Dr Yuming Zhang1, Dr Chunsheng Hu1, Dr Xiaojing Liu1, Dr Mengyu Liu1
1Centre For Agricultural Resources Research, Institute Of Genetics And Developmental Biology, Chinese Academy Of Sciences, Shijiazhuang, China
The North China Plain (NCP) is one of the main grain production bases in China. In pursuance of high yield, excessive application of chemical fertilizers has been becoming increasingly common and problematic, while, only little organic fertilizer was applied. As a result, soil quality has becoming degradation. Since the beginning of this century, crop straw return has been implemented in the North China Plain and it is beneficial for improving soil fertility and soil quality. In order to estimate the effect of straw retain on promoting soil organic matter, we collected topsoil samples to analyze the content of soil organic matter in wheat-maize rotation field in Nanpi county of the North China Plain in a 1.5km grid format in 2015 and explored the change characteristics of soil organic matter by comparing data on soil organic matter in the topsoil in 1981 (when the second national soil survey was conducted) with that in 2015. The results indicated a significant change in soil organic matter, increasing from 7.87~9.57 g/kg in 1981 to 12.1~16.2 g/kg in 2015, representing total increase of 62.4%, which represented an annual increase of 1.44%. There was a significant positive correlation between the amount of organic carbon returned from crop straw and the increase of soil organic matter. Under the current soil fertility and crop planting structure, it needs to return at least 2930kg/ha/y organic carbon to maintain the balance of soil organic matter in wheat-maize rotation field. There was no significant relationship between soil organic matter and wheat yield, while, the maize yield significantly increased with the increase of soil organic matter content. The yield potential of maize will increase by 532 kg per ha with the 1g/kg increase of soil organic matter content in the surface soil.
Name: Yuming Zhang
Qualification: Ph D
(a) Nutrient dynamics in soil-plant system, especially carbon and nitrogen transformations
(b) Greenhouse gases (N2O, CO2 and CH4) emission from farmland ecosystem