Fertilising with Nitric nitrogen is for many growers the most natural thing in the world. But the other nitrogen - ammonium - often encounters resistance. It is feared that it is bad for the pH and that it may cause rot in pepper blossom due to calcium deficiency. "But previous studies show that ammonium may very well be beneficent to the crop," says Bram van der Maas of Wageningen UR Greenhouse Horticulture in Bleiswijk. Together with his colleague Aat van Winkel, he’s conducting research on the workings of ammonium.
This Spring, they started a trial with cucumbers at GreenQ. "The crop appears to respond well to the supplementary feeding of ammonium," says Van der Maas. "It is striking that 3% ammonium provides 10% more nitrogen in the leaves." pH reacts strongly to the additional feeding. This can be seen as negative. But this disadvantage may have an upside: ammonium may be used to adjust the pH.
This Spring, they started a trial with cucumbers at GreenQ. "The crop appears to respond well to the supplementary feeding of ammonium," says Van der Maas. "It is striking that 3% ammonium provides 10% more nitrogen in the leaves." pH reacts strongly to the additional feeding. This can be seen as negative. But this disadvantage may have an upside: ammonium may be used to adjust the pH.
Aat van Winkel, Bram van der Maas and Peter Klein
A higher yield through ammonium has yet to be established. But there is strong suspicion that ammonium does have effect. One particular gain has already been found. A method was developed to base the ammonium gift on, inter alia, the pH-value and the number of doses of water per day. A possible correction in the calcium gift was also established, so this method works. Thus, it is possible to fertilize more accurately.
Based on the research results, the ion selective meter is further developed so that eventually continuous measurements will become possible. Klein: "This gives the grower an even better picture of crops during the day." The launch is expected in mid-2014.
Klappolder 150
2665 LP Bleiswijk
tel. 010 52 41 600
fax 010 52 16 702
e-mail: [email protected]