Sustainable flower bulb production: prototyping integrated flower bulb production systems on sandy soils in The Netherlands

Flower bulb production in The Netherlands is economically successful. However, production methods rely heavily on external inputs, causing contamination of surface and ground water. The use of pesticides has been estimated 100 kg active ingredient (a.i.) per ha in 1994. In the same year the annual use of nitrogen and phosphate was 310 and 130 kg per ha respectively. Over the last decade the Dutch government established targets for the input and emission of pesticides and (in)organic fertilizers, energy use and volume of production related waste. Prototype flower bulb farming systems, with regard to these objectives, were developed, tested and improved on three experimental farms. This article concentrates on the results of two experimental farms on sandy soils in the west of The Netherlands in the period 1991-1997: ‘De Noord’ at St. Maartensbrug and ‘De Zuid’ at Hillegom. At both experimental farms the use of pesticides was reduced with at least 75% compared to the reference year of 1987-1988. Considerable reduction in the use of soil fumigants and fungicides was realised, but not of herbicides and insecticides. The use of nitrogen and phosphate decreased to approximately 215 kg and 55 kg per ha respectively. The integrated prototypes of experimental farm ‘De Zuid’ were economically competitive with flowerbulb farms in the same region. Integrated farming prototypes of ‘De Noord’ were less profitable due to suboptimal soil conditions, over-ambitious research targets and i nexperienced management. As a spin-off of this farming system research, 24 flower bulb growers are converting to integrated flowerbulb growing on their farms. They are supported by research and extension worker