CO&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt; emission and structural characteristics of two calcareous soils amended with municipal solid waste and plant residue

N Yazdanpanah

doi:10.5194/se-7-105-2016

Abstract

Abstract. This investigation examines the effect of different amendments on selected soil physical and biological properties over a 24-month period in two cropland fields. Urban municipal solid waste (MSW) compost and alfalfa residue (AR) were used as different organic amendments at the rates of 0 (control), 10 and 30 Mg ha−1 to a clay loam soil and a loamy sand soil in a semiarid region. Results showed that the soil improvement was controlled by the application rate and decomposability of amendments and soil type. The addition of organic amendments to the soils improved aggregate stability and consequently enhanced total porosity, especially macropore fraction. The increased soil organic carbon (SOC) and total porosity values as compared to the control treatment were greater in the loamy sand soil than in the clay loam soil. Moreover, compared to the microbial respiration of control plots, the application of MSW resulted in higher values of microbial respiration in the clay loam soil than in the loamy sand soil, whereas the reverse was found for AR. Linear and power functions were provided for the relationships between microbial respiration and SOC in the loamy sand and clay loam soils, respectively. Also, CO2 emission was stimulated significantly as power functions of the total porosity and the ratio of macroporosity to microporosity. However, the soil microbial respiration and carbon storage improved aggregate stability and pore size distribution, and as a response, soil porosity, especially the macropore fraction, controlled CO2 flux.

Highlights

The maintenance of soil organic carbon (SOC) is important for the sustainable productivity of agroecosystems (González et al, 2010)
The soils amended with alfalfa residue (AR) exhibited significantly (p < 0.05) higher levels of SOC than those amended with municipal solid waste (MSW)
The SOC concentration under the application rate of 10 Mg ha−1 MSW and AR was about 1.5 and 1.7 times higher in the loamy sand soil and about 1.1 and 1.3 times higher in the clay loam soil than those obtained for unamended soils, respectively

Summary

Introduction

The maintenance of soil organic carbon (SOC) is important for the sustainable productivity of agroecosystems (González et al, 2010). Organic amendment has been widely used to increase the content of SOC (Fernández et al, 2009; Benbouali et al, 2013; Mahmoodabadi et al, 2013). In this regard, the application of crop residues and manure has been suggested to improve soil quality and to support the sustainable production in agricultural land (Yu and Jia, 2014; Kaleeem Abbasi et al, 2015; Musinguzi et al, 2015; Turgut, 2015). In recent years, the composted urban MSW has been added to agricultural soils for waste disposal and to im-

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Conclusion