Field-scale experiments reveal persistent yield gaps in low-input and organic cropping systems

Abstract

Knowledge of production-system performance is largely based on observations at the experimental plot scale. Although yield gaps between plot-scale and field-scale research are widely acknowledged, their extent and persistence have not been experimentally examined in a systematic manner. At a site in southwest Michigan, we conducted a 6-y experiment to test the accuracy with which plot-scale crop-yield results can inform field-scale conclusions. We compared conventional versus alternative, that is, reduced-input and biologically based-organic, management practices for a cornsoybean-wheat rotation in a randomized complete block-design experiment, using 27 commercial-size agricultural fields. Nearby plot-scale experiments (0.02-ha to 1.0-ha plots) provided a comparison of plot versus field performance. We found that plot-scale yields well matched field-scale yields for conventional management but not for alternative systems. For all three crops, at the plot scale, reduced-input and conventional managements produced similar yields; at the field scale, reduced-input yields were lower than conventional. For soybeans at the plot scale, biological and conventional managements produced similar yields; at the field scale, biological yielded less than conventional. For corn, biological management produced lower yields than conventional in both plot-and field-scale experiments. Wheat yields appeared to be less affected by the experimental scale than corn and soybean. Conventional management was more resilient to field-scale challenges than alternative practices, which were more dependent on timely management interventions; in particular, mechanical weed control. Results underscore the need for much wider adoption of field-scale experimentation when assessing new technologies and production-system performance, especially as related to closing yield gaps in organic farming and in low-resourced systems typical of much of the developing world.field experiments | scaling | corn soybean wheat rotation | weed control | organic agriculture

Concomitant phytonutrient and transcriptome analysis of mature fruit and leaf tissues of tomato (Solanum lycopersicum L. cv. Oregon Spring) grown using organic and conventional fertilizer

“…While the above ground vegetative biomass on a dry weight basis was 4.5% higher in CONV grown plants, the below ground vegetative biomass on a dry weight was 6% greater in organically (ORG) grown plants ( Supplementary Table 1). The observed reduction in yield and biomass under ORG fertilizer is as expected since the use of organic fertilizer has been implicated in the reduction of yield by 5-34% [4].…”

Compost Legacy Down‐Regulates Biological Nitrogen Fixation in a Long‐Term Field Experiment

“…Year effects on yield were high as well in our study, following the same pattern as that observed for total amount of BNF: 2008 > 2007 > 2006. In the "Scale up" experiment that involves 27 fields at the Kellogg Biological Station (where the LFL trial is located) a strong seasonal weather effect was also observed, where soybean yields varied from ~1 to 3 MG ha -1 depending on the year (Kravchenko et al, 2017).…”

Simultaneous adoption of integrated soil fertility management technologies in the Chinyanja Triangle, Southern Africa

“…What are the main controlling factors that facilitate the combined ISFM component (dis)adoption? These are among the most common questions that researchers and extension agents in southern Africa try to have prior answers to as they advance the technologies tested on small plots to the wider community (Maat, ; Kravchenko et al, ). To date, several technologies have been developed through scientific experiments and rolled out to farms through on‐farm demonstrations.…”