Crop landraces have unique local agroecological and societal functions and offer important genetic resources for plant breeding. Recognition of the value of landrace diversity and concern about its erosion on farms have led to sustained efforts to establish ex situ collections worldwide. The degree to which these efforts have succeeded in conserving landraces has not been comprehensively assessed. Here we modelled the potential distributions of eco-geographically distinguishable groups of landraces of 25 cereal, pulse and starchy root/tuber/fruit crops within their geographic regions of diversity. We then analysed the extent to which these landrace groups are represented in genebank collections, using geographic and ecological coverage metrics as a proxy for genetic diversity. We find that ex situ conservation of landrace groups is currently moderately comprehensive on average, with substantial variation among crops; a mean of 63% ± 12.6% of distributions is currently represented in genebanks. Breadfruit, bananas and plantains, lentils, common beans, chickpeas, barley and bread wheat landrace groups are among the most fully represented, whereas the largest conservation gaps persist for pearl millet, yams, finger millet, groundnut, potatoes and peas. Geographic regions prioritized for further collection of landrace groups for ex situ conservation include South Asia, the Mediterranean and West Asia, Mesoamerica, sub-Saharan Africa, the Andean mountains of South America and Central to East Asia. With further progress to fill these gaps, a high degree of representation of landrace group diversity in genebanks is feasible globally, thus fulfilling international targets for their ex situ conservation.
Tag: crops
Calophyllum inophyllum: A viable prospect for green energy and landscape restoration?
Indonesia has approximately 14 Mha of degraded lands. These lands have potential for growing biofuel species to meet needs for energy security, income generation and land restoration. One promising species, Calophyllum inophyllum, is suitable for growing on 5.7 Mha of degraded land in Indonesia, and could contribute to green energy production and restoration of this degraded land. During its early growth stage, the species can grow by up to one metre per year and is tolerant to harsh environmental conditions. Its seeds provide high levels of non-edible oil, thus making it ideal for biodiesel production. In addition, waste and by-products from the biodiesel production process can be used as raw materials in the pharmaceuticals and cosmetics industries, and as compost for soil enrichment. Growing various cash crops together with Calophyllum inophyllum in agroforestry systems can provide extra income for farmers, thus creating added value for Calophyllum inophyllum cultivation.
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Growth performance of Calophyllum inophyllum in bioenergy trial plots in Bukit Soeharto Forest, East Kalimantan
The Indonesian government has committed to providing its entire population with energy through the National Energy Policy, which highlights the importance of diversification, environmental sustainability, and enhanced deployment of domestic energy resources. The contribution of new and renewable energy (NRE) to the nation’s energy supply is mandated to reach 23% by 2025, with bioenergy an important NRE alternative. If developed and deployed appropriately, bioenergy plantations have potential to restore degraded land and enhance biodiversity and environmental services while supporting rural livelihoods. As a potential biofuel tree species suited to the tropics, Calophyllum inophyllum (nyamplung) is being tested across wide-ranging degraded forest conditions in Indonesia. Nyamplung is a potential biodiesel alternative as it grows well in harsh environmental conditions, produces non-edible seed oil, has high amounts of kernel oil and fruits profusely. Here we report growth performance in plantation trial plots established in February 2018, on previously burned land in Mulawarman University’s Bukit Soeharto Research and Educational Forest. Growth of this two-year old plantation is strong compared to other Indonesian sites, with average survival rate above 90% on Ultisol soil, which is classified as low fertility and acidic. The findings reveal that different doses of fertilizer applications and slope gradient have no significant effects on growth performance. In addition, trees have already started to flower and fruit, and are colonized by bird species and insects, including bees and butterflies.The study indicates that nyamplung adapts well to different land and soil types. Bioenergy plantations on degraded land are a promising approach for land restoration, and enhance native biodiversity and environmental services while providing a source of renewable energy.
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Potential energy yields of bioenergy crops in the tropics
Bioenergy can produce at least 25% of the global energy demand to combat climate change through reducing emissions in the energy sector. However, information on the bioenergy production potential of woody species and their suitability for silviculture on various soils in the humid tropics is limited. This slightly revised version of a short note published by Borchard et al. (2018) aims to identify tree species suitable for bioenergy production under these conditions. Data were compiled from 241 publications and nine freely available databases to assess environmental and silvicultural information on tropical tree species. Energy yield was derived from the estimated productivity of the reviewed species equivalent to an energy yield ranging between 2 and 444 GJ ha¯¹ yr¯¹. As such, these bioenergy yields are within the range reported for the lignocellulosic biomass of energy crops cultivated in Europe, the USA and Brazil. Our review identified some highyielding species (e.g., Dyera polyphylla (Miq.) Steenis, Metroxylon sagu (Rottb.), Pongamia pinnata (L.)) and leguminous species that could be beneficial in mixed stands (e.g., Elaeis oleifera (Kunth) and Pongamia pinnata) or are suitable species to grow on wet or re-wetted peatland (Dyera polyphylla). However, there are limitations to cultivating woody bioenergy species on wet peatland. Sustainable methods for managing and harvesting forests on wet or re-wetted peatland need to be developed.
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Crop-climate model in support of adjusting local ecological calendar in the Taxkorgan, eastern Pamir Plateau
Climate variability and changes threaten agriculture. In response, farmers have been forced to adjust farming practices according to locally available options. Ethnoecological knowledge of surrounding environmental events inform such adjustments. This study aims to explore observed changes in the crop calendar and changes in crop yield as response to climatic variability to support adjusting the local crop calendar. Interviews with local leaders and group discussions with farmers were organized. Climatic indices such as growing degree days (GDD) and crop evapotranspiration (ETc) were calculated and regressed with crop production data (1988–2017) from Taxkorgan County of Xinjiang, China, using the partial least square regression (PLS) technique. Survey data revealed that the sowing dates of important crops began earlier than previous decades. Spatial data showed that the growing season advanced 3.2 days per decade. PLS results suggest that GDD and ETc significantly affect crop yield. GDD during the growth period had a significant positive impact, indicating that recent warming is beneficial for crop yields in these regions. ETc during the growth period mostly had a negative impact, suggesting the need for ample water to improve crop yields in the context of further warming. The current shift in sowing is corroborated by early heat accumulation, and crop calendar adjustments can reasonably increase yields. Our results are applicable to agricultural decisions at the farm level following site-specific fieldwork. Optimal planting dates can be determined by combining results from our study and other suitable farming practices to strengthen the resilience of local ecological calendars to climate change.
A global-scale expert assessment of drivers and risks associated with pollinator decline
Pollinator decline has attracted global attention and substantial efforts are underway to respond through national pollinator strategies and action plans. These policy responses require clarity on what is driving pollinator decline and what risks it generates for society in different parts of the world. Using a formal expert elicitation process, we evaluated the relative regional and global importance of eight drivers of pollinator decline and ten consequent risks to human well-being. Our results indicate that global policy responses should focus on reducing pressure from changes in land cover and configuration, land management and pesticides, as these were considered very important drivers in most regions. We quantify how the importance of drivers and risks from pollinator decline, differ among regions. For example, losing access to managed pollinators was considered a serious risk only for people in North America, whereas yield instability in pollinator-dependent crops was classed as a serious or high risk in four regions but only a moderate risk in Europe and North America. Overall, perceived risks were substantially higher in the Global South. Despite extensive research on pollinator decline, our analysis reveals considerable scientific uncertainty about what this means for human society. © 2021, The Author(s), under exclusive licence to Springer Nature Limited.
Deciphering microplastic ecotoxicology: impacts on crops and soil ecosystem functions
Review on microplastic toxicity in agroecosystems is scarce. Thus, we develop a conceptual model (based on literature to date) that describes various microplastic effects using a size-scale. We also classify crops depending on their observed responses, and discuss several conceptual mechanisms of soil functions. The model shows that microplastic effects on crops can be positive, toxic, lethal and no-effect. Predominantly, microfibers in a wide range of sizes can positively affect crops. However, toxic effects of microplastics with/without other pollutants are more common at different sizes. Surprisingly, biodegradable plastic effects are lethal, calling into question their environmental friendliness. No-effect on crops is also possible but less observed. Unlike other crops (e.g., wheat, maize and bean), only onion seems resistant to microplastics. Crop uptake of micro/nanoplastic demands a clear benchmark to ensure food-safety. Furthermore, mixed effects are observed on soil functions. Alternation in soil enzymes and litter decomposition can affect nutrients and organic matter biogeochemistry. Hydrophobicity can be induced by increasing evaporation. Shifts in microbial community structure and activities are inevitable.
Automated crop type mapping using time-weighted dynamic time warping-A basis to derive inputs for enhanced food and Nutritional Security
The mapping of crop types is one of the most challenging tasks to derive inputs for enhanced food and nutritional security, especially in complex and diversified landscapes like tropical Asia with small landholdings. The current study tested an innovative approach like Time-Weighted Dynamic Time Warping (TWDTW) in a machine learning environment with time-series Sentinel data to map the various crop types. Using a logistic function, we examined the time series variations among the classes and assigned a time weightage through a steepness (α) and penalty (β) parameter. The parallel data processing was applied to a large data cube (band dimension: 66*6) containing the composite images for two years (2018 and 2019). Using a low penalty for time-warping less than 50 days (β) and high cost for extended time warps helped achieve 86% overall accuracy and 0.82 kappa accuracy. Cropland found the dominant land use (~82% of total area) in 2018, with the paddy fallow occupied 43.37%, followed by cotton-fallow (22.31%) and paddy-pulses (16.86%). The change area statistics from 2018 to 2019 indicate a reduction in paddy-fallow area by 238.20 ha, while the area under paddy-pulses and cotton-fallow increased by 122.50 ha 166.40 ha, respectively. The area under double cropping paddy-pulses highlights the availability of irrigation facilities in the southern part of the study area, while the northern part was dominated by single crop paddy-fallow. The study provides scopes to utilize the crop type and crop fallow maps for multi-cropping with appropriate land and water management through the government policy prescriptions.
Trees and their seed networks: The social dynamics of urban fruit trees and implications for genetic diversity
Trees are a traditional component of urban spaces where they provide ecosystem services critical to urban wellbeing. In the Tropics, urban trees’ seed origins have rarely been characterized. Yet, understanding the social dynamics linked to tree planting is critical given their influence on the distribution of associated genetic diversity. This study examines elements of these dynamics (seed exchange networks) in an emblematic indigenous fruit tree species from Central Africa, the African plum tree (Dacryodes edulis, Burseraceae), within the urban context of Yaoundé. We further evaluate the consequences of these social dynamics on the distribution of the genetic diversity of the species in the city. Urban trees were planted predominantly using seeds sourced from outside the city, resulting in a level of genetic diversity as high in Yaoundé as in a whole region of production of the species. Debating the different drivers that foster the genetic diversity in planted urban trees, the study argues that cities and urban dwellers can unconsciously act as effective guardians of indigenous tree genetic diversity.
No-till and mulching enhance energy use efficiency and reduce carbon footprint of a direct-seeded upland rice production system
Sustainability of conventional agricultural production systems is threatened by triple challenges of energy and environmental crises, deteriorating natural resources bases, and declining farm profitability. Current agricultural management practices (energy-intensive, inefficient external and natural input use, and crop biomass burning) are negatively impacting the ecosystem services which are the principal drivers for food security and human survival. Hence, there is a need to shift from unsustainable production practices to cleaner production systems. Energy use, carbon footprint (CF), and economic sustainability are important indicators of any clean production systems. Thus, a hypothesis was formulated that no-till (NT) cultivation along with mulching can provide an environmentally clean crop production practice that can enhance energy use efficiency, economic profitability, and reduce the CF. Therefore, the present experiment was conducted for four consecutive years (2012–15) to evaluate the energy budget, CF, and economics of NT along with bio-mulching for a cleaner upland rice production system. The experiment comprised of two tillage practices i.e., conventional tillage (CT) and NT in main plots and four bio- mulches in subplots i.e., rice straw mulch (RSM), Gliricidia sepium mulch (GLM), brown manuring mulch (BMM) of cowpea (Vigna unguiculata), and no mulch (NM) as a control. Results revealed that the adoption of NT curtailed energy use by 48.50%, specific energy by 49.63%, CF by 16.48%, and cost of cultivation by 35% in addition to enhancing energy use efficiency and benefit to cost ratio in comparison to CT. It was also observed that mulching, particularly the BMM, boosted the energy use efficiency, economic productivity, net returns, and benefit to cost ratio over NM. The results suggested that NT with BMM is an environmentally clean production technology to enhance the energy use efficiency, besides reducing the CF of direct-seeded upland rice production system in the Eastern Himalayas and similar eco-regions of the world.