A Method to Evaluate Seeder Performance

Evaluating in field seeder performance is challenging and sometimes requires destructive methods. An alternative method for evaluating seeder performance based on nonlinear regression was developed. This method yields parameters that describe seeder performance, such as emergence rate, initial emergence data, and emergence percent. These parameters are easy to explain to the practitioner. The proposed method was compared to a widely used method to assess emergence rate. Results assessing emergence percent were comparable between the two methods. There were differences between the emergence rate index and emergence rate determined from the proposed method. These differences were expected since the emergence rate index encompasses more information than simply the rate of emergence

Increased growing temperature reduces content of polyunsaturated fatty acids in four oilseed crops

Environmental temperature directly influences the lipid profile produced by oilseeds. If growing temperatures increase, as is predicted by current models, the precise profile of lipids produced are likely to change. This paper develops models to predict lipid profiles as a function of growing temperature. Data relating to lipid profiles of soybean (Glycine max), spring canola (Brassica napus), spring camelina (Camelina sativa), and sunflower (Helianthus annuus) were gathered from the literature and evaluated to examine the influence of temperature on relative production of oleic, linoleic, and linolenic acid. For each crop, a set of linear regressions was used to correlate temperature during the grain fill, defined as 30 days before harvest, with the molar percentages of oleic, linoleic, and linolenic acid present. An increase in temperature from 10 to 40°C resulted in an increase in the production of oleic acid and a decrease in the production of linoleic and linolenic acid in soybeans, canola, and sunflowers. Over the range of data available, the lipid profile of camelina was temperature insensitive. To test the validity of the correlations, the four crops were grown in a field study in Manhattan, Kansas simultaneously, in the same environment, in 2011. The correlations accurately predicted the field data for soybean, canola, and camelina but not for sunflower. The correlation for sunflower under-predicted the molar amount of oleic acid and over-predicted the molar amount of linoleic acid. This study indicates increasing growing temperatures from 10 to 40°C will result in more monounsaturated oils and less polyunsaturated oils in soybean, canola, and sunflower

Creating Convivial Affordances: a Study of Virtual World Social Movements

The study of technology and societal challenges is a growing area in information systems research. This paper explores how social movements can use virtual worlds to raise awareness or create safe spaces for their members. As social movements move into virtual worlds, the technical environment becomes more important. This paper presents an interpretive field study using netnographic research and empirical data from a study of a lesbian, gay, bisexual, and transgender social movement in World of Warcraft. This paper takes the position that an understanding of affordances is required for users to be able to create convivial outcomes to shape the use of virtual worlds for their own goals and intentions. The paper presents the concept of convivial affordances, which brings together the theories of affordances and conviviality, and suggests that social users can shape IT artefacts through a creative combination of affordances for their specific goals, and with community involvement

Biomass production of herbaceous energy crops in the United States: field trial results and yield potential maps from the multiyear regional feedstock partnership

Current knowledge of yield potential and best agronomic management practices for perennial bioenergy grasses is primarily derived from small-scale and short-term studies, yet these studies inform policy at the national scale. In an effort to learn more about how bioenergy grasses perform across multiple locations and years, the U.S. Department of Energy (US DOE)/Sun Grant Initiative Regional Feedstock Partnership was initiated in 2008. The objectives of the Feedstock Partnership were to (1) provide a wide range of information for feedstock selection (species choice) and management practice options for a variety of regions and (2) develop national maps of potential feedstock yield for each of the herbaceous species evaluated. The Feedstock Partnership expands our previous understanding of the bioenergy potential of switchgrass, Miscanthus, sorghum, energycane, and prairie mixtures on Conservation Reserve Program land by conducting long-term, replicated trials of each species at diverse environments in the U.S. Trials were initiated between 2008 and 2010 and completed between 2012 and 2015 depending on species. Field-scale plots were utilized for switchgrass and Conservation Reserve Program trials to use traditional agricultural machinery. This is important as we know that the smaller scale studies often overestimated yield potential of some of these species. Insufficient vegetative propagules of energycane and Miscanthus prohibited farm-scale trials of these species. The Feedstock Partnership studies also confirmed that environmental differences across years and across sites had a large impact on biomass production. Nitrogen application had variable effects across feedstocks, but some nitrogen fertilizer generally had a positive effect. National yield potential maps were developed using PRISM-ELM for each species in the Feedstock Partnership. This manuscript, with the accompanying supplemental data, will be useful in making decisions about feedstock selection as well as agronomic practices across a wide region of the country

2009 Kansas Performance Tests with Cotton Varieties

This publication presents the results of performance tests with cotton varieties. Descriptive information is presented with the results for each test. This information, including soil type, establishment methods, fertilization, pest control, irrigation, harvest dates, and growing conditions unique to that location, can help explain test and/or variety performance

2008 Kansas Performance Tests with Cotton Varieties

This publication presents the results of performance tests with cotton varieties. Descriptive information is presented with the results for each test. This information, including soil type, establishment methods, fertilization, pest control, irrigation, harvest dates, and growing conditions unique to that location, can help explain test and/or variety performance

2010 Kansas Performance Tests with Cotton Varieties

This publication presents the results of performance tests with cotton varieties. Descriptive information is presented with the results for each test. This information, including soil type, establishment methods, fertilization, pest control, irrigation, harvest dates, and growing conditions unique to that location, can help explain test and/or variety performance

2000 Kansas Performance Tests with Cotton Varieties

This publication presents the results of performance tests with cotton varieties. Descriptive information is presented with the results for each test. This information, including soil type, establishment methods, fertilization, pest control, irrigation, harvest dates, and growing conditions unique to that location, can help explain test and/or variety performance

Effect of planter speed and seed firmers on corn stand establishment

Citation: Applied Engineering in Agriculture. Vol. 20(5): 573-580 . (doi: 10.13031/2013.17457) @2004Proper planter adjustment and operation play an important role in uniform stand establishment for corn. A two−year study was conducted to assess the impact of planter speed and a seed−firming device on corn stand establishment and grain yield. A planter equipped with a vacuum metering system and commercial seed firming devices was used in this study. Corn was seeded in a randomized complete block experiment at three speeds at two locations in Kansas (USA). Plant stand was counted at regular intervals after the first plant emerged to determine emergence rate. Plant spacing within each treatment was measured after complete emergence. Mean plant spacing, standard deviation in spacing, and four spacing indices (miss, multiple, quality of feed, and precision) were calculated to evaluate the plant spacing data. The miss and multiple indices indicate the number of skips and doubles. Planter performance as measured by these indices and standard deviation in plant spacing decreased as planter speed increased. The seed firmer reduced plant spacing standard deviations at a rate equivalent to the standard deviation increase observed when planter speed increased approximately 1.6 km/h (1 mph). Corn yield was reduced as planter speed increased at one location, but not the others. This response was the result of lower plant densities at the higher planter speeds, suggesting that one of the goals of the planting process should be to establish adequate plant densities. The seed firmer had no impact on corn yield