|Olk, Daniel - Dan|
Submitted to: Rice Technical Working Group Meeting Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 3/3/2004
Publication Date: 1/10/2005
Citation: Anders, M.M., Olk, D.C., Grantham, J., Holzhauer, J. 2005. Effects of rotation, tillage, fertility, and variety on rice grain yield and nutrient uptake. Rice Technical Working Group Meeting Proceedings. P. 159-160.
Technical Abstract: In 1999, a study comparing three rice- (Oryza sativa L.) based crop rotations was initiated, including continuous rice, rice-soybean, and rice-corn. Within each rotation, conventional-and no-tillage were compared along with fertility and two varietal comparisons. Two fertility treatments were a 'standard' recommended application of 112 kg N ha-1, 45 kg P2O5 ha-1, 67 kg K2O ha-1 and an 'enhanced' application of 168 kg N ha-1, 67 kg P2O5 ha-1, and 101 kg K2O ha-1. Rice grain yields from 1999 to 2002, averaged over all treatments, varied between 9830 and 6900 kg ha-1. Fertility treatments did not differ in three of the four years. Rotation accounted for most of the differences in grain yield; the continuous rice rotation yielded significantly less than rice-soybean or rice-corn, declining from 8010 kg ha-1 in 2000 to 6650 kg ha-1 in 2002. Grain yields for the no-till treatments were significantly lower than for conventional-till in two of three years. Variety differences were not significant in any year. Total N uptake was, for the continuous rice rotation, 107 and 114 kg ha-1 in the no-till and conventional-till treatments, respectively, and for rice-soybean, 145 and 149 kg ha-1 in the no-till and conventional-till treatments. Soil phosphorus (P) levels decreased in the no-till plots compared to the conventional-till plots after the first two years. By 2003 soil P increased on average by 5 kg ha-1 in the enhanced fertility treatment regardless of tillage treatment, without any effect on grain yield. For the continuous rice rotation, soil potassium (K) increased for the 'enhanced' fertility treatment compared to the 'standard' fertility treatment by 2002, without any effect on grain yield. Rotation and tillage treatments affected nutrient uptake more than did fertilizer treatments.