Evaluation of Municipal Solid Waste Compost and/or Fertigation as Peat Substituent for Pepper Seedlings Production

Abstract

Pepper (Capsicum annuum L.) seed germination and seedling growth using municipal solid waste compost (MSWC) in various proportions was examined. MSWC extracts (10− 0 up to 10− 6 dilutions) were evaluated for seed priming/germination in Petri dishes. The MSWC extracts at 10− 1–10− 6 showed similar seedling germination, whereas extracts at 10− 1–10− 3 accelerated root radical length compared to the control treatment. However, pure extracts (at 10− 0) almost failed seed germination. Under nursery conditions, six substrates were prepared from commercial peat and MSWC and were further assessed in conjunction with the nutrient application as basic fertilizer (BF) or hydro fertilizer (HF). The addition of MSWC into peat inhibited seed emergence and increased the mean germination time, while fertigation accelerated seed emergence at 15% addition of MSWC. Addition of > 30% MSWC reduced seedling height, leaf number and fresh weight. BF and HF increased fresh weight in seedlings grown in 15% MSWC. Leaf chlorophyll and total carotenoids content decreased in > 60% MSWC into the peat. The greatest leaf photosynthetic rate was found with the application of HF, while higher leaf stomatal conductance and leaf internal CO2 concentration were found in plants grown without fertilizers for both 15 and 45% of MSWC addition. The K content decreased, Na content increased, while P content did not differ with MSWC addition. Fertigation improved seedlings’ nutritive status. No visual phytotoxicity was observed macroscopically. Low content (15–30%) of MSWC may act as alternative substitute to peat with more positive effects observed, if nutrients are provided through HF rather than BF.