Search Results (7)

More than 40% of the total oil palm area in Indonesia is owned and managed by smallholders. For large plantations, guidelines are available on so-called ‘best management practices’, which should give superior yields at acceptable costs when followed carefully. We tested a subset of such practices in a sample of smallholder plantations, aiming to increase yields and profitability. We implemented improved practices (weeding, pruning, harvesting, and fertiliser application) in 14 smallholder plantations of 13–15 years after planting in Jambi province (Sumatra) and in West-Kalimantan province (Kalimantan) for a duration of 3 to 3.5 years. During this period, we recorded yields, measured palm leaf parameters and analysed leaf nutrient contents. Yield recording then continued for an additional two years. In the treatment plots, the yields did not increase significantly, but the size of the bunches and the size of the palm leaves increased significantly and substantially. The tissue nutrient concentrations also increased significantly, although after three years, the potassium concentrations in the rachis were still below the critical value. Because of the absence of yield increase and the additional costs for fertiliser inputs, the net profit of implementing better management practices was negative, and ‘business as usual’ was justified financially. Some practices, such as harvesting at 10-day intervals and the weeding of circles and paths, were received positively by those farmers who could implement them autonomously, and were applied beyond the experiment. It is challenging to find and implement intensification options that are both sustainable and profitable, that have a substantial impact on yield, and that fit in the smallholders’ realities. On-farm experimentation and data collection are essential for achieving sustainable intensification in smallholder oil palm plantations. Full article

Palm oil production in Southeast Asia often occurs on nutrient-poor, acidic soils converted from primary forest. Both the agricultural conversion and the production of oil palm are subsidised in Indonesia. As well as depleting soil organic C and plant nutrients, agricultural production on these soils can result in the accumulation of trace elements (TEs)—including micronutrients and non-essential trace elements—from the use of TE-containing agrichemicals including phosphate fertilisers and Cu fungicides. We tested the hypothesis that palm soils will have lower C concentrations than forest soils, as well as accumulation of TEs including Cu, Zn and Cd. Soil samples from active and abandoned oil palm plantations in Sumatra, Indonesia, were analysed for general soil properties as well as TE concentrations. Soils were acidic and low in key nutrients, with production likely to be limited by deficiencies of N, P, K, Mg and Mo, present at some sites in mean concentrations as low as 0.021%, 118 mg kg⁻¹, 778 mg kg⁻¹, 1023 mg kg⁻¹ and 0.095 mg kg⁻¹, respectively. Mean organic C was lower (2.0–3.3%) than reported values in nearby forest soils (7.7%). Soils under palm production contained elevated levels of Cu, Zn, As and Pb up to 38, 91, 9.0 and 28 mg kg⁻¹, respectively, likely due to agrichemical use. The correction of nutrient deficiencies in palm production would require significant fertiliser inputs, which would exacerbate TE accumulation and reduce the net economic revenue from oil production. Our data have shown that in the plantations we have sampled, soils have become degraded. These tropical, weathered, and naturally nutrient-poor soils are ill suited to intensive production that requires high ongoing nutrient inputs. These findings have implications for the sustainability of a regionally significant production system across Southeast Asia. Full article

Nitrogen (N) deposition significantly affects forest dynamics, carbon stocks and biodiversity, and numerous assessments of N fluxes and impacts exist in temperate latitudes. In tropical latitudes, however, there are few such assessments. In this study, we measured the inorganic N concentration (wet deposition) deposited in rainfall and rainfall pH throughout one year at the boundary of a forest reserve in Malaysian Borneo. We considered that the N deposition may be either from forest and agricultural fires or derived from agricultural fertiliser. Therefore, we determined the wind trajectories using the HYSPLIT model provided by NOAA, the location of fires throughout the landscape throughout one year using NASA’s FIRM system, and obtained the land use cover map of Malaysia and Indonesia. We then correlated our monthly cumulative wet N deposition with the cumulative number of fires and the cumulative area of oil palm plantation that wind trajectories arriving at our study site passed over before reaching the rainfall sampling site. At 7.45 kg N ha⁻¹ year⁻¹, our study site had the highest annual wet inorganic N deposition recorded for a Malaysian forest environment. The fire season and the cumulative agricultural area crossed by the winds had no significant effect on N deposition, rainfall N concentration, or rainfall pH. We suggest that future research should use ¹⁵N isotopes in rainfall to provide further information on the sources of N deposition in tropical forests such as this. Full article

Palm kernel expeller (PKE) is a biowaste by-product of palm oil processing in Southeast Asia that is exported as stock fodder. Global production of PKE totals 11M t yr⁻¹, of which New Zealand imports 1.9M t yr⁻¹, worth >USD 325M, most of which supports NZ’s dairy herd of 5.5M cows. We aimed to determine the concentrations of the chemical elements in PKE imported into New Zealand and compare this to pasture, as well as to assess chemical concentrations against maximum tolerable levels (MTLs) in stockfeed for animal health and ruminant requirements. Palm kernel expeller was analysed for a suite of essential and trace elements using a HNO₃ digestion and analysis by inductively coupled plasma-mass spectrometry. Palm kernel expeller contained statistically significantly higher concentrations of B, Mg, P, Cr, Mn, Fe, Ni, Cu and Zn than pasture. Magnesium, P and Fe exceeded MTLs in PKE, whereas Al, S, K and Cu were within 90% of their MTL. The N, P and K contained in PKE represent the equivalent of 14%, 20% and 28%, respectively, of dairy fertiliser use in New Zealand. As PKE contained 3.3 mg Cd kg P ⁻¹, there may be potential for PKE to offset fertiliser use in dairy systems, with a low Cd source of P. There were statistically significant differences in elemental concentrations between different batches of PKE indicating that this product is not uniform. Further research of the effects of PKE on animal health is recommended. The excess elements contained in PKE may present risks or benefits to dairy farming systems and determining these would be beneficial in protecting both animal health and environmental sustainability. Full article

Given the challenges in reducing greenhouse gases (GHG), one of the sectors that have attracted the most attention in the Sustainable Development Agenda 2030 (SDA-2030) is the agricultural sector. In this context, one of the crops that has had the most remarkable development worldwide has been oil-palm cultivation, thanks to its high productive potential and being one of the most efficient sources of palmitic acid production. However, despite the significant presence of oil palm in the food sector, oil-palm crops have not been exempt from criticism, as its cultivation has developed mainly in areas of ecological conservation around the world. This criticism has been extended to other crops in the context of the Sustainable Development Goals (SDG) due to insecticides and fertilisers required to treat phytosanitary events in the field. To reduce this problem, researchers have used unmanned aerial vehicles (UAVs) to capture multi-spectral aerial images (MAIs) to assess fields’ plant vigour and detect phytosanitary events early using vegetation indices (VIs). However, detecting phytosanitary events in the early stages still suggests a technological challenge. Thus, to improve the environmental and financial sustainability of oil-palm crops, this paper proposes a hybrid deep-learning model (stacked–convolutional) for risk characterisation derived from a phytosanitary event, as suggested by lethal wilt (LW). For this purpose, the proposed model integrates a Lagrangian dispersion model of the backward-Gaussian-puff-tracking type into its convolutional structure, which allows describing the evolution of LW in the field for stages before a temporal reference scenario. The results show that the proposed model allowed the characterisation of the risk derived from a phytosanitary event, (PE) such as lethal wilt (LW), in the field, promoting improvement in agricultural environmental and financial sustainability activities through the integration of financial-risk concepts. This improved risk management will lead to lower projected losses due to a natural reduction in insecticides and fertilisers, allowing a balance between development and sustainability for this type of crop from the RSPO standards. Full article

African oil palm (Elaeis guineensis) is grown on 17,000,000 hectares in Southeast Asia, producing oil and the by-product, palm kernel expeller (PKE), for export. Elaeis guineensis is typically produced on weathered acidic soils, with fertilisers and fungicides used to increase production. These amendments can contain elevated concentrations of trace elements (TEs), either as the active ingredient (e.g., Cu-based fungicides) or as contaminants, including F, Zn, As, Cd, Pb and U. TEs may accumulate in soil over time, and be taken up by plants, posing a food-chain transfer risk if allowed to exceed soil guideline values. We reviewed available literature on trace elements in soil, plant material, oil and PKE to evaluate the risk of TE accumulation due to phosphate fertiliser and Cu-fungicide use. TE concentrations of Cu, Zn, and Cd were reported to be up to 69, 107 and 5.2 mg kg⁻¹, respectively, in E. guineensis plantation soils, while Cu and As were reported to be up to 28.9 and 3.05 mg kg⁻¹, respectively, in PKE (>50% their permissible limits). Iron, a TE, has also been reported in PKE up to 6130 mg kg⁻¹ (>10-fold the permissible limit). TE accumulation is an emerging issue for the palm oil industry, which, if unaddressed, will negatively affect the industry’s economic and environmental sustainability. There are critical knowledge gaps concerning TEs in palm oil systems, including a general lack of research from Southeast Asian environments and information concerning key contaminants (Fe, Cu, As and Cd) in soils, plants and PKE. Full article

Producing sustainable biodiesel from oil crops has been a great challenge, especially for oil crops plantations that involve various small and medium stakeholders. Differences in plantation activities and environments create a unique sustainability profile for each oil crop that may impose more sustainability issues such as deforestation problems in oil palm plantations. This paper embraced the unique sustainability index profile of each oil crop, and an investigation was performed to evaluate the feasibility of integrating multiple oil crops into the existing biodiesel refinery to improve its economic and sustainability performances. The selection of the process feed is proposed to be based on oil crop properties such as iodine value, peroxide value and saturated and unsaturated fatty acid contents. The sustainability profiles considered in the study include deforestation, oil yield, fertiliser impact, water impact and carbon footprint. Case studies demonstrated that a more balanced sustainability index profile could be achieved at a higher production cost—from USD 6.43 billion·y⁻¹ in a cost-saving-centric solution to USD 39.90 billion·y⁻¹ in a sustainability-improvement-centric solution. The study provided excellent insight into the impact on production cost to achieve sustainability which can help stakeholders to evaluate the feasibility of integrating multiple oil crops in the system. Full article