S13 - Session O4 - Alternative method of compost application in organic vegetable cropping systems

Authors: Ehsan Ebrahimi *, Jana Zinkernagel

Effective application of fertilizers can enhance nutrient use efficiency and decreases the accumulation of nitrates in runoff and groundwater bodies. There are different methods of nutrient management, such as applying fertilizers at different times or using different methods and rates of application. However, there is only a limited number of studies that have investigated different methods of placing the organic amendments such as compost in organic vegetable production systems. This research aimed to compare different placement methods of plant-based compost (PC) in open-vegetable field, especially the application of PC under the root plug of the transplant. The overall aim of using this method of placement was to reduce the amount of fertiliser required whilst simultaneously improving nutrient availability for the vegetables. The study included treatments with two different rates of PC, classified as low, and high. The PC was applied to the soil using two different methods: broadcast uniformly on the surface (B) and in the transplant hole under the root plug of the transplant (U). The amounts of PC used for the B method were 10 and 15 t ha -1 , and for the U method, were 5 and 10 t ha -1 for the low and high application rates, respectively. During the two years of experiment, leek and pepper were tested. Leek with U method of application had higher yield, although the results did not show a significant difference in the first year. In the second year, pepper with U method and 10 t ha -1 PC produced 13% more yield than treatment with B method and 15 t ha -1 PC. This study indicated that PC is a good medium to place close to the rhizosphere of the vegetable crops and the U method of placement was shown to be a suitable alternative to the B method for field-grown vegetables.