Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2018
Abstract
Climate change is expected to have a vigorous impact on soils and ecosystems due to elevated temperature and changes in precipitation (amount and frequency), thereby altering biogeochemical and hydrological cycles. Several phenomena associated with climate change and anthropogenic activity affect soils indirectly via ecosystem functioning (such as higher atmospheric CO2 concentration and N deposition). Continuous interactions between climate and soils determine the transformation and transport processes. Long-term gradual changes in abiotic environmental factors alter naturally occurring soil forming processes by modifying the soil water regime, mineral composition evolution, and the rate of organic matter formation and degradation. The resulting physical and chemical soil properties play a fundamental role in the productivity and environmental quality of cultivated land, so it is crucial to evaluate the potential outcomes of climate change and soil interactions. This paper attempts to review the underlying long-term processes influenced by different aspects of climate change. When considering major soil forming factors (climate, parent material, living organisms, topography), especially climate, we put special attention to soil physical properties (soil structure and texture, and consequential changes in soil hydrothermal regime), soil chemical properties (e.g. cation exchange capacity, soil organic matter content as influenced by changes in environmental conditions) and soil degradation as a result of longterm soil physicochemical transformations. The temperate region, specifically the Carpathian Basin as a heterogeneous territory consisting of different climatic and soil zones from continental to mountainous, is used as an example to present potential changes and to assess the effect of climate change on soils. The altered physicochemical and biological properties of soils require accentuated scientific attention, particularly with respect to significant feedback processes to climate and soil services such as food security.
Authors
Daniel R. Hirmas Daniel Gimenez Attila Nemes Ruth Kerry Nathaniel A. Brunsell Cassandra J. WilsonAbstract
Soil macroporosity affects field-scale water-cycle processes, such as infiltration, nutrient transport and runoff1,2, that are important for the development of successful global strategies that address challenges of food security, water scarcity, human health and loss of biodiversity3. Macropores—large pores that freely drain water under the influence of gravity—often represent less than 1 per cent of the soil volume, but can contribute more than 70 per cent of the total soil water infiltration4, which greatly magnifies their influence on the regional and global water cycle. Although climate influences the development of macropores through soil-forming processes, the extent and rate of such development and its effect on the water cycle are currently unknown. Here we show that drier climates induce the formation of greater soil macroporosity than do more humid ones, and that such climate-induced changes occur over shorter timescales than have previously been considered—probably years to decades. Furthermore, we find that changes in the effective porosity, a proxy for macroporosity, predicted from mean annual precipitation at the end of the century would result in changes in saturated soil hydraulic conductivity ranging from −55 to 34 per cent for five physiographic regions in the USA. Our results indicate that soil macroporosity may be altered rapidly in response to climate change and that associated continental-scale changes in soil hydraulic properties may set up unexplored feedbacks between climate and the land surface and thus intensify the water cycle.
Abstract
The awareness of sediment and nutrient loss from non-point sources are of increasing environmental concern as measures to reduce point source inputs to surface waters have been introduced. Mitigation efforts to reduce loss of particles and nutrients from agriculture in Norway and other countries have mainly focused on surface runoff, whereas sub-surface drainage has received little attention. However, research has shown that the sub-surface field drains are transporting both sediment and nutrients rapidly to the watercourses. Despite these established facts there has been little development of measures to reduce these losses. This article describes how Lightweight Aggregates (LWA), Leca®, can mitigate some of the environmental challenges connected to sub-surface field drains. A field experimental project was performed to assess the effects on drainage water quality hydrological performance and functionality of drainage systems based on Lightweight Aggregates compared to traditional pipe drains. Registrations of the performance of the systems were done in two separate periods, 1992–1993 and 1999–2000. After 2000 no measurement programme has run. The functionality of the drainage systems was registered in connection to ordinary farming activity. In 1999–2000 LWA drains showed particularly good performance with regard to reducing the content of Phosphorus, 40–90 % reduction in Total-P. The drainage water from the LWA drains contained less than half the amount of suspended solids compared to traditional pipe drains. The results from 1993 showed no significant difference between LWA drains and pipe drains with respect to Nitrogen. The results from 1999/2000 showed higher loss of Nitrogen through pipe drains with no envelope compared to all other systems. LWA drains may be particularly useful in reducing particles and nutrient loads from cultivated flat drained areas adjacent to environmentally sensitive and ecologically important water ecosystems. Further investigations are recommended to optimise the design of LWA drains.
Authors
Krishna Reddy Kakumanu Yella Reddy Kaluvai M. Balasubramanian Sekhar Udaya Nagothu Gurava Reddy Kotapati Sunitha KaranamAbstract
Climate change adversely affects the determinants of agriculture. Adaptation serves as an important strategy to reduce the adverse effects of climate change (variability) and vulnerability of the people. Adaptation through an innovation programme was implemented for 4 years during 2012–2016 to improve the adaptive capacity in agriculture and the water sectors through capacity building and implementation in the Krishna River Basin, India. Primary data were collected from 178 farm households of the Nagarjuna Sagar Project command area covering both adopters and non‐adopters of water‐saving interventions from the study area. The double difference method was used to analyse the impact of adaptation through capacity building and implementation. The water‐saving interventions include alternate wetting and drying (AWD) in rice, a modified system of rice intensification (MSRI) and direct seeding of rice (DSR). The capacity building and water saving increased crop yields by 0.96, 0.93 and 0.77 t ha−1 through AWD, MSRI and DSR respectively. The three practices have increased farmers’ income and decreased the cost of cultivation in DSR by Rs.11 000 (US$169) ha−1. The methods can be more focused in canal commands on a larger scale for equal distribution of water to all the head, middle and tail‐end regions.
Abstract
No abstract has been registered
Authors
Krishna Reddy Kakumanu Yella Reddy Kaluvai Sekhar Udaya Nagothu Narayan Reddy Lati Gurava Reddy Kotapati Sunitha KaranamAbstract
Climate change characterized by global warming has become a hotspot of research in recent years for water resources, agriculture,ecology and other disciplines. In India, studies have shown an increasing trend in surface temperature, with decreasing trends inrainfall. Farmers are also more affected by the climate variability which has a serious influence on their production and income.The climate change and adaptation (ClimaAdapt) programme was implemented from 2012 to 2016 to build farm-level capacitiesand enhance the adaptive capacity of the agricultural and water sectors in the Krishna basin of Andhra Pradesh and Telanganastates. Water-saving interventions such as direct seeded rice, a modified system of rice intensification and alternate wetting anddrying (AWD) of rice were implemented in a cluster approach and enhanced water productivity. The training and implementationprogrammes increased the adaptation and awareness of farmers. Water measurements were carried out by usingflumes andultrasonic sensors. The area under direct seeded rice has increased to 64% in the study district and 77% of the trained farmersare adopting the practice. Capacity building, implementation and science–policy linkages are the key pillars of the programmeto improve the adaptive capacity and scaling-up of water management practices.
Abstract
No abstract has been registered
Authors
Sekhar Udaya NagothuAbstract
No abstract has been registered
Abstract
The present work focuses on an assessment of the applicability of groundwater table (GWT) measures in the modelling of soil water retention characteristics (SWRC) using artificial neural network (ANN) methods. Model development, testing, validation and verification were performed using data collected across two decades from soil profiles at full-scale research objects located in Southwest Poland. A positive effect was observed between the initial GWT position data and the accuracy of soil water reserve estimation. On the other hand, no significant effects were observed following the implementation of GWT fluctuation data over the entire growing season. The ANN tests that used data of either soil water content or GWT position gave analogous results. This revealed that the easily obtained data (temperature, precipitation and GWT position) are the most accurate modelling parameters. These outcomes can be used to simplify modelling input data/parameters/variables in the practical implementation of the proposed SWRC modelling variants.
Authors
Øyvind Kaste Eva Skarbøvik Inga Greipsland Cathrine Brecke Gundersen Kari Austnes Liv Bente Skancke Jose-Luis Guerrero James Edward SampleAbstract
From 2017, the Norwegian River Monitoring Programme (Elveovervåkingsprogrammet) replaced the former RID programme “Riverine inputs and direct discharges to Norwegian coastal waters” which had run continuously since 1990. The present report provides the current (2017) status and long-term (1990-2017) water quality trends in the 20 rivers included in the main programme.