A field experiment was conducted to (i) examine the diurnal and seasonal soil carbon dioxide (CO(2)) fluxes pattern in rice paddy fields in central China and (ii) assess the role of floodwater in controlling the emissions of CO(2) from soil and floodwater in intermittently draining rice paddy soil. The soil CO(2) flux rates ranged from -0.45 to 8.62 µmol.m(-2).s(-1) during the rice-growing seas...

Antifungal and antibacterial activity of some heterocystous cyanobacteria from paddy-fields in the north of Iran was studied. Soil samples were collected from paddy-fields of Gillan, Mazandaran and Golestan Provinces and cyanobacteria were isolated. Supernatants, methanolic and hexane extracts from biomass of 150 strains of cyanobacteria were isolated and screened against six strains of bacteri...

We compared aquatic invertebrate diversity in paddy fields under traditional and modern management practices. We also examined the general factors that may be related to diversity within each paddy field. The Kitadan area was farmed with traditional management practices, with much longer periods of irrigations compared with the Kahoku area, which was farmed with modern agricultural practices us...

Nitrogen fixation blue-green algae make a major contribution to the fertility of soil. It has been suggested that blue-green algae (BGA) assist higher plant growth by supplying growth substances. There are numerous works about roles of blue-green algae in paddy soils and rice growth but little on other plants. In this research, 19 morphospecies belonging to three families of heterocystous and n...

Understanding the historical change of agricultural landscape patterns is the basis for promoting the sustainable development of cultivated land, as well as appropriate decision-making. In order to analyze spatio-temporal changes of cultivated land in Sanjiang Plain, from 1985–2015, Landsat Thematic Mapper (TM) and Operational Land Imager (OLI) were used to reconstruct satellite data of land us...

The behavior of As in paddy fields is of great interest considering high As contents of groundwater in several Asian countries where rice is the main staple. We determined the concentrations of Fe, Mn, and As in soil, soil water, and groundwater samples collected at different depths down to 2 m in an experimental paddy field in Japan during the cycle of flooded and non-flooded periods. In addit...

The accumulation of As in rice due to groundwater irrigation in paddy fields represents a serious health hazard in South and Southeast Asia. In Taiwan, the fate of As in long-term irrigated paddy fields is poorly understood. Groundwater, surface soil, and rice samples were collected from a paddy field that was irrigated with As-containing groundwater in southwestern Taiwan. The purpose of this ...

3,4-Dimethylpyrazole phosphate (DMPP) has been widely employed to reduce nitrogen leaching and greenhouse gas emissions in the soils of dry farmlands. However, the effects of DMPP on the dynamics of nitrogen in paddy fields remain unclear. For this study, treatments with 0%, 0.25%, 0.5%, 1%, or 1.5% DMPP levels of nitrogen fertilization plus urea were designed to determine the effects on greenh...

spiders are the powerful and efficient predators in almost all ecosystems which have effective role in different pest control. the fauna of these arthropods was surveyed during 2005-2009, and their population fluctuations and activities were studied in mazandaran paddy fields in 2005-2006. a total of 53 spider species of 44 genera were collected and identified from paddy fields of mazandaran pr...