For those interested in this topic, you also might be interested in sensors that can measure evapotranspiration (ET). ET is directly related to photosynthesis and crop yield.
Here is a quick refresher from the textbook on plant water relations:
> Stomata are microscopic valves present in all leaves, formed by the pairing of specialized cells called guard cells on the leaf surface. Stomata are the main ports through which water vapor is lost. Of equal importance is the fact that stomata also are the main ports through which carbon dioxide gas moves from the air into the leaf and is photosynthesized into plant material and accounts for most of the plant dry matter produced. - Hsiao
Our company, Tule Technologies (YC S14) is the commercial vendor of sensors that can measure evapotranspiration. We solve many of the problems mentioned in this article.
Tule | Full-Stack Developer | Oakland | Full-Time | ONSITE
Tule helps farmers grow more food with less water through precision irrigation. Our service is backed by the only sensor technology that works on large farm fields and can detect water stress problems before damage is irrevocable.
We are looking for someone who can help us build our core infrastructure as well as customer features. This includes sensor data processing pipeline, remote sensing image processing, billing integrations, mobile UI, and web UI. We are only considering senior engineers who have built impressive things in the past.
Founders are a rare combination of expertise in agriculture and venture backed software entrepreneurs.
Investors include YCombinator, Khosla Ventures, and Bloomberg Beta Ventures.
Tule - tuletechnologies.com | Full-stack Engineer | Oakland | ONSITE
Product: Help farmers improve production through optimal irrigation. Powered by novel sensor technology.
Software Stack: We use Rails for our web server, swift for our iOS app, R for our atmospheric and remote sensing data pipeline, python for working with Google Earth Engine, and we are starting to use machine learning for some unreleased prediction algorithms. As a full stack engineer, you could work across all these projects.
Mission: Increase the carrying capacity of the planet by increasing food production and reducing environmental impact.
sorry! This was a tricky title because I know the HN moderators like it to match the title in the link. However, the Forum title only makes sense in the context of the forum (where Particle is implied).
When the title isn't enough we sometimes use a heading or a bit of the leading paragraph. (I've done that here. Let me know if I got it wrong.) The main thing is to use language from the article itself, not make up one's own.
The technology definitely applies to the big dollar crops (corn, soybean, etc), and we plan to serve those markets someday. We are starting in specialty crops (almonds, grapes, tomatoes, etc) because these customers have a "hair on fire" problem with intensive irrigation management and the California draught.
I'm a cofounder of Tule and happy to answer any questions.
A few corrections for the technical crowd:
This technology hasn't existed since the 1800's. It is derived from a technology called Surface Renewal that measures the turbulent transport of mass and energy from the planetary surface to the atmosphere. The concepts behind Surface Renewal were first developed in the 1930s by chemical engineers. These chemical engineers developed a model to describe the movement of gases into liquid media by fluid volumes interacting with the air-liquid interface. In the 1990s, UC Davis researchers adapted the Surface Renewal concept to the planetary surface-to-atmosphere interface. Recent improvements in the technology enable Tule to measure the amount of water vapor carried away from crop field by wind eddies.
Our technology was validated for accuracy against the gold standard research tools used in academia, lysimetry and eddy covariance.
What truly makes our technology exciting is that we can tell farmers the optimal amount of water to apply to maximize plant growth (yield) and plant stress (quality). Studies have shown that getting irrigation right can radically change yield and quality. Before our technology, farmers have never had the feedback to optimize irrigation. This is analogous to NewRelic locating the bottlenecks in your server performance. You can't optimize until you can measure.
That wasn't at all the sort of technique I was expecting. Without knowing otherwise, I'd presumed that you were doing something that directly measured evaporation rate, and that the claim that it was covering a large area instead of a single point was just puffery based on the the hope that air conditions were constant over the whole area. This is much better.
I only glanced at the original paper, but I was lost by the end of the first sentence: "Numerous methods exist for estimating the flux density of scalars." Mathematically, that doesn't make much sense. Does scalar have a different definition in meteorology? Or is this an odd translation from another language?
Obviously I am unaccustomed to the waters of Hacker News. I meant to post this in response to nkurz's question rather than the main thread. See below.
Hi, I'm Tom, the other cofounder at Tule. I developed the recent improvements in Surface Renewal during my PhD work at UC Davis.
Examples of scalars, as the term is used in atmospheric science, are air temperature, water vapor concentration, carbon dioxide concentration, or any other constituent of the atmosphere.
Any physical quantity with a field that can be described by a single numerical value at each point in space.
A scalar quantity is distinguished from a vector quantity by the fact that a scalar quantity possesses only magnitude, whereas a vector quantity possesses both magnitude and direction. Thus, pressure is a scalar quantity and velocity is a vector quantity.
Neat stuff! I don't know much about how your sensor communicates... wifi or cell maybe. But if you happen to be using 915MHz ISM band for anything we make a little $99 MFi accessory for iOS designed for drones you might be interested in playing with. Feel free to ping me.
Clearly people who work in nurseries do more than move plants back and forth 5 feet away, but this is an interesting step in the right direction. When I worked in a nursery in high school I had 2 primary tasks a) keep the plants watered b) help customers load their cars with big items. I've read about projects that use water sensors to enable plants to request water individually as they get dry. Adding a water tank and a sprayer to these little robots might be an interesting addition if it isn't cost prohibitive. I look forward to seeing more applications of technology in agriculture.
Here is a quick refresher from the textbook on plant water relations:
> Stomata are microscopic valves present in all leaves, formed by the pairing of specialized cells called guard cells on the leaf surface. Stomata are the main ports through which water vapor is lost. Of equal importance is the fact that stomata also are the main ports through which carbon dioxide gas moves from the air into the leaf and is photosynthesized into plant material and accounts for most of the plant dry matter produced. - Hsiao
Our company, Tule Technologies (YC S14) is the commercial vendor of sensors that can measure evapotranspiration. We solve many of the problems mentioned in this article.