VEGETABLE TRANSPLANT GROWTH RESPONSE TO COMPOST AMENDED POTTING MEDIA, FERTILIZER, AND FERTILIZER REGIME (BROCCOLI, CABBAGE, LETTUCE, EGGPLANT, PEPPER, TOMATO).

摘要

Vegetable transplants of broccoli, cabbage, lettuce, eggplant, pepper, and tomato were grown on raised benches under greenhouse conditions in potting mixes containing equal parts by volume of screened fresh composted sludge (made from lime dewatered raw sewage sludge and wood chips) mixed with peat moss and perlite, peat moss and horticultural grade vermiculite (vermiculite), or perlite and vermiculite.;The results indicate that potting media amended with 1/3 by volume of screened composted sewage sludge can supply all of the micro-nutrients, P, Ca, and Mg needs of the plant species tested. For most of the species, only N at 270 mg/M.P. must be applied within 1 or 2 weeks after transplanting as a single application or in split applications. Potassium at 23 to 225 mg/M.P. in addition to 270 mg/M.P. of N is necessary for the optimum growth of tomato transplants.;Plants growing in peat moss amended compost mixes were significantly larger than in mixes where peat moss was excluded. Tissue of tomato and lettuce plants growing in compost-peat mixes amended with vermiculite contained higher concentrations of K and Fe than similar plants growing in compost-peat mixes amended with perlite. However, perlite mixes supplied higher levels of Ca and Mg to plant tissues.;Heavy metal concentrations of tissue from plants growing in compost amended mixes were consistently below those levels considered toxic for animals and human consumption. The addition of S to lower the pH of compost amended growing media did not influence the growth of either tomato or lettuce plants.;To measure the nutrient supplying capacity of the compost amended mixes and to determine frequency and need of fertilizers, the transplant growing in commercial market packs (M.P.) were fertilized one, two, three, or four weeks after transplanting with varying levels of N alone or in combination with varying levels of K. Water was applied at all other times as needed. The plants were grown to marketable size before harvesting. Six experiments were conducted to measure plant response and to evaluate the nutrient and heavy metals concentration of plants grown in compost and non-compost amended potting mixes.