Are planting site conditions more important than soil amendments when direct seeding in the semiarid Mallee in regional Victoria, Australia?

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Direct seeding is a potentially valuable method for restoration in arid areas due to its low cost and labor input but suffers from the drawback of reduced survival rates, which may lead to planting failure. As such, the addition of soil amendments may be one way to increase planting success rates. This study investigated whether the addition of three types of soil amendments (fertilizers, hydrogels, and microbial inoculants) would be able to increase the emergence and survival times of direct seeding works in the semiarid Mallee region of north‐west Victoria, Australia. Seed from four native species were mechanically directly seeded into three sites across the Mallee region, along with different combinations of soil amendments. Emergence and survival time were recorded for 1 year, and the soil properties at each planting location were analyzed. The results showed that only the two larger‐seeded species (Acacia ligulata and Callitris gracilis) were able to emerge, while the two smaller‐seeded species (Eucalyptus calycogona and Melaleuca lanceolata) showed no emergence. Soil amendments had no effect on either seedling emergence or survival time. Instead, seeding location had a significant outcome for both seedling emergence and survival. It was found that locations that showed the highest emergence did not necessarily show the highest survival. Low soil nutrient sandplains contained the highest seedling emergence counts. The longest surviving seedlings were in locations with slightly higher nitrogen levels for A. ligulata seedlings, while C. gracilis survived longest in highly sandy soil under a slightly cooler, wetter climate.