UBC Theses and Dissertations
Compost utilization in vegetables greenhouses industry Wong, Raymond Wa Leong
This study evaluates the utilization of greenhouse compost as growing media in commercial vegetable greenhouse. The greenhouse compost was generated from greenhouse waste as media and the yellow cedar sawdust was the conventional growing media used in the B.C. greenhouse industry. A series of analysis was done on the greenhouse compost and sawdust to compare their physical and chemical characteristics. The results suggested the greenhouse compost provides higher moisture retention and density, and lower porosity; for optimal growing conditions. A full growing trial was conducted to grow beefsteak tomatoes. The study was setup in a commercial greenhouse with independent control environment. The media tested were pure sawdust media, a mixture of 2:1 sawdust to greenhouse compost by volume, and pure greenhouse compost media. Each media was irrigated with either N1, N2 or N3 nutrient recipes. N1 was the conventional nutrient recipe. N2 was catered to optimize the mix and the compost media. The N2 recipe was similar with N1 with an increase amount of ammonium concentration. N3 was the same as N2 with a lower E C value to compensate the high E C in the pure compost media. The study was conducted for 10 months. During the trial, the fruit yield, fruit quality, plants growth and conditions, pH & E C were monitored. The study indicates greenhouse compost is suitable alternative as a growing medium. Greenhouse compost was able to achieve similar yield, crop health and fruit quality when compare with sawdust media. The results from pure compost indicate a significant improvement in fruit size. In addition, greenhouse compost has pH buffering capability to the conventional system. Finally, addition of greenhouse compost to yellow cedar sawdust does not appear to increase the rate of degradation of the sawdust.
Item Citations and Data