Global Maize Project in the United States: Ames, Iowa

The objective of this study is to determine whether or not an ecological intensification approach can increase yields more quickly over time than current farmer practice. The study design is a split plot. The main plot is management system: 1) farmer practice (FP), and 2) ecological intensification (EI). The split plot is: 1) N application according to the management system, and 2) no N. The treatments are in a randomized complete block, with four replications.

In 2011, there were no soybean grain yield differences between the systems (58.8 and 60.8 bu/A for FP and EI, respectively). For corn grain yield, the N application was significant between without and with N (138 and 221 bu/A for without and with N, respectively). There was no effect of management system nor was there an interaction between management system and N application. Therefore, the site was highly N responsive in both systems, but systems or differences in N source and application rate had no effect on corn yield (FP with N was 220 bu/A and EI with N was 222 bu/A). IPNI-26