Yield potential and factor influencing yield gap in industrial hemp cultivation under nemoral climate conditions

Abstract

Hemp (Cannabis sativa L.) is a productive multi-purpose crop that can be cultivated in different climatic conditions including northern latitudes. However, no comprehensive study on the hemp yield potential has been conducted, particularly in high latitude regions. This study investigates hemp development and the suitability of the AgroC model to simulate hemp growth in cool climate. Field experiments were conducted at the Lithuanian Research Centre for Agriculture and Forestry on Endogleyic Endostagnic Endocalcaric Luvisol. The AgroC model was calibrated using data sets from 2019, whereby validation was performed with 2020−2021 data sets. The model provided adequate results when simulating hemp and its individual parts biomass, leaf area index, soil water content, and development stages. The validated model was further used to provide hemp yields and water as well as temperature limited yield gaps for the historical 1990−2021 period. Simulated average hemp biomass potential reached up to 20.1 t ha−1. Average biomass yield losses due to water stress are 8.7 t ha−1 (gap 43.3 %), while reduction due to low temperatures may reach 6.4 %, but mean reduction was only 0.4 t ha−1 (gap 2.0 %). Simulated results showed water stress as the main factor defining hemp yield losses, while low temperatures are of secondary importance.