Maize in Nepal: Production Systems, Constraints, and Priorities for Research

Crop Production/Industries, Research and Development/Tech Change/Emerging Technologies,

Subsurface drainage effects on soil penetration resistance and water table depth on a clay soil in the Red River of the North Valley, USA

  Since 1993, the Red River of the North Valley in North Dakota (ND) and Minnesota (MN), in the USA has experienced increased annual rainfall which has caused localized seasonal soil waterlogging and inhibited crop yield potential in the unique, high water table clay soils of the region.  Subsurface (tile) drainage has been increasingly considered by farmers to help reduce excess water in the crop root zone.  Producers desire to manage the water table for optimizing yield and trafficability of the field.  The objective of this research was to evaluate differences in soil penetration resistance and water table depth between subsurface (drained) and non-subsurface drained treatments (undrained), using water control structures, in fallow, and cropped soybean (Glycine max L. Merr.) and wheat (Triticum aestivum L. emend. Thell.) cultivars on a Fargo-Ryan silty clay soil near Fargo, ND, USA in 2009 and 2010.  The experimental design was a randomized complete block in a split-plot arrangement with four replicates.  The whole plot treatments were drained and undrained (control structures opened and closed, respectively).  Soil penetrometer readings and water table depth were measured weekly.  Yields of each crop were not different comparing drained and undrained treatments in 2009 and 2010.  The depth averaged drained penetration resistance was 1,211 kPa compared with 1,097 kPa for undrained treatment, averaged across 2009 and 2010.  The depth-averaged drained penetration resistance values for fallow, soybean, and wheat were 1,077, 1,137, and 1,420 kPa, respectively.  The undrained values for fallow, soybean and wheat were 1,001, 1,021, and 1,267 kPa, respectively, all significantly lower than the drained treatments, indicating that the drained soil is capable of a higher load carrying capacity compared to the undrained soil.  The average depth to the water table was greater on drained soil compared to the undrained soil both early and late in the growing season.  Forty two percent of the variation in the penetration resistance can be explained by the level of the water table below the surface.  Water control structures can be used to manage the water table level and soil penetrations resistance.  The ability for land managers to enter drained fields with farm equipment earlier will likely extend the length of the growing season and potentially increase crop yields in this region.   Keywords: subsurface water management, penetration resistance, controlled drainage, water table depth, trafficability, US

Gamma-ray and radio properties of six pulsars detected by the fermi large area telescope

We report the detection of pulsed γ-rays for PSRs J0631+1036, J0659+1414, J0742-2822, J1420-6048, J1509-5850, and J1718-3825 using the Large Area Telescope on board the Fermi Gamma-ray Space Telescope (formerly known as GLAST). Although these six pulsars are diverse in terms of their spin parameters, they share an important feature: their γ-ray light curves are (at least given the current count statistics) single peaked. For two pulsars, there are hints for a double-peaked structure in the light curves. The shapes of the observed light curves of this group of pulsars are discussed in the light of models for which the emission originates from high up in the magnetosphere. The observed phases of the γ-ray light curves are, in general, consistent with those predicted by high-altitude models, although we speculate that the γ-ray emission of PSR J0659+1414, possibly featuring the softest spectrum of all Fermi pulsars coupled with a very low efficiency, arises from relatively low down in the magnetosphere. High-quality radio polarization data are available showing that all but one have a high degree of linear polarization. This allows us to place some constraints on the viewing geometry and aids the comparison of the γ-ray light curves with high-energy beam models

The Role of Binary Pulsars in Testing Gravity Theories

Radio pulsars are neutron stars (NSs) which emit collimated beams of radio waves, observed as pulses, once per rotation of the NS. A subgroup of the radio pulsars behave as highly stable clocks and monitoring the times of arrival of their radio pulses can provide an accurate determination of their positional, rotational, and orbital parameters, as well as indications on the properties of their space-time environment. In this chapter, we focus on the so-called relativistic binary pulsars, recycled NSs orbiting around a compact companion star. Some of them can be used as unique tools to test general relativity and other gravitational theories. The methodology for exploiting these sources as laboratories for gravity theories is first explained and then some of the most relevant recent results are reviewed. <P /

Comparative genome structure, secondary metabolite, and effector coding capacity across Cochliobolus pathogens.

The genomes of five Cochliobolus heterostrophus strains, two Cochliobolus sativus strains, three additional Cochliobolus species (Cochliobolus victoriae, Cochliobolus carbonum, Cochliobolus miyabeanus), and closely related Setosphaeria turcica were sequenced at the Joint Genome Institute (JGI). The datasets were used to identify SNPs between strains and species, unique genomic regions, core secondary metabolism genes, and small secreted protein (SSP) candidate effector encoding genes with a view towards pinpointing structural elements and gene content associated with specificity of these closely related fungi to different cereal hosts. Whole-genome alignment shows that three to five percent of each genome differs between strains of the same species, while a quarter of each genome differs between species. On average, SNP counts among field isolates of the same C. heterostrophus species are more than 25× higher than those between inbred lines and 50× lower than SNPs between Cochliobolus species. The suites of nonribosomal peptide synthetase (NRPS), polyketide synthase (PKS), and SSP-encoding genes are astoundingly diverse among species but remarkably conserved among isolates of the same species, whether inbred or field strains, except for defining examples that map to unique genomic regions. Functional analysis of several strain-unique PKSs and NRPSs reveal a strong correlation with a role in virulence

Basics of Corn Production in North Dakota

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North Dakota barley, oat, rye and flax variety trial results for 2010 and selection guide

Barley, oat and rye varieties currently grown in North Dakota are described in the following table

North Dakota durum wheat variety trial results for 2006 and selection guide

Durum varieties are tested each year at multiple sites throughout North Dakota. The relative performance of these varieties is presented in table form. Variety performance data are used to provide recommendations to producers. Some varieties may not be included in the tables due to insufficient testing or lack of seed availability, or they offer no yield or disease advantage over similar varieties

North Dakota barley, oat, rye and flax variety trial results for 2005 and selection guide

Some varieties may not be included in the tables because of insufficient testing, lack of seed availability or they offer no yield or disease advantage over similar varieties. Additional data from county sites are available at www.ag.ndsu.nodak.edu/aginfo/variety/index.htm and from each Research Extension Center