143 

 determine if there were any correlations with depth and the S nutri- 

 tion of the bermudagrass . Although the topography of the experimental 

 area was quite uniform with less than a 2% slope, the depth to the 

 argillic horizon varied from near 60 cm to over 200 cm (Fig. 15). The 

 area was mapped as Kendrick fine sand, but because of this large varia- 

 tion in depth to the argillic horizon, part of the plot area would 

 probably be considered Arredondo fine sand. At some of the deeper 

 points, the upper argillic horizon was very moist with some mottling 

 in contrast to the well-drained condition of the shallow argillic hori- 

 zons. While the direction of the blocks was parallel to the slope of 

 the soil surface, it was perpendicular to the slope of the argillic 

 horizon. This situation created a source of variation within the 

 experiment that could not be evaluated. The S concentration in the 

 forage was significantly correlated with depth to the argillic horizon 

 at the 0.05 level of significance, but the correlation coefficient was 

 only 0.20. Total yield was significantly correlated with N uptake 

 (r = 0.91), N concentration in the forage (r = 0.80), S uptake (r = 

 0.76), and S concentration in the forage (r = 0.45) but not with depth 

 to the argillic horizon. 

 9.3 FORAGE SULFUR CONCENTRATIONS AND N:S RATIOS 



There were few observations with S concentrations below what 

 would be considered no be a critical level. Bremer (1976) reported a 

 critical plant S concentration for 'Midland' bermudagrass of 0.10 to 

 0.15%. There is a trend toward lower yields below a S concentration 

 of 0.12%, but a critical level cannot be established with these data 

 (Fig. 16). 



