Pedosphere 27(2): 328--337, 2017
ISSN 1002-0160/CN 32-1315/P
©2017 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Changes in soil organic carbon after five years of biowaste compost application in a Mediterranean vegetable cropping system |
Salvatore BAIANO ,Luigi MORRA |
| Council for Agricultural Research and Analysis of Agricultural Economics (CREA)-Research Center for Cereals and Industrial Crop, Laboratory of Caserta, Via Torrino 2, Caserta 81100 (Italy) |
| Corresponding Author:salvatore.baiano@crea.gov.it. |
| ABSTRACT |
| Biowaste compost can influence soil organic matter accumulation directly or indirectly.A 5-year experiment was conducted to assess the influence of biowaste compost on the process of soil aggregation and soil organic carbon (SOC) accumulation in a Mediterranean vegetable cropping system.The study involved four treatments: biowaste compost (COM), mineral NPK fertilizers (MIN), biowaste compost with half-dose N fertilizer (COMN), and unfertilized control (CK).The SOC stocks were increased in COM, COMN, and MIN by 20.2, 14.9, and 2.4 Mg ha-1 over CK, respectively. The SOC concentration was significantly related to mean weight diameter of aggregates (MWD) (P<0.05, $R^{2} = 0.7984)$ when CK was excluded from regression analysis.Compared to CK, COM and COMN increased the SOC amount in macroaggregates (> 250 upmum) by 2.7 and 0.6 g kg-1 soil, respectively, while MIN showed a loss of 0.4 g kg-1 soil. The SOC amount in free microaggregates (53--250 upmum) increased by 0.9, 1.6, and 1.0 g kg-1 soil for COM, COMN, and MIN, respectively, while those in the free silt plus clay aggregates (< 53 upmum) did not vary significantly. However, when separating SOC in particle-size fractions, we found that more stable organic carbon associated with mineral fraction < 53 upmum (MOM-C) increased significantly by 3.4, 2.2, and 0.7 g kg-1 soil for COM, COMN, and MIN, respectively, over CK, while SOC amount in fine particulate organic matter (POM) fraction (53--250 upmum) increased only by 0.3 g kg-1 soil for both COM and COMN, with no difference in coarse POM > 250 upmum.Therefore, we consider that biowaste compost could be effective in improving soil structure and long-term C sequestration as more stable MOM-C. |
| Key Words: aggregates, carbon sequestration, mineral-associated organic matter, particle-size fraction, particulate organic matter, soil structure |
| Citation: Salvatore, B. and Luigi, M. 2017. Changes in soil organic carbon after five years of biowaste compost application in a Mediterranean vegetable cropping system. Pedosphere. 27(2): 328-337. |
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