Hub Uy
6 min readAug 19, 2019


Can mobile technology help rice farmers conserve water and increase yields in ever-worsening times of climate change?

Rice Farmers

The majority of Rice Farmers in the Philippines belong to the rural poor who depend on agriculture for food and income. They receive a daily income of about $4 a day, in which 20% goes to paying debt or rent because they do not own their land. According to the National Statistics Coordination Board of the Philippines, economic advancement is far from reach for these farmers because the majority finish only up to the 5th grade.

Life of a Farmer in Tanay, Rizal, Philippines

Furthermore, the farming industry in the Philippines is among the least mechanized in the world, they have basic irrigation systems in place and rely on manual labor to plow and till their land. To make matters worse, the agricultural sector receives little to no government support.

Rice Culture

It baffles me how rice has little support in the Philippines when it is the most important staple food.

According to the International Rice Research Institute or IRRI, Rice is so tied to the economy that 25% increase in rice prices translates to 7–10% drop in real incomes. Furthermore, 2.5 million households depend on Rice as a source of livelihood.

The Philippines, having the highest population growth rates in the region, is currently struggling to meet rice production demands that it is already to importing from neighboring countries, Thailand and Vietnam.

Water source at Tanay, Rizal, Philippines

One of the reasons why demand is outpacing production is that there is a serious water crisis brought about by climate change. El Nino, for example, is a drought affecting arable land for a minimum of 3 months, decreasing rainfall by 60%. Rice culture requires a tremendous amount of water compared to other crops, averaging 5,000 liters of water to produce 1 kg of rice.

Problems with Farming Rice

But the lack of water affects rice farmers in a deeper way.

First, because of the lack of water, rice farmers are forced to walk barefoot 1.2 hectares of land 3x a day (before the break of dawn, midday and before dusk) to ensure that his crops have enough water. Not only does this bring about skin and other diseases but it also consumes time, time that Mang Kiko could well invest learning a new skill or do another enterprise.

Real effects of lack of water in rice culture.

Second, cobra and other snake bites are common especially before the break of dawn, when they accidentally step on these when measuring soil moisture barefoot.

Third, because of the lack of water, a swarm of pests called Black Bugs lay eggs on unirrigated rice fields and attack rice. Just ten black bug adults per hill can cause losses of up to 35% in rice.

There are also crop management issues that result from the water scarcity.

Because the supply of water is not enough, farmers need to take turns flooding their field. This results in what is today called the “rice roulette,” a raffling of a ”schedule” forcing some farmers to break the optimal rice production calendar and transplanting their seeds before the arrival of the monsoon, causing damage or drowning half their crops.

Crop management issues in rice culture.

Furthermore, this results in corruption and red tape from those in control of the water source and infighting within the farmers association, all demanding for water, instead of collaborating to find common solutions.

It is clear that to mitigate the water crisis we need to “Produce more rice with less water.”


CropTXT is a low cost, low power network of sensors that help farmers conserve water and at the same time, make farming more convenient.

At the core of each sensor is a battery-powered-Arduino and a GSM module. Each sensor can last up to 2 weeks on a full charge.

Each sensor will detect moisture and water level and will timely send moisture data via SMS to inform the farmer that the plot needs to be irrigated.

CropTXT System Diagram

In the Philippines, plot sizes vary from place to place. But in Tanay Rizal, where I tested my sensor, the average plot size is 2000 square meters. Assuming that the plot is perfectly flat when flooded, 1 CropTXT sensor can accommodate a full 2000 square meter plot.

SMS Text Message is the interaction because GSM is currently the only form of connectivity available to farmers in rural areas and smartphone penetration in the Philippines is at 15%.

Rice culture needs to be flooded to prevent weeds and other grass to overtake rice that dramatically reduces yields.

CropTXT simulates IRRI’s Safe AWD system, a process that allows water in the field to drop 15cm below the soil surface before irrigation.

IRRI’s Safe AWD Methodology

First, the farmer sticks wireless, GSM-based sensors on the ground. From there, the sensors analyze soil conditions and the amount of water the crops need. After irrigation, the water level will gradually decrease. When the water level has dropped to 15 cm below the soil surface, CropTXT will alert the farmer to re-flood the field. Once re-flooding of 5 cm is reached, CropTXT will again send another SMS to alert the farmer to stop irrigating.

According to IRRI, the process of Safe AWD does not cause any yield decline since the roots of the rice plants will be able to take in water from the saturated soil, and at the same time still prevent weeds from growing, resulting in 25% water savings.

Competitive Landscape

CropTXT is not the only sensor in the available on the market that seeks to help farmers conserve water. In fact, others are more advanced.

NASA’s SMAP, for example, is a satellite that monitors drought and measures soil moisture to aid farmers. The problem with SMAP is that measurement is every 2–3 days and has a resolution at a 10-kilometer radius, far too wide for a Farmer’s 2,000 square meter plot.

Competitive Landscape

Skybox is a Drone Flyby, developed by scientists from Stanford University. The data is accurate, but there are none available in the Philippines.

There is also CropX and other Advanced Systems. These systems, however, are too expensive at $380 per sensor, and $520 yearly subscription. They also rely on advanced connectivity like wifi and data, and, will likely invite theft if deployed in the Philippines.

The cheapest solution available is IRRI’s pani pipe. IRRI currently recommends the use of the Pani Pipe in Safe AWD. It is analog, and it is cheap.

Competitive Landscape — IRRI’s Pani Pipe

Farmers in Tanay Rizal, have tried using the Pani pipe only to abandon them after a month of use. This is because farmers still need to do the daily rounds and do manual measurement using a tape measure, to get an accurate reading.


When I started working on CropTXT last year, I started with a prototype of $122 dollars.

First Prototypes

Today, not only is CropTXT cheaper at 26 dollars, materials used are readily and locally available in any hardware store in the Philippines — making deployment, scaling, and repairs easy for the farmers.


But 26 dollars per sensor is till far too expensive for a Rice Farmer’s $4 daily wage.

Custom code and hardware

I designed and created my own custom probes made from low cost and locally available materials to make CropTXT even cheaper.

Down the road, the goal is to scale and bring down the price of each sensor to 5 dollars, hopefully making it sustainable for non-profits to invest in. CropTXT also needs support from the telecommunications sector, grating CropTXT free access to SMS and GSM services.