DEVELOPMENT OF CULTIVATION ON PEAT SUBSTRATE AND ITS ROLE IN MODERN GREENHOUSE CULTIVATION TECHNIQUE IN FINLAND(ABSTRACT)

摘要

A cultivation technique based on the use of light-coloured Sphagnum peat and utilizing a fertilization technique based on water uptake by plants was developed in Finland in the 1970s. Initially the peat consisted of a growing place the size of a greenhouse or growing bed isolated with plastic and filled with peat. After basic fertilization the peat was irrigated with a NK fertilizer solution and kept within certain moisture and fertilizer limits. The quantity of substrate was 100-200 l/m2 and that of single irrigation 5-10 l/m2.In the 1980s the quantities of substrate dropped to approx. 20 l/m2 when growing bags were introduced, followed by growing boards. Today, the quantity of single irrigation is typically only 1-2 l/m2 and the number of irrigations 2-8/24 h. The substrate moisture has increased from 40-60 %/vol to 60-70 %/vol. All nutrients are given in the fertilizer solution instead of the previous NK fertilization since usually only lime is applied to the substrate instead of the previous basic fertilization. As a result of research and product development in Finland it has become possible to develop products from peat that give the substrate a strong structure and enable long-term cultivation and abundant irrigation.Yield curves of the most modern perennial greenhouse cultivation, moisture variations of the substrate, total salt concentrations, water consumption and water and air spaces of the substrate in cucumber, tomato, gerbera and rose cultivation in experimental conditions are presented.