PEAT AND SAND MIXTURES TO REPLACE SOIL COMPOSTS FOR VEGETABLE PLANT PRODUCTION

Experiments have been conducted for over thirty years on different standard media for growing young plants with the aim of reducing hazards in the production of vegetable seedlings. Garden composts vary in their constituents and also in their properties concerning plant production. Garden soils may be infected with plant pathogens or may be unbalanced in respect of their plant nutrient contents; unfavourable physical conditions may be another cause of poor growth of young plants and consequently of poor ultimate results in the production of vegetables.

Lawrence's John Innes Compost (1930), Fruhstorfer's Einheitserde (1948), Geislers' 'Torfkulturerde' (1954), the peat, vermiculite and clay mixture of Allerton and Ray (1955), Baumann's sphagnum peat with fertilizers (1958), and the University of California System for producing healthy container-grown plants, details of which were published by K. F. Baker (1957) are the types of standardized media proposed to replace garden composts for growing vegetable seedlings for transplanting.

From these types of media for growing young plants the University of California (UC) System, which employs a mixture of peat and fine sand, sterilized by steaming, has been the subject of experiments in the Department of Vegetable Crops in Skierniewice in the years of 1960–1961. For raising vegetable seedlings, the UC System has the following merits:

Peat and fine sand are readily available materials, steaming eliminates plant pathogens, and the basic ingredients, peat, sand and mineral fertilizers, can be used at appropriate ratios.

In Skierniewice, experiments were conducted with growing plants of tomatoes, cucumbers, kohlrabi and cauliflowers; with these last two vegetables the yields in the field have also been recorded.