Why the Field Still Wastes Water
Agriculture uses about 62% of China's water, and the effective utilization coefficient of irrigation water is only about 0.57, against 0.7–0.8 in countries that already meter the field. Flood and furrow irrigation waste the most, and the gap is sharpest in North and Northwest China. Soil-moisture probes, a weather station, and a gateway that can open a valve on demand are how smart irrigation lifts water efficiency by 30–50%. That is a food-security tool as much as a gadget.
The hardware is drip, sprinkler, or micro-irrigation. The change is the decision: from a farmer's habit or a fixed clock to soil moisture, the crop's water need, and a forecast. Pumps, valves, and probes scattered along the ditch share one network. The platform writes a plan and sends it down, so the set can run without someone standing at the pump.
The Market
Industry research puts the global smart agricultural irrigation market at about RMB 42.57 billion in 2024 and about RMB 93.77 billion by 2031, a CAGR of about 12.0% from 2025 to 2031. China is one of the largest buyers, and it is growing faster than that average. Efficient water-saving irrigation already covers more than 560 million mu. The dryland belts of the Northwest and North China are where the next smart systems are going in.
Policy and the Standards a Design Has to Meet
The 14th Five-Year Plan for Advancing Agricultural and Rural Modernization calls for smart agriculture and for water-saving irrigation that can be controlled, not just built. The National Water-Saving Action Plan wants the farmland irrigation coefficient above 0.6 by 2030. The Ministry of Agriculture and Rural Affairs, in its opinions on high-quality agricultural mechanization, encourages smart irrigation equipment. Local subsidies sit inside high-standard farmland projects.
GB/T 50485-2020, Technical Standard for Micro-Irrigation Engineering, and GB/T 50085-2007, Technical Code for Sprinkler Irrigation Engineering, are the design documents. The link is usually NB-IoT or LoRa, with sensor interfaces for soil moisture and weather. Drip tape and nozzles still have to meet their own product standards.
Who Builds It, and the Numbers on a Station
Upstream is the probe (about ±2% volumetric water content), the weather station, the solenoid valve, and the pump controller. Midstream is the irrigation cloud, the agricultural gateway, and the NB-IoT or 4G module. Downstream is the irrigation district, the cooperative, and the contractor building high-standard farmland. Of China's efficient water-saving area, drip is about 45%, sprinkler about 35%, and micro-spray about 20%. Probes are usually stacked at 10 cm, 20 cm, and 40 cm. A decision every 15–30 minutes is the usual cycle. One station on 4G or NB-IoT moves about 1–5 MB a day.
Where the Water and the Fertilizer Are Lost
A clock, not the soil. Opening the valve because it is Tuesday, or because that is how it was always done, ignores the actual water in the profile and the growth stage. Too much water leaches nutrients and salts the soil. Too little cuts the yield. A moisture probe on each layer, a crop water-requirement model, and ET (evapotranspiration) are what a precise decision is made of.
A district too wide to walk. Pumps, valves, and pipe on a large scheme are found broken or leaking late, because the inspection round is long. Current, valve position, and flow reported live, with an alarm, let a technician diagnose remotely and send a person to the right asset.
Fertilizer that does not follow the crop. Fertigation dissolves fertilizer into the irrigation water. Doing that by hand cannot change concentration as the stage changes. A controller that takes a recipe from the cloud and drives the dosing pump and the solenoid can.
What Gets Connected
The moisture network. Temperature, moisture, and EC sensors in the plot upload over 4G or NB-IoT. Weather and a crop model turn that into a water volume, then a plan for the field controller. Plots and crops can carry different rules.
The pump and the valve. A gateway on the pump house reads current, pressure, and flow, and can start, stop, or change speed from afar. Networked solenoid and motorized valves open on the plan, zone by zone and hour by hour, so nobody has to drive out to turn a handle.
The weather station. Rain, temperature, humidity, wind, and sunshine, plus a forecast API, estimate ET for the next few days. Irrigation pauses before rain and starts again from the soil reading afterward. That is "irrigate by the sky": water that would have fallen anyway is not pumped.
Three Districts
Xinjiang cotton, drip. One Xinjiang Production and Construction Corps irrigation district put in more than 5,000 moisture points and irrigates from ET. Water use fell by about 120 m³ per mu, fertilizer by about 15%, and cotton yield per mu rose about 8%.
North China wheat, sprinkler. A Hebei county tied pumps, valves, and weather stations into a high-standard farmland project. Winter and spring irrigation follows soil moisture and the forecast. The effective utilization coefficient moved from 0.52 to 0.68.
Northwest orchards, micro-irrigation. An apple district in Shaanxi runs fertigation from a controller and holds nutrient-solution EC between 1.2 and 2.0 mS/cm by growth stage. Fertilizer use efficiency is above 65%.
Terms on the Same Job
ET is evapotranspiration, crop transpiration plus soil evaporation, the number irrigation volume is calculated from. Soil moisture is the water in the profile, usually volumetric water content (%) or matric potential. Fertigation is fertilizer dissolved into the irrigation water and applied with it. Drip tape is the perforated hose that releases water at the root, slowly.
Where It Is Heading
Models trained on past seasons are starting to change the plan by themselves. A digital twin of the district is a 3D model used to try a schedule before the valves move. Water-price reform — charging by the cubic meter, and a tiered tariff — is what forces the meter to be accurate. SimtoLink supplies 4G and NB-IoT SIM cards and modules for the pump, the probe, and the controller, so a station at the far end of the ditch stays on the platform.
Summary
Smart irrigation is how a water-short farm keeps a crop without flooding the field. Moisture, a remote valve, and a weather station are the three pieces. The coefficient, the mu of water saved, and the fertilizer that stays in the root zone are the numbers that matter. SimtoLink's job on that ditch is the link: a pump and a probe that still report when the nearest town is an hour away.