![CO"2 emission in an intensively cultivated loam as affected by long-term application of organic manure and nitrogen fertilizer [An article from: Soil Biology and Biochemistry]](https://www.ebooknetworking.net/books/B00/0PC/bigB000PC0KDA.jpg)
CO"2 emission in an intensively cultivated loam as affected by long-term application of organic manure and nitrogen fertilizer [An article from: Soil Biology and Biochemistry]
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This digital document is a journal article from Soil Biology and Biochemistry, published by Elsevier in 2007. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.
Description:
A long-term field experiment was conducted to examine the influence of mineral fertilizer and organic manure on the equilibrium dynamics of soil organic C in an intensively cultivated fluvo-aquic soil in the Fengqiu State Key Agro-Ecological Experimental Station (Fengqiu county, Henan province, China) since September 1989. Soil CO"2 flux was measured during the maize and wheat growing seasons in 2002-2003 and 2004 to evaluate the response of soil respiration to additions and/or alterations in mineral fertilizer, organic manure and various environmental factors. The study included seven treatments: organic manure (OM), half-organic manure plus half-fertilizer N (NOM), fertilizer NPK (NPK), fertilizer NP (NP), fertilizer NK (NK), fertilizer PK (PK) and control (CK). Organic C in soil and the soil heavy fraction (organo-mineral complex) was increased from 4.47 to 8.61mgCg^-^1 and from 3.32 to 5.68mgCg^-^1, respectively, after the 13yr application of organic manure. In contrast, organic C and the soil heavy fraction increased in NPK soil to only 5.41 and 4.38mgCg^-^1, respectively. In the CK treatment, these parameters actually decreased from the initial C concentrations (4.47 and 3.32mgCg^-^1) to 3.77 and 3.11mgCg^-^1, respectively. Therefore, organic manure efficiently elevated soil organic C. However, only 66% of the increased soil organic C was combined with clay minerals in the OM treatment. Cumulative soil CO"2 emissions from inter-row soil in the OM and NPK treatments were 228 and 188gCm^-^2 during the 2002 maize growing season, 132 and 123gCm^-^2 during the 2002/2003 wheat growing season, and 401 and 346gCm^-^2yr^-^1 in 2002-2003, respectively. However, during the 2004 maize growing season, cumulative soil CO"2 emissions were as high as 617 and 556gCm^-^2, respectively, due to the contribution of rhizosphere respiration. The addition of organic manure contributed to a 16% increase in soil CO"2 emission in 2002-2003 (compared to NPK), where only 27%, 36% and 24% of applied organic C was released as CO"2 during the 2002 and 2004 maize growing seasons and in 2002-2003, respectively. During the 2002/2003 wheat growing season, soil CO"2 flux was significantly affected by soil temperature below 20^oC, but by soil moisture (WFPS) during the 2004 maize growing season at soil temperatures above 18^oC. Optimum soil WFPS for soil CO"2 flux was approximately 70%. When WFPS was below 50%, it no longer had a significant impact on soil CO"2 flux during the 2002 maize growing season. This study indicates the application of organic manure composted with wheat straw may be a preferred strategy for increasing soil organic C and sequestering C in soil.
Description:
A long-term field experiment was conducted to examine the influence of mineral fertilizer and organic manure on the equilibrium dynamics of soil organic C in an intensively cultivated fluvo-aquic soil in the Fengqiu State Key Agro-Ecological Experimental Station (Fengqiu county, Henan province, China) since September 1989. Soil CO"2 flux was measured during the maize and wheat growing seasons in 2002-2003 and 2004 to evaluate the response of soil respiration to additions and/or alterations in mineral fertilizer, organic manure and various environmental factors. The study included seven treatments: organic manure (OM), half-organic manure plus half-fertilizer N (NOM), fertilizer NPK (NPK), fertilizer NP (NP), fertilizer NK (NK), fertilizer PK (PK) and control (CK). Organic C in soil and the soil heavy fraction (organo-mineral complex) was increased from 4.47 to 8.61mgCg^-^1 and from 3.32 to 5.68mgCg^-^1, respectively, after the 13yr application of organic manure. In contrast, organic C and the soil heavy fraction increased in NPK soil to only 5.41 and 4.38mgCg^-^1, respectively. In the CK treatment, these parameters actually decreased from the initial C concentrations (4.47 and 3.32mgCg^-^1) to 3.77 and 3.11mgCg^-^1, respectively. Therefore, organic manure efficiently elevated soil organic C. However, only 66% of the increased soil organic C was combined with clay minerals in the OM treatment. Cumulative soil CO"2 emissions from inter-row soil in the OM and NPK treatments were 228 and 188gCm^-^2 during the 2002 maize growing season, 132 and 123gCm^-^2 during the 2002/2003 wheat growing season, and 401 and 346gCm^-^2yr^-^1 in 2002-2003, respectively. However, during the 2004 maize growing season, cumulative soil CO"2 emissions were as high as 617 and 556gCm^-^2, respectively, due to the contribution of rhizosphere respiration. The addition of organic manure contributed to a 16% increase in soil CO"2 emission in 2002-2003 (compared to NPK), where only 27%, 36% and 24% of applied organic C was released as CO"2 during the 2002 and 2004 maize growing seasons and in 2002-2003, respectively. During the 2002/2003 wheat growing season, soil CO"2 flux was significantly affected by soil temperature below 20^oC, but by soil moisture (WFPS) during the 2004 maize growing season at soil temperatures above 18^oC. Optimum soil WFPS for soil CO"2 flux was approximately 70%. When WFPS was below 50%, it no longer had a significant impact on soil CO"2 flux during the 2002 maize growing season. This study indicates the application of organic manure composted with wheat straw may be a preferred strategy for increasing soil organic C and sequestering C in soil.
