Composted Rabbit Manure as Organic Matrix for Manufacturing Horticultural Growing Media: Composting Process and Seedling Effects

Abstract

This study investigated composted rabbit manure as an organic matrix to replace peat for manufacturing horticultural growing media, where three kinds of rabbit manures were composted with temperatures > 50 °C lasting > 7 days, with a germination index > 70%. The heavy metal contents in rabbit manure were far lower than the thresholds in Chinese standards for safe use as horticultural growing media. Then, different ratios of compost and peat were mixed with perlite and vermiculite to manufacture growing media, which were evaluated in a 28-day seedling experiment with cabbage. The manufactured growing media characteristics could satisfy the seedlings’ requirements; air spaces in particular were improved from 15.7% to up to 28.7% by mixing composted manure. Seedling emergence percentages > 90% and good seedling qualities (including enhanced root length, seedling height, and chlorophyll content) indicated that composted rabbit manure could effectively replace peat to manufacture horticultural growing media. The best seedling performance was obtained with the following ratio of composted manure, peat, perlite, and vermiculite: 3:3:2:2. However, the mixing ratio could be further optimized, and other methods to reduce the salinity may be required for the different requirements of specific crops in further research.

Rabbit manure compost as a peat substitute for compound growing media: Proportioning optimization according to physiochemical characteristics and seedling effects

“…Similarly, the best seedling performance of cabbage ( Brassica rapa var. glabra Regel) was achieved when the rabbit manure compost ratio was 30% ( Li et al., 2022 ). It can be seen that rabbit manure compost can be used as a substitute for peat, regardless of crop type.…”

“…The National Livestock Station of China recommends that livestock and poultry waste should be composted to manufacture growing media trays or growing media as one of the effective ways to recycle biomass (Meng et al, 2019;Feng et al, 2020;Xu et al, 2021). Composted rabbit manure is considered suitable for use as solid growing media because of its low moisture (means low costs on collection and transport), low heavy metal (means high plant safety), high lignocellulose (means good porosity), and high nutrition (means good fertilizer effect) (Pereira et al, 2020;Ikrarwati et al, 2021;Li et al, 2022). Mahmoud et al (2014) explored the use of rabbit manure in organic tomato (Solanum lycopersicum L.) transplants and observed interesting fertilizer effects.…”

“…Çelebi (2019) used growth media designed from 71% perlite and 29% peat (v/v). Additionally, there are studies in which the ratio of peat:perlite:vermiculite was set to 2:1:1 or 3:1:1 ( Li et al., 2022 ). Still, the mixing proportion is critical because the balance of comprehensive agronomic effects, economy, environmental protection, etc., should be considered ( Chang et al., 2021 ).…”

The Effects of Rabbit Compost Tea and NPK Fertilizer on the Growth Parameters of Maize (Zea mays L.)

“…In terms of nutrients, rabbit manure is twice as rich as chicken manure and four times richer than cow or horse manure (Ame, 2021). According to Li et al (2022), rabbit manure often has low water content and a good granule structure; this makes the utilization of rabbit manure simpler when compared to some other animal and poultry excrement. Other minerals contained in rabbit manure, including calcium, sulfur, magnesium, and other micronutrients, are also abundant in rabbit manure.…”