Use of willow (Salixsp.) sawdust as a potting medium for calendula (Calendula officinalis) and marigold (Tagetes erecta) plant production

Abstract

Growth of 'Fiesta Gitana' calendula (Calendula officinalis) in growth medium prepared from 75% (vol.) composted willow (Salix sp.) sawdust (WS), with or without additional nitrogen (N) (4% w/w) during composting, and 25% (vol.) perlite was examined. Total plant dry matter, dry matter partition to flowers, and plant height at 77 days after planting were similar in media containing composted WS to values in achieved in a sphagnum peat:perlite (75:25, vol.) control medium. Relative to these media, non-composted WS:perlite (75:25, vol.) resulted in average reductions of total dry matter (57%), dry matter partition to flowers (50%), plant height (43%), flower diameter (73%), and flower buds per plant (82%). In a further study, increasing the proportion of N-enriched composted WS in perlite from 25% to 75% did not affect total dry matter, plant height, or flower number per plant of 'Fiesta Gitana' calendula or 'Perfection Gold' marigold (Tagetes erecta) compared to values achieved in the sphagnum peat:perlite (75:25, vol.) control medium. Since flower diameter decreased in both species when the N-enriched composted WS exceeded 50%, we suggest that this "waste" product can substitute for all the sphagnum peat, but should not exceed 50% volume in a perlite mixture.

Effect of Differently Matured Composts from Willow on Growth and Development of Lettuce

“…Although organic additives usually stimulate emergence and improve plant growth and development [39][40][41], the use of wood or bark composts may not result in a positive yield-forming effect. The results obtained in the second stage of the pot experiment (Figure 5b, Table 3) showed the lettuce yields obtained from the variant C samples after 1, 71 and 167 days of composting (4.70, 10.37 and 5.55 g pot −1 , respectively) were significantly higher than the yield of the control: 2.17 g pot −1 .…”

“…Many authors indicate [12,39,[42][43][44] that the effect on plant growth under the influence of organic additives may differ depending on the quality of the additive used. Analysing the data in Table 3, it can be assumed that the main factors limiting the stimulating effect of the studied composts on plant yield are low content and probably low bioavailability of basic nutrients.…”

“…Experimental results conducted by Duddigan et al [36] have shown that using growing media containing only wood-based composts did not increase yields compared to control media. Gariglio et al [20,39] reported a significant increase in yield of test plants on substrates with composted willow sawdust only compared to non-composted material. Furthermore, the results of the study by Adamczewska-Sowi ńska et al [15] indicated a negative effect of using substrates of composted willow only, on the quantity and quality characteristics of test plants.…”

“…Therefore, most authors suggest the use of composting as a method of processing willow for agricultural purposes, and also recommend enriching the substrate with nutrients, especially nitrogen. Thus, with reference to studies on composts from woodbased substrates [15,20,39,44], the evaluation of the effect on yield is extremely complex and requires understanding of many factors. Therefore, application of such composts as a single amendment may not result in a change in yield [38,39,45,46].…”

“…Thus, with reference to studies on composts from woodbased substrates [15,20,39,44], the evaluation of the effect on yield is extremely complex and requires understanding of many factors. Therefore, application of such composts as a single amendment may not result in a change in yield [38,39,45,46].…”