|CHURCHILL D B|
|HORWATH W R|
|ELLIOTT L F|
|BILSLAND D M|
Submitted to: Applied Engineering in Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/17/1995
Publication Date: N/A
Interpretive Summary: Grass seed production fields in Oregon's Willamette Valley have traditionally been burned after harvest to dispose of straw residue and to destroy the next season's potential pests and diseases. Low-input, in- the-field composting could provide an alternative for grass seed straw utilization. Composting of grass seed straw into an easily spread soil amendment has been shown to be possible without the addition of a high- nitrogen component such as inorganic nitrogen or manure. Reapplication of the soil-like product may benefit the crop by producing short-term increases in yield and/or long-term improvement in soil quality. The objectives of the research were to determine the response of perennial ryegrass to addition of known rates of nitrogen in composted grass seed straw and to assess its value as a plant nutrient source. These plots were established in a field during its fifth year of production, and its overall strength was relatively low. An application of herbicide to control grass seedlings in the fall of 1993 weakened the crop further. In this particular experiment, results showed that the benefits of application of composted grass straw to grass seed production fields solely for its nutrient value is not justified by gains in seed yield alone. However, composting straw for its disposal in lieu of other more expensive or unacceptable methods may be beneficial. Additional tests will be made to determine the long-term benefits for improved soil quality when compost and associated nutrients are returned to the field.
Technical Abstract: Compost from long and short perennial ryegrass straw was formed by turning windrows six times throughout the year with a commercial, straddle-type compost turner. The initial long and short straw, respectively, had initial C/N rations of 57:1 and 43:1. The final ratios for the composted long and short straw, respectively, were 15:1 and 11:1. The compost was broadcast over plots in an existing perennial ryegrass field at different rates based on equivalent nitrogen application of 0, 22, 50, 101, and 202 kg/ha during October 1993. One block of plots was established for application of both the normal rate of inorganic fertilizer (202 kg/ha) and compost. A second block of plots was established for application of a small initial amount of inorganic nitrogen in the fall (28 kg/ha) and compost. Both blocks received normal pesticide applications including fungicides, mollusicides, insecticides, and herbicides. Three replications sof each condition were made resulting in a total of 30 randomized plots in each of the two blocks. Addition of compost had no significant effect on seed yield at any of the rates applied but did significantly increase dry material produced per ha.