Replacing fallow with field pea in wheat production systems across western Nebraska

Integration of field pea (Pisum sativum L.) (FP) into dryland cropping systems has increased due to ecological and economic benefits, paired with a growing market for pea‐derived products. Challenges exist in the High Plains that limit the integration of crop rotations to replace fallow periods with FP in wheat (Triticum aestivum L.)‐based systems. This experiment compares chemical summer fallow to FP in a fallow–wheat rotation at two locations in western Nebraska. Soil water content, soil fertility, N mineralization, FP yield, and subsequent hard red winter wheat (HWW) yields were recorded. Subsequent HWW yields were not different between crop sequences (P = .42). The interaction of site‐year with crop sequence explained the HWW yield differences (P = .0005), mostly due to precipitation variability among site‐years. Most soil parameters tested only showed a main effect of date due to temporal changes in soil nutrient cycling. Replacing summer fallow with FP resulted in reduced soil water content, however, that did not result in long‐term moisture deficiency due to crop sequence type. System annualized gross revenue was equal to or greater for 2 site‐years for FP compared with fallow, with an average increase of US$113.15 ha–1. Pea–wheat reduced annualized net losses in 1 site‐year by $70 ha–1 compared with fallow–wheat in the "average" pricing model. Among 3 site‐years and three pricing models, pea–wheat resulted in greater net profit or reduced net losses compared with fallow–wheat in 5 site‐year comparisons. Core Ideas Soil water levels were not different between crop sequences until pod development began in pea plots. Site‐year and date explained soil water content variability more accurately than the crop sequence. Field pea did not decrease soil nutrients, although seasonal nutrient cycling was observed during the study. Available soil nutrients varied among site‐years and date of sampling, due to nutrient cycling dynamics. Replacing fallow with field pea resulted in reduced subsequent wheat yield in 1 of 3 site‐years.