scholarly journals Vegetation Options for Increasing Resilience in Pastoral Hill Country

2021 ◽  
Vol 5 ◽  
Author(s):  
Katherine Tozer ◽  
Grant Douglas ◽  
Mike Dodd ◽  
Karin Müller
Keyword(s):  
Structural Stability ◽  
Land Surface ◽  
Ground Cover ◽  
Farming Systems ◽  
Rooting Depth ◽  
Hill Country ◽  
Grazed Pasture ◽  
Soil Structural Stability ◽  
Novel Applications ◽  
The Impact

Steep, uncultivable hill country below 1,000 m comprises about 40% of New Zealand's land surface area. Hill country farmers require options to increase the resilience of their farms to climatic and economic extremes while addressing soil conservation and water quality issues. We profile and discuss two options that can assist in transforming hill country. The first comprises a simple approach to grazing management in hill country pastures to increase pasture resilience and the second approach focuses on including selected forage shrubs (and trees) to create grazed pasture-shrublands. Deferred grazing, the cessation of grazing from flowering until seed dispersal of the desirable species in a pasture, is an old practice which has novel applications to improve resilience of hill country farming systems. We draw on current research and practitioner experience to demonstrate the impact of deferred grazing on the resilience of the deferred pasture and the farm system. We propose that deferred grazing will: (i) increase resilience of a pasture by enabling it to better recover from biotic and abiotic stresses and (ii) reduce the risk of nutrient and sediment losses in hill country by increasing ground cover, rooting depth and soil structural stability. Introducing woody forage shrubs into hill country pastures is another option that can improve farm profitability and resilience to current and future economic and climatic variabilities. The extensive root networks of shrubs can increase soil structural stability and reduce the risk of soil erosion. In addition, shrubs can supply many other ecosystem services, such as forage and shelter for livestock. In this paper, we discuss: (i) the potential benefits of a grazed pasture-shrubland at farm, landscape and national scales; (ii) candidate woody exotic and indigenous forage species; and (iii) priorities for research.

Impact of an Exponential Profile of Saturated Hydraulic Conductivity within the ISBA LSM: Simulations over the Rhône Basin

2006 ◽  
Vol 7 (1) ◽  
pp. 61-80 ◽  
Author(s):  
B. Decharme ◽  
H. Douville ◽  
A. Boone ◽  
F. Habets ◽  
J. Noilhan
Keyword(s):  
High Resolution ◽  
Hydraulic Conductivity ◽  
Land Surface ◽  
Large Scale ◽  
Saturated Hydraulic Conductivity ◽  
Rooting Depth ◽  
Surface Model ◽  
Low Resolution ◽  
The Impact ◽  
Hydrological Applications

Abstract This study focuses on the influence of an exponential profile of saturated hydraulic conductivity, ksat, with soil depth on the water budget simulated by the Interaction Soil Biosphere Atmosphere (ISBA) land surface model over the French Rhône River basin. With this exponential profile, the saturated hydraulic conductivity at the surface increases by approximately a factor of 10, and its mean value increases in the root zone and decreases in the deeper region of the soil in comparison with the values given by Clapp and Hornberger. This new version of ISBA is compared to the original version in offline simulations using the Rhône-Aggregation high-resolution database. Low-resolution simulations, where all atmospheric data and surface parameters have been aggregated, are also performed to test the impact of the modified ksat profile at the typical scale of a climate model. The simulated discharges are compared to observations from a dense network consisting of 88 gauging stations. Results of the high-resolution experiments show that the exponential profile of ksat globally improves the simulated discharges and that the assumption of an increase in saturated hydraulic conductivity from the soil surface to a depth close to the rooting depth in comparison with values given by Clapp and Hornberger is reasonable. Results of the scaling experiments indicate that this parameterization is also suitable for large-scale hydrological applications. Nevertheless, low-resolution simulations with both model versions overestimate evapotranspiration (especially from the plant transpiration and the wet fraction of the canopy) to the detriment of total runoff, which emphasizes the need for implementing subgrid distribution of precipitation and land surface properties in large-scale hydrological applications.

What’s the impact of improved soil representations in the ECMWF land surface model and how does it affect the extremes?

2021 ◽  
Author(s):  
Souhail Boussetta ◽  
Gabriele Arduini ◽  
Gianpaolo Balsamo ◽  
Emanuel Dutra ◽  
Anna Agusti-Panareda ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Land Surface ◽  
Soil Depth ◽  
Soil Column ◽  
Carbon Fluxes ◽  
Moisture Stress ◽  
Rooting Depth ◽  
Surface Model ◽  
Soil Moisture Stress ◽  
The Impact

<p>With increasingly higher spatial resolution and a broader applications, the importance of soil representation (e.g. soil depth, vertical discretisation, vegetation rooting) within land surface models is enhanced. Those modelling choices actually affects the way land surfaces store and regulate water, energy and also carbon fluxes. Heat and water vapour fluxes towards the atmosphere and deeper soil, exhibit variations spanning a range of time scales from minutes to months in the coupled land-atmosphere system. This is further modulated by the vertical roots' distribution, and soil moisture stress function, which control evapotranspiration under soil moisture stress conditions. Currently in the ECMWF land Surface Scheme the soil column is represented by a fixed 4 layers configuration with a total of approximately 3m depth.</p><p>In the present study we explore new configurations with increased soil depth (up to 8m) and higher vertical discretisation (up to 10 layers) including a dissociation between the treatment of water and heat fluxes. Associated with the soil vertical resolution, the vertical distribution of roots is also investigated. A new scheme that assumes a uniform root distribution with an associated maximum rooting depth is explored. The impact of these new configurations is assessed through surface offline simulations driven by the ERA5 meteorological forcing against in-situ and global products of energy, water and carbon fluxes with a particular focus on the diurnal cycle and extreme events in recent years.</p>

Process-based modelling to understand which ryegrass characteristics can increase production and decrease leaching in grazed grass–legume pastures

2013 ◽  
Vol 64 (3) ◽  
pp. 265 ◽  
Author(s):  
V. O. Snow ◽  
T. A. White
Keyword(s):  
Irrigation Management ◽  
Farming Systems ◽  
Breeding Program ◽  
Rooting Depth ◽  
Pastoral Systems ◽  
Pasture Production ◽  
Urine Patch ◽  
Potential Impact ◽  
The Impact ◽  
Pastoral Farming

A significant challenge for the pastoral farming systems is to maintain or increase production while reducing leaching of nitrogen, and for pastoral systems, this means reducing leaching from urine patches. Here we explore the potential impact of four ryegrass characteristics to increase pasture production and reduce leaching from ryegrass–white clover pastures. We focus on understanding which characteristics are desirable, the stage before investigating the achievability of those characteristics in a breeding program. Those characteristics were: the winter- or summer-dominance of growth (GP); the ability of the plant to intercept radiation at low pasture mass (LI); rooting depth (RD); and resistance to moderate water stress (WF). The impact of these ryegrass characteristics, both singly and combined within a ryegrass–clover pasture, was explored across a range of soils, climates, irrigation management, and urine patch concentrations using the process-based model APSIM. Of the four characteristics tested, LI was the most effective in increasing production and reducing leaching in all environments. The characteristics RD and WF were moderately effective, with RD having a greater impact on reducing leaching whereas WF had a greater effect on increasing production. The characteristic with the least impact was GP and it seems that ryegrass is currently well adapted for typical temperatures in New Zealand. The production and environmental effects of the characteristics were additive. The characteristics should be investigated further in the typically more diverse mixtures normally found in pastures but show promise for achieving improved production while reducing leaching provided they can be achieved in a breeding program.

scholarly journals Pastoral fallow for improving low fertility hill country pastures

1991 ◽  
pp. 209-213
Author(s):  
A.D. Mackay ◽  
P.J. Budding ◽  
D.J. Ross ◽  
K.R. Tatez ◽  
V.A. Orchard ◽  
...  
Keyword(s):  
Farming Systems ◽  
Low Fertility ◽  
Rooting Depth ◽  
Individual Plant ◽  
Research Station ◽  
N Fixation ◽  
Available N ◽  
Soil C ◽  
Hill Country ◽  
Legume Growth

The effect of a pastoral fallow (the 'spelling' of a pasture from early spring (September) to autumn (April/May)), with or without added fertiliser, on pasture and legume growth rates, total pasture biomass accumulation, nitrogen fixation, and on soil carbon and nitrogen cycling in the year of the fallow, and in the year after thef allow, wa sevaluated on 55ha of moderate to steep~low fertility, summermoist hill country at Ballantrae, DSIR Grasslands Hill Country Research Station. The major effect was to open the sward, increase individual plant size, vigour and rooting depth, increase the presence and vigour of white clover by creating new niches for growth, and improve N fixation by legumes in the year after the fallow only. The data on soil C and N dynamics are consistent with the concept of fallowing adding a pool of potentially available N to the soil. The benefits of a fallow for moist hill country and other pastoral farming systems are discussed. Keywords pastoral fallow, hill pastures, nitrogen, legume growth

scholarly journals Impact of monovalent cations on soil structure. Part II. Results of two Swiss soils

2018 ◽  
Vol 32 (1) ◽  
pp. 69-80 ◽  
Author(s):  
Elham Farahani ◽  
Hojat Emami ◽  
Thomas Keller
Keyword(s):  
Structural Stability ◽  
Water Retention ◽  
Agricultural Soils ◽  
Clay Content ◽  
Air Permeability ◽  
Soil Samples ◽  
Soil Structural Stability ◽  
The Impact ◽  
Dispersible Clay ◽  
Cation Ratio

AbstractIn this study, we investigated the impact of adding solutions with different potassium and sodium concentrations on dispersible clay, water retention characteristics, air permeability, and soil shrinkage behaviour using two agricultural soils from Switzerland with different clay content but similar organic carbon to clay ratio. Three different solutions (including only Na, only K, and the combination of both) were added to soil samples at three different cation ratio of soil structural stability levels, and the soil samples were incubated for one month. Our findings showed that the amount of readily dispersible clay increased with increasing Na concentrations and with increasing cation ratio of soil structural stability. The treatment with the maximum Na concentration resulted in the highest water retention and in the lowest shrinkage capacity. This was was associated with high amounts of readily dispersible clay. Air permeability generally increased during incubation due to moderate wetting and drying cycles, but the increase was negatively correlated with readily dispersible clay. Readily dispersible clay decreased with increasing K, while readily dispersible clay increased with increasing K in Iranian soil (Part I of our study). This can be attributed to the different clay mineralogy of the studied soils (muscovite in Part I and illite in Part II).

Pathways ahead for New Zealand hill country farming

2016 ◽  
Vol 78 ◽  
pp. 73-82 ◽  
Author(s):  
F.G. Scrimgeour
Keyword(s):  
New Zealand ◽  
Rural Communities ◽  
New Technologies ◽  
Service Providers ◽  
Farming Systems ◽  
Hill Country ◽  
The Status ◽  
And Performance ◽  
Hill Farming ◽  
The Hill

This paper provides a stocktake of the status of hill country farming in New Zealand and addresses the challenges which will determine its future state and performance. It arises out of the Hill Country Symposium, held in Rotorua, New Zealand, 12-13 April 2016. This paper surveys people, policy, business and change, farming systems for hill country, soil nutrients and the environment, plants for hill country, animals, animal feeding and productivity, and strategies for achieving sustainable outcomes in the hill country. This paper concludes by identifying approaches to: support current and future hill country farmers and service providers, to effectively and efficiently deal with change; link hill farming businesses to effective value chains and new markets to achieve sufficient and stable profitability; reward farmers for the careful management of natural resources on their farm; ensure that new technologies which improve the efficient use of input resources are developed; and strategies to achieve vibrant rural communities which strengthen hill country farming businesses and their service providers. Keywords: farming systems, hill country, people, policy, productivity, profitability, sustainability

Impact of LULC Changes on LST in Rajshahi District of Bangladesh: A Remote Sensing Approach

2020 ◽  
Vol 3 (1) ◽  
pp. 11-23 ◽  
Author(s):  
Abdulla Al Kafy ◽  
Abdullah Al-Faisal ◽  
Mohammad Mahmudul Hasan ◽  
Md. Soumik Sikdar ◽  
Mohammad Hasib Hasan Khan ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Surface Temperature ◽  
Land Surface ◽  
Agricultural Land ◽  
Global Climate ◽  
Urban Expansion ◽  
Water Bodies ◽  
Landsat 8 ◽  
Lulc Changes ◽  
The Impact

Urbanization has been contributing more in global climate warming, with more than 50% of the population living in cities. Rapid population growth and change in land use / land cover (LULC) are closely linked. The transformation of LULC due to rapid urban expansion significantly affects the functions of biodiversity and ecosystems, as well as local and regional climates. Improper planning and uncontrolled management of LULC changes profoundly contribute to the rise of urban land surface temperature (LST). This study evaluates the impact of LULC changes on LST for 1997, 2007 and 2017 in the Rajshahi district (Bangladesh) using multi-temporal and multi-spectral Landsat 8 OLI and Landsat 5 TM satellite data sets. The analysis of LULC changes exposed a remarkable increase in the built-up areas and a significant decrease in the vegetation and agricultural land. The built-up area was increased almost double in last 20 years in the study area. The distribution of changes in LST shows that built-up areas recorded the highest temperature followed by bare land, vegetation and agricultural land and water bodies. The LULC-LST profiles also revealed the highest temperature in built-up areas and the lowest temperature in water bodies. In the last 20 years, LST was increased about 13ºC. The study demonstrates decrease in vegetation cover and increase in non-evaporating surfaces with significantly increases the surface temperature in the study area. Remote-sensing techniques were found one of the suitable techniques for rapid analysis of urban expansions and to identify the impact of urbanization on LST.

Ecosystem modeling of methane and carbon dioxide fluxes for boreal forest sites

2001 ◽  
Vol 31 (2) ◽  
pp. 208-223 ◽  
Author(s):  
Christopher Potter ◽  
Jill Bubier ◽  
Patrick Crill ◽  
Peter Lafleur
Keyword(s):  
Carbon Dioxide ◽  
Boreal Forest ◽  
Land Surface ◽  
Net Primary Production ◽  
Ground Cover ◽  
Methane Flux ◽  
Growing Season ◽  
Ecosystem Model ◽  
Heat Fluxes ◽  
Water Levels

Predicted daily fluxes from an ecosystem model for water, carbon dioxide, and methane were compared with 1994 and 1996 Boreal Ecosystem–Atmosphere Study (BOREAS) field measurements at sites dominated by old black spruce (Picea mariana (Mill.) BSP) (OBS) and boreal fen vegetation near Thompson, Man. Model settings for simulating daily changes in water table depth (WTD) for both sites were designed to match observed water levels, including predictions for two microtopographic positions (hollow and hummock) within the fen study area. Water run-on to the soil profile from neighboring microtopographic units was calibrated on the basis of daily snowmelt and rainfall inputs to reproduce BOREAS site measurements for timing and magnitude of maximum daily WTD for the growing season. Model predictions for daily evapotranspiration rates closely track measured fluxes for stand water loss in patterns consistent with strong controls over latent heat fluxes by soil temperature during nongrowing season months and by variability in relative humidity and air temperature during the growing season. Predicted annual net primary production (NPP) for the OBS site was 158 g C·m–2 during 1994 and 135 g C·m–2 during 1996, with contributions of 75% from overstory canopy production and 25% from ground cover production. Annual NPP for the wetter fen site was 250 g C·m–2 during 1994 and 270 g C·m–2 during 1996. Predicted seasonal patterns for soil CO2 fluxes and net ecosystem production of carbon both match daily average estimates at the two sites. Model results for methane flux, which also closely match average measured flux levels of –0.5 mg CH4·m–2·day–1 for OBS and 2.8 mg CH4·m–2·day–1 for fen sites, suggest that spruce areas are net annual sinks of about –0.12 g CH4·m–2, whereas fen areas generate net annual emissions on the order of 0.3–0.85 g CH4·m–2, depending mainly on seasonal WTD and microtopographic position. Fen hollow areas are predicted to emit almost three times more methane during a given year than fen hummock areas. The validated model is structured for extrapolation to regional simulations of interannual trace gas fluxes over the entire North America boreal forest, with integration of satellite data to characterize properties of the land surface.

Private Agricultural R&D: Do the Poor Benefit?

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jock R. Anderson ◽  
Regina Birner ◽  
Latha Najarajan ◽  
Anwar Naseem ◽  
Carl E. Pray
Keyword(s):  
Poverty Reduction ◽  
Agricultural Research ◽  
Farming Systems ◽  
Agricultural Technologies ◽  
Policy Makers ◽  
The Public ◽  
The Poor ◽  
The World ◽  
Agricultural Research And Development ◽  
The Impact

Abstract Private agricultural research and development can foster the growth of agricultural productivity in the diverse farming systems of the developing world comparable to the public sector. We examine the extent to which technologies developed by private entities reach smallholder and resource-poor farmers, and the impact they have on poverty reduction. We critically review cases of successfully deployed improved agricultural technologies delivered by the private sector in both large and small developing countries for instructive lessons for policy makers around the world.

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