Comparison between pivot and drip irrigation in corn cultivation

The main problem concerning corn cultivation is water stress: the most critical phases that suffer from water shortages, which can lead to significant production losses, are from the emission of the plume to flowering and the ripening stage.

In order to obtain high yields, it is necessary to satisfy the evapotranspiration demand of the crop, which is between 0.16 and 0.22 inches/yard per day.

For this reason, it becomes essential to select an efficient and economical irrigation system. The market offers various systems including the most well-known and widely-used option of central pivot and the newer solution of drip irrigation.

What are the differences between the two systems?

Among the relevant differences to consider is the investment cost, adaptability to the rotation, weather conditions, irrigation availability and the efficiency of any fertigation.

Pivot vs Drip irrigation: economic comparisons

In a study conducted by the University of Turin, the costs and efficiency of the two systems were analyzed. Researchers considered the same water supply and an average life of 10 years for the surface drip irrigation and 20 years for the pivot.

According to that study, drip irrigation requires a cost of $1,711 per acre, of which 50% is due to the hoses. The efficiency is between 0.90% and 0.95.

Meanwhile, the central pivot requires a cost of $720 per acre, of which 50% is due to depreciation. The efficiency is between 0.8 and 0.85.

In practice, these figures will be influenced by various factors such as the yield and market price of corn, the extent of cultivation and the effective duration of the system, which depends on the proper design and maintenance.

In fact, according to a study carried out by the University of Kansas, the performance of the pivot system is always higher than a drip irrigation system on large surfaces. The pivot system has maximum potential when the yield and the market price are high; for example, when the yields are above 28.8 Mg/acre and the price is above $108/Mg.

If the price isn't lower than an average price of $108/Mg and the yield is above 31.2 Mg/acre, the drip irrigation system can be equally advantageous in large areas.

In general, the drip system is suitable for small surfaces, while the central pivot is much more efficient in extensive corn crops, and when the yield and market price are rather low.

Pivot vs Drip irrigation: practical aspects