Soil erosion and risk-assessment for on- and off-farm impacts: A test case using the Midhurst area,West Sussex,UK

Soil erosion on agricultural land is a growing problem in Western Europe and constitutes a threat to soil quality and to the ability of soils to provide environmental services. The off-site impacts of runoff and eroded soil, principally eutrophication of water bodies, sedimentation of gravel-bedded rivers, loss of reservoir capacity, muddy flooding of roads and communities, are increasingly recognised and costed. The shift of funding in the European Union (EU) from production-related to avoidance of pollution and landscape protection, raises issues of cross-compliance: public support for agriculture has to be seen to give value-for-money. In this context risk-assessment procedures have been introduced to help farmers recognise sites where either certain crops should not be grown or anti-erosion measures are required. In England, Defra [Defra, 2005a. Controlling Soil Erosion: a Manual for the Assessment and Management of Agricultural Land at Risk of Water Erosion in Lowland England. Revised September 2005. Department for Environment, Food and Rural Affairs, London] sets out a system of risk-assessment, including ranking of crops susceptible to erosion and anti-erosion measures, that may be selected. We assess this system using field data for an area of erodible soils in the Rother valley, Sussex. The Defra approach correctly identifies most at-risk fields and, taken together with land-use maps, allows non-compliance with advice to be highlighted. We suggest a simple extension to the system which would further identify at-risk fields in terms of possible damage to roads and rivers from muddy runoff. The increased risk of erosion in the study area is associated with certain crops: potatoes, winter cereals, maize and grazed turnips and seems unlikely to be the result of changes in rainfall which over the last 130 years are minimal. We have not evaluated proposed anti-erosion measures in the area because few have been put into practice. The European Water Framework Directive will increasingly focus attention on agricultural fields as a source of river pollution. Assessing the risk of erosion and the need for field testing of suggested approaches, are not simply issues for the EU, but for the management of global agricultural systems.     

Children's behavioral traits and risk of injury: Analyses from a case-control study of agricultural households

Problem

Children on family agricultural operations have high risk of injury. The association between children's behavioral traits and their risk of injury is not well understood.

Method

Data from the Regional Rural Injury Study-II were used to assess behavioral risk factors for injury to children ages six to < 20 years. A total of 379 injury events (cases) and 1,562 randomly selected controls were identified. Adjusted odds ratios (OR) and 95% confidence intervals (CI), calculated using logistic regression, were used to estimate injury risk in reference to behavioral traits.

Results

Injury risks were greater for children with high levels of depressive symptoms (OR = 1.9, CI = 1.0-3.7) and aggression (OR = 1.6, CI = 0.9-2.7), and low levels of careful/cautious behavior (OR = 1.8, CI = 1.1-2.9). Children with low levels of self-regulation had reduced risks (OR = 0.4, CI = 0.2-0.8).

Discussion

Results suggest that children's behaviors affect their risk of agricultural injury. Additional research could elucidate mechanisms and inform interventions.

Impact on industry

The development of multifaceted, sustainable approaches for prevention is necessary for this unique population. These findings suggest a need for interventions that incorporate specific behavior-related risk factors in the context of family farms and ranches.     

Understanding large-scale deforestation in southern Jinotega, Nicaragua from 1978 to 1999 through the examination of changes in land use and land cover

Nicaragua, home to the largest remaining extent of rainforest in Central America (total surface area) and to a significant indigenous population, has lost approximately half of its forest cover since 1950. This major and rapid loss of forest cover has been explained as the consequence of an eastward moving agricultural frontier that cuts through the region of Jinotega. If the current deforestation rate continues, the country could lose its remaining forest cover over the course of the next two decades; therefore, it is essential that the dynamics and relationships of land-use and land-cover change (LUCC) in this region are understood. To examine LUCC in Nicaragua over time, Landsat imagery from the southern portion of the region of Jinotega, taken in 1978, 1987, and 1999 was utilized. A remote-sensing method, supervised classification, which allows for the grouping of spectrally similar values for each year, followed by an image change detection analysis (postclassification comparison) was conducted. Groundtruthing (field validation) was conducted in 2006 to validate the data, which yielded increasing overall accuracy rates of 71.68% for 1978, 82.35% for 1987, and 84.38% for 1999. The classification and change detection results showed that if the agricultural cultivation overtook this region, it happened before 1978. Therefore, the possibility that either deforestation did not actually occur along an agricultural frontier or that it was located further east exists; this would be an interesting subject for future studies. There was, however, clear evidence of increased forest cover from 1987 to 1999 near the urban center, correlating with the enforced reforestation law in the city of Jinotega.     

Regional Management of Farmland Feeding Geese Using an Ecological Prioritization Tool

Wild geese foraging on farmland cause increasing conflicts with agricultural interests, calling for a strategic approach to mitigation. In central Norway, conflicts between farmers and spring-staging pink-footed geese feeding on pastures have escalated. To alleviate the conflict, a scheme by which farmers are subsidized to allow geese to forage undisturbed was introduced. To guide allocation of subsidies, an ecological-based ranking of fields at a regional level was recommended and applied. Here we evaluate the scheme. On average, 40 % of subsidized fields were in the top 5 % of the ranking, and 80 % were within the top 20 %. Goose grazing pressure on subsidized pastures was 13 times higher compared to a stratified random selection of non-subsidized pastures, capturing 67 % of the pasture feeding geese despite that subsidized fields only comprised 13 % of the grassland area. Close dialogue between scientists and managers is regarded as a key to the success of the scheme.     

UTILIZATION OF AGRICULTURAL WASTE CORN COB FOR THE PREPARATION OF CARBON ADSORBENT

In the present study, a series of activated carbons were prepared from agricultural waste corn cob by chemical and physical activations with potassium hydroxide (KOH)/potassium carbonate (K₂CO₃) and carbon dioxide (CO₂). The effect of process variables such as impregnation ratio, impregnation time, activation temperature and soaking time of CO₂ was studied in order to relate these preparation parameters with the physical properties of final carbon products. The resulting activated carbons were characterized by nitrogen adsorption[ch-[chdesorption isotherms at 77 K. The surface areas and pore volumes of carbons were estimated by the BET equation, the Langmuir equation and the t-plot method. Under the experimental conditions investigated, the main parameters in the activation of corn cob were found to be the impregnation ratio and activation temperature. The soaking time of CO₂ is another important variable, which had a strong effect on the pore volume development. The BET surface area and total pore volume were as large as about 2000 m²/g and about 1.0 cm³/g, respectively. This study showed that the activation of agricultural waste corn cob with KOH/K₂CO₃ and CO₂ was suitable for the preparation of large-surface-area activated carbons.     

Sensitivity of agricultural runoff loads to rising levels of CO2 and climate change in the San Joaquin Valley watershed of California

The Soil and Water Assessment Tool (SWAT) was used to assess the impact of climate change on sediment, nitrate, phosphorus and pesticide (diazinon and chlorpyrifos) runoff in the San Joaquin watershed in California. This study used modeling techniques that include variations of CO₂, temperature, and precipitation to quantify these responses. Precipitation had a greater impact on agricultural runoff compared to changes in either CO₂ concentration or temperature. Increase of precipitation by ±10% and ±20% generally changed agricultural runoff proportionally. Solely increasing CO₂ concentration resulted in an increase in nitrate, phosphorus, and chlorpyrifos yield by 4.2, 7.8, and 6.4%, respectively, and a decrease in sediment and diazinon yield by 6.3 and 5.3%, respectively, in comparison to the present-day reference scenario. Only increasing temperature reduced yields of all agricultural runoff components. The results suggest that agricultural runoff in the San Joaquin watershed is sensitive to precipitation, temperature, and CO₂ concentration changes.     

Steroid estrogens, conjugated estrogens and estrogenic activity in farm dairy shed effluents

Agricultural wastes are a source of steroid estrogens and, if present, conjugated estrogens may add to the estrogen load released to soil and aquatic environments. Dairy shed effluent samples were collected from 18 farms for analysis of steroid estrogens by GC-MS, conjugated estrogens by LC-MS-MS, and estrogenic activity by E-screen in vitro bioassay. 17α-estradiol was found at highest concentrations (median 730 ng l⁻¹), followed by estrone (100 ng l⁻¹) and 17β-estradiol (24 ng l⁻¹). Conjugated estrogens (estrone-3-sulfate, 17α-estradiol-3-sulfate and 17β-estradiol-3,17-disulfate) were measured in most samples (12-320 ng l⁻¹). Median estrogenic activity was 46 ng l⁻¹ 17β-estradiol equivalents. Conjugated estrogens contributed up to 22% of the total estrogen load from dairy farming, demonstrating their significance. Steroid estrogens dominated overall estrogenic activity measured in the samples. Significantly, 17α-estradiol contributed 25% of overall activity, despite potency 2% that of 17β-estradiol, highlighting the importance in environmental risk assessments of this previously neglected compound.     

Land use change and population growth in the Morobe Province of Papua New Guinea between 1975 and 2000

The relation between human population growth and land use change is much debated. Here we present a case study from Papua New Guinea where the population has increased from 2.3 million in 1975 to 5.2 million in 2000. Since 85% of the population relies on subsistence agriculture, population growth affects agricultural land use. We assessed land use change in the Morobe province (33,933 km2) using topographic maps of 1975 and Landsat TM images of 1990 and 2000. Between 1975 and 2000, agricultural land use increased by 58% and population grew by 99%. Most new agricultural land was taken from primary forest and the forest area decreased from 9.8 ha person(-1) in 1975 to 4.4 ha person(-1) in 2000. Total population change and total land use change were strongly correlated. Most of the agricultural land use change occurred on Inceptisols in areas with high rainfall (>2500 mm year(-1)) on moderate to very steep slopes (10-56%). Agricultural land use changes in logged-over areas were in the vicinity of populated places (villages), and in close proximity to road access. There was considerable variation between the districts but districts with higher population growth also had larger increases in agricultural areas. It is concluded that in the absence of improved farming systems the current trend of increased agriculture with rapid population growth is likely to continue.     

Socioeconomic Dimensions of Changes in the Agricultural Landscape of the Mediterranean Basin: A Case Study of the Abandonment of Cultivation Terraces on Nisyros Island,Greece

Agricultural landscapes illustrate the impact of human actions on physical settings, and differential human pressures cause these landscapes to change with time. Our study explored changes in the terraced landscapes of Nisyros Island, Greece, focusing on the socioeconomic aspects during two time periods using field data, cadastral research, local documents, and published literature, as well as surveys of the islanders. Population increases during the late 19^th to early 20^th centuries marked a significant escalation of terrace and dry stone wall construction, which facilitated cultivation on 58.4% of the island. By the mid-20^th century, the economic collapse of agricultural activities and consequent emigration caused the abandonment of cultivated land and traditional management practices, dramatically reducing farm and field numbers. Terrace abandonment continued in recent decades, with increased livestock grazing becoming the main land management tool; as a result, both farm and pasture sizes increased. Neglect and changing land use has led to deterioration and destruction of many terraces on the island. We discuss the socioeconomic and political backgrounds responsible for the land-use change before World War II (annexation of Nisyros Island by the Ottoman Empire, Italy, and Greece; overseas migration opportunities; and world transportation changes) and after the war (social changes in peasant societies; worldwide changes in agricultural production practices). The adverse landscape changes documented for Nisyros Island appear to be inevitable for modern Mediterranean rural societies, including those on other islands in this region. The island’s unique terraced landscapes may qualify Nisyros to become an archive or repository of old agricultural management techniques to be used by future generations and a living resource for sustainable management.     

Incentives for low-input land-use types and their influence on the attractiveness of landscapes

Changes in agricultural policy have traceable effects on landscape aesthetics. For the catchment area of Lake Greifensee, an economic land-use model predicted land-use changes caused by agricultural policy. Three scenarios implementing different direct payment schemes show that land-use intensity will decrease by 2011 compared with the ‘reference status’ 2000.The output of the economic land-use model is explicit in space. It was assessed by the ‘naturalness’ perception factor of the method proposed by Hoisl et al. [1989. Landschaftsästhetik in der Flurbereinigung. Materialien zur Flurbereinigung—Heft 17. Bayerisches Staatsministerium für Ernährung, Landwirtschaft und Forsten, München] with regard to landscape aesthetics. Even though lower land-use intensity is generally predicted by 2011, the values of the ‘naturalness’ perception factor do not significantly improve if the payment scheme remains unchanged, or if the payment scheme is amended by incentives for specific location of the ecological compensation areas (ECAs). A significant reduction in the values of the ‘naturalness’ perception factor was found when subsidies for ECA's were cancelled. This leads us to the conclusion that in order to keep Swiss landscapes as attractive as they are at present, policy must sustain incentives for low-intensity land-use types.