Study showcases: Richer harvest and healthier plants through automatic irrigation

A study conducted by the Weihenstephan-Triesdorf University of Applied Sciences on behalf of Gardena shows that the use of automatic irrigation leads to a more efficient use of water, a richer harvest and healthier plants.

Water is essential for the growth and health of plants. Since the hot summers of 2003 and 2018 at the latest, awareness of how important water is as a re-source has also been growing in Europe. Natural precipitation is not available to a sufficient extent at times, so that additional irrigation must be used in the garden to ensure respective results. The goal, however, should be to use wa-ter as sparingly as possible while providing plants with the best possible sup-ply. In addition, the user should be able to achieve the desired results with a reasonable amount of time, even when having rudimentary horticultural knowledge. Efficient irrigation solutions are therefore particularly in demand.
To clarify this question Gardena has commissioned the Weihenstephan-Triesdorf University of Applied Sciences. During the 2018 season, various irrigation trials were carried out in the greenhouse and field using Gardena technical components for control and application of water. The crops studied were head lettuce, tomatoes, kale and a summer pile mixture. Although it is approved by the manufacturer to use these products exclusively in private gardens, the scientific experiments regarding crop management, yield and quality assessment were carried out and evaluated in accordance with the guidelines for commercial horticulture. Gardena's system products had to prove themselves here.

Drip irrigation ensures higher yields

The study provided numerous interesting results. For example, the auditors found out that micro-drip irrigation in particular can achieve a considerably better result in terms of quantity and quality of crop yield. The regular provi-sion of water adapted to the needs of the plants thus contributes significantly to the good development of the stock.
The micro-drip irrigation proved to be particularly advantageous for loamy soil because it was able to supply deeper soil layers with water without silting up the surface.
However, the investigation also showed that careful installation of the irrigation system is essential. If leaks occur because connections come loose, savings are quickly destroyed by an uncontrolled outflow of water.

Smart adjustment of watering times

The watering times were set with the Gardena app, which has proven to be an easy-to-use and useful aid for irrigation concepts in terms of user guidance and questions, according to the study directors.
Additionally, Gardena's smart Sensor has demonstrated to be a valuable cor-rective to casting schedules. The recommended standard schedule proved to be very generous. By using the smart Sensor, it was possible to better align the water release with an actual demand and thus achieve a saving of almost 50 percent. For both outdoor crops (lettuce and tomatoes), the Sensor was also able to optimize the water supply and thus improve the plant quality.
Automatic irrigation resulted in significantly higher yields of tomatoes and a significantly lower proportion of fruit with blossoming rot in contrast to water-ing by hand.

Effective prevention of decay

The experiments in the greenhouse with lettuce and tomatoes showed that the automatically irrigated plants stood out noticeably in terms of quality from the hand watered plants - there was less to no rot. In the case of tomatoes, drip irrigation proved to be more suitable than the more irregular manual irrigation, which was carried out only once a day to help minimise the dreaded flower rot. The coupling of time control with the regulation by the soil moisture sensor also led to a certain reduction in the amount of water required.

Soil moisture sensors save water

In the field, natural precipitation is an additional factor. In combination with the Gardena MultiControl and Gardena SelectControl irrigation control units, the Gardena rain and soil moisture sensors were used. The precipitation days in the period of the investigation highlighted the different modes of operation.
The rain sensor successfully helped to prevent irrigation processes on rainy days. With the soil moisture sensor, irrigation was also possible on a rainy day when rainfall was too low to humidify the soil up to a sufficient depth. After heavy precipitation, irrigation did not occur for several days. The soil moisture sensor thus proved to be a more sensible device for implementing plant- and soil-related irrigation and for saving water in the field.
However, the use of nozzle and micro-drip irrigation systems in conjunction with the corresponding sensors always led to better quality and higher crop yields – through small irrigation and slow water supply, the water could pene-trate deeper into the soil compared to manual irrigation and left the surface mostly dry, especially during micro-drip irrigation so tomatoes, lettuce & Co. did not end up with "wet feet". In almost every application scenario, the Gar-dena systems ensured better developed and healthier plants.