Determination of the best management for soybean cropping following barley

In order to identify the best management method for soybean [Glycine max (L.) Merr.] following barley (Hordeum vulgare L.), a field study was carried out at the Sari Agriculture College Station during two years. The experiment was conducted as a split-split plot design based on complete blocks with two methods of residue management (burning or non-burning of barley residue) as the main plot factor, three tillage methods (plow + disk, double disk and no-tillage) as sub-plot factor, and three within row plant spacings (4, 8 and 12 cm, with 50 cm row width) as sub-subplot factor. The experiment was performed in four replications and soybean cultivar Hill was used. The combined analysis of the data showed that the effect of tillage methods and spacing within rows on yield was significant at the 1% level of probability. No significant interaction among experimental factors was observed. Comparison of means (Duncan's multiple range test) indicated that yield means of plow + disk and double disk were significantly different (2371 and 2412 kg/ha, respectively) compared with no tillage (2115 kg/ha), but the difference between them was not significant. Yield means of 4 and 8 cm within row spacings (2452 and 2405 kg/ha, respectively) were significantly different compared to 12 cm spacing within the row (2041 kg/ha), but a significant difference between them was not observed. Results of this study showed that residue non-burning, plow + disk or double disk and 4 or 8 cm within-row-spacings are the best planting methods for soybean following barley.