Effect of land use change from paddy rice cultivation to upland crop cultivation on soil carbon budget of a cropland in Japan

Changes of anaerobic to aerobic conditions but not of crop type induced bulk soil microbial community variation in the initial conversion of paddy soils to drained soils

“…The effects of conversion on SOC varied in different studies (Nishimura et al, 2008;Wang et al, 2014;Darilek et al, 2010). In the current study, the soil SOC did not differ significantly between RR and MM or SP (Table 1).…”

“…Land use conversion, particularly within cropland, is a common occurrence driven by market economy (Houghton et al, 1999). The alteration of land use changes plant species, the associated management strategies and disturbance intensity, and thus strongly influences soil physicochemical properties, soil microbial biomass and community composition (Bossio et al, 2005;Lauber et al, 2008;Nishimura et al, 2008;Wang et al, 2014). However, few studies have been conducted to identify the effects of the changes in plant species and in soil environment.…”

“…The rice area in China accounts for approximately 19% of the global rice area and plays an important role in China's food security and agricultural production (Zhang et al, 2005). However, in recent years, a considerable quantity of rice fields has been converted to maize, soybean and vegetable fields due to water shortages and economic benefits (Nishimura et al, 2008;Sun et al, 2011;Yuan et al, 2016). For example, in the Huai river basin in northern China, the main crops approximately 20 years ago were winter wheat and lowland rice (in summer); however, farmers started replacing lowland rice with crops such as maize, soybean, and cotton because of increasing water shortages (Tong et al, 2003).…”

“…After land use conversion from a paddy to a drained field, the soil environment changes from anaerobic to aerobic; this significantly influences the soil water content and soil pH, which have profound effects on the soil microbial community (Wang et al, 2014). Moreover, converted drained fields have been planted to many different types of crops (Nishimura et al, 2008), which would also influence the soil microbial community. However, few studies have focused on converted crop types to determine how they influence the soil microbial community.…”

Agricultural landscape change in China's Yangtze Delta, 1942–2002: A case study

“…While these new patches of woody vegetation and trees were usually too small to observe by coarser-resolution remote sensing, they increased from about 0.4% of the site in 1942 to about 1% in 2002-a significant change not observable by conventional remote sensing approaches to land change measurement . Even more complexity is involved in evaluating the global climate impacts of some land changes because of their potential to have conflicting effects on climate, such as the transition from rice paddy to rainfed crops, which causes significant carbon loss from soils (Nishimura et al, 2008), while substantially reducing methane emissions at the same time. Another local example of simultaneous environmental impacts of a single land use change is the expansion of impervious surfaces to more than 10% of village landscapes in 2002, which has certainly caused increased surface water runoff, enhancing water pollution, while likely enhancing regional warming by a rural version of the ''urban heat-island'' effect Shi et al, 2007).…”