Paddy Field Management Research Articles

Status Kesuburan Tanah sebagai Dasar Strategi Pengelolaan Lahan Sawah di Kabupaten Bantul, Indonesia

<em>Rice is the main food commodity in Indonesia. The main factor affecting rice productivity is soil fertility. This study aims to determine the soil fertility status of paddy fields in the Bantul Regency. The research was conducted by surveying soil characteristics supported by laboratory analysis. The survey area consists of 4 Land Map Units (LMU) which are made based on the type of soil, where for each LMU 3 soil sampling points are taken. Soil fertility status is represented by Soil Fertility Index (SFI). The results showed that the SFI in Bantul Regency was moderate (0.72). SFI in LMU-1 is moderate (0.70), LMU-2 is moderate (0.71), LMU-3 is high (0.83) and LMU-4 is moderate (0.64). Significant indicators that were positively correlated with SFI were organic C, total N and available K. The management of paddy fields is based on factors related to SFI. The recommended land management for increasing soil fertility is the addition of organic matter in the form of Azolla which can increase the total N and organic C of the soil as well as the application of manure. Proper management of paddy fields can maintain soil fertility and sustainable rice productivity.</em>

Electrical Conductivity-based Mapping of Paddy Yield using TDR Soil Sensor

Electrical conductivity is a physio-chemical property of soil that correlates with soil properties that affect crop productivity. A study was conducted to map the paddy yield on the basis of apparent electrical conductivity (ECa ) at three depth levels (L1 = 76 mm, L2 = 122 mm, L3 = 203.2 mm) measured using the Time Domain Reflectometry (TDR). The statistical correlations between ECa and paddy yield were established and variations in paddy yield were mapped. The correlation coefficient between crop yield and ECa was highest (r2 =0.47) for measurements taken at L3, whereas paddy yield was poorly correlated with ECa measurements at L1 (r2 =0.03). At L3, the highest paddy yield was 6.78 t.ha-1 at ECa of 0.359 mS.m-1; whereas, the lowest (5.63 t.ha-1) was at ECa of 0.319 mS.m-1. ECa at L1, L2, and L3 was significantly related to paddy yield with a coefficient of determination value of 0.26. The variability maps of paddy yields would help in better management of paddy fields.

Model-based evaluation of methane emissions from paddy fields in East Asia

Evaluating regional budgets of methane (CH4), a potent greenhouse gas and short-lived climate forcer, is an important task for future climate management. This study estimated historical CH4 emissions from paddy fields in East Asia by using a process-based terrestrial biogeochemical model driven by climate and land-use data. To capture the range of estimation uncertainty, this study used two CH4 emission schemes, four paddy field maps, and two seasonal inundation methods for a total of 16 simulations. The mean CH4 emission rate during 2000-2015 was estimated to be 5.7 Tg CH4 yr-1, which is similar to statistical inventories and other estimates. However, the large standard deviation (± 3.2 Tg CH4 yr-1) among the simulations implies that serious estimation uncertainties remain. Three factors - CH4 emission scheme, paddy field map, and inundation seasonality - were responsible for the disparity of the estimates. Because of the lack of historical management data, the model simulation did not show a decreasing trend in the agricultural CH4 emissions. A sensitivity analysis for temperature indicated that a 1-2 °C temperature rise (typical warming in mitigation-oriented scenarios) would substantially enhance CH4 emissions. However, a sensitivity analysis for water management indicated that a lower water-table depth would largely mitigate the emission increase. Additional studies to improve agricultural datasets and models for better paddy field management are still needed.

A Paddy Field Segmentation Method Combining Attention Mechanism and Adaptive Feature Fusion

HighlightsA paddy field segmentation network model, SA-DeepLabv3+, for hilly areas in southern China is proposed.SA-DeepLabv3+ uses attention mechanism and adaptive spatial feature fusion algorithm.The deep model was trained end-to-end using a few annotated image datasets.SA-DeepLabv3+ has good segmentation results for the four common types of paddy fields.Abstract. The hilly areas of southern China have complex feature distributions, and the boundaries of cultivated land are irregular. This kind of environment causes several image segmentation problems such as low accuracy of UAV low-altitude remote sensing arable land image interpretation. This paper proposes a SA-DeepLabv3+ paddy field segmentation model that combines attention mechanism and adaptive spatial feature fusion algorithm based on DeepLabv3+ semantic segmentation model. The sampling areas include Yangwan Village, Duchang County, Jiangxi Province, China, Keli Village, Xinjian County, Nanchang City and Chengxin Farm, Nanchang City. A high-resolution image dataset was found by capturing low-altitude remote sensing images of paddy fields with DJI UAVs, and the dataset images are categorised into four types of paddy fields. By analysing the image features of the dataset, the feature map is remapped by incorporating scSE attention mechanism module in the backbone network of the DeepLabv3+ encoder to enhance the paddy field feature representation. The ASFF algorithm is applied in the decoder, which obtains an adaptive weight coefficient to improve the problem of inadequate fusion of multi-scale features in the upsampling. By comparing the segmentation results of models with different ASPP dilation rates, the optimal set of dilation rates is determined to improve the model's ability to extract fine features of paddy fields. Finally, the performance of this model for paddy fields segmentation is verified by comparison experiments of different models. The data show that the mean values of PA, MIoU, Recall, and F1 score of the SA-DeepLabv3+ paddy field segmentation model are 0.955, 0.875, 0.865, and 0.908, respectively, which are improved by 0.019, 0.032, 0.008, and 0.005, and also has a higher segmentation performance compared with the typical segmentation models of UNet, SegNet, and PSPNet. The results show that the SA-DeepLabv3+ paddy field segmentation model with high accuracy and robustness, which provides an important basis for further acquiring high-precision paddy field boundary positioning information and constructing high-precision maps of several paddy fields in larger areas, and plays a positive role in promoting efficient and accurate information management of paddy fields. Keywords: Attention mechanism, ASFF, DeepLabv3+ network, Paddy field.

The Bidayuh People of Sarawak Borneo: Ritual and Ceremonies

This study aims to analyse the role of rituals and ceremonies of the Bidayuh tribes in Sarawak Borneo as a way of life of the Bidayuh people. Therefore, the cultural history of the Bidayuh people as well as the function and influence to the entire community which becomes the pride and identity is analysed. The data were taken from the Bajo asal (traditional songs), girite Bidayuh damba (stories and legendary), and the exploration and preview of the authenticity of the role in the manifestation of the Bidayuh culture and tradition in the numerous villagers through dynamic modernization. The content analysis was used to identify the rituals and ceremonies of the ethnic group. With this regard, emic perspective approach was applied to the study of the description of Bidayuh ritual, focussing on the internal elements and their functions in the Bidayuh society area in Bau, Padawan, and Serian division of Sarawak. Among the findings of this community is how important it is to preserve their beliefs to make sure the management of paddy fields are always cared for and preserve abundant harvests, apart from the ‘guardians’ to safe keep the peace of the village. The function and preservation through the ritual and ceremonies as their weltanschauung, influences the peasant society in that area. The study is highlighted to ensure people that the existence of the ritual and ceremonies is still implemented in the modern era as a part of the ancient heritage in Borneo Island- Sarawak.

A Model for Accelerating Rice Planting in Paddy Fields to Provide Food in Banten Province during the Covid-19 Pandemic

The Indonesian government continues to ensure the availability of rice as a staple food through various programs, including optimization of paddy fields. Paddy field management is directed and encouraged more intensively by accelerating planting and minimizing idle land. The form of support and stimulation provided by the government to farmers is in the form of counseling and assistance, providing seed assistance, and facilitation of agricultural machinery and other facilities so that rice fields can be more intensive and productive. The study was conducted in Lebak Regency and Serang City, Banten Province from April to August 2020. Data and information were obtained through surveys and interviews with farmers, extension agents, researchers, and agricultural department officials. The research method used a systems approach based on soft systems methodology. The results of the study showed the acceleration of planting as an indicator of the optimization of wetland land in Lebak Regency and Serang City had been achieved as targeted. The role of the extension agents as a driving force was very decisive in the achievement of additional planting areas. The use of information technology, such as applications for monitoring standing crops, was very helpful for extension agents in detecting land to be planted, planting achievements, and reported data. The system of coordination and guidance between agencies and officers to accelerate planting was quite effective and efficient. Support and facilities for agricultural extension agents had to be improved to achieve accelerated planting performance.

Visual detection of rice rows based on Bayesian decision theory and robust regression least squares method.

Paddy field management is complicated and labor intensive. Correct row detection is important to automatically track rice rows. In this study, a novel method was proposed for accurate rice row recognition in paddy field transplanted by machine before the disappearance of row information. Firstly, Bayesian decision theory based on the minimum error was used to classify the period of collected images into three periods (T1: 0-7 d; T2: 7-28 d; T3: 28-45 d), and resulting in the correct recognition rate was 97.03%. Moreover, secondary clustering of feature points was proposed, which can solve some problems such as row breaking and tilting. Then, the robust regression least squares method (RRLSM) for linear fitting was proposed to fit rice rows to effectively eliminate interference by outliers. Finally, a credibility analysis of connected region markers was proposed to evaluate the accuracy of fitting lines. When the threshold of credibility was set at 40%, the correct recognition rate of fitting lines was 96.32%. The result showed that the method can effectively solve the problems caused by the presence of duckweed, high-density inter-row weeds, broken rows, tilting (±60°), wind and overlap. Keywords: rice rows detection, Bayesian decision theory, clustering, RRLSM, credibility analysis, automatic tracking DOI: 10.25165/j.ijabe.20211401.5910 Citation: He J, Zang Y, Luo X W, Zhao R M, He J, Jiao J K. Visual detection of rice rows based on Bayesian decision theory and robust regression least squares method. Int J Agric & Biol Eng, 2021; 14(1): 199–206.

Yield Gap Assessment in Rice-Grown Fields Using CPA and BLA Approaches in Northern Iran

Narrowing the yield gaps is one of the major concerns in developing countries. Closing yield gap to obtain attainable yield is a viable option for providing information regarding the reason of yield loss. Hence, accurate estimation of the yield gap has many practical applications for enhancing production of crops. This research was conducted for assessing the yield gap of rice-grown fields using boundary-line analysis (BLA) and comparative performance analysis (CPA) methods. Collection of 100 rice-grown fields data were done in Sari region, Mazandaran province, one of the major rice production areas in northern Iran from 2015 to 2016. All paddy field management operations from preparation of nursery to harvest of yield has been recorded for local rice varieties. The CPA model calculate the potential yield and factors causing yield gap. In contrast, BLA model were fitted to the edge of data cloud of rice yield versus field managing variables from monitoring. Analysis of data in 100 monitored paddy fields demonstrated that rice yield varied from 3100 to 5430 kg ha−1. Prediction of potential yield for CPA and BLA methods were 5703 and 5369 kg ha−1, respectively. The yield gaps calculated by CPA and BLA methods in 1212 and 881 kg ha−1, respectively. In the CPA, the share of yield gap for variables entered in the model were 5% for cover crop of canola, 18% for legumes before rice cultivation, 4% for seed disinfection, 10% for seeding date in nursery, 11% for seedling age, 11% for seedling growth stage for transplanting, 5% for mechanized transplanting, 4% for fertilizer top-dressing, 27% for number of top-dressing and 6% for foliar application of nutrients. In the BLA, an average attainable yield, based on the optimum level of the 12 studied variables, was 5369 kg ha−1 with an 881 kg ha−1 yield gap. Regarding the fact that calculated yield in CPA and BLA, it has been stated that this potential yield is attainable. CPA and BLA are cheap and simple tools that, without the need for expensive experimentation, is able to detect yield gap and its causes in a district. Therefore, these methods can be used effectively in developing countries where the highest yield gaps exist.

Transformation of Japan’s rice policy toward innovation creation for a sustainable development

This research clarifies the necessity to transform Japan’s rice policy toward the creation of innovation, particularly to market-creating innovation. We introduced two analytical methods in the research. One is a survey of existing research on Japan’s rice policy and innovation in paddy field management, and the other is the case analysis of innovation by focusing on the spread of rice flour and organic rice cultivation. We obtained the following conclusions from the analysis. Rice policy (pushing institutions) so far is not having the desired effects on creating and sustaining well-functioning system in Japan’s rice sector. Although rice production adjustment was officially abolished, it still exists in the form of game equilibrium and customary institutions. Even if there are structural reform conditions (liquidation measures) in the economic domain, a major innovation has not occur due to Peasantism as the cultural belief system was dominant in the political and social domains for institutions. Therefore, to change such a situation and realize a sustainable development of rice sector, a policy transformation toward innovation creation, particularly to ‘market-creating innovation’ is called for. In addition, it is important to consider innovation as a process of organizational learning that involves the drastic change of collective cognition among producers, consumers and governments. Market-creating innovations can change the culture of the entire society, including the cognition of producers and consumers toward rice, rice products and rice cultivation. Furthermore, policy for promoting environment-friendly rice cultivation should pay attention to the public concern over economic impacts on the quality of the global commons that implies de facto gradual transfer of environment rights from the corporate sector to the community at large.

Cadmium mapping and contamination potential on different paddy field managements in Sragen Regency, Indonesia

Cadmium (Cd) is a harmful metal for paddy soil that is affected by inorganic fertilizer, pesticides, and industrialization. This study aimed to investigate the Cd contents in paddy soil, plant tissue, and grain, as well as the spatial distribution of potential Cd contamination. This study was conducted in Sragen Regency on paddy fields with different management, i.e., organic paddy fields, conventional paddy fields (Alfisols, Entisols, Inceptisols, and Vertisols), and paddy fields that often use wastewater (textiles, batik, and sugar factories) for irrigation. Forest land was used as a control. This study used descriptive explorative methods based on overlay land use, soil type, and industrial distribution map of Sragen Regency. The results showed that paddy soils with different management had higher Cd content than the forest soil. Organic paddy field had the lowest Cd content in soil (0.019 ppm) and rice grain (0.0006 ppm). Approximately 1,914.4 ha (3%) of paddy field in Sragen Regency that uses sugarcane industry wastewater as irrigation had the highest soil Cd content (0.16 ppm). In contrast, the highest Cd content in rice grain (0.046 ppm) was observed in conventional paddy field. The management of paddy field and rice cultivation significantly affected Cd contamination in soil and rice grain; therefore, environmentally friendly paddy field management needs to be encouraged.

Development of an Android Application for Smart Farming in Crop Management

Agriculture technologies have shown potential to improve agriculture management. This awareness has attracted researchers to develop technologies for farmers to ease their daily routine and also to reduce cost of labor and increase the yield production. Smartphone is one of the gadgets that can be useful in agriculture because of its useful functions, portability and affordable. It helps users to find locations, access information and capture images and sound. Smartphone functions can be combined to build versatile mobile agriculture applications. These helps to deliver information about crops and management needs. This paper develops an Android application for smart farming in crop management known as Padi2U. Padi2U is a mobile application developed to help farmers in their paddy field management. The application is developed using Master App Builder, a software that is used to create mobile applications. This application contains information about PadiU Putra paddy variety, agriculture agency, sites information, planting schedule, drone images, paddy disease, pest, weed, weather forecast, yield information and farmer report. All information is described in the native language of the farmers that is the Malay language. Final results of this project is the mobile application which will is useful to manage crops and improve the management. The same method can be applied to different crops in the future.

Identifying rice seedling bands based on slope virtualization clustering

In this paper, a method for identifying rice seedling band tracks by using LIDAR data is proposed, and the method provides navigation information for straight-line driving to minimize seedling injuries when paddy field management machinery enters a rice field. In this paper, the reconstruction of seedling band tracks is realized by constructing a three-dimensional (3D) point cloud image by collecting LIDAR data. Based on a two-dimensional servo platform, a mean-shift clustering algorithm is designed with slope virtualization, iterative zone clustering and linearization processes. The point cloud data of rice field on the 35th day of transplanting were simulated by Matlab. In the environment 2–3 m in the forward-looking direction and a standard plant spacing of 21 cm, the reconstructed seedling trajectory was compared with the real seedling trajectory. The maximum parallelism of the seedling belt trajectory was 45 mm, and the maximum median deviation was 7 mm. These values meet the needs of paddy field management machinery for achieving nondestructive seedling driving trajectories and verify the feasibility of the slope-blurred mean-shift clustering algorithm for seedling identification.

Penggunaan Kompos Sampah Kota dalam Upaya Merehabilitasi Tanah Sawah Terdegradasi di Desa Aras Kabu Kecamatan Beringin Kabupaten Deli Serdang


 Pendahuluan: Penelitian ini bertujuan untuk mengkaji alternatif pengelolaan lahan sawah melalui pemberian pupuk organik kompos sampah kota di Desa Aras Kabu, Kecamatan Beringin, Kabupaten Deli Serdang.
 Metode Penelitian: Penelitian ini dilaksanakan di Desa Aras Kabu Kecamatan Beringin, Kabupaten Deli Serdang dengan ketinggian 11 meter diatas permukaan laut. Analisa tanah dilaksanakan di Laboratorium Fisika Tanah, Konservasi Tanah & Air, dan Laboratorium Riset Teknologi, Fakultas Pertanian Universitas Sumatera Utara. Penelitian ini dilaksanakan pada Maret-Juli 2017. Penelitian ini menggunakan Rancangan Acak Kelompok non-faktorial dengan dosis bahan organik (B) kompos sampah kota, yaitu B0 = kontrol, B1 = 1,5% (28,70 ton/ha), B2 = 3,0% (57,40 ton/ha), B3 = 4,5% (96,10 ton/ha), B4 = 6,0% (104,80 ton/ha).
 Hasil Penelitian: Pemberian kompos sampah kota sebanyak 96,10 - 104,80 ton/ha dapat memperbaiki sifat tanah di Desa Aras Kabu, Kecamatan Beringin hingga kandungan bahan organik tanah mencapai 3%.

A Comparison of Ecological Environments and Labor Productivity among Historical Types of Paddy Fields and Consideration of Future Management Scenarios

During the 20th Century, most part of Japanese paddy fields were transformed to productive efficient allotments by the “Agricultural Land Improvement Projects”. However, the rich biodiversity, which was maintained in traditional paddy field forms with nature-near water supply systems, has led to a loss. In this research, the methodology of sustainable paddy field management which is aimed at balancing “efficient paddy field management” and “ecosystem conservation” was proposed by conducting the following three points. The focused site was Asami district in Matsuzaka city. First, the paddy fields were classified into 3 types according to the introduction of the agricultural land improvement project. Secondly, the differences of biodiversity and labor productivity by farmers among the three types were clarified. Thirdly, the future paddy field management scenarios were proposed and examined by considering a compromise point in this trade-off relationship between biodiversity and labor productivity.

Clusterization Of Paddy Field Farmers Condition In Kota Metro Lampung Province Indonesia Using K-Means Clustering Algorithm

Metro City is one of the administrative cities in Lampung province, Indonesia and also one of important rice producing regions in Lampung. Application of intensive agriculture in trend of declining area, low quality of land and differences of farmers internal characteristics that requires special treatment as solutions. Clustering farmers using the K-Means Cluster algorithm and Elbow Method can be used to facilitate policy makers determine programs and activities must be taken. Results showed that farmers are ideally grouped into 5 clusters (C1, C2, C3, C4 and C5). C1 members having most family members (4,54 persons). C2 members are the oldest age (68 years old) with longest farming experience (52.00 years) but have lowest formal education (7.67 years), least family members (3.33 person) and lowest total area (0.37 hectare). C3 having highest formal education (14.60 years) and largest paddy fields (0.80 hectare) but don't use any pesticides in paddy cropping management. Whereas farmers in C4 have largest family members helped (2.00 people). Farmers in C5 are the youngest (45.50 years old) and having the shortest experience (29.50 years) but use the most types (4 brands) and amounts of pesticides (400.00 mm.hectare.rotation-1) in paddy field management practices in Metro City.

The Assessment of Soil Quality Index for Paddy Fields with Indicator Biology in Jatipurno Districts, Wonogirl

Increased rice needs in an extensive use of paddy fields in the Jatipurno, Wonogiri. Managing rice fields can reduce soil quality. Proper management can improve soil quality, Jatipurno has management such as organic, semi-organic and inorganic paddy field management which have a real effect on soil quality. Assessment of soil quality is measured by physical, chemical and biological indicators, where each factor has a different effect. The chemical indicators are often used as the main indicators for determining soil quality, whereas every parameter has the opportunity to be the main indicator. So, biological indicators can play indicators. The main indicators are obtained from the correlation test (p-values ≤ 0,05 - < 0,01) and Principal Component Analysis with high value, eigenvalues > 1 have the potential to be used as Minimum Data Sets. The result is biological can be able to use as the Minimum Data Set such as microbial carbon biomass, respiration, and total bacterial colonies. The Soil Quality Index (SQI) of various paddy management practices shows very low to low soil quality values. The management of organic rice systems shows better Soil Quality Index with a score of 0,20 compared to other management. The practice of organic rice management shows that it can improve soil quality.

Changes in paddy field management in Sindang Hamlet, Rancakalong Village, Sumedang District, West Java, Indonesia

Abstract. Hidayat R.A, Partasasmita R, Iskandar J, Gunawan B. 2020. Changes in paddy field management in Sindang Hamlet, Rancakalong Village, Sumedang District, West Java, Indonesia. Biodiversitas 21: 98-105. Farmers have traditional ecological knowledge related to the management of their fields, including knowledge of climate, soil types, soil fertility, various plants and animals, plant pests and irrigation. This knowledge is based on customs, beliefs and cosmos. Over time, government policies in agriculture such as the green revolution were implemented with the aim of increasing productivity of rice in wet-rice field farming. This initiated a change in the community's farming system from subsistence farming to commercial farming. Not to mention the existence of climate change that requires people to adapt. This change has an impact on ecological, economic and social aspects which are interesting to study. This study conducted in Sindang Hamlet, Rancakalong Village, Sumedang District, West Java, which is known to have local rice cultivars and still practices rituals related to rice management. This study aims to analyze the changes in paddy management system in Sindang Hamlet due to green revolution and climate change, using qualitative data collection methods such as semi-structured interviews (deep interviews) with competent locals and participatory observations. Result of study showed that presently there are 3 groups of farmers in Sindang Hamlet, farmers who plant only local rice cultivars, farmers who plant only superior rice cultivars, and farmers who plant both local rice and superior rice cultivars in their land. Most farmers in Sindang Hamlet planted local rice but the diversity of local rice has decreased leaving only six cultivars, namely rayot, mesir, omas, torondol, mataram and randa kaya. There are still farmers in Sindang Hamlet who practice traditional farming, but many are starting to use modern tools and synthetic chemicals. The rice field management ritual called ngalaksa is still observed by the community, although there are some changes over time. The changes in rice field management have a negative impact on the local environment, economy and social aspects.

Modeling CH4 and N2O emission patterns and mitigation potential from paddy fields in Shanghai, China with the DNDC model

The flooded paddy field ecosystem is an important source of CH4 and N2O emissions from agricultural lands. Denitrification-Decomposition (DNDC), a process-based model, was used in this study to evaluate the effects of different field management practices on CH4 and N2O emissions from flooded paddy fields in Shanghai, China. The results indicated that the predicted seasonal patterns of CH4 (R2 = 0.76, ME = 0.71) and N2O (R2 = 0.71, ME = 0.67) emissions were in line with the observations from our experimental paddy field under traditional management practices. The total CH4 and N2O fluxes from paddy fields in the Shanghai region in the 2013 rice season reached 32,300 and 175 tons, respectively, and varied widely across 101 simulated rice-cultivating towns. A sensitivity analysis indicated that CH4 emissions were positively correlated with the organic fertilizer rate, the straw returned fraction, the tillage depth and the soil organic carbon (SOC) content and negatively correlated with the soil clay fraction. N2O emissions had a positive relationship with precipitation, the urea rate, the tillage depth and the SOC content and a negative relationship with the soil pH and the clay fraction. Based on the sensitivity analysis, four field management variables, including the fertilization rate, the irrigation method, the straw returned fraction and the tillage depth, were selected to construct several management scenarios for the DNDC scenario simulation tests. The simulated results indicated that reducing the rate of fertilization by 20% combined with moistening irrigation (keeping the paddy soil saturated with water but not covered with a layer of water) was the best practice for long-term sustainable management of paddy fields. This best management practice could reduce integrated emissions of CH4 and N2O (CO2-equivalent) by 33%, while maintaining optimal rice yields. However, straw returning and deep plowing increased CH4 emissions from paddy fields in Shanghai.

Performance and Long Distance Data Acquisition via LoRa Technology of a Tubular Plant Microbial Fuel Cell Located in a Paddy Field in West Kalimantan, Indonesia.

A Plant Microbial Fuel Cell (Plant-MFCs) has been studied both in the lab and in a field. So far, field studies were limited to a more conventional Plant-MFC design, which submerges the anode in the soil and places the cathode above the soil surface. However, for a large scale application a tubular Plant-MFC is considered more practical since it needs no topsoil excavation. In this study, 1 m length tubular design Plant-MFC was installed in triplicate in a paddy field located in West Kalimantan, Indonesia. The Plant-MFC reactors were operated for four growing seasons. The rice paddy was grown in a standard cultivation process without any additional treatment due to the reactor instalation. An online data acquisition using LoRa technology was developed to investigate the performance of the tubular Plant-MFC over the final whole rice paddy growing season. Overall, the four crop seasons, the Plant-MFC installation did not show a complete detrimental negative effect on rice paddy growth. Based on continuous data analysis during the fourth crop season, a continuous electricity generation was achieved during a wet period in the crop season. Electricity generation dynamics were observed before, during and after the wet periods that were explained by paddy field management. A maximum daily average density from the triplicate Plant-MFCs reached 9.6 mW/m2 plant growth area. In one crop season, 9.5–15 Wh/m2 electricity can be continuously generated at an average of 0.4 ± 0.1 mW per meter tube. The Plant-MFC also shows a potential to be used as a bio sensor, e.g., rain event indicator, during a dry period between the crop seasons.

Rice Cultivation without Synthetic Fertilizers and Performance of Microbial Fuel Cells (MFCs) under Continuous Irrigation with Treated Wastewater

To obtain a high rice yield and quality for animal feed without synthetic fertilizers, an experiment with bench-scale apparatus was conducted by applying continuous irrigation with treated municipal wastewater (TWW). Uniform rice seedlings of a high-yield variety (Oryza sativa L., cv. Bekoaoba) were transplanted in five treatments to examine different TWW irrigation directions (“bottom-to-top” and “top-to-top” irrigation) and fertilization practices (with and without P-synthetic fertilizers) as well as one control that simulated the irrigation and fertilization management of normal paddy fields. The highest rice yield (14.1 t ha−1), shoot dry mass (12.9 t ha−1), and protein content in brown rice (14.6%) were achieved using bottom-to-top irrigation, although synthetic fertilizers were not applied. In addition, this subsurface irrigation system could contribute to environmental protection by removing 85–90% of nitrogen from TWW more effectively than the top-to-top irrigation, which showed a removal efficiency of approximately 63%. No accumulation of heavy metals (Fe, Mn, Cu, Zn, Cd, Ni, Pb, Cr, and As) in the paddy soils was observed after TWW irrigation for five months, and the contents of these metals in the harvested brown rice were lower than the permissible limits recommended by international standards. A microbial fuel cell system (MFC) was installed in the cultivation system using graphite-felt electrodes to test the capacity of electricity generation; however, the electricity output was much lower than that reported in normal paddy fields. Bottom-to-top irrigation with TWW can be considered a potential practice to meet both water and nutrient demand for rice cultivation in order to achieve a very high yield and nutritional quality of cultivated rice without necessitating the application of synthetic fertilizers.