High Agricultural Use Research Articles

Support for an area-heterogeneity tradeoff for biodiversity in croplands.

Rapid expansion of the human population poses a challenge for wildlife conservation in agricultural landscapes. One proposal for addressing this challenge is to increase biodiversity in such landscapes by increasing crop diversity. However, studies report both positive and negative effects of crop diversity on biodiversity. One possible explanation, derived from the "area-heterogeneity tradeoff hypothesis," is that the effect of crop diversity on biodiversity depends on a tradeoff between increasing the number of crop types in a landscape and decreasing the amount of each single crop type. This should cause positive effects of increasing crop diversity at low to intermediate crop diversity and negative effects at intermediate to high crop diversity. We also propose two factors that could change the point at which the effect of increasing crop diversity shifts from positive to negative. First, we predicted that this shift would occur at a lower crop diversity when the surrounding landscape contains less semi-natural habitat and at a higher crop diversity when the landscape contains more semi-natural habitat. This should increase the likelihood of detecting negative effects of crop diversity when semi-natural cover is low and positive effects when it is high. Second, we predicted that the shift from a positive to negative effect would occur at a lower crop diversity when it is measured locally than when it is measured at greater distances from the site, making detection of negative crop diversity effects more likely when measurements are at local extents. We tested these predictions using data on the biodiversity of herbaceous plants, butterflies, syrphid flies, woody plants, bees, carabid beetles, spiders, and birds at 221 crop field edges in Eastern Ontario, Canada. We found support for an area-crop diversity tradeoff. Semi-natural cover and measurement extent influenced the biodiversity-crop diversity relationship, with positive effects when semi-natural cover was high and negative effects when semi-natural cover was low and when crop diversity was measured at local extents. The results suggest that policies/guidelines designed to increase crop diversity will not benefit biodiversity in the landscapes where conservation action is most urgently needed, that is, in landscapes with high agricultural use and low semi-natural cover.

Environmental Land Use Conflicts in a Macroscale River Basin: A Preliminary Study Based on the Ruggedness Number

Inadequate land use planning is one of the main driving forces leading to the occurrence of erosion and environmental degradation. The negative impacts of poor planning influence soil physical quality and fertility, agricultural productivity, water quality and availability, biodiversity and other ecosystem services. In some areas, actual land use is not consistent with potential use. When this occurs, the area is termed as being in environmental land use conflict. Many studies have demonstrated the efficiency of the ruggedness number (RN) method for determining land use potential in watersheds. The RN method is simple and can be carried out using geographic information systems (GIS). However, the absence of potential land use or agricultural land suitability assessments is recurrent in territorial management plans or integrated water resources plans (IWRP), especially for macroscale river basins. Therefore, the aim of this preliminary study is to identify possible environmental land use conflicts at the Rio Grande Basin (BHRG), Brazil, using the Ruggedness Number. The results indicate high agricultural use potential and the predominance of appropriate or acceptable soil use at the BHRG. However, class 1, 2 and 3 environmental conflicts were identified in some Rio Grande sub-basins, suggesting greater environmental degradation risks. The findings clearly indicate that more exhaustive studies on environmental quality (soil capability, water, biodiversity) are required at the BHRG, especially in environmental land use conflict areas. We emphasize that this is an important preliminary study which may be carried out in any other macroscale hydrographic basin.

Body Size Increases with Elevation in Pyrenean Newts (Calotriton asper)

Abstract Habitat disturbance is an important cause of global amphibian declines, with especially strong effects in areas of high agricultural use. Determining the influence of site characteristics ...

Microplastic hotspots in the Snake and Lower Columbia rivers: A journey from the Greater Yellowstone Ecosystem to the Pacific Ocean

It is widely understood that microplastics (MPs) are ubiquitous in the marine environment yet less is known about MP abundance in freshwater rivers, particularly those of the western United States. This study documents MP pollution along the Snake River (∼1735 km) and from its confluence with the Columbia River to the Pacific Ocean. Grab and plankton net samples (mesh size 100 μm) were collected from the top 25 cm of surface water every 80.5 river km. MPs were identified if they met visual criteria and were verified with the hot needle test. A small representative subset of MPs from the net samples (16.7%) were selected based on appearance for micro-Raman spectroscopy in effort to provide examples of polymer types found in this study. Seventy-five percent of grab samples and 92.8% of net samples contained MPs, with concentrations ranging from 0 to 5.405 MP L−1 and 0 to 0.014 MP L−1 (0 to 13.7 MP m−3), respectively. The majority of fragments, films and beads were between 100 μm and 333 μm. This study identifies potential hotspots of MP pollution along the Snake and Lower Columbia rivers and prioritizes areas where more intensive sampling is needed. Sites with low flow or those further down river had higher numbers and the top two hotspots were located in areas with low population density but high agricultural use. Monitoring MP abundance in freshwater systems is important for establishing baseline levels of MP pollution and can direct laboratory toxicology studies in using more environmentally relevant concentrations for a better indication of how MP pollution affects ecosystems.

Association between Pesticide Profiles Used on Agricultural Fields near Maternal Residences during Pregnancy and IQ at Age 7 Years.

We previously showed that potential prenatal exposure to agricultural pesticides was associated with adverse neurodevelopmental outcomes in children, yet the effects of joint exposure to multiple pesticides is poorly understood. In this paper, we investigate associations between the joint distribution of agricultural use patterns of multiple pesticides (denoted as “pesticide profiles”) applied near maternal residences during pregnancy and Full-Scale Intelligence Quotient (FSIQ) at 7 years of age. Among a cohort of children residing in California’s Salinas Valley, we used Pesticide Use Report (PUR) data to characterize potential exposure from use within 1 km of maternal residences during pregnancy for 15 potentially neurotoxic pesticides from five different chemical classes. We used Bayesian profile regression (BPR) to examine associations between clustered pesticide profiles and deficits in childhood FSIQ. BPR identified eight distinct clusters of prenatal pesticide profiles. Two of the pesticide profile clusters exhibited some of the highest cumulative pesticide use levels and were associated with deficits in adjusted FSIQ of −6.9 (95% credible interval: −11.3, −2.2) and −6.4 (95% credible interval: −13.1, 0.49), respectively, when compared with the pesticide profile cluster that showed the lowest level of pesticides use. Although maternal residence during pregnancy near high agricultural use of multiple neurotoxic pesticides was associated with FSIQ deficit, the magnitude of the associations showed potential for sub-additive effects. Epidemiologic analysis of pesticides and their potential health effects can benefit from a multi-pollutant approach to analysis.

EMISSIONS OF GREENHOUSE GASES FROM DIESEL CONSUMPTION IN AGRICULTURAL PRODUCTION OF TURKEY

Agricultural sector is both energy consumer in the form of human labor, fossil fuels, electricity, seeds, fertilizer, and pesticides and energy producer in the form of food, feed, and biofuels. High agricultural use of energy inputs results in adverse environmental issues such as global climate change, pollution of water, soil and air, and unsustainable agricultural production. In this study, 35 agricultural crops such as cereals, fruits, and vegetables were evaluated in terms of consumption of diesel fuel during their production process including soil preparation, fertilization, sowing, spraying, harvesting and transportation, based on minimum and maximum values reported in related literature. Greenhouse gas (GHG) emissions from diesel consumption can be expressed as total carbon dioxide equivalent (CO 2eq ) emissions (2.76 kg per liter). a map showing total CO 2eq emissions from diesel consumption for agricultural production. Our estimates showed that minimum and maximum GHG emissions varied between 0.48 and 3.75 Tg CO 2eq for wheat, 17.15 and 65.45 Gg CO 2eq for chickpea, and 0.088 and 0.153 Tg CO 2eq for tomatoes, respectively. In order to reduce diesel-related GHG emissions, there is an urgent need for innovative agricultural practices and technologies to be put into place.

Widespread occurrence of neonicotinoid insecticides in streams in a high corn and soybean producing region, USA

Neonicotinoid insecticides are of environmental concern, but little is known about their occurrence in surface water. An area of intense corn and soybean production in the Midwestern United States was chosen to study this issue because of the high agricultural use of neonicotinoids via both seed treatments and other forms of application. Water samples were collected from nine stream sites during the 2013 growing season. The results for the 79 water samples documented similar patterns among sites for both frequency of detection and concentration (maximum:median) with clothianidin (75%, 257 ng/L:8.2 ng/L) > thiamethoxam (47%, 185 ng/L:<2 ng/L) > imidacloprid (23%, 42.7 ng/L: <2 ng/L). Neonicotinoids were detected at all nine sites sampled even though the basin areas spanned four orders of magnitude. Temporal patterns in concentrations reveal pulses of neonicotinoids associated with rainfall events during crop planting, suggesting seed treatments as their likely source.

Endosulfan wet deposition in Southern Florida (USA)

The atmosphere is an important transport route for semi-volatile pesticides like endosulfan. Deposition, which depends on physical–chemical properties, use patterns, and climatic conditions, can occur at local, regional, and global scales. Adverse human and ecological impact may result. We measured endosulfan wet deposition in precipitation over a 4-year period within an area of high agricultural use in Southern Florida (USA) and in nearby Biscayne and Everglades National Parks. Endosulfan's two isomers and degradate, endosulfan sulfate, were detected at high frequency with the order of detection and concentration being β-endosulfan>α-endosulfan>endosulfan sulfate. Within the agricultural area, detection frequency (55 to 98%) mean concentrations (5 to 87ngL−1) and total daily deposition (200ngm−2day−1) exceeded values at other sites by 5 to 30-fold. Strong seasonal trends were also observed with values at all monitored sites significantly higher during peak endosulfan use periods when vegetable crops were produced. Relatively high deposition in the crop production area and observations that concentrations exceeded aquatic life toxicity thresholds at all sites indicated that endosulfan volatilization and wet deposition are of ecotoxicological concern to the region. This study emphasizes the need to include localized volatilization and deposition of endosulfan and other semi-volatile pesticides in risk assessments in Southern Florida and other areas with similar climatic and crop production profiles.

Quantifying sample biases of inland lake sampling programs in relation to lake surface area and land use/cover

We quantified potential biases associated with lakes monitored using non-probability based sampling by six state agencies in the USA (Michigan, Wisconsin, Iowa, Ohio, Maine, and New Hampshire). To identify biases, we compared state-monitored lakes to a census population of lakes derived from the National Hydrography Dataset. We then estimated the probability of lakes being sampled using generalized linear mixed models. Our two research questions were: (1) are there systematic differences in lake area and land use/land cover (LULC) surrounding lakes monitored by state agencies when compared to the entire population of lakes? and (2) after controlling for the effects of lake size, does the probability of sampling vary depending on the surrounding LULC features? We examined the biases associated with surrounding LULC because of the established links between LULC and lake water quality. For all states, we found that larger lakes had a higher probability of being sampled compared to smaller lakes. Significant interactions between lake size and LULC prohibit us from drawing conclusions about the main effects of LULC; however, in general lakes that are most likely to be sampled have either high urban use, high agricultural use, high forest cover, or low wetland cover. Our analyses support the assertion that data derived from non-probability-based surveys must be used with caution when attempting to make generalizations to the entire population of interest, and that probability-based surveys are needed to ensure unbiased, accurate estimates of lake status and trends at regional to national scales.

Toxic Chemical Survey of Municipal Drinking Water Sources in Atlantic Canada 1985-1988

Abstract During the period of 1985 to 1988, municipal water supply sources in Atlantic Canada were sampled and analyzed for various compounds including major ions, nutrients, heavy metals, pesticides and synthetic organic chemicals. Both surface and ground water sources were sampled. Ninety-eight percent of supply sources were within the health-related maximum acceptable concentrations of the Guidelines for Canadian Drinking Water Quality (Health and Welfare Canada 1987), and eighty-five percent within the aesthetic guidelines. A geographic information system was used to classify the municipal sources by surrounding land-use and comparisons made to nitrate-N. All samples reported as 1.0 mg.L−1 or greater were from ground water supplies in areas classed as high agricultural use. Though a direct input from agriculture was established for two wells, the source of nitrate-N at the remaining sites was attributed to soil-N and/or fertilizer-N.