Moed Katan 2: Damage from failing to irrigate

Today we began Moed Katan in Daf Yomi. The Mishna (on 2a) begins with the idea that on Chol HaMoed, one can irrigate his field which required irrigation.

מתני' משקין בית השלחין במועד  

MISHNAH. AN IRRIGATED FIELD MAY BE WATERED DURING THE FESTIVAL [WEEK].

Not watering an irrigated field will cause damage, as the gemara explains:

מאן תנא דפסידא אין הרווחה לא

Who may be the [unnamed] Tanna who maintains that [work to prevent] loss is allowed, but [to augment] profit is not allowed?

How is not watering an irrigated field a case of loss? It is the loss of profit, sure, because that time that you didn't water it, it won't improve. But how exactly is this loss?

Fortuitously, just today, the blog Overlawyered linked to this article at Economics 21, which illustrates the loss quite nicely. Look at the two sentences I have bolded:

The proposed regulation, stemming from the 2011 Food Safety Modernization Act, would limit E. coli levels in irrigation water for any foods that could be consumed raw. This sounds like a justified reason for government action since E. coli outbreaks have the potential to sicken consumers. Just one problem, onions are not subject to E. coli contamination from irrigation. 

According to a thorough field study led by Oregon State University Agricultural Professor Clinton Shock, there is absolutely no risk of E. coli contamination from irrigation water, regardless of method used and bacteria levels in the water. This confirms what farmers and their customers have long known.

Complying with this regulation would have substantial financial consequences for farmers. Their irrigation water would need to be tested weekly and they would have to stop watering if E. coli levels were found to be too high. Onions are finicky and even a small break in irrigation could drastically reduce crop yields. 

Currently, most onion farmers would not be in compliance with the proposal. Yet there are no outbreaks of E. coli from onions. Why does FDA insist on meddling where there is clearly no problem?

So we can see that a break in irrigation can cause tremendous loss.