7,025 research outputs found
Crop phenology literature review for corn, soybean, wheat, barley, sorghum, rice, cotton, and sunflower
There are no author-identified significant results in this report
Canadian crop calendars in support of the early warning project
The Canadian crop calendars for LACIE are presented. Long term monthly averages of daily maximum and daily minimum temperatures for subregions of provinces were used to simulate normal daily maximum and minimum temperatures. The Robertson (1968) spring wheat and Williams (1974) spring barley phenology models were run using the simulated daily temperatures and daylengths for appropriate latitudes. Simulated daily temperatures and phenology model outputs for spring wheat and spring barley are given
AgRISTARS: Supporting research. Spring small grains planting date distribution model
A model was developed using 996 planting dates at 51 LANDSAT segments for spring wheat and spring barley in Minnesota, Montana, North Dakota, and South Dakota in 1979. Daily maximum and minimum temperatures and precipitation were obtained from the cooperative weather stations nearest to each segment. The model uses a growing degree day summation modified for daily temperature range to estimate the beginning of planting and uses a soil surface wetness variable to estimate how a fixed number of planting days are distributed after planting begins. For 1979, the model predicts first, median, and last planting dates with root mean square errors of 7.91, 6.61, and 7.09 days, respectively. The model also provides three or four dates to represent periods of planting activity within the planting season. Although the full model was not tested on an independent data set, it may be suitable in areas other than the U.S. Great Plains where spring small grains are planted as soon as soil and air temperatures become warm enough in the spring for plant growth
Engaging Diversity And Marginalization Through Participatory Action Research: A Model For Independent School Reform
Authored by a university researcher, school practitioner, and high school student, this article examines how independent schools can utilize participatory action research (PAR) to bolster diversity and inclusion efforts. A case study approach was taken to showcase a two-year PAR project at a progressive independent school that sought to: (a) enrich institutional knowledge of student diversity, (b) capture the present-day schooling experiences of historically marginalized students in independent school settings, and (c) develop a dynamic action plan to ameliorate school issues that emerged through the PAR inquiry process. Committed to institutional research that informs school policy and practice, we argue that PAR provides a rigorous, student-centered, and democratic model for independent school reform
Estimating solar radiation for plant simulation models
Five algorithms producing daily solar radiation surrogates using daily temperatures and rainfall were evaluated using measured solar radiation data for seven U.S. locations. The algorithms were compared both in terms of accuracy of daily solar radiation estimates and terms of response when used in a plant growth simulation model (CERES-wheat). Requirements for accuracy of solar radiation for plant growth simulation models are discussed. One algorithm is recommended as being best suited for use in these models when neither measured nor satellite estimated solar radiation values are available
Methane measurement by the Pioneer Venus large probe neutral mass spectrometer
The Pioneer Venus Large Probe Mass Spectrometer detected a large quantity of methane as it descended below 20 km in the atmosphere of Venus. Terrestrial methane and Xe-136, both originating in the same container and flowing through the same plumbing, were deliberately released inside the mass spectrometer for instrumental reasons. However, the Xe-136 did not exhibit behavior similar to methane during Venus entry, nor did CH4 in laboratory simulations. The CH4 was deuterium poor compared to Venus water and hydrogen. While the inlet to the mass spectrometer was clogged with sulfuric acid droplets, significant deuteration of CH4 and its H2 progeny was observed. Since the only source of deuterium identifiable was water from sulfuric acid, we have concluded that we should correct the HDO/H2O ratio in Venus water from 3.2 x 10(exp -2) to (5 plus or minus 0.7) x 10(exp -2). When the probe was in the lower atmosphere, transfer of deuterium from Venus HDO and HD to CH4 can account quantitatively for the deficiencies recorded in HDO and HD below 10 km, and consequently, the mysterious gradients in water vapor and hydrogen mixing ratios we have reported. The revision in the D/H ratio reduces the mixing ratio of water vapor (and H2) reported previously by a factor of 3.2/5. We are not yet able to say whether the methane detected was atmospheric or an instrumental artifact. If it was atmospheric, its release must have been episodic and highly localized. Otherwise, the large D/H ratio in Venus water and hydrogen could not be maintained
Variability of crop calendar stage dates
There are no author-identified significant results in this report
Crop yield literature review for AgRISTARS crops: Corn, soybeans, wheat, barley, sorghum, rice, cotton, and sunflowers
There are no author-identified significant results in this report
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