![Sample our Environment & Agriculture journals, sign in here to start your access, latest two full volumes FREE to you for 14 days]({"type":"image" , "src" : "/sda/5934/TOC-Subject-Sample-2021-Environment-Agriculture.jpg"})
Abstract
Black soils (Mollisols) are distributed in the Songnen Plain in the north‐east of China and underpin a large agricultural production base. Over the years, these highly fertile and productive soils have suffered a deterioration of properties under intensive cultivation, including a loss of soil organic carbon, which has reduced their yield potential. To develop a more sustainable agriculture and to help maintain continuing high grain yields, a long‐term fertilisation experiment was conducted at the Key Observation Station of the Harbin Black Soil Ecology, Ministry of Agriculture, Heilongjiang province, China. Four simple fertiliser treatments have been maintained for 28 years (since 1979), these being: no fertiliser (CK), simple chemical fertiliser (NPK), simple organic fertiliser (M), and chemical plus organic fertiliser (NPKM). These treatments were investigated for their effects on soil aggregation stability and microbial activity. Organic fertiliser application (NPKM and M) increased organic carbon (OC) concentration in whole soil and in some of the aggregate size fractions, promoting macro‐aggregate formation, particularly in the larger (1–2 mm) fractions. Microbial activity (quantified as cumulative microbial respiration) increased larger fractions (>0.5 mm), but decreased the smaller fractions (<0.5 mm). Microbial synthesis products serve as binding agents for aggregate formation. The combination of chemical and organic fertilisers was most effective for increasing macro‐aggregate stability.
