Key unknowns in nitrogen budget for oil palm plantations. A review

Abstract

Nitrogen (N) losses in agroecosystems are a major environmental and economic issue. This issue is particularly pronounced in oil palm cultivation because oil palm production area is expected to increase to 12 Mha by 2050. N fertilization in oil palm plantations is mainly provided by mineral fertilizers, palm oil mill by-products, and biological fixation using legume cover crops. N loss has a major environmental impact during cultivation. For instance, 48.7 % of the greenhouse gases emitted to produce 1 t of palm oil fruit are due to N fertilization. Actually, there is little comprehensive knowledge on how to calculate N budgets in oil palm plantation in order to optimize fertilization, taking into account N leaching and N gases emissions. Here we modeled knowledge about all N fluxes in an oil palm field following standard management practices of industrial plantations, on a mineral soil, from planting to felling after a 25-year-growth cycle. The largest fluxes are internal fluxes, such as oil palm uptake, with 40-380 kg N ha, and the decomposition of felled palms at the end of the cycle, with 465-642 kg N ha

Agroecological practices in oil palm plantations: examples from the field

“…However, they also show some potential problem shifting and trade-offs that need to be considered. First, the oil palm co-products recycled in the field can contribute to some environmental issues, such as the provision of habitats to pest such as O. rhinoceros or Topical Issue S. sunidesalis, in South-East Asia notably, or Fusarium in Africa, or the high nitrogen leaching during the palm immature phase (Pardon et al, 2016). Second, there may be competitive uses for co-products either as amendment brought back to the field or as bioenergy feedstock exported.…”

“…Reducing costs is achieved by reducing the input-output (leakage) flows and enhancing recycling internal flows. This is actually quite critical in oil palm agroecosystems because of the large internal fluxes over the whole perennial cycle (Pardon et al, 2016) and the necessary close spatial connection to the mill (within a radius of 50 km), and its in and out fluxes, due to the perishable fruits that must be processed within 24 hours after harvest (Lake et al, 2016).…”

“…For instance, N doses ranges from 48 to 90 kg N. ha À1 .yr À1 for immature palms (Banabas, 2007;Choo et al, 2011;Henson, 2004) and from 56 to 206 kg N.ha À1 .yr À1 for mature palms (FAO, 2004;Foster, 2003;Hansen, 2007;Pardon et al, 2016;Wicke et al, 2008). In an established palm plantation, fertilisers can account for 46 to 85% of field costs Goh and Härdter, 2003;Goh and Po, 2005;Pardon et al, 2016;Silalertruksa et al, 2012). Moreover, part of these fertilisers may be lost to the environment leading to potential environmental impacts such as eutrophication or climate change.…”

Breeding the oil palm (Elaeis guineensisJacq.) for climate change

“…The effects of increased atmospheric CO 2 and warmer temperatures À both individually and combined À on soil microbial activity, including mycorrhizas and N-fixing organisms will change together with their implications for nutrient availability (Carron et al, 2015;Pardon et al, 2016). Potential changes to plant growth, and the combined effects of soil and plant changes on nutrient uptake are currently explored (Fig.…”

Deciphering agricultural practices and environmental impacts in palm oil plantations in Riau and Jambi provinces, Indonesia

“…These fluxes can be determined according to various principles and methods, which may vary depending on the studied substances. A mechanistic approach necessitates a complete understanding and modelling of substance cycling (Pardon et al 2016a). However, knowledge is still lacking and most emission models used in environmental impact assessments consist of empirical operational models that allow for estimating potential rather than actual emissions and impacts.…”