scholarly journals Previous Crop and Cultivar Effects on Methane Emissions from Drill-Seeded, Delayed-Flood Rice Grown on a Clay Soil

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Alden D. Smartt ◽  
Kristofor R. Brye ◽  
Christopher W. Rogers ◽  
Richard J. Norman ◽  
Edward E. Gbur ◽  
...  
Keyword(s):  
Clay Soil ◽  
Growing Season ◽  
Pure Line ◽  
Cultural Factors ◽  
Rice Production ◽  
Anaerobic Conditions ◽  
Flooded Rice ◽  
Previous Crop ◽  
The Us ◽  
Line Standard

Due to anaerobic conditions that develop in soils under flooded-rice (Oryza sativaL.) production, along with the global extent of rice production, it is estimated that rice cultivation is responsible for 11% of global anthropogenic methane (CH4) emissions. In order to adequately estimate CH4emissions, it is important to include data representing the range of environmental, climatic, and cultural factors occurring in rice production, particularly from Arkansas, the leading rice-producing state in the US, and from clay soils. The objective of this study was to determine the effects of previous crop (i.e., rice or soybean (Glycine maxL.)) and cultivar (i.e., Cheniere (pure-line, semidwarf), CLXL745 (hybrid), and Taggart (pure-line, standard-stature)) on CH4fluxes and emissions from rice grown on a Sharkey clay (very-fine, smectitic, thermic Chromic Epiaquerts) in eastern Arkansas. Rice following rice as a previous crop generally had greater (p<0.01) fluxes than rice following soybean, resulting in growing season emissions (p<0.01) of 19.6 and 7.0 kg CH4-C ha−1, respectively. The resulting emissions from CLXL745 (10.2 kg CH4-C ha−1) were less (p=0.03) than those from Cheniere or Taggart (15.5 and 14.2 kg CH4-C ha−1, resp.), which did not differ. Results of this study indicate that common Arkansas practices, such as growing rice in rotation with soybean and planting hybrid cultivars, may result in reduced CH4emissions relative to continuous rice rotations and pure-line cultivars, respectively.

Soil sorption characteristics of benzobicyclon hydrolysate and estimated leaching risk in soils used for rice production

2020 ◽  
Vol 17 (6) ◽  
pp. 445
Author(s):  
Cammy D. Willett ◽  
Erin M. Grantz ◽  
Matthew G. Sena ◽  
Jung Ae Lee ◽  
Kristofor R. Brye ◽  
...  
Keyword(s):  
Soil Solution ◽  
Oryza Sativa L ◽  
Water Flux ◽  
Growing Season ◽  
Rice Production ◽  
Soil Sorption ◽  
Regression Parameters ◽  
The Us ◽  
Average Water ◽  
Plough Layer

Environmental contextThe behaviour of herbicides in the environment is largely determined by the partitioning of the compounds between soil solids and soil solution. We determined that the rice herbicide-metabolite benzobicyclon hydrolysate partitions more into soil solution, and does so increasingly as pH increases. These results indicate that benzobicyclon hydrolysate is a risk for leaching in much of the rice-producing area in the US mid-South. AbstractBenzobicyclon hydrolysate (BH) is the major metabolite and active molecule in the pro-herbicide benzobicyclon (BZB), which is pending registration for use in US mid-Southern rice (Oryza sativa L.) production. The current study objectives were to (i) determine BH soil sorption coefficients; (ii) quantify relationships among BH sorption and soil properties; and (iii) estimate leaching potential using calculated retardation factors (RFs). Sorption coefficients for 10 representative Arkansas rice-production soils were determined by batch-equilibration experiments. Soil sorption (KD=0.25–44.3mLg−1), soil organic carbon partitioning (KOC=28.2–7480mLg−1), and soil organic matter partitioning (KOM=17.9–2580mLg−1) coefficients were negatively correlated with soil pH (r=−0.93 – −0.94). Clay and silt were significant secondary regression parameters, accounting for up to 93% of the variation in KD in combination with pH. Clay and silt effects on sorption coefficients increased when regression analyses excluded the lowest pH soil. Soil sorption coefficients were greater in soils with clay ≥27%, which may be a useful parameter for informing herbicide-use rates. Using the calculated RF’s, the estimated depth of leaching over the growing season exceeded the assumed 15-cm plough layer depth in eight of the 10 soils, and only two of the 10 soils had an estimated time to plough layer breakthrough less than the typical six-month growing season (April–September) under average water flux conditions. The results suggest that BH leaching below the plough layer is a potential risk for much of the rice-producing area in the US mid-South.

Study of Structural Change in Paddy Agriculture under Reorganization of Direct Payment Policy

Impact ◽  
2020 ◽  
Vol 2020 (6) ◽  
pp. 55-57
Author(s):  
Kunio Nishikawa
Keyword(s):  
Structural Change ◽  
Rice Production ◽  
Direct Payment ◽  
Japan Society ◽  
Payment Policy ◽  
The Us ◽  
Shed Light

Rice has long been an integral part of Japan's culture and economy, as well as an important commodity in Japan-US relations, but farmers in Japan are concerned that trouble is afoot due to competition from countries such as the US, where rice production is more competitive, as well as reorganization of direct payment policy. The question is, how can rice production in Japan remain competitive amidst such competition? One researcher is seeking to shed light on the situation and explore how paddy agriculture in Japan can potentially flourish. Dr Kunio Nishikawa is based at Ibaraki University, Japan, whose Japan Society for the Promotion of Science (JSPS)-funded work is exploring the discrepancy in crop output in the US versus Japan, and seeking to find new ways to boost Japan's agriculture.

Crossing the Last Frontier: Transatlantic Movements of Asian Maritime Workers, c. 1900-1945

2007 ◽  
Author(s):  
G. Balachandran
Keyword(s):  
Twentieth Century ◽  
Hong Kong ◽  
Cultural Factors ◽  
Immigration Policies ◽  
World War ◽  
The Us ◽  
Migration Network ◽  
Over Time ◽  
Us Immigration

This essay explores the maritime migration network between Asia and America by way of Europe during the first half of the twentieth century. It pays particular attention to the maritime activity of ‘lascar’ seamen, and the movement of labour between Britain, America, India, China, and Hong Kong. It examines the changes that underwent the network over time, the quantities of migrants and their intended destinations, and the period of upheaval caused by each World War. It also examines the racial, social, political, and cultural factors that shaped British and US immigration policies during the period. It concludes by stating that the US was undoubtedly a primary destination for Asian labourers, despite the well-broatcast perils relating to wages, racism, nationalism, and subjugation.

Spatial Analysis of Climate-Viticulture Indices for the Eastern United States

2016 ◽  
Vol 7 (4) ◽  
pp. 23-37 ◽  
Author(s):  
Rosalyn Francine MacCracken ◽  
Paul R. Houser
Keyword(s):  
United States ◽  
Spatial Analysis ◽  
Growing Season ◽  
Climate Indices ◽  
Growing Degree Days ◽  
Eastern United States ◽  
Degree Days ◽  
The Us ◽  
Resolution Dataset ◽  
Effective Degree

This study characterizes the climate structure in the Eastern United States for suitability of winegrape growth. For this study, the Eastern US is defined as the 44 contiguous Eastern most states. This excludes the premium wine growing states of California, Washington, Oregon and Idaho. For this characterization, a comparative study is performed on the four commonly used climate-viticulture indices (i.e., Average Growing Season Temperature, Growing Degree Days, Heliothermal Index and Biologically Effective Degree Days), and a new climate-viticulture index, the Modified-GSTavg (Mod-GSTavg). This is accomplished using the 1971 – 2000 PRISM 800-meter resolution dataset of climate temperature normal for the study area of 44 states and 62 American Viticultural Areas across the Eastern United States. The results revealed that all the climate indices have similar spatial patterns throughout the US with varying magnitudes and degrees of suitability.

scholarly journals Introduction to the Special Issue

2019 ◽  
Vol 34 (01) ◽  
pp. 1-13
Author(s):  
Fabrice Bensimon
Keyword(s):  
Industrial Revolution ◽  
Cultural Factors ◽  
High Wage ◽  
Economic Aspects ◽  
Special Issue ◽  
Male And Female ◽  
Associational Life ◽  
Local Populations ◽  
The Us ◽  
Social And Cultural Factors

AbstractIn the period 1815–1870, several thousand British workers and engineers went to the continent for work purposes, playing a decisive part in European industrialisation. Workers emigrated because they could market their skills at good value; or because their British employers sought to make the most of their technical lead by setting businesses up abroad, and by producing on the continent, they could avoid protective tariffs.Which social and cultural factors enabled British capital to flow to continental and indeed global enterprise, British skills to shape labour processes overseas, and British male and female labourers to seek and find overseas employment? This introduction to the Special Issue raises a series of questions on these flows. It asks what numbers went to the continent, in comparison with the large flows to the US and the British World. It addresses the legislative and economic aspects of these labour migrations and tries to relate these to the discussion on the supposed ‘high-wage economy’ of the British industrial revolution. It also focuses on the practicalities of migration. Last, it is also interested in the cultural, religious and associational life of the British migrants, as well as in the relations with the local populations.

scholarly journals Modeling soil CO<sub>2</sub> production and transport with dynamic source and diffusion terms: testing the steady-state assumption using DETECT v1.0

2018 ◽  
Vol 11 (5) ◽  
pp. 1909-1928 ◽  
Author(s):  
Edmund M. Ryan ◽  
Kiona Ogle ◽  
Heather Kropp ◽  
Kimberly E. Samuels-Crow ◽  
Yolima Carrillo ◽  
...  
Keyword(s):  
Differential Equation ◽  
Steady State ◽  
Root Respiration ◽  
Clay Soil ◽  
Growing Season ◽  
Production Model ◽  
Precipitation Event ◽  
Soil Co2 ◽  
Microbial Decomposition ◽  
C Cycle

Abstract. The flux of CO2 from the soil to the atmosphere (soil respiration, Rsoil) is a major component of the global carbon (C) cycle. Methods to measure and model Rsoil, or partition it into different components, often rely on the assumption that soil CO2 concentrations and fluxes are in steady state, implying that Rsoil is equal to the rate at which CO2 is produced by soil microbial and root respiration. Recent research, however, questions the validity of this assumption. Thus, the aim of this work was two-fold: (1) to describe a non-steady state (NSS) soil CO2 transport and production model, DETECT, and (2) to use this model to evaluate the environmental conditions under which Rsoil and CO2 production are likely in NSS. The backbone of DETECT is a non-homogeneous, partial differential equation (PDE) that describes production and transport of soil CO2, which we solve numerically at fine spatial and temporal resolution (e.g., 0.01 m increments down to 1 m, every 6 h). Production of soil CO2 is simulated for every depth and time increment as the sum of root respiration and microbial decomposition of soil organic matter. Both of these factors can be driven by current and antecedent soil water content and temperature, which can also vary by time and depth. We also analytically solved the ordinary differential equation (ODE) corresponding to the steady-state (SS) solution to the PDE model. We applied the DETECT NSS and SS models to the six-month growing season period representative of a native grassland in Wyoming. Simulation experiments were conducted with both model versions to evaluate factors that could affect departure from SS, such as (1) varying soil texture; (2) shifting the timing or frequency of precipitation; and (3) with and without the environmental antecedent drivers. For a coarse-textured soil, Rsoil from the SS model closely matched that of the NSS model. However, in a fine-textured (clay) soil, growing season Rsoil was ∼ 3 % higher under the assumption of NSS (versus SS). These differences were exaggerated in clay soil at daily time scales whereby Rsoil under the SS assumption deviated from NSS by up to 35 % on average in the 10 days following a major precipitation event. Incorporation of antecedent drivers increased the magnitude of Rsoil by 15 to 37 % for coarse- and fine-textured soils, respectively. However, the responses of Rsoil to the timing of precipitation and antecedent drivers did not differ between SS and NSS assumptions. In summary, the assumption of SS conditions can be violated depending on soil type and soil moisture status, as affected by precipitation inputs. The DETECT model provides a framework for accommodating NSS conditions to better predict Rsoil and associated soil carbon cycling processes.

scholarly journals Teprotumumab Treatment for Thyroid-Associated Ophthalmopathy

2020 ◽  
Vol 9 (Suppl. 1) ◽  
pp. 31-39
Author(s):  
Terry J. Smith
Keyword(s):  
Paradigm Shift ◽  
Vision Loss ◽  
Standard Of Care ◽  
Autoimmune Process ◽  
First Line ◽  
Thyroid Associated Ophthalmopathy ◽  
The Us ◽  
Fundamental Research ◽  
Line Standard

<b><i>Background:</i></b> Thyroid-associated ophthalmopathy (TAO), an autoimmune process affecting the tissues surrounding the eye, most commonly develops in individuals with Graves’ disease. It is disfiguring, can cause vision loss, and dramatically lessens the quality of life in patients. There has been an absence of approved medical therapies for TAO with proven effectiveness and safety in multicenter, placebo-controlled, and adequately powered clinical trials. <b><i>Summary:</i></b> The following is a brief overview of the rationale for developing a monoclonal antibody inhibitor of the insulin-like growth factor-I receptor into a treatment for TAO. This area of fundamental research has yielded an effective and safe medication, namely teprotumumab, based on two multicenter, placebo-controlled trials. Teprotumumab, marketed as Tepezza, has been approved recently by the US Food and Drug Administration for the treatment of TAO. Given its remarkable effectiveness, Tepezza is poised to become the first-line standard of care for TAO. <b><i>Key Messages:</i></b> Introduction of Tepezza into our armamentarium of therapeutic strategies for TAO represents a paradigm shift in the management of the disease. I proffer that the drug will replace glucocorticoids as a first-line treatment for TAO.

Sign in / Sign up

Export Citation Format

Share Document