The effect of crop residues, cover crops, manures and nitrogen fertilization on soil organic carbon changes in agroecosy
- PDF / 790,747 Bytes
- 24 Pages / 439.37 x 666.142 pts Page_size
- 6 Downloads / 175 Views
The effect of crop residues, cover crops, manures and nitrogen fertilization on soil organic carbon changes in agroecosystems: a synthesis of reviews Martin A. Bolinder 1 & Felicity Crotty 2 & Annemie Elsen 3 & Magdalena Frac 4 & Tamás Kismányoky 5 & Jerzy Lipiec 4 & Mia Tits 3 & Zoltán Tóth 5 & Thomas Kätterer 1 Received: 6 July 2018 / Accepted: 27 May 2020/ # The Author(s) 2020
Abstract
International initiatives are emphasizing the capture of atmospheric CO2 in soil organic C (SOC) to reduce the climatic footprint from agroecosystems. One approach to quantify the contribution of management practices towards that goal is through analysis of longterm experiments (LTEs). Our objectives were to analyze knowledge gained in literature reviews on SOC changes in LTEs, to evaluate the results regarding interactions with pedo-climatological factors, and to discuss disparities among reviews in data selection criteria. We summarized mean response ratios (RRs) and stock change rate (SCR) effect size indices from twenty reviews using paired comparisons (N). The highest RRs were found with manure applications (30%, N = 418), followed by aboveground crop residue retention and the use of cover crops (9–10%, N = 995 and 129), while the effect of nitrogen fertilization was lowest (6%, N = 846). SCR for nitrogen fertilization exceeded that for aboveground crop residue retention (233 versus 117 kg C ha−1 year−1, N = 183 and 279) and was highest for manure applications and cover crops (409 and 331 kg C ha−1 year−1, N = 217 and 176). When data allows, we recommend calculating both RR and SCR because it improves the interpretation. Our synthesis shows that results are not always consistent among reviews and that interaction with texture and climate remain inconclusive. Selection criteria for study durations are highly variable, resulting in irregular conclusions for the effect of time on changes in SOC. We also discuss the relationships of SOC changes with yield and cropping systems, as well as conceptual problems when scaling-up results obtained from field studies to regional levels. Keywords Soil organic carbon . Carbon sequestration . Management practices . Meta-analysis . Relative response ratio . Stock change rates
* Martin A. Bolinder [email protected] Extended author information available on the last page of the article
Mitigation and Adaptation Strategies for Global Change
1 Introduction The total stock of organic carbon in the plant-soil biosphere amounts to a pool of about 2100 Gt C, of which approximately 30% is plant biomass and 70% soil organic C (SOC) to a depth of 1 m (Janzen 2015; Paustian et al. 2016). Since these two constituents are part of a dynamic system together with the atmosphere and represent a relatively large pool compared to the latter (≈ 800 Gt C), even small variations in the C flux balance between these three components can be important enough to significantly affect CO2 concentrations in the atmosphere (Paustian et al. 1997; Stockmann et al. 2013). The United Nations Framework Convention for C
Data Loading...
