scholarly journals Predicting pasture production under poplars using canopy closure images

2006 ◽  
pp. 325-330
Author(s):  
A.J. Wall ◽  
P.D. Kemp ◽  
A.D. Mackay
Keyword(s):  
Soil Erosion ◽  
Soil Conservation ◽  
Dry Matter ◽  
High Growth ◽  
High Growth Rate ◽  
Tree Canopy ◽  
Canopy Closure ◽  
Pasture Production ◽  
Poplar Trees ◽  
The Impact

Poplar trees serve a wide variety of purposes on New Zealand farms. Their high growth rate and ability to establish from poles make them a very suitable tree species for soil conservation plantings on erosion-prone hill pastures. The impact that such plantings have on understorey pasture production as the tree canopy develops in size was determined by measuring pasture dry matter (DM) production on three North Island sheep and beef hill farms. Poplars markedly reduced annual pasture production by up to 50% at high canopy closure. To maintain pasture production at 65-75% of uneroded open pasture, poplar canopy closure should not exceed 50%. However, it must be emphasised that the loss in production through soil erosion (e.g. slips or earthflows) without poplars can be even greater, more permanent, and much more unpredictable. Keywords: Populus, soil erosion, agroforestry, digital images, canopy closure, understorey pasture

Effect of defoliation frequency and summer irrigation on survival of perennial (Lolium perenne) and biennial (Lolium multiflorum) ryegrass in the subtropics

1997 ◽  
Vol 37 (5) ◽  
pp. 537 ◽  
Author(s):  
D. J. Donaghy ◽  
J. M. Scott ◽  
W. J. Fulkerson
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Dry Matter ◽  
Seed Set ◽  
Seedling Recruitment ◽  
Early Summer ◽  
Pasture Production ◽  
Second Year ◽  
The Impact ◽  
Tropical Grass

Summary. The present study investigated, in a subtropical environment, the timing of defoliation treatments in spring and summer irrigation management on the survival of perennial (Lolium perenne cv. Yatsyn) and biennial (L. multiflorum cv. Noble) ryegrass in a mixed ryegrass–white clover (Trifolium repens) pasture over the first summer, and seedling recruitment the following autumn. Defoliation options were related to various ryegrass plant development stages such as the number of leaves per tiller attained during regrowth, stem elongation and seed set. The criterion for timing of frequent defoliation was 1 leaf/tiller regrowth and infrequent defoliation 3 leaves/tiller. Both pasture types were defoliated either frequently or infrequently at specific times from sowing to mid summer. Half the plots were irrigated from 30 November to 6 April while the remaining plots were not irrigated over this period. There was no survival of biennial ryegrass plants into autumn of the second year and pasture production was entirely from seedling recruitment of seed set in the previous spring. The maximum seedling recruitment (plant population 89% of spring in establishment year) was achieved by infrequent defoliation in mid spring and then cessation of defoliation until mid summer to allow plants to set seed. However, this resulted in a production loss of 3094 kg dry matter/ha of ryegrass and clover. In contrast, production of perennial ryegrass in the second year was reliant almost exclusively on individual ryegrass plants surviving the summer, as there was little seed set and virtually no seedling recruitment. There would appear to be 2 contrasting defoliation requirements to optimise perennial ryegrass persistence. Infrequent defoliation from sowing to early spring (22 March–2 September) and frequent defoliation in early summer (19 November–3 February) resulted in maximum plant survival and minimum tropical grass incursion. Frequent, compared with infrequent, defoliation up to 2 September decreased root dry matter in February by 45% to 1.66 g dry matter/plant. However in early summer, frequent defoliation maximised survival, presumably by reducing shading by tropical grasses, and preventing a closed canopy which encourages ‘rust’ infestation of the ryegrass. Irrigation of ryegrass over summer, in situations likely to become waterlogged, will only be of benefit in dry years and if scheduling is frequent enough to benefit ryegrass rather than tropical grass. These results highlight the importance of maintaining an infrequent defoliation interval to maximise persistence of perennial ryegrass in the subtropics. More frequent defoliation may be necessary in late spring/early summer to reduce the impact of leaf rust.

scholarly journals The 'Landcare' approach to soil conservation in the Philippines: an assessment of farm-level impacts

2007 ◽  
Vol 47 (6) ◽  
pp. 721 ◽  
Author(s):  
R. A. Cramb ◽  
D. Catacutan ◽  
Z. Culasero-Arellano ◽  
K. Mariano
Keyword(s):  
Soil Erosion ◽  
Crop Yield ◽  
Soil Conservation ◽  
The Philippines ◽  
Conservation Practices ◽  
Short Term ◽  
Farm Level ◽  
Conservation Farming ◽  
The Impact

‘Landcare’ is a group-based approach to the promotion of conservation farming. A case study of the Landcare program in Lantapan in the southern Philippines is presented to assess the farm-level impacts of this approach. The program was successful in promoting the formation of Landcare groups and a municipal Landcare association, resulting in rapid and widespread adoption of conservation practices, particularly among maize farmers. This in turn significantly reduced soil erosion, though the impact on crop yield and income was somewhat delayed. Adoption was thus not motivated primarily by short-term returns but by a concern to reduce soil erosion and provide a basis for diversification into agroforestry.

scholarly journals Magnesium biofortification of Italian ryegrass (Lolium multiflorum L.) via agronomy and breeding as a potential way to reduce grass tetany in grazing ruminants

2019 ◽  
Vol 457 (1-2) ◽  
pp. 25-41 ◽  
Author(s):  
Diriba B. Kumssa ◽  
J. Alan Lovatt ◽  
Neil S. Graham ◽  
Sarah Palmer ◽  
Rory Hayden ◽  
...  
Keyword(s):  
Dry Matter ◽  
Lolium Multiflorum ◽  
High Growth ◽  
Italian Ryegrass ◽  
Field Conditions ◽  
Controlled Environment ◽  
Application Rates ◽  
Fertiliser Application ◽  
The Impact ◽  
Cattle And Sheep

Abstract Aim Magnesium (Mg) deficiency (known as grass tetany) is a serious metabolic disorder that affects grazing ruminants. We tested whether Mg-fertiliser can increase Mg concentration of Italian ryegrasses (Lolium multiflorum L.) including a cultivar (cv. Bb2067; ‘Magnet’), bred to accumulate larger concentrations of Mg. Methods Under controlled environment (CE) conditions, three cultivars (cv. Bb2067, cv. Bb2068, cv. RvP) were grown in low-nutrient compost at six fertiliser rates (0–1500 μM MgCl2.6H2O). Under field conditions, the three cultivars in the CE condition and cv. Alamo were grown at two sites, and four rates of MgSO4 fertiliser application rates (0–200 kg ha−1 MgO). Multiple grass cuts were taken over two-years. Results Grass Mg concentration increased with increasing Mg-fertiliser application rates in all cultivars and conditions. Under field conditions, cv. Bb2067 had 11–73% greater grass Mg concentration and smaller forage tetany index (FTI) than other cultivars across the Mg-fertiliser application rates, sites and cuts. Grass dry matter (DM) yield of cv. Bb2067 was significantly (p < 0.05) smaller than cv. Alamo. The effect of Mg-fertiliser rate on DM yield was not significant (p ≥ 0.05). Conclusions Biofortification of grass with Mg through breeding and agronomy can improve the forage Mg concentration for grazing ruminants, even in high-growth spring grass conditions when hypomagnesaemia is most prevalent. Response to agronomic biofortification varied with cultivar, Mg-fertiliser rate, site and weather. The cost:benefit of these approaches and farmer acceptability, and the impact on cattle and sheep grazing on grasses biofortified with Mg requires further investigation.

Impact of Economic Reforms on External Sector

2005 ◽  
Vol 40 (3) ◽  
pp. 72-100
Author(s):  
R.K. Kaundal
Keyword(s):  
Emerging Economies ◽  
High Growth ◽  
Economic Reforms ◽  
High Growth Rate ◽  
Balance Of Payments ◽  
Tariff Protection ◽  
Indian Economy ◽  
Reform Period ◽  
External Sector ◽  
The Impact

The impact of economic reforms on the external sector during the post reform period was extremely successful in meeting the balance of payments crisis of 1990s. These reforms improved the openness of the Indian economy vis-a-vis other emerging economies. Indian economy is more deeply integrated with the world economy today than it was in 1991 as a result of high growth rate of both exports and imports. Much, however, remains to be done. Indian economy is still relatively closed compared to its “peer competitors”. Further reduction to tariff protection and liberalisation of capital flows will enhance the efficiency of the economy and along with reforms of domestic policies will stimulate investment and growth.

scholarly journals The Effect of Soil Conservation Measures on Runoff, Soil Erosion, TN, and TP Losses Based on Experimental Runoff Plots in Northern China

Water ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2334
Author(s):  
Haiyan Fang
Keyword(s):  
Soil Erosion ◽  
Soil Conservation ◽  
Soil Loss ◽  
Northern China ◽  
Nutrient Losses ◽  
Study Region ◽  
Conservation Measures ◽  
The Impact ◽  
Soil Conservation Measures ◽  
Runoff Plots

Total nitrogen (TN) and total phosphorous (TP) are the main pollutants affecting the water quality of the Miyun Reservoir, Beijing. However, few studies have been conducted on their responses to implemented soil conservation measures at a slope scale in northern China. To explore the impact of soil conservation measures on TN and TP losses, field monitored data from 18 runoff plots under natural rainfalls were used to analyze the changing characteristics of runoff, soil loss, and nutrient losses during 2014–2019. The results indicated that runoff, soil erosion, as well a TN and TP losses from the plots varied significantly, depending on land use and soil conservation measures. Bare plots suffered the highest soil, TN, and TP losses, followed by cultivated plots without soil conservation measures, cultivated plots with contour tillage, and other plots. Event-averaged runoff and soil loss rates ranged from 0 to 7.9 mm and from 0 to 444.4 t km−2 yr−1, and event-averaged TN and TP losses from cultivated plots were the highest, with values of 39.8 and 3.0 kg km−2, respectively. Bare and cultivated plots were the main sediment and nutrient sources. Among the cultivated plots, the terraced plot had the lowest soil and nutrient losses. The vegetated plots had insignificantly lower soil and nutrient losses. Most TN and TP were lost in particulate status from the plots, especially from the plots with soil conservation measures. Soil conservation measures can effectively prevent TN and TP losses. To guarantee water resource use, contour tillage is preferred for the bare and cultivated lands in the study region.

Competition among pasture plants. I. Intraspecific competition among annual pasture plants

1951 ◽  
Vol 2 (4) ◽  
pp. 355 ◽  
Author(s):  
CM Donald
Keyword(s):  
Growth Rate ◽  
Dry Matter ◽  
Unit Area ◽  
Maximum Yield ◽  
High Growth ◽  
High Growth Rate ◽  
Fertility Level ◽  
Practical Applications ◽  
Final Yield ◽  
Pasture Plants

A series of experiments was conducted to examine the influence of density, stage of growth, and fertility level on intra-specific competition among annual pasture plants. At sowing there is a linear relationship between density and yield (weight of embryos or embryo + endosperm per unit area). Competition is evident in dense populations shortly after germination and thereafter becomes operative progressively in populations of lower and lower density. Because of the extreme reduction in growth rate in dense swards later in the season and the high growth rate in sparse swards, the sparse sward tends to approach the more dense sward in its final yield. Final yield of dry matter is constant from moderate to high densities. There is no reduction in dry matter per unit area even in extremely dense swards. This maximum yield of dry matter for the environment is controlled by some factor of the environment. It is considered that nitrogen was the factor in two of the experiments here reported and light in the third. The significance of light in competition in pastures is discussed. Practical applications of these findings are discussed.

Impact of climate change on soil erosion and the efficiency of soil conservation practices in Austria

2010 ◽  
Vol 148 (5) ◽  
pp. 529-541 ◽  
Author(s):  
A. KLIK ◽  
J. EITZINGER
Keyword(s):  
Climate Change ◽  
Soil Erosion ◽  
Soil Conservation ◽  
Soil Loss ◽  
Climatic Conditions ◽  
Future Climate ◽  
Management Systems ◽  
Strong Increase ◽  
Climate Scenarios ◽  
The Impact

SUMMARYThe goal of the present study was to assess the impact of selected soil protection measures on soil erosion and retention of rainwater in a 1·14 km2 watershed used for agriculture in the north-east of Austria. Watershed conditions under conventional tillage (CT), no-till (NT) and under grassland use were simulated using the Water Erosion Prediction Project (WEPP) soil erosion model. The period 1961–90 was used as a reference and results were compared to future Intergovernmental Panel on Climate Change (IPCC) scenarios A1B and A2 (2040–60).The simulations for the NT and grassland options suggested runoff would decrease by 38 and 75%, respectively, under the current climatic conditions. The simulation results suggest that, under future climate scenarios, the effectiveness of the selected soil conservation measures with respect to runoff will be similar, or decreased by 16–53%.The actual average net soil losses in the watershed varied from 2·57 t/ha/yr for conventional soil management systems to 0.01 t/ha/yr for grassland. This corresponds to a maximum average annual loss of about 0·2 mm, which is considered to be the average annual soil formation rate and therefore an acceptable soil loss. The current soil/land use does not exceed this limit, with most of the erosion occurring during spring time. Under future climate scenarios, the simulations suggested that CT would either decrease soil erosion by up to 55% or increase it by up to 56%. Under these conditions, the acceptable limits will partly be exceeded. The simulations of NT suggested this would reduce annual soil loss rates (compared to CT) to 0·2 and 1·4 t/ha, i.e. about the same or slightly higher than for NT under actual conditions. The simulation of conversion to grassland suggested soil erosion was almost completely prevented.The selected soil conservation methods maintain their protective effect on soil resources, independent of the climate scenario. Therefore, with small adaptations, they can also be recommended as sustainable soil/land management systems under future climatic conditions.However, based on the available climate scenarios, climate-induced changes in the frequency and intensity of heavy rainstorms were only considered in a limited way in the present work. As the general future trend indicates a strong increase of rainstorms with high intensity during summer months, the results of the present study may be too optimistic.

scholarly journals Options for Financing the Budgetary Deficit, Money Supply, and Growth of Banking Sector

1991 ◽  
Vol 30 (4II) ◽  
pp. 769-784
Author(s):  
A. R. Kemal
Keyword(s):  
Money Supply ◽  
Banking Sector ◽  
High Growth ◽  
High Growth Rate ◽  
High Rate ◽  
Price Stability ◽  
Fiscal Deficit ◽  
Monetary Expansion ◽  
Rate Structure ◽  
The Impact

The fiscal deficit has assumed alarming proportions in Pakistan; it was as large as 8.5 percent of the GDP in 1987-88. Though it has fallen somewhat in recent years, yet it still is around 6.7 percent of GDP. While the fiscal deficit was expected to result in a high rate of inflation and slow growth of output, Pakistan has sustained a high growth rate of output with price stability. This makes Pakistan a fascinating case study.l The impact of the fiscal deficit on monetary expansion, growth of output and price stability in various countries has been extensively analysed. For example, see Cline (1987); Collins and Park (1989), Corbo (1985,1989); Corbo and de Melo (1989); Corbo and Nam (1988); Dornbusch and de Pablo (1989); Easterly (1989); Edwards (1989); Enders and Mattione (1984); Gil Diaz (1988); Haque (1987); Kim and Yun (1988); Kormendi (1983); Modigliani and Sterling (1986); Nash (1988); Ocampo (1987); Reisen and van Trotsenburg (1988); van Wijnbergen (1987) and Yellen (1989). However, very little work is available on Pakistan. The present study is an attempt to fill that important gap. By analysing trends in the budgetary deficit and in the pattern of financing the deficit, the present study explores their implications for the interest rate structure, monetary expansion, and growth of the banking sector in Pakistan. The paper is divided into four sections. Section I traces the trends in the fiscal deficit over time. Patterns of financing the deficit and implications for monetary expansion are analysed in Section II. Section III examines the implications of changes in the rate structure of interest for the growth of money supply and the banking sector. Section IV presents the main conclusions of the study.

scholarly journals Watershed Drought and Ecosystem Services: Spatiotemporal Characteristics and Gray Relational Analysis

2021 ◽  
Vol 10 (2) ◽  
pp. 43
Author(s):  
Jizhou Bai ◽  
Zixiang Zhou ◽  
Yufeng Zou ◽  
Bakhtiyor Pulatov ◽  
Kadambot H. M. Siddique
Keyword(s):  
Ecosystem Services ◽  
Soil Erosion ◽  
Vegetation Cover ◽  
Soil Conservation ◽  
Swat Model ◽  
Vegetation Restoration ◽  
Gray Relational Analysis ◽  
Relational Analysis ◽  
Spatiotemporal Characteristics ◽  
The Impact

This study explored the spatiotemporal characteristics of drought and ecosystem services (using soil conservation services as an example) in the YanHe Watershed, which is a typical water basin in the Loess Plateau of China, experiencing soil erosion. Herein, soil conservation was simulated using the Soil and Water Assessment Tool (SWAT), and the relationship between drought, soil conservation services, and meteorological, vegetation, and other factors since the implementation of the ‘Grain for Green’ Project (GFGP) in 1999, were analyzed using the gray relational analysis (GRA) method. The results showed that: (1) The vegetation cover of the Watershed has increased significantly, and evapotranspiration (ET) increased by 14.35 mm·a−1, thereby increasing water consumption by 8.997 × 108 m3·a−1 (compared to 2000). (2) Drought affected 63.86% of the watershed area, gradually worsening from south to north; it decreased in certain middle areas but increased in the humid areas on the southern edge. (3) The watershed soil conservation services, measured by the soil conservation modulus (SCM), increased steadily from 116.87 t·ha−1·a−1 in 2000 to 412.58 t·ha−1·a−1 in 2015, at a multi-year average of 235.69 t·ha−1·a−1, and indicated great spatial variations, with a large variation in the downstream and small variations in the upstream and midstream areas. (4) Integrating normalized difference vegetation index (NDVI) data into SWAT model improved the model simulation accuracy; during the calibration period, the coefficient of determination (R2) increased from 0.63 to 0.76 and Nash–Sutcliffe efficiency (NSE) from 0.46 to 0.51; and during the validation period, the R2 increased from 0.82 to 0.93 and the NSE from 0.57 to 0.61. (5) The GRA can be applied to gray control systems, such as the ecosystem; herein, vegetation cover and drought primarily affected ET and soil conservation services. The analysis results showed that vegetation restoration enhanced the soil conservation services, but increased ET and aggravated drought to a certain extent. This study analyzed the spatiotemporal variations in vegetation coverage and the response of ET to vegetation restoration in the YanHe Watershed, to verify the significant role of vegetation restoration in restraining soil erosion and evaluate the extent of water resource consumption due to ET in the semi-arid and semi-humid Loess-area basin during the GFGP period. Thus, this approach may effectively provide a scientific basis for evaluating the ecological effects of the GFGP and formulating policies to identify the impact of human ecological restoration on ecosystem services.

scholarly journals Growth, mortality and susceptibility of oyster Crassostrea spp. to Perkinsus spp. infection during on growing in northeast Brazil

2017 ◽  
Vol 26 (4) ◽  
pp. 401-410 ◽  
Author(s):  
Marcos Paiva Scardua ◽  
Rogério Tubino Vianna ◽  
Sâmia Sousa Duarte ◽  
Natanael Dantas Farias ◽  
Maria Luíza Dias Correia ◽  
...  
Keyword(s):  
Growth Rate ◽  
Infection Intensity ◽  
High Growth ◽  
High Growth Rate ◽  
Shell Color ◽  
Tropical Regions ◽  
The Mean ◽  
Productive Traits ◽  
The Impact ◽  
Crassostrea Species

Abstract Crassostrea rhizophorae and C. gasar oysters are cultivated in the northeast region. Perkinsus parasites infect bivalves, and their effects on oysters from tropical regions are poorly understood. This study evaluated the impact of Perkinsus infection on the productive traits of native oysters. Oysters were sampled bimonthly during 7 months, from July 2010 to February 2011, to evaluate growth rate, mortality and shell color patterns (white and dark-gray) (n = 500), and to determine the prevalence and intensity of Perkinsus (n = 152). Perkinsus and Crassostrea species were determined using molecular tools. Results showed that most dark-gray (90%, n = 20) and white (67%, n = 18) oysters were C. gasar and C. rhizophorae, respectively. Oysters showed a high growth rate and moderate cumulative mortality (44%). C. gasar oysters grew better and showed lower mortality and lower incidence of Perkinsus compared to C. rhizophorae. The mean prevalence of Perkinsus was moderate (48%), but the infection intensity was light (2.2). Perkinsosis affected very small oysters (19.4 mm). In conclusion, native oysters, especially C. gasar, have a great potential for culture, mortality is not associated with perkinsosis, and the shell color of oysters can be used to improve selection for spats with better performance.

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