Biochar-compost mixture as amendment for improvement of polybag-growing media and oil palm seedlings at main nursery stage

International Journal of Recycling of Organic Waste in Agriculture (2018) 7:11–23 https://doi.org/10.1007/s40093-017-0185-3 ORIGINAL RESEARCH Biochar‑compost mixture as amendment for improvement of polybag‑growing media and oil palm seedlings at main nursery stage Rovica Radin1 · Rosenani Abu Bakar1 · Che Fauziah Ishak1 · Siti Hajar Ahmad2 · Lim Chin Tsong1 Received: 12 April 2017 / Accepted: 4 November 2017 / Published online: 17 November 2017 © The Author(s) 2017. This article is an open access publication Abstract Purpose Production of oil palm seedling in the nursery mainly utilises top soil as polybag medium. These soils, especially in tropical regions, are acidic and have low organic matter content. The aim of this study was to investigate the effects of oil palm empty fruit bunch (EFB) biochar and compost incorporation as amendment in polybag medium for oil palm seedlings growth at the nursery stage. Methods A polybag experiment was conducted with four biochar rates (0, 0.5, 1.0 and 1.5% w/w C addition), two compost rates (0 and 30% v/v), and two fertiliser application rates (75 and 100% of recommended rate). The effects of biochar, compost, and biochar-compost combination on oil palm seedling growth was evaluated and the effectiveness of EFB biochar in retaining soil nutrients was determined indirectly by measuring amount of nutrient leached through the polybag medium. Results Biochar, compost, and biochar-compost amendment improved polybag media’s chemical properties (pH, total C and N, C:N ratio, CEC, Mg, and Ca). There were no significant effects of the amendments on shoot biomass. However, root growth and shoot:root ratio significantly improved with 1.5% w/w C addition and 30% (v/v) compost with 75% recommended fertiliser rates applied. Furthermore, nutrient leaching measurement indicates that, EFB biochar significantly reduced ammonium-N leaching up to 21–46%. Conclusions Overall, this study demonstrates the potential of biochar and compost co-application to improve the chemical properties of polybag medium and root development of oil palm seedlings. Keywords Oil palm nursery · Oil palm waste · Biochar · Compost · Nutrient retention Introduction The Malaysian oil palm industry has grown tremendously over the past few decades and has become a major contributor to the gross domestic product (GDP) from agriculture sector, amounting to 46.9% in 2015 (DOSM 2017). Currently, oil palm plantation occupied 5.39 million ha of total planting area with production of 20 million tonnes of crude * Rovica Radin 1 Department of Land Management, Faculty of Agriculture, Universiti Putra Malaysia (UPM), 43400 Serdang, Selangor, Malaysia 2 Department of Crop Science, Faculty of Agriculture, Universiti Putra Malaysia, Serdang, Selangor, Malaysia palm oil (MPOB 2016), making the most significant plantation commodity in Malaysia. There are two main stages in oil palm cultivation: nursery stage and renewal or definitive area, where the palms are grown for 20–25 years, the economic life period of oil palm (Zulkifli et al. 2010). Seedlings are established in the nursery stage for 10–14 months before field planting. For good oil palm establishment after transplanting in the field, it is uttermost importance to produce good quality oil palm seedlings (Gillbanks 2003; Mathews et al. 2008). A common practice of oil palm seedling production in the nursery is using top soils as the polybag medium. Malaysian soils (mostly Ultisols and Oxisols) are known to be highly weathered acidic soils with low organic matter content. Mineral fertilisers are normally used as sources of nutrients for raising a good vegetative growth of oil palm seedlings (Paramananthan 2003; Verheye 2010). However, the efforts to maintain soil nutrient status through chemical fertilisation come with certain cost, 13 Vol.:(0123456789) 12 International Journal of Recycling of Organic Waste in Agriculture (2018) 7:11–23 negative environmental impact, and increase in production cost of oil palm seedlings. Thus, there is a need for sustainable production of good oil palm seedlings, potentially with recycled organic waste in the form of compost and biochar, hence leading to less chemical fertiliser usage. Several studies of oil palm seedling in the nursery stage showed a positive effect of soil amended with organic material on the vegetative growth of oil palm seedlings (Danso et al. 2013; Suryanto et al. 2015). The most common organic material used as soil amendment are compost and animal manure (Scotti et al. 2015). Compost, a by-product of organics recycling programme, contains significant amount of humic substances, valuable plant nutrients, and essential trace elements (Donn et al. 2014; Bedada et al. 2014). It restores soil organic matter which has direct effects on soil microbial biomass and enzyme activities (Ouni et al. 2013; Blanchet et al. 2016), consequently improving crop growth and yield (D’Hose et al. 2014; Ninh et al. 2015). In the past decade, the use of biochar as a soil amendment and tool for C sequestration has a good potential in increasing crop productivity. Biochar is a carbonaceous material produced by pyrolysis of biomass in a limited oxygen condition (Schahczenski 2010). Numerous studies showed that adding biochar into infertile soils can potentially increase the cation exchange capacity of the soil and nutrient sorption (Jien and Wang 2013; Gray et al. 2014); stimulate soil microorganisms activities (Ducey et al. 2013), and reduce plant nutrients leaching losses from the soil (Kameyama et al. 2012). Moreover, several studies have highlighted the positive effects of biochar on root growth (Ogawa and Okimori 2010; Prendergast-Miller et al. 2014), particularly increased root biomass (Xiao et al. 2016) and root length (Solaiman et al. 2012; Olmo et al. 2016). There is also increasing interest in the combination of biochar with compost for improvement of soil quality other than C sequestration. The synergistic effects of biochar-compost combination theoretically could be achieved through the stability of biochar which promotes C sequestration, apart from improvement of soil properties and source of plant available nutrients as compost mineralises and eventually adds to the organic matter pool (Kammann et al. 2016). In Malaysia, there are several available biomass wastes that have the potential to be converted into biochar as an alternative in waste management. The conversion of oil palm waste into biochar is a promising strategy towards obtaining carbon credit for the oil palm industry as part of the efforts to achieve sustainability in palm oil production. Biochar and compost may have important contribution in waste management and nutrient recycling in the oil palm industry. The oil palm waste based compost and biochar may be returned into oil palm field as fertiliser and amendment in the nursery for oil palm seedling production. However, limited research has been carried out to demons (...truncated)