α BHC,β BHC,δ BHC, γ BHC, p,p' DDE, p,p' DDD, p,p' DDT, o,p' DDT ranged from 7 5 to 71 1 ng/g in wastewater irrigated vegetable and maize field and from 3 0 to 16 5ng/g in wastewater irrigated paddy field.
The trial of soil conditioner Mianshengeng, with the applications of 3000g, 3750g, and 4500 g / hm 2, in paddy field for no tillage rice cultivation was carried out. The results showed that compared to the check, the treatment significantly out yielded by 967.5 to 1237.5 kg / hm 2 , of which the most obvious efficiency was the application of 3750 g / hm 2 with 2.67 of output / input ratio.
Off-line experiments have been conducted with IAP94 land surface model on different surface types (cropland, forest and paddy field) in different seasons (spring, summer and autumn) over the Huaihe River basin.
Pronounced concentration-dissipation law of total function score value occurs in paddy field units, with three ranges, i.e., 79～68.5, 68.5～59 and 59～51.
Paddy field quality is divided into three gradations, and the scales are 18 220.9 ha, 5410.6 ha and 2890.9 ha.
A 21-day laboratory incubation experiment was conducted to investigate the impact of pesticides (insecticide, herbicide, fungicide) on paddy field soil health under controlled moisture (flooded soil) and temperature (25°C) environment.
N2O emission from paddy field under different rice planting modes
In the rice field methane is produced in the soil layer with depths of 2-25 cm.
The degradation of pencycuron in waterlogged tropic rice field was investigated.
To determine oogenesis in first-generation females (summer females) and its relations to temperature, females were collected from a rice field in early and mid-July and reared on young rice plants at 28, 31 and 34°C in the laboratory.
Carp of about 150 mm body length were released in small plots set in a rice field in southern Japan at 0, 0.2, or 0.6 carp/m2.
In the present study, we examined the role of leucine-enkephalin on moulting and vitellogenesis of the fresh water rice field crab, Oziotelphusa senex senex.
This further indicates that a sequence of different land uses including flooded rice fields is an important factor determining N outflow in basins in Japan.
Model for methane emission from rice fields and its application in southern china
The model has been used to calculate the methane emission from rice fields.
The influence of climate conditions, field water management, organic fertilizers and soil types on methane emission from rice fields are considered.
Soil organic matter content and soil physics and chemistry are major factors that determine the total season average emission rate, while soil temperature controls the temporal variation of methane emission from rice fields.