6 ms·

While true in theory, this doesn't hold up in practice. The farmers here are constrained in space by roads on all sides and by the price of each irrigation mac

While true in theory, this doesn't hold up in practice. The farmers here are constrained in space by roads on all sides and by the price of each irrigation machine. Many small circular irrigation machines will be more expensive and harder to maintain than one large one. The article you linked shows how given a square area, the packing efficiency of a non-square packing order increases past 80% only after you have around 30 circles and even then the increase is negligible. It would take well over 100 circles to hit the 10% additional area usage you're talking about. For farmers who want to make use of those corners of their field just use an irrigation system which can handle corners and make 100% use of their land.

WJW 6y ago
There are these type of linear irrigation devices that will cover square/rectangular fields more completely: https://www.valleyirrigation.com/linears https://www.valleyirrigation.com/linears . In practice I don't think super optimal land use is very critical for most farmers though, when compared to the additional cost for acquiring and maintaining more complex irrigators.
- neckardt 6y ago
  I initially thought the use of circular irrigation devices would be when land is cheap, but after some research I think the main reason to use them is when water is far more expensive than land. I zoomed in to various areas in the Midwest US, and I didn't see a single use of the circular devices, only square fields which are likely using the linear irrigation device you described. However, in areas where water is more expensive such as Colorado, I see the opposite: Only circular irrigation devices. I think what's happening here is that circular devices shoot the water down which causes all of it to land on the crops. The farms in my area generally use a firehose style sprinkler which shoots the water up. This causes a large chunk of water to get lost but it hits the corners of the land. Due to the cheaper water costs in the midwest, this is acceptable.
  - contingencies 6y ago
    If water cost is the key concern then surely alternate technologies such as drip-lines, inter-cropping, greenhouses/poly-tunnels, windbreaks and mulch could be explored? Also, selecting less water-intensive crop varieties. Fundamentally, spraying water through the air is a great way to lose a lot of it, both in transit and in evaporation thereafter.
    - AlotOfReading 6y ago
      Industrial farmers are a bit trapped in what they can sell and how they produce it. They generally can't change varieties much because the plants they're producing are what the factory wants, and anything outside that expectation will sell for significantly less. Secondly, industrial crop fields tend to be hyper optimized towards using harvesters, which don't easily permit intercropping or things in the field to get tangled. Windbreaks in the form of trees are already common in many areas.
      - contingencies 6y ago
        All good points, but kinda tangential. To summarize, perhaps we can agree that there are opportunities for technology to make a substantial difference in the resource efficiency of agriculture, but there remain significant factors effecting inertia and lock-in to existing 20th century industrial agricultural processes which must first be overcome.
  - icegreentea2 6y ago
    My understanding is that many farms in the midwest (as least corn farms) don't irrigate - rainfall is sufficient. Linear and circular systems should in principle be able to achieve the same water efficiency (within their swept area). They're the same thing - an above ground wheeled mechanism to deposit water. If you're farming in an area where you're water constrained, then you might not necessarily care about parts of your field not being used (as long as it's reasonably small), since what you care about is your input to output cost. Some advantages of central pivot is that: a) you only need to feed water to a single fixed point - in a linear system you either need a ditch to draw out of (that's water loss right there), or drag a hose around (that's a possible point of failure) b) you don't need to figure out how to regulate the two ends of your line to keep them in line.
darkerside 6y ago
Makes sense. Land is so cheap out there, that's the last place to be optimizing your trade offs.
azepoi 6y ago
This is only true if the circles are all of equal radius. With only 5 circles and 2 sizes you can get a significant increase to 87%. But the problem of practicality and cost benefit still stands.

WJW 6y ago

There are these type of linear irrigation devices that will cover square/rectangular fields more completely: https://www.valleyirrigation.com/linears https://www.valleyirrigation.com/linears . In practice I don't think super optimal land use is very critical for most farmers though, when compared to the additional cost for acquiring and maintaining more complex irrigators.

neckardt 6y ago
I initially thought the use of circular irrigation devices would be when land is cheap, but after some research I think the main reason to use them is when water is far more expensive than land. I zoomed in to various areas in the Midwest US, and I didn't see a single use of the circular devices, only square fields which are likely using the linear irrigation device you described. However, in areas where water is more expensive such as Colorado, I see the opposite: Only circular irrigation devices. I think what's happening here is that circular devices shoot the water down which causes all of it to land on the crops. The farms in my area generally use a firehose style sprinkler which shoots the water up. This causes a large chunk of water to get lost but it hits the corners of the land. Due to the cheaper water costs in the midwest, this is acceptable.
- contingencies 6y ago
  If water cost is the key concern then surely alternate technologies such as drip-lines, inter-cropping, greenhouses/poly-tunnels, windbreaks and mulch could be explored? Also, selecting less water-intensive crop varieties. Fundamentally, spraying water through the air is a great way to lose a lot of it, both in transit and in evaporation thereafter.
  - AlotOfReading 6y ago
    Industrial farmers are a bit trapped in what they can sell and how they produce it. They generally can't change varieties much because the plants they're producing are what the factory wants, and anything outside that expectation will sell for significantly less. Secondly, industrial crop fields tend to be hyper optimized towards using harvesters, which don't easily permit intercropping or things in the field to get tangled. Windbreaks in the form of trees are already common in many areas.
    - contingencies 6y ago
      All good points, but kinda tangential. To summarize, perhaps we can agree that there are opportunities for technology to make a substantial difference in the resource efficiency of agriculture, but there remain significant factors effecting inertia and lock-in to existing 20th century industrial agricultural processes which must first be overcome.
- icegreentea2 6y ago
  My understanding is that many farms in the midwest (as least corn farms) don't irrigate - rainfall is sufficient. Linear and circular systems should in principle be able to achieve the same water efficiency (within their swept area). They're the same thing - an above ground wheeled mechanism to deposit water. If you're farming in an area where you're water constrained, then you might not necessarily care about parts of your field not being used (as long as it's reasonably small), since what you care about is your input to output cost. Some advantages of central pivot is that: a) you only need to feed water to a single fixed point - in a linear system you either need a ditch to draw out of (that's water loss right there), or drag a hose around (that's a possible point of failure) b) you don't need to figure out how to regulate the two ends of your line to keep them in line.

darkerside 6y ago

Makes sense. Land is so cheap out there, that's the last place to be optimizing your trade offs.

azepoi 6y ago

This is only true if the circles are all of equal radius. With only 5 circles and 2 sizes you can get a significant increase to 87%. But the problem of practicality and cost benefit still stands.