This database is the result of a meta-analysis of organic amendment impact on soil carbon and sequestration potential. The initial search terms are located in the READ_ME sheet of the main file. The search was conducted on May 30, 2019, and with the specific filter of peer-reviewed scientific articles only, included 1457 articles from site across the globe for possible inclusion, spanning from 1953 to 2019. The studies must also contain an organic amendment treatment and a control, rather than a tillage treatment; thus leaving 1053 articles. With the additional filter of whole plot experiments in situ with a replicated experimental design created a final database of 62 scientific experiments.
The main parameters extracted from each study included response of soil carbon fractions and tightly linked soil nitrogen content, including: amount of carbon in aggregates, mineral associated carbon or particulate organic carbon, microbial biomass carbon and nitrogen, water extractable carbon, specific carbon chemistry such as alkyl-C or aromatic C, carbon liability or oxidation, and crop metrics such as carbon content, biomass, and yield. Other critical data extracted included sample size, and measurement of variation. Table values were directly extracted, and figures were saved into Image J and measured manually(imagej.net).