Effects of Quality Composts and other Organic Amendments and their Humic and Fulvic Acid Fractions on the Germination and Early Growth of Slick Spot Peppergrass (Lepidium Papilliferum) and Switchgrass in Various Experimental Conditions

摘要

During the 3rd and 4th semester (2nd year) of this research, a series of experiments was performed in order to evaluate the effects of different dissolved organ matter (DOM), or fulvic acid, samples obtained from composts under study on the germination of the native American species slickspot peppergrass (Lepidium papilliferum). Briefly, the three DOM fractions were previously isolated from three selected composts, a green compost (GC-DOM), a mixed compost (MC-DOM) and a green coffee compost (GCC-DOM). The main physical and chemical properties of the three compost samples and their DOM fractions were shown and described in detail in the first report of this Project. Sixty (60) seeds of slickspot peppergrass for each treatment were germinated. After 7 days, germinated seeds were counted and primary root and shoot lengths were measured. Since seed germination continued in the days after transplanting, germinated seeds were counted also after 15 days. The early- growth experiments were started on germinated seeds (seedlings) of slickspot peppergrass collected from the Petri dishes immediately after the end of the germination trials. At the end of early-growth experiments (30 days), the most vigorous seedlings of slickspot peppergrass for each treatment were transplanted into plastic pots containing a commercial growing substrate in order to continue the growth up to 60 days and 6 months. The effects of the three DOM samples on the seeds of slickspot peppergrass after 15-days germination are given. The effects of MC-DOM at different dilutions and of the three DOM samples at the lowest dilution on the growth of slickspot peppergrass in a commercial growing substrate after 6 months.