Managing Oil Palm Plantations More Sustainably: Large-Scale Experiments Within the Biodiversity and Ecosystem Function in Tropical Agriculture (BEFTA) Programme

Conversion of tropical forest to agriculture results in reduced habitat heterogeneity, and associated declines in biodiversity and ecosystem functions. Management strategies to increase biodiversity in agricultural landscapes have therefore often focused on increasing habitat complexity; however, the large-scale, long-term ecological experiments that are needed to test the effects of these strategies are rare in tropical systems. Oil palm (Elaeis guineensis Jacq.)—one of the most widespread and important tropical crops—offers substantial potential for developing wildlife-friendly management strategies because of its long rotation cycles and tree-like structure. Although there is awareness of the need to increase sustainability, practical options for how best to manage oil palm plantations, for benefits to both the environment and crop productivity, have received little research attention. In this paper we introduce the Biodiversity and Ecosystem Function in Tropical Agriculture (BEFTA) Programme: a long-term research collaboration between academia and industry in Sumatra, Indonesia. The BEFTA Programme aims to better understand the oil palm agroecosystem and test sustainability strategies. We hypothesise that adjustments to oil palm management could increase structural complexity, stabilise microclimate, and reduce reliance on chemical inputs, thereby helping to improve levels of biodiversity and ecosystem functions. The Programme has established four major components: (1) assessing variability within the plantation under business-as-usual conditions; (2) the BEFTA Understory Vegetation Project, which tests the effects of varying herbicide regimes; (3) the Riparian Ecosystem Restoration in Tropical Agriculture (RERTA) Project, which tests strategies for restoring riparian habitat; and (4) support for additional collaborative projects within the Programme landscape. Across all projects, we are measuring environmental conditions, biodiversity, and ecosystem functions. We also measure oil palm yield and production costs, in order to assess whether suggested sustainability strategies are feasible from an agronomic perspective. Early results show that oil palm plantation habitat is more variable than might be expected from a monoculture crop, and that everyday vegetation management decisions have significant impacts on habitat structure. The BEFTA Programme highlights the value of large-scale collaborative projects for understanding tropical agricultural systems, and offers a highly valuable experimental set-up for improving our understanding of practices to manage oil palm more sustainably

Potential of Core-Collapse Supernova Neutrino Detection at JUNO

JUNO is an underground neutrino observatory under construction in Jiangmen, China. It uses 20kton liquid scintillator as target, which enables it to detect supernova burst neutrinos of a large statistics for the next galactic core-collapse supernova (CCSN) and also pre-supernova neutrinos from the nearby CCSN progenitors. All flavors of supernova burst neutrinos can be detected by JUNO via several interaction channels, including inverse beta decay, elastic scattering on electron and proton, interactions on C12 nuclei, etc. This retains the possibility for JUNO to reconstruct the energy spectra of supernova burst neutrinos of all flavors. The real time monitoring systems based on FPGA and DAQ are under development in JUNO, which allow prompt alert and trigger-less data acquisition of CCSN events. The alert performances of both monitoring systems have been thoroughly studied using simulations. Moreover, once a CCSN is tagged, the system can give fast characterizations, such as directionality and light curve

Detection of the Diffuse Supernova Neutrino Background with JUNO

As an underground multi-purpose neutrino detector with 20 kton liquid scintillator, Jiangmen Underground Neutrino Observatory (JUNO) is competitive with and complementary to the water-Cherenkov detectors on the search for the diffuse supernova neutrino background (DSNB). Typical supernova models predict 2-4 events per year within the optimal observation window in the JUNO detector. The dominant background is from the neutral-current (NC) interaction of atmospheric neutrinos with 12C nuclei, which surpasses the DSNB by more than one order of magnitude. We evaluated the systematic uncertainty of NC background from the spread of a variety of data-driven models and further developed a method to determine NC background within 15\% with {\it{in}} {\it{situ}} measurements after ten years of running. Besides, the NC-like backgrounds can be effectively suppressed by the intrinsic pulse-shape discrimination (PSD) capabilities of liquid scintillators. In this talk, I will present in detail the improvements on NC background uncertainty evaluation, PSD discriminator development, and finally, the potential of DSNB sensitivity in JUNO

Crop residue management in oil palm plantations: soil quality, soil biota and ecosystem functions

The application of crop residues is one of the most common agricultural practices used to maintain soil ecosystems and crop productivity. This thesis focuses on the oil palm (Elaeis guineensis) agroecosystem, an important tropical crop that has expanded rapidly over the past four decades. Both land conversion and business-as-usual practices within the plantations have contributed to soil degradation. The application of oil palm residues, such as empty fruit bunches (EFB) and oil palm fronds, are thought to have positive effects on the soil ecosystem; yet there is currently a deficit of knowledge on their effectiveness. This thesis aims to examine the effects of oil palm residue application on soil physicochemical properties, soil biota, and ecosystem functions. It reports the results of extensive field trials, sample collection, and statistical analysis of crop residue applications in oil palm plantations in Central Sumatra, Indonesia. Four key results emerged from the thesis. First, in this study site land conversion from secondary forest to oil palm does not affect litter decomposition rate, but positively influences soil fauna activity. Second, there is greater soil fauna activity following EFB application than oil palm fronds or chemical fertilizers, and the fauna activity is highly associated with changes in soil chemical properties and soil moisture conditions. Third, EFB application enhances soil ecosystem functions, through the direct provision of organic matter, and by influencing soil biota. Finally, over 15 years of application, EFB appears to be effective in maintaining or increasing annual crop yield in comparison to chemical fertiliser treatment. Temporal changes in crop yield under EFB application appear to be associated with climatic conditions and soil organic carbon. Overall, these findings improve our understanding of the potential of oil palm residue applications to increase soil quality, soil biota, and ecosystem functions. They also provide useful information for a wider audience of soil ecologists, agricultural managers, and policy makers to improve sustainable management of the oil palm ecosystem.</p

Characterization of the roles of CIPK23 and PP2C in nitrate signaling in Arabidopsis

硝酸鹽不但是植物的主要氮源，也是一訊息分子，調控相關基因的表現及植物的發育。前人研究發現，阿拉伯芥的硝酸鹽雙親合性轉運蛋白CHLorate resistant mutant 1 (CHL1)可能同時扮演感應硝酸鹽的角色，並參與在硝酸鹽傳訊機制中。從本實驗室先前的Affymetrix microarray 實驗，篩選可能參與在硝酸鹽傳訊機制的基因。本篇研究針對 CBL-Interacting Protein Kinase 23 (CIPK23, At1g30270)及PP2C-type phosphatase(At4g32950)，分析兩者在硝酸鹽傳訊機制所扮演的角色。 本篇研究先以逆遺傳策略，分離出不具CIPK23基因表現的T-DNA 插入突變株 (cipk23 mutant)。由qRT-PCR 分析顯示，早期受硝酸鹽誘導反應的基因CHL1及NRT2.1在cipk23 mutant中較wild-type有較高表現，推測CIPK23在早期硝酸鹽誘導反應中可能扮演抑制者的角色。而cipk23 mutant在短期或長期對硝酸鹽的吸收能力與野生型無明顯差異。以高濃度或低濃度硝酸鹽誘導cipk23 mutant根部生長，其主根長與野生型無顯著差異。此外，在阿拉伯芥葉肉原生質細胞中表現CIPK23-GFP，證實CIPK23表現於細胞質。由Bimolecular fluorescence complementation (BiFC)實驗，推測在特定濃度硝酸鹽處理下， CIPK23與CHL1在阿拉伯芥原生質細胞的細胞膜上有蛋白質交互作用。 此外，本篇以細胞學的方法分析PP2C在硝酸鹽傳訊機制所扮演的角色。在阿拉伯芥葉肉原生質細胞中表現PP2C-GFP，顯示PP2C位於細胞膜上，但比對PP2C的蛋白質序列，發現其不具有跨膜區域 (transmembrane domain)。以Palmitoylation 的抑制劑 2-bromopalmitate (2-BrPA) 處理，發現部分原生質細胞的PP2C-GFP轉而堆積在細胞質中，推測PP2C藉由palmitoylation附著到細胞膜上。BiFC 實驗顯示PP2C與CHL1在原生質細胞的細胞膜上有蛋白質交互作用。由本研究與實驗室先前的研究成果，推測CIPK23 與PP2C可能直接與CHL1進行蛋白質交互作用而參與在硝酸鹽傳訊機制中。Nitrate is one of the most important nutrients for plants. It not only serves as a nitrogen source but also a potent signal molecule to regulate gene expression, plant metabolism and development. Recent studies in our lab indicated that CHLorate resistant mutant 1 (CHL1), a dual affinity nitrate transporter, also functions as a nitrate sensor. In addition, two potential candidates involved in nitrate signaling, CBL-interacting protein kinase 23 (CIPK23, At1g30270) and a PP2C-type phosphatase (At4g32950), were identified by Affymetrix microarray analysis in our lab. In cipk23 mutant, expression level of CHL1, as well as other primary nitrate response genes, were higher than that in wild-type, suggesting that CIPK23 is a negative regulator of primary nitrate response in high affinity phase. Neither 15NO3 uptake activity nor nitrate-regulated primary root growth was altered in cipk23 mutant. Transient expressing CIPK23-GFP in Arabidopsis protoplasts indicated that CIPK23 was localized in the cytoplasm. Bimolecular fluorescence complementation (BiFC) analysis suggested that under certain nitrate conditions tested, CHL1 may interact with CIPK23 at the plasma membrane of Arabidopsis protoplasts. In addition, the role of PP2C in nitrate signaling was analyzed by GFP localization study and BiFC. Protein sequence analysis indicated that PP2C is a soluble protein, but PP2C-GFP was localized at the plasma membrane. When treated with palmitoylation inhibitor 2-bromopalmitate, PP2C-GFP became cytosolic-localized, suggesting that PP2C was targeted to the plasma membrane by palmitoylation. BiFC analysis showed that CHL1 interacted with PP2C at the plasma membrane of Arabidopsis protoplasts. Together with other studies in our lab, the data suggested that CIPK23 and PP2C participate in nitrate signaling by directly interacting with CHL1.致謝………………………………………………………………………....i文摘要...………………………………………………………………... ii文摘要……………………………………………………………….iiiHAPTER 1. INTRODUCTION…………………………………………1HAPTER 2. MATERIALS AND METHODS………………………….8. Plant materials 8. Primer sequence 8. Media 9. General techniques 9. Isolation of cipk23 knock out mutant 12. Gene expression analysis 12.15N content in roots and 15N uptake activity 14. Primary root length analysis 15. Subcellular localization and BiFC assay constructions 15. Protoplast isolation, PEG transfection and Confocal Microscopy 19HAPTER 3. RESULTS………………………….……………………22HAPTER 4. DISCUSSION……………………………………………..31EFERENCE………………………………………………….…………6

Application of oil palm empty fruit bunch effects on soil biota and functions: a case study in Sumatra, Indonesia

Oil palm (Elaeis guineensis) is an important tropical crop which provides one-fifth of the world’s vegetable oil, yet its rapid expansion can negatively influence the soil ecosystem.Identifying suitable agronomic management such as crop residue application is important for the sustainable development of oil palm. We examined the effects of adding empty fruit bunches (EFB), a major oil palm residue, on multiple soil abiotic properties, soil biota, and indicators of soil functions. We compared treatments of EFB applications withthree application rates, and a chemical fertilizer treatment in a 15–year trial in Central Sumatra, Indonesia. EFB application increased pH and aggregate stability in 0–10 cm soils and decreased the soil bulk density. EFB application increased the abundance of soil detritivore mites, soil fauna feeding activity, and soil microbial activity. EFB application decreased the biomass of a dominant invasive earthworm species, Pontoscolex corethrurus(Müller, 1857). Results from structural equation modelling suggested that EFB directly affected soil biota and functions, rather than through altering soil abiotic properties. The effects of EFB application on most soil abiotic properties, soil biota and functionindicators were independent of the application rate. Our results revealed that EFBapplication has a high potential to enhance soil biota and functions in oil palm plantations

Application of oil palm empty fruit bunch effects on soil biota and functions:A case study in Sumatra, Indonesia

Oil palm (Elaeis guineensis) is an important tropical crop which provides one-fifth of the world’s vegetable oil, yet its rapid expansion can negatively influence the soil ecosystem. Identifying suitable agronomic management such as crop residue application is important for the sustainable development of oil palm. We examined the effects of adding empty fruit bunches (EFB), a major oil palm residue, on multiple soil abiotic properties, soil biota, and indicators of soil functions. We compared treatments of EFB applications with three application rates, and a chemical fertilizer treatment in a 15–year trial in Central Sumatra, Indonesia. EFB application increased pH and aggregate stability in 0–10 cm soils and decreased the soil bulk density. EFB application increased the abundance of soil detritivore mites, soil fauna feeding activity, and soil microbial activity. EFB application decreased the biomass of a dominant invasive earthworm species, Pontoscolex corethrurus (Müller, 1857). Results from structural equation modelling suggested that EFB directly affected soil biota and functions, rather than through altering soil abiotic properties. The effects of EFB application on most soil abiotic properties, soil biota and function indicators were independent of the application rate. Our results revealed that EFB application has a high potential to enhance soil biota and functions in oil palm plantations

Corrigendum to “Application of oil palm empty fruit bunch effects on soil biota and functions: A case study in Sumatra, Indonesia” [Agric. Ecosyst. Environ. 256 (2018) 105–113]

The authors regret that the first sentence in Section 3.2 “A total of 168 earthworms were collected, with a mean density of 1344 ind m−2”, should be corrected to “A total of 168 earthworms were collected, with a mean density of 13.44 ind m−2”. The authors would like to apologise for any inconvenience cause

Variations in yield gaps of smallholder cocoa systems and the main determining factors along a climate gradient in Ghana

Improving management practices of cocoa (Theobroma cacao L.) cultivation especially under future climate change requires knowledge of yield gaps and their determining factors. In this study, we assessed yield gaps and their determining factors through multiple regression modelling in smallholder cocoa agroforestry systems in Ghana along a climatic gradient. The studied zones referred to as dry, mid and wet with annual rainfall of 1200, 1200–1400 and 1400–2000 mm respectively, represent established “climate suitability zones” across the cocoa belt of West Africa, where 70% of the global cocoa is produced. Data was collected from 150 cocoa farmers and their plantation across the zones. Information about socioeconomic and management characteristics was collected through interviews. In each plantation, soil characteristics and cocoa plantation properties were recorded. Yield data for three consecutive years (2012/13–2014/15) and soil properties (0–30 cm layer) were analysed. Yield gap was estimated as the difference between attainable yield (AY) and actual farmers yield (FY) in each zone based on the approach of maximum farmer yields determined from survey. Average farmer and attainable yield of 211 and 645 kg ha−1 year−1 in the dry, 477 and 1174 kg ha−1 year−1 in the mid and 999 and 2125 kg ha−1 year−1 in the wet zone were recorded, respectively. Relative yield gaps were significantly larger in the dry (67%) than the wet zone (53%). In the dry zone with significantly older farmers (average age of 64), increasing labour cost (use of hired labour) significantly reduced yield gap. Contrary, increasing labour cost significantly increased yield gap in the mid zone where plantations were significantly larger. Yield gap increased significantly with increasing farmer age (54 years) in the mid zone but decreased significantly with farmer age (47 years) in the wet zone. Significant positive relationship between plantation size and yield gap was observed in both mid and wet zones. Soil available phosphorous (P) and fungicide use significantly reduced yield gap in the dry and mid zones. Finally, quantity of pesticide, proportion of hybrid cocoa plants and number of trainings received by farmers significantly reduced yield gap in the wet zone. In the dry zone, closing the yield gap against the climate risk might be unlikely. Transformation into more drought resistant systems such as cashew might be promising. However, in the mid and wet zones, labour availability for effective management of large plantations might be the major barrier for intensification, which needs to be addressed by intervention strategies

Fertilizer management effects on oil palm yield and nutrient use efficiency on sandy soils with limited water supply in Central Kalimantan

Identifying optimal fertilizer management to ensure high nutrient use efficiency is important to reduce negative environmental impacts in oil palm (Elaeis guineensis) cultivation. A 4-year fertilizer trial was established in an oil palm plantation, located at a sandy area with occasional monthly water deficit in Central Kalimantan. We examined the responses of oil palm yield and nutrient use efficiency to fertilizer application frequency (standard frequency of 1–2 times yr−1 versus 4 times yr−1) and rate (standard rate of 136, 12, and 200 kg ha−1 yr−1 of N, P and K, respectively versus 80% of standard rate). There were no treatment effects on annual yield in fresh fruit bunch, bunch number, or individual bunch weight. Increasing fertilizer frequency did not increase nutrient use efficiency at the last 2 years of the trial. In contrast, reducing fertilizer rate resulted in higher nutrient use efficiency in K, compared to the standard treatment and increasing fertilizer frequency. Average concentrations of N, P, K, Mg, Ca, and Cl in leaflet under all treatments were above critical levels both in the beginning and at the end of the trial. Monthly yield in fresh fruit bunch correlated positively with soil water balance with correlation coefficients of 0.24–0.29, during the developmental period of inflorescence sex differentiation at 28–30 months before fruit maturity. Our study provides useful information for fertilizer management optimization in sandy areas with occasional water deficit, corresponding to most of the new expansion areas of oil palm in Southeast Asia