A model for evaluating production and environmental performance of kenaf in rotation with conventional row crops

The potential inclusion of kenaf (Hibiscus cannabinus L.) into the conventional corn (Zea mays L.) and soybean (Glycine max L.) rotation of the U.S. Midwest requires investigation. A new kenaf model within the Agricultural Production Systems Simulator (APSIM) was developed and subsequently used to address questions needed for decision making: 1) what is the optimum planting date of kenaf under water-nitrogen limited and non-limited conditions in central Iowa; 2) does soil nitrate accumulation vary among kenaf, corn, and soybean crops?; 3) is soil organic matter (SOC) influenced in the long term?; and 4) how do kenaf water use efficiency (WUE) and nitrogen use efficiency (NUE) compare to corn and soybean? The model indicated that simulated optimum planting date for maximizing kenaf production ranged from April 15 to June 1. Model analysis of different rotation systems showed that there was a slight tradeoff between kenaf stem biomass and soybean yield. Long term soil organic carbon simulations (30 years) indicated a slight decrease over time while inclusion of kenaf in the corn-soybean (C-S) rotation did not affect this trend. In conclusion, this study brings to the scientific literature a new kenaf model that provided information that was missing for decision support.