Mass balance analysis and water quality model development for paddy field were performed using field experimental data during 2001-2002. About half (47-62%) of the total outflow was lost by surface drainage, with the remainder (490-530 mm) occurring by evapotranspiration. Most of nutrient inflow and outflow were mediated by fertilization and plant uptake, respectively. Nutrient outflow by surfa...

The aim of the research was analysis of rural women’s role in paddy cultivation practices in Tonekabon Township. Research population was consisted of paddy farmers women in Tonekabon Township (N=14539), whose 130 ones were selected using Cochran’s formula. Data were gathered by cluster random sampling method. The instrument for data collection was a questionnaire which its validity was confirme...

The number of syntrophic butyrate-degrading bacteria in a flooded paddy field soil was 1.7 x 10(3) MPN/g dry soil. Butyrate was degraded to acetate and methane when paddy soils were incubated anaerobically with the addition of butyrate. However, butyrate degradation was completely suppressed by the addition of the specific inhibitor of methanogenesis, 2-bromoethanesulfonate (BES) to the soil. A...

the purpose of this study was to survey impacts of drought on socio-economic conditions of guilan paddy farmers. besides recognizing these impacts, it ranked them according to the viewpoint of the paddy farmers. it was of the descriptive- correlation type. questionnaire was the main tool of this study. to determine the validity of questionnaire used of comments of panel experts and reliability ...

Denitrification occurs markedly in rice paddy fields; however, few microbes that are actively involved in denitrification in these environments have been identified. In this study, we used a laboratory soil microcosm system in which denitrification activity was enhanced. DNA and RNA were extracted from soil at six time points after enhancing denitrification activity, and quantitative PCR and cl...

Pollen and phytolith analyses were undertaken at the Jiangli site in Suzhou, Jiangsu Province, combined with studies on macrofossils by flotation. The concentration of pollen decreased while the percentage of Poaceae pollen in the profile increased from the late phase of the Majiabang Culture to the Songze Culture suggesting that human impact on the local environment intensified gradually. The ...

Butachlor is the most commonly used herbicide on paddy fields in Taiwan and throughout Southeast Asia. Since paddy fields provide habitat for pond breeding amphibians, we examined growth, development, time to metamorphosis, and survival of alpine cricket frog tadpoles (Fejervarya limnocharis) exposed to environmentally realistic concentrations of butachlor. We documented negative impacts of but...

The occurrence of sterigmatocystin (STC) in paddy and processed rice samples produced in Italy was surveyed. After extraction and purification, STC was analysed using HPLC-MS/MS. STC was detected in all paddy rice samples (n = 49), in the range 0.29-15.85 μg·kg-1. As regards processed rice, a widespread contamination was found in brown and parboiled rice. All the brown rice samples were contami...

The rapid increase of paddy field acreage has led to widely descending of groundwater table in well irrigation paddy area of low-land in Sanjiang Plain recent years. More and more “hanging pump” and partial over pumping phenomenon have been occurring in well irrigation paddy area of low-land. Therefore, the groundwater resources in Sanjiang Plain need to be recharged urgently. For solving the m...

The anaerobic oxidation of ammonium (anammox) process has been observed in diverse terrestrial ecosystems, while the contribution of anammox to N2 production in paddy soils is not well documented. In this study, the anammox activity and the abundance and diversity of anammox bacteria were investigated to assess the anammox potential of 12 typical paddy soils collected in southern China. Anammox...