Long-term research needed to avoid spurious and misleading trends in sustainability attributes of no-till

Abstract

Agricultural management recommendations based on short-term studies can produce findings inconsistent with long-term reality. Here, we test the long-term relative profitability and environmental sustainability of continuous no-till agriculture practices on crop yield, soil moisture, and N2O fluxes. Using a moving window approach, we investigate the development and stability of several attributes of continuous no-till as compared to conventional till agriculture over a 29-year period at a site in the upper Midwest, U.S. We find that over a decade is needed to detect the consistent benefits of no-till on important attributes at this site. Both crop yield and soil moisture required periods 15 years or longer to generate patterns consistent with 29-year trends. Only marginally significant trends for N2O fluxes appeared in this period. Importantly, significant but misleading short-term trends appeared in more than 20% of the periods examined. Relative profitability analysis suggests that 10 years after initial implementation, 86% of periods recuperated the initial expense of no-till implementation, with the probability of higher relative profit increasing with longevity. Results underscore the essential importance of decade and longer studies for revealing the long-term dynamics and emergent outcomes of agricultural practices for different sustainability attributes and are consistent with recommendations to support the long-term adoption of no-till management.\n\nGRAPHICAL ABSTRACT\n\nO_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=187 SRC=\"FIGDIR/small/788240v1_ufig1.gif\" ALT=\"Figure 1\">\nView larger version (42K):\norg.highwire.dtl.DTLVardef@1e7529eorg.highwire.dtl.DTLVardef@1e11268org.highwire.dtl.DTLVardef@17f8995org.highwire.dtl.DTLVardef@2196fe_HPS_FORMAT_FIGEXP M_FIG C_FIG HIGHLIGHTSO_LIWe test long-term effects of no-till on yield, soil moisture, and N2O fluxes\nC_LIO_LIWe examine 29 years of data with a moving window and relative profitability method\nC_LIO_LIIt takes at least a decade to detect consistent benefits of no-till\nC_LIO_LIShorter studies can produce significant but misleading findings\nC_LIO_LILong studies are essential to reveal the dynamics of agricultural management\nC_LI