Submitted to: Journal of Applied Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/8/2012
Publication Date: 4/1/2012
Publication URL: http://naldc.nal.usda.gov.d2.nal.usda.gov/catalog/54489
Citation: Madsen, M.D., Davies, K.W., Williams, J.B., Svejcar, A.J. 2012. Agglomerating seeds to enhance native seedling emergence and growth. Journal of Applied Ecology. 49:431-438. Interpretive Summary: Non-biotic soil-surface crusts can act as a significant barrier to seedling emergence in many arid and semiarid regions of the world. The objective of this study was to determine if seedling emergence of bluebunch wheatgrass could be improved by agglomerating multiple seeds into a single pellet, so that the seedlings will collectively generate sufficient force to penetrate the soil crust. The agglomeration treatment was performed using a rotary seed coater. This short duration “proof of concept” study indicated that both the seed coating materials used to form the agglomerates and the act of agglomerating the seeds together improves bluebunch wheatgrass seedling emergence and above-ground biomass production. Further development and evaluation is merited to determine if this technology should be recommended as a native plant restoration treatment.
Technical Abstract: 1. Restoration in rangelands is constrained by low establishment of seeded species. Non-biotic soil-surface crust is one of the major factors limiting reseeding success by acting as a barrier to seedling emergence. 2. The objective of this study was to determine if seedling emergence of Pseudoroegneria spicata could be improved by agglomerating multiple seeds into a single pellet, so that the seedlings growing from the pellet will collectively generate sufficient force to penetrate the soil crust. To evaluate this technology we compared seedling emergence and biomass production from agglomerated, single, and non-coated seed (control). In the greenhouse, seeds were sown in either crust-forming clay or non-crusting sandy soil and studied for a 25 day period. Starting seed density was constant across treatments. 3. In the clay soil, seedling emergence from the agglomeration treatment was 1.3 and 1.9 times higher than the single seed coating and control, respectively. In the sandy soil, the agglomeration and single seed coating responded similarly, producing 1.4 times more seedlings than the control. 4. Biomass production followed a similar trend as plant density. In the clay soil, increased biomass of the agglomeration treatment was not only due to higher plant densities but was also a product of having greater biomass per-plant. 5. Synthesis and applications. This short duration “proof of concept” study indicates that both the seed coating materials used to form the agglomerates and the act of agglomerating the seeds together improves P. spicata emergence and plant growth. It also appears that facilitation may outweigh competition for agglomeration plantings.