Preliminary Report, Soybean Performance Tests - 1971

The data presented below represent the preliminary results of the 1971 Soybean Performance Tests. A more complete version of the data, including data from previous years, will be published at a later date in Results of the Kentucky Soybean Performance Tests - 1971

York Soybeans Added to Recommended List

York soybean, a pure line selection developed by the Virginia Agricultural Experiment Station from a cross of Dorman X Hood, was recently added to the recommended list for Kentucky. It was released jointly in 1967 by Virginia, Maryland, and North Carolina

Preliminary Report Soybean Performance Tests 1970

The data presented below represent the preliminary results of the 1970 Soybean Performance Tests . A more complete version of the data, including data from previous years , will be published at a later date in Results of the Kentucky Soybean Performance Tests - 1970

Seed Biology and Yield of Grain Crops

Description from CABI (Centre for Agriculture and Biosciences International): This new edition of an established title examines the determination of grain crop yield from a unique perspective, by concentrating on the influence of the seed itself. As the food supply for an expanding world population is based on grain crops harvested for their seeds, understanding the process of seed growth and its regulation is crucial to our efforts to increase production and meet the needs of that population. Yield of grain crops is determined by their assimilatory processes such as photosynthesis and the biosynthetic processes in the seed, which are partly regulated within the seed itself. Providing a timely update in this field and highlighting the impact of the seed on grain crop yields, this book: Describes all aspects of seed growth and development, including environmental and genetic effects on growth rate and length of the filling period. Discusses the role of the seed in determining the two main yield components: individual seed weight and number of seeds per unit area. Uses the concepts and models that have been developed to understand crop management and yield improvement. Substantially updated with new research and further developments of the practical applications of the concepts explored, this book is essential reading for those concerned with seed science and crop yield, including agronomists, crop physiologists, plant breeders, and extension workers. It is also a valuable source of information for lecturers and graduate students of agronomy and plant physiology.https://uknowledge.uky.edu/pss_book/1005/thumbnail.jp

Formaldehyde over the central Pacific during PEM-Tropics B

Formaldehyde, CH2O, mixing ratios are reported for the central Pacific troposphere from a series of 41 flights, which took place in March-April 1999 as part of the NASA Pacific Exploratory Mission (PEM) -Tropics B mission. Ambient CH2O was collected in aqueous media and quantified using an enzyme-derivatization fluorescence technique. Primary calibration was performed using aqueous standards and known flow rates. Occasionally, CH2O gas standard additions to ambient air were performed as a secondary calibration. Analytical blanks were determined by replacing ambient air with pure air. The estimated precision was ±30 pptv and the estimated accuracy was the sum of ±30 parts per trillion by volume (pptv) ±15% of the measured value. Approximately 25% of the observations were less than the instrumental detection limit of 50 pptv, and 85% of these occurred above 6 km. CH2O mixing ratios decreased with altitude; for example, near the equator the median value in the lowest 2 km was 275 pptv, decreased to 150 pptv by 6 km and was below 100 pptv above 8 km. Between 130 and 170 W and below 1km, a small variation of CH2O mixing ratio with latitude was noted as near-surface median mixing ratios decreased near the equator (275 pptv) and were greater on either side (375 pptv). A marked decrease in near-surface CH2O (200 pptv) was noted south of 23° S on two flights. Between 3° and 23° S, median CH2O mixing ratios were lower in the eastern tropical Pacific than in the western or central Pacific; nominal differences were >100 pptv near the surface to ∼100 pptv at midaltitude to ∼50 pptv at high altitude. Off the coast of Central America and Mexico, mixing ratios as high as 1200 pptv were observed in plumes that originated to the east over land. CH2O observations were consistently higher than the results from a point model constrained by other photochemical species and meteorological parameters. Regardless of latitude or longitude, agreement was best at altitudes above 4 km where the difference between measured and modeled CH2O medians was less than 50 pptv. Below 2 km the model median was approximately 150 pptv less than the measured median. Copyright 2001 by the American Geophysical Union

Black carbon contributes to organic matter in young soils in the Morteratsch proglacial area (Switzerland)

Most glacier forefields of the European Alps are being progressively exposed since the glaciers reached their maximum expansion in the 1850s. Global warming and climate changes additionally promote the exposure of sediments in previously glaciated areas. In these proglacial areas, initial soils have started to develop so that they may offer a continuous chronosequence from 0 to 150-yr-old soils. The build-up of organic matter is an important factor of soil formation, and not only autochthonous but also distant sources might contribute to its accumulation in young soils and surfaces of glacier forefields. Only little is known about black carbon in soils that develop in glacier forefields, although charred organic matter could be an important component of organic carbon in Alpine soils. The aim of our study was to examine whether black carbon (BC) is present in the initial soils of a proglacial area, and to estimate its relative contribution to soil organic matter. We investigated soil samples from 35 sites distributed over the whole proglacial area of Morteratsch (Upper Engadine, Switzerland), covering a chronosequence from 0 to 150 yr. BC concentrations were determined in fine earth using the benzene polycarboxylic acid (BPCA) marker method. We found that charred organic matter occurred in the whole area, and that it was a main compound of soil organic matter in the youngest soils, where total Corg concentrations were very low. The absolute concentrations of BC in fine earth were generally low but increased in soils that had been exposed for more than 40 yr. Specific initial microbial communities may profit from this additional C source during the first years of soil evolution and potentially promote soil development in its early stage

Foliar Fertilization of Soybeans

Research reported by Iowa State University during the winter of 1975-76 suggested that a means of increasing soybean yields by use of a specific foliar fertilizer had been demonstrated (1976). Theory proposed to explain the reported responses was as follows: Up to the seed filling period in soybean growth, soybean roots and activity of nitrogen-fixing bacteria contained in root nodules are capable of supplying the necessary nutrients to meet the plants demands. However, as seed filling begins root growth stops and nodule activity declines. This results in nutrients being redistributed from leaves to seeds and a reduction in rate of photosynthesis. Consequently, studies were conducted to evaluate methods of foliar fertilization in an attempt to maintain photosynthetic rate and nutrient supply during seed filling, the objective being to increase yields

The Influence of Soil Temperature on Soybean Seed Emergence

The best way to obtain adequate soybean stands is to plant high quality seed in an optimum soil environment. But this year many farmers may not be able to obtain enough high quality soybean seed and some acreage may be planted with seed of lower than normal quality. Thus it will be even more important to have an optimum soil environment

Iron deficiency up-regulates iron absorption from ferrous sulphate but not ferric pyrophosphate and consequently food fortification with ferrous sulphate has relatively greater efficacy in iron-deficient individuals

Fe absorption from water-soluble forms of Fe is inversely proportional to Fe status in humans. Whether this is true for poorly soluble Fe compounds is uncertain. Our objectives were therefore (1) to compare the up-regulation of Fe absorption at low Fe status from ferrous sulphate (FS) and ferric pyrophosphate (FPP) and (2) to compare the efficacy of FS with FPP in a fortification trial to increase body Fe stores in Fe-deficient children v. Fe-sufficient children. Using stable isotopes in test meals in young women (n 49) selected for low and high Fe status, we compared the absorption of FPP with FS. We analysed data from previous efficacy trials in children (n 258) to determine whether Fe status at baseline predicted response to FS v. FPP as salt fortificants. Plasma ferritin was a strong negative predictor of Fe bioavailability from FS (P<0·0001) but not from FPP. In the efficacy trials, body Fe at baseline was a negative predictor of the change in body Fe for both FPP and FS, but the effect was significantly greater with FS (P<0·01). Because Fe deficiency up-regulates Fe absorption from FS but not from FPP, food fortification with FS may have relatively greater impact in Fe-deficient children. Thus, more soluble Fe compounds not only demonstrate better overall absorption and can be used at lower fortification levels, but they also have the added advantage that, because their absorption is up-regulated in Fe deficiency, they innately ‘target' Fe-deficient individuals in a populatio

An Early-Planted, Early Maturing Soybean Cropping System: Yield and Harvest Losses

Most soybean varieties used In Kentucky, whether grown full season or double-cropped behind wheat or barley, are from Maturity Groups (MG) IV or V. Some MG III varieties are also grown; however, virtually no MG 1/ or earner varieties are planted. Agronomists and soybean producers in Kentucky· have generally felt that MG IV and V varieties produce the highest yield. Since the driest months in Kentucky are August, September,and October, MG IV and V varieties frequently encounter moisture stress during the important seed fill stage. The use of earlier maturing varieties was initially proposed as a means of getting a major portion of seed fill to occur before the driest part of the growing season, thus getting higher yields in dry years