Fall Cover Crop Influence on Spring Potato Production

Use of cover crops is becoming a common practice among vegetable producers. Cover crops provide multiple benefits such as building of organic matter, erosion and weed suppression, nitrogen fixation, and improvement of soil health. Cereal rye is the most widely planted cover crop in Iowa, however, cover crops such as oats, oilseed radish, and clovers are gaining popularity. The goal of this project was to evaluate and study three fall-planted cover crops and their effect on spring-planted potato. The three cover crops studied were Cereal Rye, Oilseed Radish, and Crimson Clover. The control treatment for the study was a no-cover crop plot. The treatments were chosen based on their optimal growing season as well as flexibility to fit in a vegetable crop rotation

Effect of Plastic Mulch on Sweet Potato Yield and Quality

Sweet potato, Ipomoea batatas, is a warmseason vegetable predominantly grown in the southern part of the United States. In recent years, its production region has expanded quite rapidly to various Midwestern and Eastern states

Bok Choy Cultivar Trial for Spring High Tunnel Production

Bok choy, also known as pak choy or pac choi, is a leafy vegetable that belongs to the mustard family. It is commonly referred to as ‘chinese cabbage.’ Bok choy is a non-heading form of Chinese cabbage and has thick white or pale green leafstalks (petioles). Leaves are dark green in color but there are cultivars with red leaves as well. Chinese cabbage is a coolseason annual vegetable and is grown by a number of vegetable growers in the state. The crop grows best with short days and moderate to cool temperatures (60 to 70° F mean temperature). Higher temperatures lead to soft and bitter heads and often lead to seed stalk formation (bolting)

Architecture of soil microaggregates: Advanced methodologies to explore properties and functions

The functions of soils are intimately linked to their three-dimensional pore space and the associated biogeochemical interfaces, mirrored in the complex structure that developed during pedogenesis. Under stress overload, soil disintegrates into smaller compound structures, conventionally named aggregates. Microaggregates (<250 µm) are recognized as the most stable soil structural units. They are built of mineral, organic, and biotic materials, provide habitats for a vast diversity of microorganisms, and are closely involved in the cycling of matter and energy. However, exploring the architecture of soil microaggregates and their linkage to soil functions remains a challenging but demanding scientific endeavor. With the advent of complementary spectromicroscopic and tomographic techniques, we can now assess and visualize the size, composition, and porosity of microaggregates and the spatial arrangement of their interior building units. Their combinations with advanced experimental pedology, multi-isotope labeling experiments, and computational approaches pave the way to investigate microaggregate turnover and stability, explore their role in element cycling, and unravel the intricate linkage between structure and function. However, spectromicroscopic techniques operate at different scales and resolutions, and have specific requirements for sample preparation and microaggregate isolation; hence, special attention must be paid to both the separation of microaggregates in a reproducible manner and the synopsis of the geography of information that originates from the diverse complementary instrumental techniques. The latter calls for further development of strategies for synlocation and synscaling beyond the present state of correlative analysis. Here, we present examples of recent scientific progress and review both options and challenges of the joint application of cutting-edge techniques to achieve a sophisticated picture of the properties and functions of soil microaggregates

Analysis of the annual cycle of the precipitable water vapour over Spain from 10-year homogenized series of GPS data

This study reports a characterization of the precipitable water vapor (PWV) at ten sites over Spain from 10 years of hourly data from ground-based GPS receivers. The GPS-PWV data series turned out to be inhomogeneous due to the change in the calibration procedure of the variations of the antenna phase center in November 2006. Radiosonde data were used to homogenize the GPS data series and to assess the quality of the GPS measurements. The annual average value of PWV ranges from 14.5 to 20.0 mm, with an average of 18.3 ± 1.9 for the entire Spain. The highest values are registered at the sites on the coast, especially on the Mediterranean coast, and the lowest ones at inland sites. The PWV presents a clear annual cycle, with a minimum in winter and maximum at the end of the summer. However, the southwestern sites present a relative minimum in July. This minimum seems to be related with the presence of drier air masses in the atmospheric layers between 1 and 4 km altitude. The amplitude of the cycle ranged from 8.9 to 18.7 mm. The largest amplitudes are found at the Mediterranean coastal sites (approx. 15-19 mm) and the lowest ones at inland sites (approx. 9-10 mm). A harmonic analysis of the annual cycle showed that the 12-month period harmonic explains, on average, over 96 % of the variance. The average annual regime of PWV followed the cycle of the temperature, except for the relative minimum of PWV in July at the southwestern sites

Inclusive Search for Anomalous Production of High-pT Like-Sign Lepton Pairs in Proton-Antiproton Collisions at sqrt{s}=1.8 TeV

We report on a search for anomalous production of events with at least two charged, isolated, like-sign leptons with pT > 11 GeV/c using a 107 pb^-1 sample of 1.8 TeV ppbar collisions collected by the CDF detector. We define a signal region containing low background from Standard Model processes. To avoid bias, we fix the final cuts before examining the event yield in the signal region using control regions to test the Monte Carlo predictions. We observe no events in the signal region, consistent with an expectation of 0.63^(+0.84)_(-0.07) events. We present 95% confidence level limits on new physics processes in both a signature-based context as well as within a representative minimal supergravity (tanbeta = 3) model.Comment: 15 pages, 4 figures. Minor textual changes, cosmetic improvements to figures and updated and expanded reference

Search for Kaluza-Klein Graviton Emission in ppˉp\bar{p} Collisions at s=1.8\sqrt{s}=1.8 TeV using the Missing Energy Signature

We report on a search for direct Kaluza-Klein graviton production in a data sample of 84 ${pb}^{-1}$ of \ppb collisions at $\sqrt{s}$ = 1.8 TeV, recorded by the Collider Detector at Fermilab. We investigate the final state of large missing transverse energy and one or two high energy jets. We compare the data with the predictions from a $3+1+n$-dimensional Kaluza-Klein scenario in which gravity becomes strong at the TeV scale. At 95% confidence level (C.L.) for $n$=2, 4, and 6 we exclude an effective Planck scale below 1.0, 0.77, and 0.71 TeV, respectively.Comment: Submitted to PRL, 7 pages 4 figures/Revision includes 5 figure

Measurement of the average time-integrated mixing probability of b-flavored hadrons produced at the Tevatron

We have measured the number of like-sign (LS) and opposite-sign (OS) lepton pairs arising from double semileptonic decays of $b$ and $\bar{b}$-hadrons, pair-produced at the Fermilab Tevatron collider. The data samples were collected with the Collider Detector at Fermilab (CDF) during the 1992-1995 collider run by triggering on the existence of $\mu \mu$ and $e \mu$ candidates in an event. The observed ratio of LS to OS dileptons leads to a measurement of the average time-integrated mixing probability of all produced $b$-flavored hadrons which decay weakly, $\bar{\chi} = 0.152 \pm 0.007$ (stat.) $\pm 0.011$ (syst.), that is significantly larger than the world average $\bar{\chi} = 0.118 \pm 0.005$.Comment: 47 pages, 10 figures, 15 tables Submitted to Phys. Rev.