Hay Wilson in TX - 6/29/2013 04:18

Something that is not considered in most literature is the water use efficiency with good fertility.

The round numbers essential element removal with hay are for typical hay analysis results and may not fit your situation. It appears that California is happy with irrigated alfalfa at 1.70% K while for dryland alfalfa 2.20% K is a more desired potassium level.
For drought conditions alfalfa will do better with closer to 3.00% K.

For sulfur it is better to look for a 11/1 N/S ratio in the plant analysis or hay analysis.

For each essential element there is a yield to element level bell curve. These bell curves interact and change with the interaction.
Also consider that forages are not as sensitive to a lack of or excess of the different elements like we see with truck crops.

This should work regardless of climate, as long as the humidity during harvest is compatible with the operation.