Chemical weeding in dry direct seeding fields of single cropping middle-late rice was studied in Huida vegetable farm of Huizhou City in 2012. The main treatment was herbicide( pretilachlor + bensulfuron-methyl,Yang...Chemical weeding in dry direct seeding fields of single cropping middle-late rice was studied in Huida vegetable farm of Huizhou City in 2012. The main treatment was herbicide( pretilachlor + bensulfuron-methyl,Yangguo and butachlor),and the sub-treatment was application method( soil treatments,seedling treatment and integrated treatment). The results showed that 80 g pretilachlor + bensulfuron-methyl( 36% pretilachlor + 4% bensulfuron-methyl) diluted with 50 kg water could be sprayed or 200 g Yangguo( 23. 9% butachlor + 1. 1% bensulfuron-methyl) mixed with 15 kg sandy soil could be broadcasted per 667 m2 on the sowing day or the second day under moist condition of soil,which could effectively control weeds in dry direct seeding fields of single cropping middle-late rice.展开更多
Dry deposited particles, larger than 1.3 μm, were collected under clear, cloudy, and foggy conditions during a cruise, traversing the Yellow Sea and the East China Sea from 23 March to 8 April 2011. In these areas, a...Dry deposited particles, larger than 1.3 μm, were collected under clear, cloudy, and foggy conditions during a cruise, traversing the Yellow Sea and the East China Sea from 23 March to 8 April 2011. In these areas, air masses are influenced by pollution outflows from the Asian continent. The size and elemental composition of dry deposited particles were investigated using a scanning electron microscope. Number-size distributions of these particles were approximately lognormal. Under clear conditions, the mode size was about 5.0 μm, with a mean diameter of 6.9 μm. Under cloudy and foggy conditions, the mean diameters were 5.7 and 6.0 μm, respectively, but the mode sizes were vague. Non-mixed mineral particles, sea salt, and mixed mineral-sea salt particles were the major particle types. Correspondingly, Al and Si were the most frequently detected elements. Frequencies of K-, Ca-, and S-containing particles were highest under foggy conditions, while the frequency of Na-containing particles was lowest. These results indicate that fog favored sulfate production on the particles and led to the deposited mineral particles more abundant in secondary salt, suggesting the importance to consider the dependence of the comoosition of deoosited mineral narticles on weather as well as narticle size.展开更多
基金Supported by National Science and Technology Support Program(2007BAD89B14)Special Fund for Agro-scientific Research in the PublicInterest(00803028)+3 种基金Major Technical Research Project of Ministry of Agriculture for Agricultural Structure Adjustment(06-03-07B)Project ofGuangdong Provincial Finance Department(YCY[2005]No.11,YCJ[2006]No.187)Agricultural Research Project of Guangdong ProvincialScience and Technology Department(2005B20101001)Special Fund forAgro-scientific Research in the Public Interest(201103001)
文摘Chemical weeding in dry direct seeding fields of single cropping middle-late rice was studied in Huida vegetable farm of Huizhou City in 2012. The main treatment was herbicide( pretilachlor + bensulfuron-methyl,Yangguo and butachlor),and the sub-treatment was application method( soil treatments,seedling treatment and integrated treatment). The results showed that 80 g pretilachlor + bensulfuron-methyl( 36% pretilachlor + 4% bensulfuron-methyl) diluted with 50 kg water could be sprayed or 200 g Yangguo( 23. 9% butachlor + 1. 1% bensulfuron-methyl) mixed with 15 kg sandy soil could be broadcasted per 667 m2 on the sowing day or the second day under moist condition of soil,which could effectively control weeds in dry direct seeding fields of single cropping middle-late rice.
基金This study was supported by the Education Bureau of Hebei Province for Excellent Young Scholars (YQ2014020), the Natu- ral Science Foundation of Hebei Province (D2016402120) and the National Natural Science Foundation of China (41541038). The Chinese Scholarship Council (CSC) supported Wei Hu's research at the Prefectural University of Kumamoto, Japan. We thank Ms. Jin-hui Shi and Ms. Cheng-cheng Chen for their assistance with particle collection, and Nicholas James O'Connor for his assistance with editing.
文摘Dry deposited particles, larger than 1.3 μm, were collected under clear, cloudy, and foggy conditions during a cruise, traversing the Yellow Sea and the East China Sea from 23 March to 8 April 2011. In these areas, air masses are influenced by pollution outflows from the Asian continent. The size and elemental composition of dry deposited particles were investigated using a scanning electron microscope. Number-size distributions of these particles were approximately lognormal. Under clear conditions, the mode size was about 5.0 μm, with a mean diameter of 6.9 μm. Under cloudy and foggy conditions, the mean diameters were 5.7 and 6.0 μm, respectively, but the mode sizes were vague. Non-mixed mineral particles, sea salt, and mixed mineral-sea salt particles were the major particle types. Correspondingly, Al and Si were the most frequently detected elements. Frequencies of K-, Ca-, and S-containing particles were highest under foggy conditions, while the frequency of Na-containing particles was lowest. These results indicate that fog favored sulfate production on the particles and led to the deposited mineral particles more abundant in secondary salt, suggesting the importance to consider the dependence of the comoosition of deoosited mineral narticles on weather as well as narticle size.