Effect of crop rotation and different nitrogen sources on soil water retention and silage corn forage yield and quality in boreal climate

Abstract

By implementing crop rotation and different nitrogen (N) sources, farmers can improve soil properties, leading to increased soil water retention (SWR) and ultimately enhancing crop yield and quality. This thesis research aimed to examine the impact of crop rotation and N sources on SWR, silage corn yield, and quality in boreal climates. A field trial was established in 2019 – 2021. Treatments were arranged in a split-plot design with four replicates. Rotation sequences were the main plots, and N sources were the subplots. Three models (van Genuchten, Brooks & Corey, and Durner) were applied to predict SWR curves (SWRC). The van Genuchten and Durner models provided more accurate predictions of SWRC than the Brooks & Corey model. Corn-corn-corn*agrotain (AG) showed superior agronomic performance and produced 17.75 Mg h-1 of forage yield compared to all others intreactions. SuperUTM produced higher non-fibrous carbohydrates, whereas AG produced higher forage energies (net energy of laction, net enery of gain, net enery of maintenance) and total digestible nutrient (TDN), than control. These findings suggest that AG and SU could be suitable choices to attain high forage yield and quality for dairy livestock under boreal climate.