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Posted by akniss on 06 Sep 2016 at 00:02 GMT

The initial version of this manuscript contains an error that we are currently working with the PLOS ONE editors to correct. In the interest of transparency and disclosure, we are also noting the error here.

Description of the error: The error is relatively minor, in that it only affects one crop (haylage) out of the 25 we included in the manuscript. However, the error makes a rather large difference in the results for that particular crop. USDA reports haylage data in both green weight and dry weight. In the initial article, we used the dry weight for haylage for conventional yield, but the green weight for organic yield. This led to much higher yield in organic than conventional. We have corrected the haylage data so that both are reported in green weight. This reduces the yield ratio substantially, from 1.64 reported in the initial manuscript to 0.76 using the corrected data.

Corrected Fig 1 and supplementary figures S5 Fig and S8 Fig can be found here (along with the other supplementary figures):

The error makes little difference in the 'big picture' results of our study, as haylage is a relatively minor crop and we only referenced it twice in the manuscript text. The biggest change is the reduction of the "overall" organic yield referenced in the abstract; when all crop yield ratios are averaged, organic crops produced 67% of conventional crop yields (as opposed to 80% in the original manuscript). This overall difference was due to a combination of the haylage data error and a second calculation error that was carried forward from an earlier manuscript revision.

We apologize for the error.

Competing interests declared: My competing interests are disclosed in the article.