How to Choose Sprinkler Heads for Irrigation Machines? Keep This Buying Guide

Many users focus on the irrigation machine itself when purchasing one, and rarely consider the sprinkler head configuration and sprinkler head quality. In fact, no matter how excellent the mechanical part of the irrigation machine is, it ultimately comes down to whether it can save water and energy, and whether it can increase yield and income. There are many factors affecting the final result, and sprinkler head selection and configuration is one of the most important factors.

1. Choose sprinkler heads according to soil infiltration rate

At present, most large irrigation machines in China use D3000 impact sprinkler heads, with relatively low price being the main reason.

The Nelson D3000 impact sprinkler head has the highest irrigation intensity and the smallest spraying radius. Due to the high irrigation intensity, surface runoff is easily generated under relatively heavy clay soil conditions, affecting the normal operation of the machine, affecting irrigation quality, wasting water and fertilizer, and affecting the increase of yield and benefits.

In addition to the D3000 impact sprinkler head, Nelson also produces R3000, S3000, A3000 and other rotary sprinkler heads. The hydraulic performance parameters of various sprinkler heads are as follows:

Under the same nozzle conditions, the irrigation intensity from high to low is as follows:

D3000>A3000>S3000>R3000.

In order not to produce runoff, D3000 should be sprayed on sandy soil as much as possible, and R3000 is suitable for clay soil and loam.

Irrigation intensity can be divided into average irrigation intensity and instantaneous irrigation intensity.

Average irrigation intensity refers to the average rainfall per unit time within the wetted range. Instantaneous irrigation intensity refers to the rainfall per unit time at a specified point at a certain instant. The instantaneous irrigation intensity of impact sprinkler heads is higher than that of rotary sprinkler heads. It easily causes loamy clay to become compacted, affecting rainfall infiltration and easily causing surface runoff. The harm of surface runoff lies in causing uneven irrigation and fertilization, wasting water, wasting fertilizer, polluting groundwater, and affecting the normal operation of the irrigation machine (wheels sinking into mud).

2. The impact of spraying range on irrigation effect

Sprinkler heads with a large throw have a wide wetting range and low rain intensity, which is conducive to soil infiltration, is less likely to produce surface runoff, provides uniform irrigation, and gives good results. The spraying range of R3000 is the largest among all 3000 series sprinkler heads.

3. The impact of water droplet size on irrigation effect

The kinetic energy of water droplets has an impact on soil infiltration and is a factor that needs careful consideration. If water droplets strike the soil weakly, it is easy to keep soil capillaries open and maintain a high soil water absorption rate. Small water droplets are conducive to infiltration in clay soil.

Under the same nozzle conditions, increasing the working pressure can reduce the diameter of water droplets and reduce the striking force on the soil.

4. The impact of sprinkler head installation height on irrigation effect

Generally speaking, a higher sprinkler head installation height is conducive to improving irrigation uniformity. The reason is that if it is installed high, it sprays relatively farther, and there is more spray overlap. However, the installation height must comprehensively consider the structure of the irrigation system. If the sprinkler head is installed close to the canopy, then the spacing between sprinkler heads must be reduced. Designers should carefully check the sprinkler head performance parameters and choose the nozzle, sprinkler head spacing, and installation height well.

5. Choose dual-nozzle spraying

Choosing dual-nozzle spraying is conducive to crop seedling cultivation. Choosing and installing Nelson 3TN dual-nozzle sprinkler heads and using nozzles with reduced irrigation intensity during the seedling stage can effectively reduce soil erosion and seed washing, which is conducive to emergence and seedling-stage development. As the seedlings grow, the water demand becomes greater and greater, and the root system becomes deeper and deeper, so large-flow nozzles need to be used. Dual-nozzle sprinkler heads provide great convenience for changing nozzles within the season.

6. Installing pressure regulators can greatly improve irrigation uniformity

The role of the pressure regulator is to adjust inlet pressure changes caused by water pressure loss, terrain differences, and pump operating conditions to the designed working pressure. The benefits of installing pressure regulators are as follows:

1. Improve irrigation uniformity

2. Effectively control sprinkler head working performance, such as water droplet size and spraying distance

3. Increase the flexibility of use of the irrigation system. For example, after installing pressure regulation, the irrigation effect on sloping land will be improved.

Users in the United States configure a pressure regulator for each sprinkler head.

The pressure regulator can adjust the inlet pressure to the designed working pressure. However, the inlet pressure cannot be too high, otherwise the pressure regulation function will be poor. Nelson pressure regulators allow the inlet working pressure to be 0.35kg/cm2 greater than the designed working pressure. For example: if the designed working pressure is 1.4kg/cm2, then an inlet pressure of about 1.75kg/cm2 is relatively good. If Nelson sprinkler heads are used, it is best to use Nelson pressure regulators, otherwise the sprinkler head working effect will be poor.

7. Selection of wind resistance of sprinkler heads

The wind resistance performance of irrigation machine sprinkler heads affects irrigation quality.

8. Choose sprinkler heads by comprehensively considering irrigation effect and price

Impact sprinkler heads (D3000) are low in price, but the spraying effect is not good. Impact sprinkler heads have a small throw, so a sprinkler head must be installed at every outlet of the irrigation machine. In this way, the number of sprinkler heads on one irrigation machine is greater than with rotary sprinkler heads. Considering the increase in the number of sprinkler heads and the increase in pressure regulators and fittings, the cost of the whole set is not much lower than that of rotary sprinkler heads. But the spraying quality is much worse than that of rotary sprinkler heads. No users in the United States still use D3000 series sprinkler heads.

9. Selection of end guns for irrigation machines

Using an end gun to irrigate the corners formed by a center pivot irrigation machine can expand the irrigated area and increase land use rate. If the end pressure is insufficient, a booster pump can be equipped, or a Nelson end gun with good low-pressure performance can be selected.

The Nelson end gun series is as follows:

P85AS, brass impact sprinkler head.

Flow rate: 4.5kg/cm2~28.4kg/cm2.

Throw: 15-28 m

Stable performance, durable.

SR75 large end gun

Flow rate 6.8m3/h~36.3m3/h. Throw 23.5~43.5m, 18º elevation angle.

10. Summary of performance of Nelson D3000, R3000, S3000, A3000 irrigation machine sprinkler heads

D3000

-D3000 is the cheapest sprinkler head

-D3000 has relatively high irrigation intensity, is not suitable for crops sensitive to rainfall intensity, and is also not suitable for machines with long spans. The irrigation uniformity of D3000 is lower than that of R3000, S3000 and A3000.

-D3000 easily produces surface runoff and soil erosion. Surface runoff causes waste of water and fertilizer and causes reduced yield. Surface runoff and relatively high irrigation intensity can also cause wheels to sink into muddy water, preventing the irrigation machine from operating normally.

-D3000 has the shortest throw, and a sprinkler head must be installed at every water outlet of the irrigation machine.

--The spraying water flow of D3000 strikes the soil more strongly than other rotary sprinkler heads. The effect is poor for certain soils and crops.

--D3000 can be reconfigured as a LEPA sprinkler head (low energy precision application), reducing evaporation and transpiration losses. It also has a relatively good effect on certain crops whose leaves cannot be wetted.

R3000

-Rotary spray sprinkler head

-R3000 is the most widely used sprinkler head in the world for growing potatoes and high-value crops;

-R3000 has the longest throw among all sprinkler heads used on irrigation machines. Small number of sprinkler heads used, good spraying coverage, good uniformity

-The spraying water flow of R3000 strikes the soil weakly and does not easily erode soil

-R3000 has low rain intensity and long soil infiltration time, which is conducive to water absorption in loam and clay soil.

A3000

-Rotary spray sprinkler head.

-Relatively fast rotating sprinkler head (faster than R3000).

-Good low-pressure effect (but not as good as S3000), energy-saving.

-Strong water flow penetration ability, suitable for high-stalk crops such as corn and sugarcane for inter-row spraying.

-Relatively strong wind resistance

-Low rain intensity, conducive to infiltration in loam and clay soil.

-Good uniformity.

-Spraying range larger than D3000.

-Low-priced rotary sprinkler head.

S3000

-Fastest rotating sprinkler head.

-Very good low-pressure effect.

-Like R3000, high uniformity.

-Small water droplets, weak impact on soil, conducive to water infiltration in clay and loam soil. It will not wash away seeds and affect emergence.

-Very beneficial for irrigation of nurseries and leafy vegetable crops