1. Grain Sorghum Rotations
By Gary Strickland
Extension Educator, Jackson County, Ag/4H/CED 1

2. Discussion Topics Advantages to Rotation Systems
Grain Sorghum Herbicides in Rotations
Altus Tillage and Cropping Systems Data 2

3. Rotation System Advantages
Crop residues increased in season precipitation use efficiency
Over a 58 year time period, yield increases were related 46% to improved hybrids and 93% to improved soil water at planting
This study showed that Grain Sorghum and Wheat Yields were greater in rotation sequences than in mono-crop situations 3

4. Rotation System Advantages Cont’d.
With wheat, soil water at planting was increased with corn and grain sorghum rotations but not with sunflower or soybean.
Wheat grain fill and number of heads were better with corn and grain sorghum rotations.
Study showed that high mineral N in the one inch seed zone area indicated that starter-band or side-dress applications were not necessary for optimum economic return to N fertilization. 4

5. Rotation System Advantages Cont’d.
Soil organic matter increased by 35% in the 0-5 cm range in the NT system when compared to the CT system
Potentially mineralizable N increased in this same soil depth range by 54% in the NT system
However when looking at the 0-15 cm soil depth range there were no tillage differences 5

6. Grain Sorghum Herbicides in Rotations
Herbicides utilized in a rotation program should increase weed control potential
Differing M.O.A. sites and chemistry will address weed species diversity
Roundup – preplant and preemergence
Dual – Pre-emergence herbicide, probably better in CT Systems (Cinch ATZ Lite in NT Systems, soil texture type specific)
Peak, Buctril, or Basagran – Broadleaf post-emergence herbicides
Atrazine – Good broadleaf option, with some grass control benefits but watch the pH and crop rotation issues. 6

7. Altus Tillage and Cropping Systems Rotation Data7

8. Grain Sorghum Yields 2003-2007 Cropping Systems 2003 Yield Lbs./A 2004
2005
2006
2007
C-W-GS
---
2274 (NT)
0 (CT)
C-GS
3108 (NT)
3774 (CT)
3709 (NT)
W-DCGS-C
1023 (NT)
1092 (CT)
0 (NT) GS
2955 (NT)
2627 (CT)
4963 (NT)
4827 (CT)
2864 (NT)
4441 (NT)
2415 (CT) 8

9. Total Returns above Production Inputs
Cropping
Systems
Total Returns above Production Inputs
$/A
Harvested Crops
C-W-GS
(NT)
(CT)
2 C, 1 W, 1 GS
C-GS
(NT)
(CT)
3 C, 2 GS
W-DCGS-C
(NT)
(CT)
2 W, 2 GS, 2 C GS
(NT)
71.28 (CT)
4 GS 9

10. W-DCGS-C
C-W-GS
C-GS
C-W GS C W 10

11. W-DCGS-C
C-W-GS
C-GS
C-W C W GS 11

12. W-DCGS-C
C-W-GS
C-W
C-GS C W GS 12

13. W-DCGS-C
C-W-GS
C-W
C-GS C W GS 13

14. Any Questions 14