Effects of Nitrogen Fertiliser on Nitrate Leaching and Production of Autumn-Sown Italian Ryegrass in a Double-Cropping System on a New Zealand Dairy Farm

On intensive dairy farms in New Zealand, winter Italian ryegrass crops are combined with summer maize silage crops in double-cropping systems. Limited data (Davies & Neilson, 1975) showed variable ryegrass yield responses to nitrogen (N) fertiliser when grown after maize. Nitrogen leaching losses were not measured in this experiment but Ledgard et al. (1988) showed that late autumn/early winter N applications are vulnerable to leaching. Different rates of N fertiliser were applied to Italian ryegrass grown after maize to assess yield responses and levels of nitrate leaching

Reducing Ammonia Emissions from Dairy Cattle Production via Cost-Effective Manure Management Techniques in China

This study analyzed ammonia reduction potential and related costs and benefits of several ammonia emission reduction technologies applicable for dairy production from cattle in China. Specifically, these included diet manipulation, manure acidification, manure/slurry covers, and solid manure compaction. Ammonia emissions for China were estimated using the GAINS and NUFER models, while mitigation potentials of technologies were determined from laboratory studies. Ammonia reduction potentials from dairy production in China ranged from 0.8 to 222 Gg NH3 year–1 for the selected technologies. Implementation costs ranged from a savings of US$15 kg–1 NH3 abated to an expenditure of US$45 kg–1 NH3 abated, while the total implementation costs varied from a savings of US$1.5 billion in 2015 to an expenditure of a similar size. The best NH3 reduction technology was manure acidification, while the most cost-effective option was diet optimization with lower crude protein input. For most abatement options, material costs were the critical element of overall costs. The fertilizer value of manure could partly offset the implementation cost of the options tested. Furthermore, benefits due to avoided health damage, as a result of reducing NH3 emissions, could make all abatement options (except for manure compaction) profitable on the scale of a national economy

Measured and Simulated Nitrous Oxide Emissions from Ryegrass- and Ryegrass/White Clover-Based Grasslands in a Moist Temperate Climate

There is uncertainty about the potential reduction of soil nitrous oxide (N2O) emission when fertilizer nitrogen (FN) is partially or completely replaced by biological N fixation (BNF) in temperate grassland. The objectives of this study were to 1) investigate the changes in N2O emissions when BNF is used to replace FN in permanent grassland, and 2) evaluate the applicability of the process-based model DNDC to simulate N2O emissions from Irish grasslands. Three grazing treatments were: (i) ryegrass (Lolium perenne) grasslands receiving 226 kg FN ha−1 yr−1 (GG+FN), (ii) ryegrass/white clover (Trifolium repens) grasslands receiving 58 kg FN ha−1 yr−1 (GWC+FN) applied in spring, and (iii) ryegrass/white clover grasslands receiving no FN (GWC-FN). Two background treatments, un-grazed swards with ryegrass only (G–B) or ryegrass/white clover (WC–B), did not receive slurry or FN and the herbage was harvested by mowing. There was no significant difference in annual N2O emissions between G–B (2.38±0.12 kg N ha−1 yr−1 (mean±SE)) and WC-B (2.45±0.85 kg N ha−1 yr−1), indicating that N2O emission due to BNF itself and clover residual decomposition from permanent ryegrass/clover grassland was negligible. N2O emissions were 7.82±1.67, 6.35±1.14 and 6.54±1.70 kg N ha−1 yr−1, respectively, from GG+FN, GWC+FN and GWC-FN. N2O fluxes simulated by DNDC agreed well with the measured values with significant correlation between simulated and measured daily fluxes for the three grazing treatments, but the simulation did not agree very well for the background treatments. DNDC overestimated annual emission by 61% for GG+FN, and underestimated by 45% for GWC-FN, but simulated very well for GWC+FN. Both the measured and simulated results supported that there was a clear reduction of N2O emissions when FN was replaced by BNF

Apes and Agriculture

Non-human great apes – chimpanzees, gorillas, bonobos, and orangutans – are threatened by agricultural expansion, particularly from rice, cacao, cassava, maize, and oil palm cultivation. Agriculture replaces and fragments great ape habitats, bringing them closer to humans and often resulting in conflict. Though the impact of agriculture on great apes is well-recognized, there is still a need for a more nuanced understanding of specific contexts and associated negative impacts on habitats and populations. Here we review these contexts and their implications for great apes. We estimate that within their African and South-East Asian ranges, there are about 100 people for each great ape. Given that most apes live outside strictly protected areas and the growing human population and increasing demand for resources in these landscapes, it will be challenging to balance the needs of both humans and great apes. Further habitat loss is expected, particularly in Africa, where compromises must be sought to re-direct agricultural expansion driven by subsistence farmers with small fields (generally <0.64 ha) away from remaining great ape habitats. To promote coexistence between humans and great apes, new approaches and financial models need to be implemented at local scales. Overall, optimized land use planning and effective implementation, along with strategic investments in agriculture and wildlife conservation, can improve the synergies between conservation and food production. Effective governance and conservation financing are crucial for optimal outcomes in both conservation and food security. Enforcing forest conservation laws, engaging in trade policy discussions, and integrating policies on trade, food security, improved agricultural techniques, and sustainable food systems are vital to prevent further decline in great ape populations. Saving great apes requires a thorough consideration of specific agricultural contexts

Perceptions of trekking tourism and social and environmental change in Nepal's Himalayas

The Himalayas are among the world’s youngest mountain ranges. In addition to the geologic processes of mountain building and erosion, they are also highly vulnerable to human influenced change, occurring at local, national, regional, and international scales. A photo-elicitation methodology is employed to show how residents perceive those changes from historical perspectives, as well as their current conditions and impacts on their daily lives. Nepal’s Khumbu region has undergone major social and environmental transformations since the 1960s when international trekking first began to influence the area's economy. The current perceptions of Khumbu residents of these changes is assessed through photo-elicitation interviews. Their responses are placed in the historical context of: (i) institutional and political changes, much of which have been driven by national government policies; (ii) social and economic changes, for which the tourism economy has been central; and (iii) environmental changes, reflecting the impacts of resource management and climate change. The mostly positive perceptions of Khumbu residents toward how their region has changed reflects general improvements in the physical and cultural landscapes of the Khumbu over time, as well as its continuing geographic isolation, which has helped to slow the rate of globalization, while also keeping the region a dynamic and popular tourist destination

The value of manure - Manure as co-product in life cycle assessment

Research ArticleLivestock production is important for food security, nutrition, and landscape maintenance, but it is associated with several environmental impacts. To assess the risk and benefits arising from livestock production, transparent and robust indicators are required, such as those offered by life cycle assessment. A central question in such approaches is how environmental burden is allocated to livestock products and to manure that is re-used for agricultural production. To incentivize sustainable use of manure, it should be considered as a co-product as long as it is not disposed of, or wasted, or applied in excess of crop nutrient needs, in which case it should be treated as a waste. This paper proposes a theoretical approach to define nutrient requirements based on nutrient response curves to economic and physical optima and a pragmatic approach based on crop nutrient yield adjusted for nutrient losses to atmosphere and water. Allocation of environmental burden to manure and other livestock products is then based on the nutrient value from manure for crop production using the price of fertilizer nutrients. We illustrate and discuss the proposed method with two case studiesinfo:eu-repo/semantics/publishedVersio

Software Testing Techniques Revisited for OWL Ontologies

Ontologies are an essential component of semantic knowledge bases and applications, and nowadays they are used in a plethora of domains. Despite the maturity of ontology languages, support tools and engineering techniques, the testing and validation of ontologies is a field which still lacks consolidated approaches and tools. This paper attempts at partly bridging that gap, taking a first step towards the extension of some traditional software testing techniques to ontologies expressed in a widely-used format. Mutation testing and coverage testing, revisited in the light of the peculiar features of the ontology language and structure, can can assist in designing better test suites to validate them, and overall help in the engineering and refinement of ontologies and software based on them