Give your alfalfa stand a regular health checkup by digging up several plants from different locations throughout the field. Cut into the taproot and visually assess the plant according to the chart below. A healthy root will be firm and white or slightly yellow. Crown rot is present in the field if roots have dark brown areas extending down the center.
0 = Healthy plant
1 = Some discoloration
2 = Moderate discoloration and rot 3 = Significant discoloration and rot
4 = Greater than 50% discoloration 5 = Dead
| PLANT DENSITY |
| Period |
Plants/sq. ft. |
| 1st production year |
10-15 |
| 2nd production year |
6-10 |
| 3rd production year |
4-6 |
| STEM DENSITY |
| Stand density(stems/sq. ft.) |
Suggested action
|
| >55 |
Stem density not limiting yield |
| 40-55 |
Some yield reduction expected |
| <39 |
Consider replacing stand |
| PLANT HEALTH |
| Average root score |
Suggested action |
| 0-2 |
Keep stand in production |
| 2-3 |
Consider replacing stand |
| 3-5 |
Rotate stand out of production |
If you get an average score of greater than two from 10 to 20 specimens across the field, consider rotating to another crop that will benefit from alfalfa’s nitrogen (N) credit — between 80 and 120 units of nitrogen. Assuming nitrogen is $0.60 per unit of N, you receive $48 to $72 per acre added value from your alfalfa crop. Plus, proactive rotation puts you in a better position to sell a higher percentage of your hay into the higher-value dairy market.