Use of water hyacinth (eichhornia crassipes) compost as a peat substitute in soilless growth media

Abstract

This study was conducted to investigate the feasibility of using water hyacinth composted with (WHCM) and without (WHC) pig manure as a peat substitute in substrates for tomato seedling nursery and Chinese cabbage production. The main physical and chemical characteristics of substrates with 30% (S1), 50% (S2), and 60% (S3) WHC or with 30% WHCM (S4) were analyzed. The total porosity and air porosity of the substrates fell below the range for ideal substrates and tended to decrease with the increasing WHC proportions. Water holding capacity was significantly lower in S4 than in S1. Electrical conductivity levels were significantly raised by the compost additions, especially by WHCM addition. Substrates with 30%–60% WHC performed equally well in tomato seedling germination (92.0%–95.3%), while substrate with 30% WHCM gave a poor result (76.0%). The stem diameter, plant height, and biomass of tomato seedlings showed a trend of decrease with the increasing WHC proportions or with addition of WHCM in the substrates. The performance and quality of Chinese cabbage were generally reduced by addition of the composts in the order of S1 > S2 > S3 > S4. Growth parameters of the plants did not differ significantly between S1 and S2. These results suggested that the percentage of WCH in the substrates could be added up to 50% without apparently affecting the growth or product quality of Chinese cabbage.