Conservation Tillage

Contents: Wind Erosion Emergency Tillage Know Your Soil: Your Soil is a Factory. Factory or Soil, Both Need Management. Plant Nutrient Storehouse. Erosion Cuts New Return: Why Erosion Occurs-How to Prevent It. Erosion Control Methods and Structures:Strip Cropping. Barrier Strips. Contouring. Terraces. Stubble Mulching. How Much Residue. Cropping Practices and Rotations: Crops and Cropping Systems. Tillage--Good and Bad. Rotation System. Machines, Costs and Returns: A Choice of Implements. Planning Your Program. Tillage Considerations. Seeding Equipment. Not Enough Residue? Too Much Residue? Examples of Programs

The Effect of Bicarbonate in Irrigation Waters on the Exchangeable Sodium Status of the Soil

Farmers and ranchers are becoming more interested each year in supplemental irrigation, particularly where water sources such as permanent streams, rivers and underground aquifers are available. Many of these waters are of doubtful quality and if used for irrigation along with improper management could inducement unfavorable soil conditions, both chemical and physical. Western United States has numerous examples of irrigation projects that have failed because if the use of waters of inferior quality. Several of the surface flooding waters in western South Dakota are abnormally high in total soluble salts and contain high concentrations of sodium and bicarbonate. The Mormon River Project was abandoned by the Bureau of Reclamation because of the high salt and high sodium content of the waters of this river, and development of the Grand River Project is being held in abeyance pending further investigations which are in progress at the present time. A development farm near the Shadehill reservoir on the Grand River has been established to study on a field basis the effects such water has in the soils of this locality. The nature of the Grand River water is such that a moderately high sodium ion content is combined with a bicarbonate ion content approximately equivalent to the alkaline earths. The principal objective of the study reported here within is to determine to what extent the ration of the concentration of bicarbonate ion to the sum of calcium plus magnesium ions affects the exchangeable sodium and soluble salt status of the soil. When irrigation water becomes the soil solution it suffers a shrinkage in volume, because of transpiration and evaporation, resulting frequently in precipitation of the least soluble constituents, which in this case are calcium and magnesium carbonates. The soluble sodium percentage of the soil solution then increases, favoring adsorption of sodium in the cation exchange of the soil. Adsorption of sodium by the cation exchange complex beyond the point of 12 to 15 percent of the cation exchange capacity results almost without exception in deleterious physical and chemical effects, These effects are those characteristically associated with true alkali solid, for example, extreme swelling and shrinkage, high plasticity, poor aeration poor tilth, high pH and dispersion of organic and inorganic collcide

Fertilizing Pasture and Hayland

This publication provides guidance on fertilizer rates at seeding time and fertilizing established stands for legumes, grasses, and grass-legume mixtures. Fertilizing irrigated forage is also discussed

Reduce Wind Erosion : West-Central South Dakota

This publication provides tables, maps, and guidance for determining the area on farms in west-central South Dakota that can be protected from wind erosion during the spring of the average year. It includes information on the causes of erosion and control measures to reduce soil loss

Reduce Wind Erosion : Eastern South Dakota

This publication provides tables, maps, and guidance for determining the area on farms in eastern South Dakota that can be protected from wind erosion during the spring of the average year. It includes information on the causes of erosion and control measures to reduce soil loss

Reduce Wind Erosion : Western South Dakota

This publication provides tables, maps, and guidance for determining the area on farms in western South Dakota that can be protected from wind erosion during the spring of the average year. It includes information on the causes of erosion and control measures to reduce soil loss

Fertilizing Pasture and Hayland

Guide to fertilizing pasture and hayland discusses fertilization for forage production, established grass-legume mixtures, new seedings, and seed production

Clostridial Neurotoxins and Substrate Proteolysis in Intact Neurons BOTULINUM NEUROTOXIN C ACTS ON SYNAPTOSOMAL-ASSOCIATED PROTEIN OF 25 kDa

Clostridial neurotoxins are zinc endopeptidases that block neurotransmission and have been shown to cleave, in vitro, specific proteins involved in synaptic vesicle docking and/or fusion. We have used immunohistochemistry and immunoblotting to demonstrate alterations in toxin substrates in intact neurons under conditions of toxin-induced blockade of neurotransmitter release. Vesicle-associated membrane protein, which co-localizes with synaptophysin, is not detectable in tetanus toxin-blocked cultures. Syntaxin, also concentrated in synaptic sites, is cleaved by botulinum neurotoxin C. Similarly, the carboxyl terminus of the synaptosomal-associated protein of 25 kDa (SNAP-25) is not detectable in botulinum neurotoxin A-treated cultures. Unexpectedly, tetanus toxin exposure causes an increase in SNAP-25 immunofluorescence, reflecting increased accessibility of antibodies to antigenic sites rather than increased expression of the protein. Furthermore, botulinum neurotoxin C causes a marked loss of the carboxyl terminus of SNAP-25 when the toxin is added to living cultures, whereas it has no action on SNAP-25 in in vitro preparations. This study is the first to demonstrate in functioning neurons that the physiologic response to these toxins is correlated with the proteolysis of their respective substrates. Furthermore, the data demonstrate that botulinum neurotoxin C, in addition to cleaving syntaxin, exerts a secondary effect on SNAP-25

Use of the piggyBac transposon to create HIV-1 gag transgenic insect cell lines for continuous VLP production

Background Insect baculovirus-produced Human immunodeficiency virus type 1 (HIV-1) Gag virus-like-particles (VLPs) stimulate good humoral and cell-mediated immune responses in animals and are thought to be suitable as a vaccine candidate. Drawbacks to this production system include contamination of VLP preparations with baculovirus and the necessity for routine maintenance of infectious baculovirus stock. We used piggyBac transposition as a novel method to create transgenic insect cell lines for continuous VLP production as an alternative to the baculovirus system. Results Transgenic cell lines maintained stable gag transgene integration and expression up to 100 cell passages, and although the level of VLPs produced was low compared to baculovirus-produced VLPs, they appeared similar in size and morphology to baculovirus-expressed VLPs. In a murine immunogenicity study, whereas baculovirus-produced VLPs elicited good CD4 immune responses in mice when used to boost a prime with a DNA vaccine, no boost response was elicited by transgenically produced VLPs. Conclusion Transgenic insect cells are stable and can produce HIV Pr55 Gag VLPs for over 100 passages: this novel result may simplify strategies aimed at making protein subunit vaccines for HIV. Immunogenicity of the Gag VLPs in mice was less than that of baculovirus-produced VLPs, which may be due to lack of baculovirus glycoprotein incorporation in the transgenic cell VLPs. Improved yield and immunogenicity of transgenic cell-produced VLPs may be achieved with the addition of further genetic elements into the piggyBac integron