Long-term biochar addition alters the characteristics but not the chlorine reactivity of soil-derived dissolved organic matter.

Biochar is widely and increasingly applied to farmlands. However, it remains unclear how long-term biochar addition alters the characteristics and chlorine reactivity of soil-derived dissolved organic matter (DOM), an important terrestrial disinfection byproduct (DBP) precursor in watersheds. Here, we analyzed the spectroscopic and molecular-level characteristics of soil-derived DOM and the formation and toxicity of DBP mixtures from DOM chlorination for two long-term (5 and 11 years) biochar addition experimental farmlands.

[Effects of land use change on soil organic carbon and total nitrogen storage in Karst immigration regions of Guangxi Province, China.].

Land use change is an important factor affecting soil carbon and nitrogen cycle, and this is a hot spot in the study of global climate change. Based on the fixed depth method (FD) and the equivalent mass method (ESM), we explored the effects of land use change on soil organic carbon (SOC) and total nitrogen (TN) storage from the perspectives of forest reclamation and farmland vegetation restoration in Karst area. The storage of SOC and TN significantly decreased after the fore-sts were converted to grassland, eucalyptus and farmland.

[Effects of biochar amendment on cropland soil bulk density, cation exchange capacity, and particulate organic matter content in the North China Plain].

A 3-year field experiment with randomized block design was conducted to study the effects of biochar amendment on the soil bulk density, cation exchange capacity (CEC), and particulate organic matter C (POM-C) and N (POM-N) contents in a high-yielding cropland in the North China Plain. Four treatments were installed, i.e.