Hi Susan, Thanks for taking time and putting thoughts on this issue. Here are the responses to your queries. How many REPs were there at each location? Four Is the N fertilizer applied to REPs or to whole plots within a REP? N fertilizers rates were applied to whole plots within each rep. How many levels of N fertilizer are there? Five (0, 50, 100, 150, and 200 kg N/ha) Did you use the same physical experimental units (REPs, whole plots, subplots) each year? Yes experimental units were same each year. Plots were established in 2011 and received same treatment until the end of study (2015). Did you reapply N fertilizer each year? If so, did each REP or whole plot (whichever is appropriate) receive the same level of N fertilizer each year? Yes, N fertilizer was applied each year to respective plots. And, yes each plot received same fertilizer rate and same crop each year during the study period. Was each subplot planted with the same species each year? Yes. For example, if a plot was assigned corn and n rate 150 in 2011 then same N rate was applied and same crop was planted in subsequent years. Similarly, if another plot was assigned N rate 0 and crop as dual purpose sorghum in 2011 then same treatments were applied each subsequent years. All above given responses are applicable to each site. One unique observation: In 2015, at one site, all the crops failed that means we didn't have harvest that year at that site. This has happened only at one site which is supposed to be least marginal among three sites. This shows that there is a potential risk of growing crops at marginal sites and at this moment I am thinking to consider as part of the analysis rather than excluding from the overall analysis. As we were growing these species continuously over years, so this failure is not surprising. Please let me know if you have more questions. Thank you, Bhupinder
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