On-farm trials with rice fish cultivation in the west Kano rice irrigation scheme, Kenya

The viability of integrating rice farming with fish culture was studied in ten (10) rice plots. The on-farm research was done during one rice-growing season starting May 2003. The rice variety used was IR 2793-80-1 while the fish species was the Nile tilapia, Oreochromis niloticus. The fish culture period lasted 77 days. An average fish production of 132.4 kg/ha was obtained. The mean recovery rate of tilapia was 43 per cent. Total rice yield from the fields stocked with fish was lower than from unstocked fields. The net returns were not significantly different

Rice Fields Chemical and Physical Properties and the Implications on Breeding Strategie

Soil related constraints are major limiting factors in crop production in the Sahel. The objective of this study was to assess the properties of farmer's fields soil and irrigation water in Niger and the implications in rice improvement. Composite soil samples were collected from irrigated and non-irrigated fields. Sample of irrigation water was also collected. Physical and chemical analyses were performed in the laboratory. The results showed that most of rice fields were clayey and the non irrigated ones were mostly sandy. The soils were acidic and saline, the electrical conductivity ranged from 2.2 to 16.5 decisiemens per meter. The T-test showed that total dissolved salt, sodium adsorption ratio, cation exchange capacity, and organic matter percentage were significantly higher in irrigated fields than non-irrigated fields. The irrigated soils pH varied from 3.2 to 6.8, the electrical conductivity was greater than 4, and the sodium adsorption ratio was below 13 while the exchangeable sodium percentage was below 15. The irrigation water samples varied in term of ion content from site to site. The total sodium quantity estimated to be deposited varied from 87 kg/ha/year to 218 kg/ha/year. Rice fields' soils are saline and are getting worsened by irrigation water that contains salt. Therefore, the development of rice varieties that could withstand osmotic and ionic salt stress is necessary for sustainable production in the Sahel ecozone

Suitability of Mycorrhiza-Defective Rice and Its Progenitor for Studies on the Control of Nitrogen Loss in Paddy Fields via Arbuscular Mycorrhiza

Employing mycorrhiza-defective mutants and their progenitors does not require inoculation or elimination of the resident microbial community in the experimental study of mycorrhizal soil ecology. We aimed to examine the suitability of mycorrhiza-defective rice (non-mycorrhizal, Oryza sativa L., cv. Nipponbare) and its progenitor (mycorrhizal) to evaluate nitrogen (N) loss control from paddy fields via arbuscular mycorrhizal (AM) fungi. We grew the two rice lines in soils with the full community of AM fungi and investigated root AM colonization. In the absence of AM fungi, we estimated rice N content, soil N concentration and microbial community on the basis of phospholipid fatty acids; we also quantified N loss via NH3 volatilization, N2O emission, runoff and leaching. In the presence of AM fungi, we did not find any evidence of AM colonization for non-mycorrhizal rice while mycorrhizal rice was colonized and percentage of root colonization was 17–24%. In the absence of AM fungi, the two rice lines had similar N content, soil N concentration and microbial community. Importantly, there was no significant difference in N loss via all the four pathways between mycorrhizal and non-mycorrhizal systems. This mycorrhizal/non-mycorrhizal rice pair is suitable for further research on the role of AM fungi in the control of soil N loss in paddy fields

Exploring within-host diversity of plant viruses in rice agrosystems using two high-throughput sequencing strategies

The virome is an essential component of the phytobiome as viruses correspond to the most abundant and diverse biological entity in Nature and interact with all living organisms. The recent advances in high-throughput sequencing (HTS) has proven efficient for characterizing within-host diversity of several viruses, which has shed light on the influence of this diversity on the global fitness and virulence of viruses. We here aimed at evaluating the impact of rice management on the within-host diversity of Rice yellow mottle virus (RYMV) in order to optimize the cultural practices and to limit the burden of Rice yellow mottle disease in Africa. We worked on rice plants collected from traditional and intensive rice fields in East Africa, which is the center of origin of Rice yellow mottle virus. Interestingly, several strains with contrasted pathogenic and epidemiological parameters co -exist in this region and recombination between strains were identified recently. We selected twelve RYMV sympto-matic samples from fields managed under different types of practices that were analyzed using two HTS strategies: a metagenomics-based approach and a RYMV specific sequencing approach. Combining both strategies, we tested if the RYMV was associated with other viral species in rice, and if some cases of co-infections between RYMV strains occurred. Both approaches indicate a significant within-host RYMV diversity, which allows us to perceive the diversification processes of RYMV strains at the field scale. The detection of recombinants and the comparison of the within-host genetic diversity depending on the cultivation practices are underway

Culture of fish in rice fields

Rice is presently grown in 113 countries. Rice farming also offers a suitable environment for the culture of fish and other aquatic organism. This publication synthesizes the available information on the role that aquaculture can play in rice-based farming systems towards food security and poverty alleviation. The review describes the history behind integrating aquaculture with different rice ecosystems, the various production systems in operation such as concurrent, rotational and alternate, the modifications needed to the fields in order to integrate fish with rice farming, and the agronomic and aquaculture management that is necessary. The benefits of integration to communities - economic and environmental - are also described with reviews of the experiences from values countries. The real impacts of rice-fish farming and its future potential in terms of improved income and nutrition are significant but generally underestimated and undervalued. Notable changes have taken place in pest management in rice farming, and in fish seed production and availability making this a particularly relevant moment for emphasizing the importance of rice-fish farming. There is considderable potential for rice-fish farming to expand further in many countries and to contribute substantially towards global food and nutritional security.Freshwater fish, Fish culture

Cercariae (Digenea: Strigeidae, Diplostomidae) in Biomphalaria straminea (Planorbidae) from a rice field in Northeastern Argentina

The rice fields can provide habitats for many species of aquatic invertebrates, as insects, molluscs, crustaceans; and vertebrates, as fish, amphibians, reptiles and birds, which may act as hosts in the life cycles of digenean parasites. In this context, the goal of the present study was to describe the cercariae found in Biomphalaria straminea from a rice field in Northeastern Argentina. This freshwater snail inhabits a wide variety of environments, favoring shallow, temporary and standing or slow-flowing freshwater bodies. For this study, snails were collected from the cultivated parcels and irrigated channels during the flooding periods (from the time of sowing to soon after harvesting of the rice) between December 2010 and May 2011 and December 2011 and April 2012, in a rice field from Corrientes province, one of the main rice producers of Argentina. A total of 5 510 snails were examined of which 26 were infected with three different larval trematodes belonging to Strigeidae, Furcocercaria V (0.40 %) and Furcocercaria XX (0.04 %), and Diplostomidae, Furcocercaria XIX (0.04 %). Furcocercaria XX and Furcocercaria XIX were present in one rice cultivation cycle, while Furcocercaria V was present in both rice cultivation cycles. The prevalence of the different furcocercariae was somewhat higher in the second rice cultivation cycle. The cercariae described are new records for Argentina that added to 53 cercariae previously reported for Biomphalaria spp. in different aquatic environments of country. The study of the digenean larval in rice fields is important because contribute to the knowledge of the biodiversity of these environments.Fil: Fernández, María Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Hamann, Mónika Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; Argentin

Multi-site monitoring of heat stresses and micrometeorological conditions in the rice plants communities under various climates. The micrometeorological measurements system for a common measure of the paddy environments

Rice yield can be reduced substantially when the crop is exposed to excessive hest, which will likely occur more frequently under future climates, but the magnitudes of yield losses under open-field conditions are still difficult to predict, despite many efforts being conducted to detennine temperature response in the closed environments. To better understand the occurrence of heat stress under field conditions. we need thermal conditions of rice canopy under heat conditions, which can be very much different depending on other environmental factors, but taking correct measurements of canopy micrometeorology needs careful considerations. In this study, we will distribute a simple but well-designed system for measuring thermal environments of the canopy to different rice growing regions covering continental and coastal climates in low and mid latitude regions. With them, we attempt to establish a monitoring network of canopy thermal environments in the paddy fields that will help to bridge gaps between chamber and open-field and to better assess potential impacts of climate change on rice production. Keyword.: Canopy heat budget, Climate change, Micrometeorology, Multi-lateral research network, Rice. (Résumé d'auteur

Identifikasi Lahan Sawah Menggunakan Ndvi Dan Pca Pada Citra Landsat 8 (Studi Kasus: Kabupaten Demak, Jawa Tengah)

Paddy (Oryza sativa, sp) is one of the most important agricultural sector in Indonesia, because rice is the main food for more than 90% of Indonesia\u27s population. Based on BPS-Susenas data, consumption of rice per capita in 2013 amounted to 97.4045 kg/capita/year. Based on Statistical Data of Agriculture Ministry of Agriculture by 2014, Indonesia rice field area in 2013 amounted to 8,112,103 ha. In 2017, the Government has the mission of realizing Indonesia became self-sufficient in food. Therefore, the Government should be able to seek the stability of the fulfillment of basic needs for food, such as wetlands mapping. It\u27s accurate mapping can use a quick and easy method such as Remote Sensing.In this study, carried out the identification of rice fields using multitemporal Landsat 8 based on Rice Planting Time 1st in Demak that range between the end of October 2013 to early March 2014. The methods which was used Normalized Difference Vegetation Index (NDVI), Principal Component Analysis (PCA) and combination bands. Image classification is processed by using nine classes, those are water, settlements, mangrove, gardens, fields, rice fields 1st, rice fields 2nd, rice fields 3rd and rice fields 4th. The results showed the rice fields area obtained from the PCA method was 50,009 ha, combination bands was 51,016 ha and NDVI method was 45,893 ha. The accuracy level was obtained PCA method (84.848%), combination bands (81.818%), and NDVI method (75.758%)

Weed Populations and their buried seeds in rice fields of the Muda Area, Kedah, Malaysia

Twenty weed species belonging to 15 families were found in rice fields near Kampung Tandop, in the Muda Irrigation Scheme, Kedah, Malaysia. The dominant weeds in dry-seeded rice were Utriculatia aurea Lour., Fimbristylis miliacea (L.) Vahl., Echinochloa cruss-galli (L.) Beauv., Monochoria vaginalis (Burm. f) Presl and Najas graminea (Del.) Ridl.. In the wet-seedled rice, the dominant species were N. graminea, Lemna minor L, Sphenoclea zeylanica Gaertn., U. aurea, and Sagiuaria guayanensis H.B.K. while in volunteer seedling rice fields, the dominant species were Echinochloa colollllm (L.) Link., Fimbristylis alboviridis C.B. Clarke, F. miliacca, Cyperus babakan Steud. and Fuirena umbellata Rottb.. Dry-seeded rice fields contained the highest number of weed seeds (930,910/m2. in the top 15 inch of soil); volunteer seedling rice fields contained 793, 162/m2 and wet-seeded rice fields 712,228/m2. In general, seed number declined with increasing soil depth. At 10-15 cm depth, seed of U. aurea and S. zeylanica were tile most abundant in dry- and wet-seeded rice fields, whilst seeds of Scirpus juncoides Roxb. and F. miliacea were most abundant in volunteer seedling fields