As analyzed by Cheng Gang, the land transfer area is large and the speed is fast in Jiangsu in recent years. In detail, the area proportion has reached over 40% from the less than 20% in 2014. Land transfer has brought a big change in the planting mode: more than 60% big farmers choose mechanic rice transplanting now. The population of the transplanting method brings changes in the grass situation in fields. In the past, main grass varieties in the dry direct sowing fields are mainly barnyardgrass, Chinese sprangletop and common crabgrass; after the population of mechanic rice transplanting, barnyardgrass and Chinese sprangletop still dominate and the volume of broad-leaf weeds and sedge is growing.
The change in grass situation promotes the changes in the choice and use of herbicides: the use of soil treatment agents is more and more; in the treatment of stems and leaves, broad-spectrum herbicides that can kill barnyardgrass, Chinese sprangletop, broad-leaf grass and sedge are preferred. It is worth mentioning that with the constant increase in the labor costs, those herbicides that save time and labor have become rigid market demand. In recent years, many distributors recommend to farmers the mixed formulation of penoxsulam and cyhalofop-butyl. It can be predicted that along with the launch of home-made penoxsulam, the mixed formulation will become a mainstream one in the prevention and control of weeds for rice fields in the next two years.