Crop and soil responses to 24 years of wheat residue removal and tillage

Abstract

Retaining crop residue on agricultural land mitigates soil erosion and conserves nutrients, but its removal generates a valuable commodity for competing uses in agriculture and industry. Understanding long‐term effects of crop residue removal on crop performance and soil condition is essential to guide management decisions regarding recommended practices, particularly in arid and semiarid regions where limited precipitation contributes to low levels of non‐harvested aboveground biomass. This report shares crop and soil outcomes over a 24‐year period from a continuous spring wheat ( Triticum aestivum L.) production system with and without straw removal under minimum and no‐tillage. Treatments were included in a long‐term experiment near Mandan, ND, on a site with nearly level topography (0–1%) and Temvik–Wilton silt loam soils (Fine‐silty, mixed, superactive, frigid Typic, and Pachic Haplustolls). Soil coverage by residue was significantly greater with straw retention compared to straw removal (80% vs. 72%, p  = 0.025), and no‐tillage provided greater soil coverage by residue compared to minimum tillage (87% vs. 66%, p  = 0.004). Grain and straw production, however, were not affected by residue management or tillage treatments. Among soil properties measured, only water‐stable aggregates were affected by treatments at 0–7.6 cm, exhibiting greater values with straw retention compared to straw removal (31% vs. 22%, p  = 0.044). Degradation‐related attributes of wheat straw such as high C:N ratio and lignin content, coupled with treatment features that limited N inputs and soil disturbance in a monoculture system, are hypothesized to have contributed to observed outcomes in this study.