Ren Wanjun

Effects on Soil Fertility and Microbial Populations of Broadcast-Transplanting Rice Seedlings in High Standing-Stubble Under No-Tillage in Paddy Fields

No-tillage broadcast-transplanting of rice is a new cultivation technology developed in recent years (Xia, 2003; Liu et al., 2002). Our system involves no-tillage of rice paddies, which leaves high standing stubble, and raising seedlings on dryland beds. Then, we developed the technology of broadcast-transplanting seedlings in the field with high standing-stubble under no-tillage condition (Fig.1~4), which has several advantages such as lower fuel costs, savings in labour and time (yang et al., 2000; Liu, 2006; Ren et al., 2008). The first experiments of broadcast-transplanting of rice began in 1950s, reported by Peiris (1956) in Sri Lanka. In the 1980s, broadcast-transplanting of rice was successfully used in China (Zhang et al., 1993). From the middle and late 1990s, Guangdong province (Liu et al., 2002) and Guangxi province (Jiang et al., 2005) experimented with no-tillage broadcasttransplanting of rice under two rice crops and Sichuan province (Liu and Li, 2002) under single indica rice crop. Compared with conventional tillage broadcast-transplanting, the notillage broadcast-transplanting rice grew slower and had fewer tillers at the early stage (Liu et al., 2002) , as well, root biomass and length were reduced during the seedling standing period (Jiang et al., 2005), but it brought to a higher spike-bearing rate and more grains.