Abstract
Long-term manure application is recognized as an efficient management practice to enhance soil organic carbon (SOC) accumulation and nitrogen (N) mineralization capacity. A field study was established in 1979 to understand the impact of long-term manure and/or chemical fertilizer application on soil fertility in a continuous maize cropping system. Soil samples were collected from field plots in 2012 from 9 fertilization treatments (M0CK, M0N, M0NPK, M30CK, M30N, M30NPK, M60CK, M60N, and M60NPK) where M0, M30, and M60 refer to manure applied at rates of 0, 30, and 60 t ha−1 yr−1, respectively; CK indicates no fertilizer; N and NPK refer to chemical fertilizer in the forms of either N or N plus phosphorus (P) and potassium (K). Soils were separated into three particle-size fractions (2000–250, 250–53, and <53 μm) by dry- and wet-sieving. A laboratory incubation study of these separated particle-size fractions was used to evaluate the effect of long-term manure, in combination with/without chemical fertilization application, on the accumulation and mineralization of SOC and total N in each fraction. Results showed that long-term manure application significantly increased SOC and total N content and enhanced C and N mineralization in the three particle-size fractions. The content of SOC and total N followed the order 2000–250 μm > 250–53μm > 53 μm fraction, whereas the amount of C and N mineralization followed the reverse order. In the <53 μm fraction, the M60NPK treatment significantly increased the amount of C and N mineralized (7.0 and 10.1 times, respectively) compared to the M0CK treatment. Long-term manure application, especially when combined with chemical fertilizers, resulted in increased soil microbial biomass C and N, and a decreased microbial metabolic quotient. Consequently, long-term manure fertilization was beneficial to both soil C and N turnover and microbial activity, and had significant effect on the microbial metabolic quotient.
Highlights
Soil organic carbon (SOC) and nitrogen (N) mineralization are fundamental biogeochemical processes that underpin soil fertility and crop production
A number of studies have shown that long-term application of organic manure significantly increased soil organic carbon (SOC) and total N in bulk soil, and in soil particlesize fractions [6, 7]; especially when manure was applied in combination with chemical fertilizers
Long-term manure application, with/without chemical fertilizer application, significantly increased SOC and total N in bulk soil and all particle-size fractions, indicating that manure application was effective at building new soil organic matter in this agro-ecosystem [24, 25]
Summary
Soil organic carbon (SOC) and nitrogen (N) mineralization are fundamental biogeochemical processes that underpin soil fertility and crop production. A number of studies have shown that long-term application of organic manure can significantly increase SOC and total N both in bulk soil and particle-size fractions [6, 7]; especially when applied in combination with chemical fertilizers. A number of studies have shown that long-term application of organic manure significantly increased SOC and total N in bulk soil, and in soil particlesize fractions [6, 7]; especially when manure was applied in combination with chemical fertilizers. There is little available information on the relative contribution of SOC and N mineralization from different particle-size fractions to bulk soil under long-term chemical fertilizer application compared with manure. The overall target was to improve the understanding of manure application on soil fertility improvement within this agro-ecosystem
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
