Browsing by Browse by FOR 2020 "3002 Agriculture land and farm management"

Livestock have long been integral to food production systems, often not by choice but by need. While our knowledge of livestock greenhouse gas (GHG) emissions mitigation has evolved, the prevailing focus has been—somewhat myopically—on technology applications associated with mitigation. Here, we (1) examine the global distribution of livestock GHG emissions, (2) explore social, economic and environmental co-benefits and trade-offs associated with mitigation interventions and (3) critique approaches for quantifying GHG emissions. This review uncovered many insights. First, while GHG emissions from ruminant livestock are greatest in low- and middle-income countries (LMIC; globally, 66% of emissions are produced by Latin America and the Caribbean, East and southeast Asia and south Asia), the majority of mitigation strategies are designed for developed countries. This serious concern is heightened by the fact that 80% of growth in global meat production over the next decade will occur in LMIC. Second, few studies concurrently assess social, economic and environmental aspects of mitigation. Of the 54 interventions reviewed, only 16 had triple-bottom line benefit with medium–high mitigation potential. Third, while efforts designed to stimulate the adoption of strategies allowing both emissions reduction (ER) and carbon sequestration (CS) would achieve the greatest net emissions mitigation, CS measures have greater potential mitigation and co-benefits. The scientific community must shift attention away from the prevailing myopic lens on carbon, towards more holistic, systems-based, multi-metric approaches that carefully consider the raison d'être for livestock systems. Consequential life cycle assessments and systems-aligned 'socio-economic planetary boundaries' offer useful starting points that may uncover leverage points and cross-scale emergent properties. The derivation of harmonized, globally reconciled sustainability metrics requires iterative dialogue between stakeholders at all levels. Greater emphasis on the simultaneous characterization of multiple sustainability dimensions would help avoid situations where progress made in one area causes maladaptive outcomes in other areas.

The determination of key phenological growth stages of banana plantations, such as flower emergence and plant establishment, is difficult due to the asynchronous growth habit of banana plants. Identifying phenological events assists growers in determining plant maturity, and harvest timing and guides the application of time-specific crop inputs. Currently, phenological monitoring requires repeated manual observations of individual plants’ growth stages, which is highly laborious, time-inefficient, and requires the handling and integration of large field-based data sets. The ability of growers to accurately forecast yield is also compounded by the asynchronous growth of banana plants. Satellite remote sensing has proved effective in monitoring spatial and temporal crop phenology in many broadacre crops. However, for banana crops, very high spatial and temporal resolution imagery is required to enable individual plant level monitoring. Unoccupied aerial vehicle (UAV)- based sensing technologies provide a cost-effective solution, with the potential to derive information on health, yield, and growth in a timely, consistent, and quantifiable manner. Our research explores the ability of UAV-derived data to track temporal phenological changes of individual banana plants from follower establishment to harvest. Individual plant crowns were delineated using object-based image analysis, with calculations of canopy height and canopy area producing strong correlations against corresponding ground-based measures of these parameters (R² of 0.77 and 0.69 respectively). A temporal profile of canopy reflectance and plant morphology for 15 selected banana plants were derived from UAV-captured multispectral data over 21 UAV campaigns. The temporal profile was validated against ground-based determinations of key phenological growth stages. Derived measures of minimum plant height provided the strongest correlations to plant establishment and harvest, whilst interpolated maxima of normalised difference vegetation index (NDVI) best indicated flower emergence. For pre-harvest yield forecasting, the Enhanced Vegetation Index 2 provided the strongest relationship (R² = 0.77) from imagery captured near flower emergence. These findings demonstrate that UAV-based multitemporal crop monitoring of individual banana plants can be used to determine key growing stages of banana plants and offer pre-harvest yield forecasts.

Agricultural production (especially intensive rice production) is a primary income source for over 2.0×10⁷ people in the Vietnamese Mekong River Delta. However, adverse climate change impacts, socio-economic change, and high dependence on farm inputs for intensive production constrain the longer-term sustainability of rice systems. Government and agribusiness actors are encouraging more farmers to grow non-rice crops and supporting the upscaling of alternative crops to paddy rice. We used a qualitative approach to investigate the value chain characteristics, as well as constraints and opportunities of alternative crops via two case studies (baby corn and honeydew melon) in An Giang and Hau Giang provinces, Vietnam. Data collection involved focus group discussions with local farmers and interviews with farmers and industry experts. Thematic analysis was used to compile the findings, and the results were validated with local government staff. The baby corn value chain featured on-going and stable market demand (including value-addition) and better vertical coordination (e.g., written contracts and financial support). The honeydew melon value chain featured positive relationships between farmers and traders despite lessdeveloped vertical coordination. There are opportunities for value chain engagement through product quality certification, value-addition, and accessing high-value domestic and export markets. However, farmers require crop-specific and generic support from private and public sectors. Increased labour requirements and limited access to finance and credit limit value chain participation. Upscaling and marketing alternative crops can enhance farmer profitability and support non-farming agricultural business establishment, economic growth, and community development. Efficient value chains will be critical to ensure the adoption of alternative crops and development of crop-specific agribusiness models. These findings can inform policy-makers and change facilitators in designing targeted interventions to support the adoption of alternative crops in the study area as well as in Vietnam and globally

The role of livestock in sustainable food systems is an area of ongoing development, requiring a careful balance of assessment at the animal, system, and human nutrition/wellbeing levels. However, such assessments are made more difficult by the lack of consensus in methods and perspectives, and many studies focus on only one of the above levels, leading to a “race to the bottom” focus to minimize impacts in terms of carbon footprint or other single indicators, many of which are poorly correlated (Ridoutt et al. 2017, Harrison et al. 2021). This misses the biophysical flows between systems, supply chains and/or stages of production, leading to biased results that may not reflect the true context and impact of food production (Harrison et al. 2021). To address this, a circular agriculture/circular economy perspective can be applied, specifically capturing nutrient flows and recycling of mass and nutrient between and within food chains or other processes (Van Zanten et al. 2018, 2019). Such methods can be used to compare the net impacts of different proposed changes on not just specific product systems, but product sectors, or even on a global level.

Background and aims Pasture systems occupy approximately three billion hectares and contribute almost $21 trillion to the global economy. They are important for food production, carbon storage, water catchment reserves, biodiversity maintenance and cultural and recreational needs. However, pasture systems sustainability and productivity may be reduced with increasing climate hazards, such as heat stress and drought, due to global warming. Strategically integrating trees into pastoral landscapes may improve pasture system resilience and productivity by benefting pasture leaf function and enhancing soil fertility.

Methods To evaluate if trees in pasture systems are favourable for pasture performance and sustainability, we conducted feld experiments in the New England Tablelands of New South Wales and assessed soil properties and measured leaf functional traits of pasture species, under tree canopies, at tree canopy edges and beyond tree canopies (i.e. in open felds). Functional traits measured were net carbon assimilation, photosynthetic heat tolerance, specific leaf area and leaf nitrogen content.

Results Aboveground and belowground pasture biomass were significantly higher under paddock tree canopies compared with canopy edges and in open fields. Similarly, concentrations of measured soil elements (organic carbon, nitrogen, phosphorus and potassium) were all significantly higher under tree canopies compared with canopy edges and in open fields. Leaf functional traits did not vary with proximity from paddock tree canopies, and higher undercanopy pasture biomass was not associated with leaf functional traits. Leaf trait-trait relationships were mixed and varied with proximity from paddock tree canopies.

Conclusions This study demonstrates the significant role of paddock trees within tree-pasture systems in driving pasture productivity, particularly through improved soil fertility. The results emphasize that paddock trees can contribute to climate change resilience of pastures in grazing systems by facilitating greater resource capture.