Transplant Quality, Yield, and Heavy-Metal Accumulation of Tomato, Muskmelon, and Cabbage Grown in Media Containing Sewage Sludge Compost1

Abstract

Transplant quality, as measured by height and dry weight, of cabbage (Brassica oleracea L. Capitata group) and tomato (Lycopersicon esculentum Mill.) was lower for plants grown in media containing sewage sludge compost with a high heavy-metal concentration (HM) than for plants grown in peat-vermiculite (P-V) or low-metal (LM) sewage sludge compost media. Compost source had no significant effect on transplant quality of muskmelon (Cucumis melo L.) seedlings. Marketable yield of cabbage, tomato, or muskmelon was similar regardless of the media used to grow the transplants. The concentration of Zn, Cu, Mn, Ni, and Cd were significantly higher in transplants grown in HM media than in those grown in LM media. With the exception of Cd, metal levels in transplants grown in LM media were similar to those grown in P-V. Transplant media had little influence on the heavy-metal concentrations found in either foliar samples or the edible portions of the crops studied. Heavy-metal concentrations in foliar samples of all 3 crops were lower than those found in transplants. The lowest concentrations were found in tomato and muskmelon fruit, and in cabbage heads. The Cd concentrations in edible portions were very low regardless of the source of compost in the transplant media, indicating that sewage sludge composts, particularly those low in heavy metals, can be used safely in the growing media of vegetable transplants.

Effects of Sludge, Bed, and Genotype on Cucumber Growth and Elemental Concentrations in Fruit and Peel

“…None of the previously mentioned research efforts has dealt with cucumbers. Fruit crops have been studied, but they have been crops that are consumed when approaching their maturity, for example, sweet com, tomatoes, peas, and muskmelon (12,26,30). On the other hand, cucumber is a popular garden crop (13) that is eaten usually in an immature stage of development.…”

Effect of Different Types and Rates of Composted Sewage Sludge on Yield and Composition of Two Strawberry Cultivars

“…Mean values of shoot and total K uptake in Camarosa were significantly higher than in Chandler. Increasing plant NPK contents and uptakes by applying sewage sludge or its compost to the soil were reported by several workers (Albergts and Howard, 1979;Sterrett et al, 1983b;Harrison, 1986;Harrison and Staub, 1986;Bugbee and Frink, 1989).…”

“…Several workers obtained similar results on the effect of sewage sludge or its compost on plant dry weight. Amending soil with sludge or composted waste has resulted in increasing yield of some vegetable crops including strawberry (Albergts and Howard, 1979), tomato and cabbage (Sterrett et al, 1983a), carrot (Harrison, 1986), cucumber (Harrison and Staub, 1986), cranberry (Bugbee and Frink, 1989), and pepper (Roe et al, 1997).…”

“…In waste-amended soils, heavy metal concentrations often do not buildup to phytotoxic levels (Sterrett et al, 1983a). In addition, it has been observed for cucumber, tomato, muskmelon and cabbage that amending the growing media with sludge containing low concentrations of metals resulted in very low concentrations of these metals in the edible portions of the plants ( Ozores-Hampton et al 1994;Falahi-Ardakani et al, 1988;Sterrett et al, 1983b).…”