fertigation: beneficial for seed-grown onions

The Dutch magazine Uien (Onions) asked the experts at fertilizer and biostimulant producer Van Iperen for their views on fertigation. The company has been advising growers on fertigation in seed-grown onions for two years now. Van Iperen says it’s a great way to achieve higher, more consistent yields.

Fertigation – fertilization combined with irrigation – enables growers to give their crops the correct nutrients and amounts of water at the right times during the growing season. This creates favorable conditions that lead to steadier crop growth. It also allows for a more efficient use of water, nutrients and crop protection, resulting in a highquality, more sustainable final product. “The longer a crop suffers from a natural moisture deficit, the more fertigation will increase yields, since moisture and nutrients are two major factors in growth,” Van Iperen says. With weather extremes becoming more frequent, the company sees fertigation as a great way for growers to achieve higher, more consistent yields.

Benefits of fertigation The system has several advantages. It's a plant-friendly way of delivering water by applying it on or in the soil instead of over the crop, enabling optimum uptake. Experience shows that frequent sprinkling of crops is more likely to lead to deterioration and a greater chance of microbial or fusarium damage, especially in hot weather. By contrast, when irrigation is combined with carefully planned doses of nutrients, yields can increase by as much as 100 per- cent. This is because, on the one hand, the minerals can't be washed away and lost, and on the other, applying them in water where the plants need them allows for immediate absorption. Fertigation is useful for growers who draw their water from wells and basins, as it allows them to use that water efficiently. As long as enough clean water is available, fertigation provides a high likelihood of good yields, especially in dry years. It facilitates steadier growth, which is a precondition for harvesting quality produce. And that makes production more sustainable overall. Used in an optimum manner, the system enhances plant vigour, according to Van Iperen.

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Further refinement Van Iperen’s innovation team is working to further optimize its fertigation system. In this system, the sowing technique is adapted and a wide sow coulter is used. In crops like onions, which are becoming increasingly challenging, in part because of restrictions on crop protection, it's becoming more and more important to cultivate steady-growing crops with better resistance to diseases and pests. Fertigation can help a lot.

According to Van Iperen, there’s a growing need for even more precise control in fertigation, to optimize crop growth. To achieve this the company has written fertilizer calculation programs. In the future, these may be able to do the work of providing crops with water and nutrients, precisely geared to each week’s or day’s expected growth.

De Groot en Slot is closely following developments in the field of fertigation. The company wants to know what these will mean for the varieties it sells in the Netherlands, and particularly for the growth curves of different varieties. Quality is also a vitally important aspect in the onion business. When onions can be cultivated without growth disorders, mature evenly and the tops will fall gradually, their quality is greatly enhanced. De Groot en Slot and Van Iperen plan to study the advances in fertigation in depth during the new growing season.

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