Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: March 3, 1999
Publication Date: N/A
Interpretive Summary: One practical method for integrating kenaf, a new fiber crop, into existing agricultural systems would be the inclusion of kenaf as a rotational crop with more traditional crops. Crop rotations can be an important management strategy to reduce pest populations (weeds, insects, and diseases), reduce pesticide applications, improve soil quality, and increase crop yields. Unfortunately there is very limited information concerning kenaf as a rotational crop. A three-year (1989-1991) field study was conducted at Haskell, Oklahoma to determine the effect of six kenaf/soybean rotations on crop yields. The research established that kenaf and soybean were compatible crops within the same rotational system, neither crop adversely affecting the other crop's yield. The research also discovered an unexpected beneficial pest control aspect of kenaf in a soybean crop rotation, a reduction in the populations of stunt nematode, a soybean pest. Not only did stunt nematode populations decrease during kenaf production, but the stunt nematode populations at planting for the following year's crop were also lower. The research demonstrated that a kenaf/soybean rotation is a viable cropping alternative for integrating kenaf into existing cropping systems.
Technical Abstract: As kenaf (Hibiscus cannabinus L., Malvaceae) production in the United States continues to increase it is essential to integrate this alternative fiber crop into existing cropping systems. Soybean (Glycine max (L.) Merr., Fabaceae) is now grown widely in the same production areas where kenaf can be successfully produced. A kenaf/soybean rotational system could have long term economic and pest control advantages, if there are no adverse effects of rotating these two crops. A three-year field study was conducted at Haskell, Oklahoma to determine the effect of six kenaf/soybean rotations on kenaf and soybean yield components. The kenaf cultivar 'Everglades 41' and soybean cultivar 'Forrest' were planted on a Taloka silt loam soil in mid May and harvested each October. The crops received no irrigation, rainfall was the only source of moisture. The individual kenaf/soybean rotations did not adversely affect the kenaf stalk yields or soybean seed yields. The research discovered that stunt nematode populations decreased during kenaf production and were significantly less at planting for the following year's crop. Kenaf stalk yields across all rotational combinations and years averaged 7.9 t/ha, while soybean seed yields averaged 866 kg/ha. Seasonal rainfall affected soybean growth and yields more than any effects due to the cropping sequence. A continuous kenaf rotation produced the greatest kenaf yields (9.4 t/ha) in the final year. It was determined that either a three-year continuous or rotational cropping system can be used for kenaf and soybean production without reducing crop yields.