recommendations as adaptation measures for stakeholders to improve livelihoods and mitigate flood disasters. This study highlights the importance of integrating multispectral and synthetic aperture radar (SAR) data for flood crop mapping using machine learning. Decision-makers will benefit from the flood crop mapping framework developed in this study in a number of spatial planning applications.

Noxious Weed Species Monochoria vaginalis Resistant to Synthetic Auxin and Acetolactate Synthase Inhibitor Herbicides

<em>Monochoria vaginalis</em> (Burm. f.) C. Presl is a dominant weed in paddy rice cultivation, significantly threatening productivity and farming sustainability. In Subang, Indonesia, synthetic auxin and acetolactate synthase (ALS) inhibitors are commonly used to control <em>M. vaginalis</em>. However, farmers have currently reported declining efficacy of these herbicides. Therefore, this study aimed to confirm the resistance of <em>M. vaginalis</em> to the early post-emergence application of synthetic auxin and ALS inhibitors. Plant bioassays were conducted using the pot test method to determine resistance level. Herbicides were applied 2 weeks after planting <em>M. vaginalis</em> at 0.25, 0.5, 1.0, 2.0, 4.0, and 8.0 times the recommended dose, and untreated plants as control. Herbicides tested were 2,4-D, bensulfuron-methyl, bispyribac sodium, penoxulam, and sulfentrazone. The results obtained based on resistance index values (RI) showed that <em>M. vaginalis</em> populations from Kediri and Gandasari, Subang, had moderately to high resistance to 2,4-D (RI: 8.15 and 13.0) and bensulfuron-methyl<em> </em>(RI: 205.61 and 21.80). Weed was moderately resistant to bispyribac sodium<em> </em>(RI of Kediri biotype: 8.79) and had low to moderate resistance to penoxulam herbicides (RI: 8.94 and 3.56). In contrast, <em>M. vaginalis-</em>resistant biotypes remained susceptible to sulfentrazone (protoporphyrinogen oxidase/PPO inhibitors) herbicide. A significant increase in GR50 was observed between 28 and 56 days after herbicide application, signifying enhanced regrowth. The resistance of <em>M. vaginalis</em> to synthetic auxin and ALS inhibitors presents the need for farmers to consider alternative herbicides, such as PPO inhibitors, to prevent the development of resistant weeds.

Water Management and Hydrological Characteristics of Paddy-Rice Fields under Alternate Wetting and Drying Irrigation Practice as Climate Smart Practice: A Review

Paddy-rice cultivation using the traditional continuous flooding method requires much water, up to 2500 L, to produce 1 kg of rice. Decreasing water availability is being exacerbated by climate dynamics, i.e., droughts and rainfall variability negatively affecting food security in developing regions, particularly Africa. Alternate wetting and drying (AWD) practice is a climate-smart water management strategy that, together with puddling (a critical field preparation process), significantly affects soil hydrological and physicochemical regimes, such as soil water dynamics and oxidation states in paddy fields. However, there are limited reviews on the effects and interaction of the AWD duration on hydrological conditions in the paddy-rice rhizosphere continuum under AWD practice at different rice growth stages. Our review synthesizes key scientific literature to examine water management and hydrological properties of paddy soils under AWD practice with climate change and sheds light on why farmers are skeptical in adopting the practice. To develop this paper, we reviewed scientific information from published journal articles, reliable reports, and our knowledge on paddy-rice cultivation and water management with climate change in Asia and Sub-Saharan Africa. Several studies confirm that AWD practice increases water–rice–crop productivity, yields, and reduces methane emissions. Limitations and challenges of AWD irrigation, including changes in soil structure that influence irrigation water application, variations in hydraulic conductivity caused by the duration and frequency of irrigation cycles, and frequent manual water level (WL) monitoring, are discussed. Opportunities to improve the integration of AWD strategies within government policies, irrigation schemes, and farmer acceptance due to skepticism, limited knowledge, and fear of unreliable water hindering adoption are highlighted. Future research suggestions include the following: (i) long-term measurement of water stress indices using infrared thermometers; (ii) seasonal suitability mapping using NDVI, GIS, and remote sensing; and (iii) application of smart sensors based on the Internet of Things (IoT) to address AWD challenges for precision water management in paddy fields with climate change.

An automatic rice mapping method based on an integrated time-series gradient boosting tree using GF-6 and sentinel-2 images

ABSTRACT Timely and accurate mapping of paddy rice cultivation based on remote sensing technology is crucial and valuable for ensuring food security and sustainable environmental management. In most relevant studies, rice mapping was conducted using time-series images, but conventional rice mapping methods are not specifically designed for time-series data, making it difficult to extract the deep information contained in these data. To address these problems, in this paper, an automatic rice mapping method based on an integrated time-series gradient boosting tree (Auto-ITSGBT) is proposed using GF-6 WFV and Sentinel-2 MSI data. This method accounts for the local and overall shape features of time-series curves, and fully exploits the information related to phenological characteristics between time-series data. The proposed rice mapping method is tested and validated in three typical rice-producing areas, which are located in different provinces of China characterized by diverse climate conditions, planting times or topographies. The results show that the overall accuracy and Kappa coefficient of the method exceeded 95% and 0.93, respectively, at all study sites, respectively. Our method performs better than the existing competing methods, with an overall accuracy improvement of 2% to 4%. To identify the rice planting areas as early as possible, rice mapping was conducted by reducing the number of images one by one. The rice distribution map was obtained in mid-July with an overall accuracy of at least 90%, thus obtaining a spatial distribution map of rice with high accuracy before harvesting.

EFISIENSI TEKNIS USAHATANI PADI SAWAH PADA PERTANIAN PERKOTAAN DI KOTA SEMARANG: PENDEKATAN STHOCHASTIC FRONTIER

Improving food self-sufficiency requires a strategy to increase paddy rice production. The urban agriculture initiative in Semarang City is seen as a suitable policy. However, the current increase in agricultural productivity through improved production efficiency is hampered by land conversion and inappropriate use of production inputs. The objective of this study is to assess the technical efficiency of wet-rice farming and its influencing factors in Semarang City. Cross-sectional data from 68 respondents were used in this study. The data analysis strategy used in this study is Maximum Likelihood Estimation (MLE) combined with Stochastic Frontier Cobb Douglas production function. The results show that land area, seeds, NPK, urea, and pesticides are the main determinants of rice production. Paddy rice cultivation in Semarang City is technically efficient (0.73). Formal education and other sources of off-farm income are factors that influence the level of technical inefficiency of wet-rice cultivation. Strategies to achieve food self-sufficiency in urban agriculture include developing extension strategies and improving agricultural infrastructure.

Paddy rice methane emissions, controlling factors, and mitigation potentials across Monsoon Asia

Rice is a staple food for more than half of humanity, and 90 % of rice is grown and consumed in Asia. However, paddy rice cultivation creates an ideal environment for the production and release of methane (CH4). How to estimate regional CH4 emissions accurately and how to mitigate them efficiently have been of key concern. Here, with a machine learning method, we investigate the spatiotemporal changes, the major controlling factors and mitigation potentials of paddy rice CH4 emissions across Monsoon Asia at a resolution of 0.1° (∼10 km). Spatially CH4 emissions are highly heterogeneous, with the Indo-Gangetic Plain, Deltas of the Mekong, and Yangtze River Basin as the hotspots. Nationwide, China, India, Bangladesh and Vietnam are the major emitters. Straw applied on season is a critical controlling factor for CH4 emission in rice fields. The single-season rice contributes to over 80 % of the total emissions. CH4 emissions from Monsoon Asia have notably declined since 2007. Three mitigation strategies, including water management techniques, off-season straw return, and straw to biochar, may reduce CH4 emissions by 27.66 %, 23.78 %, and 21.79 %, respectively, with the most effective strategy being rice cultivation type-specific and environment-specific. Our findings gain new insights into CH4 emissions and mitigations across Monsoon Asia, providing evidence to adopt precise mitigation strategies based on rice cultivation types and local environment.

Assessing paddy methane emissions through the identification of rice and winter crop areas using Sentinel-2 imagery in Korea

The global efforts on reducing methane (CH4) emissions was emphasized in COP 28 and the potential for improved estimation became feasible through bottom-up data acquisition with advanced remote sensing technology. The objectives of this study were to extract summer rice and winter crop cultivation areas based on satellite images and to incorporate into estimating CH4 emissions in South Korea for the year 2020. Satellite images of Sentinel-1 and Sentinel-2 were acquired from European Space Agency. Rice paddy was classified with backscattering coefficient from Sentinel-1 images, while the normalized difference vegetation index from Sentinel-2 images was used to identify winter cropping field. The equation of IPCC guidelines was used to estimate CH4 emissions by incorporating the areas of rice paddy and winter crop extracted with the respective satellite image. National farming statistics were used to determine the scaling factors for paddy organic matter and water management practices. The estimated areas for rice paddy and winter crop cultivation were 712,237 ha and 117,840 ha, respectively. The rice paddy areas were primarily concentrated in the western regions of the Korean peninsula, whereas winter crop cultivation was predominantly found in southern part of the country. The total amount of CH4 emissions was 6272 Gg CO2 eq./yr when considering rice straw and winter cropping practices into estimation (modified Tier 2 method). This represents a 7% increase compared to the method that considered solely the rice straw incorporation (current Tier 2 method). The CH4 emissions per unit area were also 8.82 tons CO2 eq./ha/yr with the modified Tier 2 method, indicating a 10% greater compared to the current Tier 2 method. Substantial CH4 emissions were primarily concentrated in western regions where extensive rice paddy cultivation occurs, while greater CH4 emissions per unit area were predominantly found in southern regions with substantial winter crop cultivation. The study findings hold importance for improving the accuracy of CH4 emissions estimation by employing bottom-up approach that utilizes satellite imagery to assess rice paddy and winter cropping areas. Further study would be needed to incorporate field-based data on rice crop management practices, such as rice straw and water management, to further refine CH4 emission estimation method.

Active Soil Organic Carbon Pools Decrease with Increased Time since Land-Use Transition from Rice Paddy Cultivation to Areca Nut Plantations under the Long-Term Application of Inorganic Fertilizer

Many croplands in the tropics of China have been converted over the last decades into areca nut plantations due to their high economic returns. This land-use transition was accompanied by changes in agricultural practices such as soil moisture regimes and fertilizer inputs, which may affect soil organic carbon (SOC) and its fractions, especially in tropical soils with low fertility and high nitrogen loss. Yet, how the time since land-use transition from rice paddy cultivation to areca nut plantations affects soil carbon dynamics and their underlying mechanisms in the tropics of China remains elusive. Here, areca nut plantation soils with different ages (2, 5, 10, 14, and 17 years) and paddy fields in the tropical region of China were investigated. The study result indicates that the contents of dissolved organic carbon (DOC), particulate organic carbon (POC), easily oxidized organic carbon (EOC), light organic carbon (LFOC), and microbial biomass carbon (MBC) decreased significantly with increased time since land-use transition from rice paddy cultivation to areca nut plantations. Similarly, the ratios of DOC/SOC, MBC/SOC, POC/SOC, LFOC/SOC, and EOC/SOC decreased significantly with increased time since land-use transition. Compared with the paddy soil, the carbon pool management index decreased by 36.6–76.7% under the areca nut plantations, concluding that increasing the time since land-use transition from rice paddy cultivation to areca nut plantations with high application rates of chemical fertilizers resulted in reduced soil active carbon fractions and SOC supply capacity. Therefore, agricultural practices such as the use of organic fertilizers should be applied to improve the soil’s ability to supply organic carbon in managed plantation ecosystems in the tropics of China.

Examining underutilized jackfruit (Artocarpus heterophyllus) seeds as a potential source of human subsistence in the Byse community, India

IntroductionThe seeds of jackfruit are often overlooked and discarded globally, leading to the underutilization of this valuable resource. This study explored the potential of utilizing underutilized jackfruit seeds as an alternative source of human subsistence by investigating the availability of jackfruit, the utilization and underutilization of seeds at the household level, and the types of subsistence activities in the community.MethodsWe used a case study of Byse village in Karnataka, India, to understand this topic. A mixed research approach was used. First, a descriptive research design was employed to collect and describe the data, while a correlation design was used to examine the relationships among variables related to jackfruit seed utilization. Second, a bibliometric analysis was conducted to explore global trends in jackfruit seed utilization.Results and DiscussionThe findings indicated that agriculture, particularly arecanut farming followed by paddy rice cultivation, was the primary means of subsistence in the community. While human consumption of jackfruit seeds is statistically significant, it has a detrimental effect on seed utilization in the community (r = −0.295, p = 0.008). The study also revealed that consuming jackfruit seeds in a semidry form had a positive and significant influence (r = 0.345, p = 0.002) compared to eating them in a fresh form. Consequently, more focus could be placed on encouraging the consumption of semidry jackfruit seeds as a preferred option among residents. Despite the abundance of jackfruits, their seeds are rarely used, with a mean utilization score of 1.77. Since jackfruit seeds are limited in their application and are readily available, they could be utilized as an alternative source for sustainable human subsistence. sustainable human subsistence.

Improving a herbicide risk assessment model in paddy rice cultivation

Herbicides play a pivotal role in paddy rice cultivation by effectively controlling weeds, thus ensuring optimal resource utilisation and higher crop yields, making them indispensable for efficient rice production systems. However, herbicide applications could be related to potential environmental impacts such as water contamination and harm to non-target species, requiring special attention in their management to ensure the long-term sustainability of rice farming practices. The development and utilisation of robust risk assessment indicators for pesticides are essential tools in evaluating and mitigating potential environmental and human health hazards associated with pesticide use in agricultural practices. The Environmental Potential Risk Indicator for Pesticides (EPRIP) is not suitable for rice paddy cultivation due to its limitations in accurately assessing pesticide risk in this specific agricultural context. This is primarily attributed to the unique hydrological characteristics and ecosystem dynamics of paddy fields, which significantly differ from other agricultural systems. To address this issue and to enhance the accuracy of pesticide risk assessment in rice paddy fields, EPRIP has been improved and validated in two agricultural seasons. A synergistic approach involving field experiments and enhanced EPRIP model simulations was employed to assess the risk associated with the application of two herbicides in Italian paddy rice systems. The observed and model-predicted surface water (SW) concentrations exhibited a close alignment, though an overestimation was observed for groundwater (GW). In general, the estimated Risk Points (1 for SW and 4 for GW) were largely in accord with those derived from the field experiments (1 for SW and 3 for GW), suggesting that the refined EPRIP model holds promise for conducting reliable risk assessments following herbicide applications in such contexts.

Response of Bacterial Community Structure in the Bulk Soil and Rice Straw Residues under Different Crop Rotation Systems

This study investigated the effect of upland crop rotation on soil bacterial community in bulk soil and rice straw residues in the alluvial soils. Soil samples and rice straw residues in two crop rotation models including triple rice and rice-upland crops were collected for incubation under anaerobic and aerobic conditions. Data were analyzed from Denaturing Gradient Gel Electrophoresis band patterns. The results showed that the composition and diversity of communities colonizing the rice straw residues differed from those inhabiting the bulk soil. The bacterial community composition and diversity were only moderately affected by rice straw residues in the bulk soil. Especially, this study indicated that the composition of the bacterial community associated with the bulk soil and rice straw residues was dynamic in two incubation conditions (aerobic or anaerobic) and the different crop rotation models. The findings of this study demonstrated that the bacterial diversity was not affected by the difference in continuous paddy rice cultivation compared to the upland crop rotation system.

Kajian Penerapan Teknologi Budidaya Tanaman Dan Produktivitas Padi Sawah (Oryza sativa L.) Di Kecamatan Dumoga

The objective of the study was to assess the application of crop cultivation technology and productivity of paddy rice in Dumoga District, Bolaang Mongondow Regency, North Sulawesi Province. The research was conducted from November to December 2022. The research was located in Dumoga District, Bolaang Mongondow Regency, North Sulawesi Province. This research was qualitative research by conducting surveys and interviews with 30 farmers in Dumoga Subdistrict using a prepared questionnaire, including the identity of farmers, farming conditions and cultivation techniques of paddy rice in Dumoga Subdistrict (North Mopugad Main Village, North Mopugad 1, North Mopugad, South Mopugad, South Mopugad 1, South Mopuya, and Amertabuana). The research location was determined by purposive sampling, namely Dumoga Sub-district, Bolaang Mongondow Regency, with the consideration that the area is the center of paddy rice production in North Sulawesi. The data analysis used was a qualitative descriptive analysis technique. The data obtained were then processed and tabulated in the form of tables and diagrams. The results showed that the application of paddy rice cultivation technology carried out by farmers in Dumoga District included the application of land preparation using a hand tractor, a single planting pattern, a direct seed planting system of direct seed planting (Tabela), the spacing used was 20×20 cm, fertilization using fertilizers (Urea, Phonska, TSP and SP36), water sources came from irrigation irrigation, pest control using pesticide active ingredients and harvesting already using harvesting machines, and paddy rice production in Dumoga District reached 4 tons of GKG, with a productivity of 1.6 tons/ha.

Future climate change may pose pressures on greenhouse gas emission reduction in China’s rice production

Paddy rice cultivation is a vital food source but also a significant contributor to greenhouse gas (GHG) emissions, particularly methane. Management measures such as improved water management and fertilization are being pursued to sustain rice production while cutting down the emissions. However, climate change may pose further challenges for sustainable rice agriculture by either impacting rice production or GHG emissions. Based on a database consisting of 1216 observations across China, we established machine learning models predicting rice yield and GHG emissions, taking into account climate, soil, and management variables. We tested three machine learning methods including random forest, support vector machine and artificial neural networks. The models were trained on 70% of the dataset with the remaining 30% used to evaluate the model performance. Random forest performed best with R2 of 0.59 to 0.72 and modelling efficiency of 52% to 72%. Farmland management emerged as the most important variable to the model prediction, followed by climate and soil variables. Rice production and GHG emissions were estimated to be 245.36 Tg and 218.95 Tg CO2-eq in 2018, respectively. By the year 2050, rice yield was expected to experience a modest decrease ranging from 0.6% to 1.2% due to the combined effects of global change variables, but GHG emissions were projected to increase by 2.1% to 4.9% under different climate change scenarios (Representative Concentration Pathways) in China. A large spatial variability in the impact of climate change was observed, and climate change will have the most significant impact in the Northeast agricultural region of China due to the warming effect. Through the analysis of region-specific farmland management scenarios, this study underscores a “Code Red” situation, signifying that future climate change could pose unprecedented risks to the sustainability of rice production in China, despite ongoing management improvements.

Temporal variations in carbon stocks and soil fertility in Inceptisols after 12 years of paddy rice cultivation

Temporal variations in carbon stocks and soil fertility in Inceptisols after 12 years of paddy rice cultivation

ANALYSIS OF THE ADOPTION LEVEL OF INTEGRATED CROP MANAGEMENT FOR RICE COMMODITIES IN THE SESAYAP DISTRICT

Over the last three years, Paddy rice production in Tana Tidung Regency has been approximately 500-700 tons. This production is considered low, even when compared to rice production in other regencies located in North Kalimantan Province. One of the factors supporting high production is the crop management system used by farmers. This research aims to analyse the level of adoption of Integrated Crop Management (ICM) in the paddy rice commodity in the Sesayap District. ICM is an innovative approach in agriculture aimed at reducing the use of chemical pesticides and promoting sustainable pest and disease control. This study was conducted to understand the extent to which farmers in Sesayap District have adopted ICM technology in paddy rice cultivation and the factors influencing this adoption. The research method was a structured questionnaire survey from a sample of paddy rice farmers in the Sesayap District. The sample was selected using the purposive sampling method, with the criteria that they are part of farmer groups and actively cultivate paddy rice. The total number of respondents obtained was 57 individuals. The primary data collected were then described to illustrate the level of ICM adoption and the influencing factors. The results of this research indicate that the level of ICM adoption in the paddy rice commodity in Sesayap District is at 105, categorising it as moderate. Significant factors influencing the adoption level include farmers' level of education, knowledge about ICM, accessibility to information sources and training on ICM, the availability of institutional support, and farmers' perception of the benefits and effectiveness of ICM in increasing productivity and reducing production costs.

The use of urea hydrogen peroxide as an alternative N-fertilizer to reduce accumulation of arsenic in rice grains

A greenhouse experiment was conducted to examine the effects of urea hydrogen peroxide (UHP) on reducing the accumulation of As in rice grains. The results show that UHP effectively triggered Fenton-like reaction by reacting with Fe2+ in the paddy soils. This significantly inhibited the activities of As(V)-reducing microbes, causing impediment of As(V)–As(III) conversion following inundation of dryland crop soils for paddy rice cultivation. As-methylating microbes were also inhibited, adversely affecting As methylation in the soils. These processes led to the reduction in phyto-availability of As in the soil solutions for uptake by rice plant roots, and consequently reduced the accumulation of As in the rice grains. In this study, an UHP application rate of 0.0625% on three occasions (tillering, heading and filling) during the rice growth period was sufficient to lower the rice grain-borne As concentration to below 0.2 mg/kg, meeting the quality standard set by the Chinese government. No additive effect on reducing grain-borne As was observed for the joint application of UHP and biochar or biochar composite. The use of UHP for soil fertilization had no adverse impact on rice yield in comparison with the application of urea at an equal amount of nitrogen.

PERAN PENYULUH PERTANIAN MELALUI ADOPSI TEKNOLOGI DAN FAKTOR-FAKTOR PRODUKSI USAHATANI PADI SAWAH DI DESA LAMOERI KECAMATAN ANGATA KABUPATEN KONAWE SELATAN

The objective of this study is to determine the impact of agricultural extension workers on technology adoption and production factors in enhancing wet-rice farming in Lamoeri Village, Angata Subdistrict, South Konawe Regency. The study population consists of 180 registered rice paddy farmers who are members of 10 farmer groups affiliated with the Agricultural Extension Center (BPP). The study sample consisted of 36 individuals, which represents 20% of the population. The sampling method used was simple random sampling. Data was collected through interviews and documentation using questionnaires as instruments. The data was analyzed quantitatively using the class interval formula. The study found that agricultural extension officers in Lamoeri Village played a positive role in assisting rice paddy farmers. Their roles included facilitating, communicating, motivating, and consulting. The study also revealed that the adoption of innovations in rice paddy cultivation technology was generally successful. Extension workers have optimally carried out the stages of adoption of interest, evaluation, trial, and adoption. However, their role in the awareness stage needs improvement. The production process of paddy rice farming is influenced by natural factors, labor, facilities and infrastructure, and expertise factors. Therefore, it is crucial to always consider and prioritize these factors in order to increase farm productivity.