NF95-243 Soil Compaction Tips

This NebFact offers 50 tips to prevent soil compaction

NF95-243 Soil Compaction Tips

This NebFact offers 50 tips to prevent soil compaction

Determining the Student Services which Align with Undergraduate Student Expectations A Study of Student Perceptions and University Service Delivery

Extant research demonstrates that student support services are a vital link in the success of students and a major component in student per- sistence to graduation. This paper reports the results of an empirical study examining enrolled undergraduate student attitudes and expec- tations regarding student services at two-similarly-sized universities in a major metropolitan area in the southwestern United States. Using survey data and a sample of several hundred students at each school, it analyzes their knowledge of and attitudes about student services, such as health services, career counseling, computer laboratories, student organizations and clubs, and sporting events. This study compares student perspectives at private versus public universities and further analyzes possible differing student needs and expectations that may occur among various student demographic groups. The results of this study are important for several reasons. First, it compares student and administrator perspectives on university services to see if they are similar or if there are possible differences in their views. Since the data informs universities about student attitudes and expectations, the data can help universities to do a better job in aligning services to student perceived needs. Second, the study tests the view that students at private universities may have higher expectations of services versus public university students, and then we explore possible differences between various student demographic groups, clarifying how the needs and expectations may differ among these demographic groups. Finally, the results can help universities to determine the services that are viewed as most critical and invest in those services which are more successfully attracting and retaining those students

Tillage Systems for Row Crop Production

Selecting the tillage system best suited to a particular farming situation is an important management decision. Formerly, the traditional system was a moldboard plow operation followed by several secondary tillage operations before planting. This system can be appropriate for poorly drained soils having little or no slope and low erosion potential. However, plowing has several disadvantages . The potential for soil erosion is high on sloping lands, and labor and fuel requirements can be substantially higher than with other tillage and planting systems. Today, conservation tillage systems are used to reduce preplant tillage operations, thus reducing soil erosion and moisture loss while saving labor and fuel. The label conservation tillage represents a broad spectrum of farming methods, and is most often defined by the amount of residue cover remaining on the soil surface. The minimum amount recommended is 20 to 30 percent after planting. Research in Nebraska and other Midwestern states has shown that leaving at least this much residue will reduce erosion by more than 50 percent of that occurring from a cleanly tilled field. To achieve effective erosion control, this minimum residue cover should be maintained during the critical soil erosion period between spring seedbed preparation and crop canopy establishment. Conservation tillage does not necessarily require new equipment. Most conventional farm implements can be used. For corn, grain sorghum, or wheat residue, one or two passes with a field cultivator, disk, or chisel plow will usually leave more than the 20 percent minimum cover. Additional operations reduce the amount of residue, and thus reduce erosion control. Other tillage and planting systems such as ridge-plant (till-plant) and no till leave even more residue, and thus offer greater erosion control. However, no-till planting is the only method that consistently leaves the minimum surface cover in the more fragile and less abundant soybean residue. No single tillage system is best for all situations at all times. Selecting the best tillage system for a particular soil and cropping situation requires matching the operation to the crop sequence, topography, and soil type. Rotating systems to coincide with crop rotations often provides an excellent combination. For example, a no till system could follow soybeans while a chisel or disk system might follow corn. This tillage rotation provides the best erosion control following soybeans, and provides an opportunity for some tillage in the less fragile and more abundant corn residue

Tillage Systems for Row Crop Production

Selecting the tillage system best suited to a particular farming situation is an important management decision. Formerly, the traditional system was a moldboard plow operation followed by several secondary tillage operations before planting. This system can be appropriate for poorly drained soils having little or no slope and low erosion potential. However, plowing has several disadvantages . The potential for soil erosion is high on sloping lands, and labor and fuel requirements can be substantially higher than with other tillage and planting systems. Today, conservation tillage systems are used to reduce preplant tillage operations, thus reducing soil erosion and moisture loss while saving labor and fuel. The label conservation tillage represents a broad spectrum of farming methods, and is most often defined by the amount of residue cover remaining on the soil surface. The minimum amount recommended is 20 to 30 percent after planting. Research in Nebraska and other Midwestern states has shown that leaving at least this much residue will reduce erosion by more than 50 percent of that occurring from a cleanly tilled field. To achieve effective erosion control, this minimum residue cover should be maintained during the critical soil erosion period between spring seedbed preparation and crop canopy establishment. Conservation tillage does not necessarily require new equipment. Most conventional farm implements can be used. For corn, grain sorghum, or wheat residue, one or two passes with a field cultivator, disk, or chisel plow will usually leave more than the 20 percent minimum cover. Additional operations reduce the amount of residue, and thus reduce erosion control. Other tillage and planting systems such as ridge-plant (till-plant) and no till leave even more residue, and thus offer greater erosion control. However, no-till planting is the only method that consistently leaves the minimum surface cover in the more fragile and less abundant soybean residue. No single tillage system is best for all situations at all times. Selecting the best tillage system for a particular soil and cropping situation requires matching the operation to the crop sequence, topography, and soil type. Rotating systems to coincide with crop rotations often provides an excellent combination. For example, a no till system could follow soybeans while a chisel or disk system might follow corn. This tillage rotation provides the best erosion control following soybeans, and provides an opportunity for some tillage in the less fragile and more abundant corn residue

G91-1046 Conservation Tillage and Planting Systems

Tillage system descriptions and comparisons are included here. Moldboard plowing, followed by such secondary tillage operations as disking and harrowing, was once the most common, or traditional, tillage system before planting. Soil erosion potential from rainfall on sloping lands was great and requirements for labor and fuel were high compared to other tillage and planting systems. One of the most commonly used tillage systems in Nebraska today is two diskings followed by field cultivation. Unfortunately, the potential for soil erosion may be great because the number of tillage operations involved may not leave adequate residue cover for erosion control. Today conservation tillage systems reduce soil erosion and moisture losses while saving labor and fuel. Conservation tillage can represent a broad spectrum of farming methods, provided at least 30 percent of the soil surface remains covered with crop residue following planting. Research in Nebraska and other midwestern states has shown that leaving at least 30 percent residue cover reduces erosion from water by more than 50 percent, as compared to a cleanly tilled field

G91-1046 Conservation Tillage and Planting Systems

Tillage system descriptions and comparisons are included here. Moldboard plowing, followed by such secondary tillage operations as disking and harrowing, was once the most common, or traditional, tillage system before planting. Soil erosion potential from rainfall on sloping lands was great and requirements for labor and fuel were high compared to other tillage and planting systems. One of the most commonly used tillage systems in Nebraska today is two diskings followed by field cultivation. Unfortunately, the potential for soil erosion may be great because the number of tillage operations involved may not leave adequate residue cover for erosion control. Today conservation tillage systems reduce soil erosion and moisture losses while saving labor and fuel. Conservation tillage can represent a broad spectrum of farming methods, provided at least 30 percent of the soil surface remains covered with crop residue following planting. Research in Nebraska and other midwestern states has shown that leaving at least 30 percent residue cover reduces erosion from water by more than 50 percent, as compared to a cleanly tilled field

The role of reward and reward uncertainty in episodic memory

Declarative memory has been found to be sensitive to reward-related changes in the environment. The reward signal can be broken down into information regarding the expected value of the reward, reward uncertainty and the prediction error. Research has established that high as opposed to low reward values enhance declarative memory. Research in neuroscience suggests that high uncertainty activates the reward system, which could lead to enhanced learning and memory. Here we present the results of four behavioural experiments that examined the role of reward uncertainty in memory, independently from any other theoretically motivated reward-related effects. Participants completed motivated word learn- ing tasks in which we varied the level of reward uncertainty and magnitude. Rewards were dependent upon memory performance in a delayed recognition test. Overall the results suggest that reward uncer- tainty does not affect episodic memory. Instead, only reward outcome appears to play a major role in modulating episodic memory

Assessing the potential of autonomous submarine gliders for ecosystem monitoring across multiple trophic levels (plankton to cetaceans) and pollutants in shallow shelf seas

A combination of scientific, economic, technological and policy drivers is behind a recent upsurge in the use of marine autonomous systems (and accompanying miniaturized sensors) for environmental mapping and monitoring. Increased spatial–temporal resolution and coverage of data, at reduced cost, is particularly vital for effective spatial management of highly dynamic and heterogeneous shelf environments. This proof-of-concept study involves integration of a novel combination of sensors onto buoyancy-driven submarine gliders, in order to assess their suitability for ecosystem monitoring in shelf waters at a variety of trophic levels. Two shallow-water Slocum gliders were equipped with CTD and fluorometer to measure physical properties and chlorophyll, respectively. One glider was also equipped with a single-frequency echosounder to collect information on zooplankton and fish distribution. The other glider carried a Passive Acoustic Monitoring system to detect and record cetacean vocalizations, and a passive sampler to detect chemical contaminants in the water column. The two gliders were deployed together off southwest UK in autumn 2013, and targeted a known tidal-mixing front west of the Isles of Scilly. The gliders’ mission took about 40 days, with each glider travelling distances of >1000 km and undertaking >2500 dives to depths of up to 100 m. Controlling glider flight and alignment of the two glider trajectories proved to be particularly challenging due to strong tidal flows. However, the gliders continued to collect data in poor weather when an accompanying research vessel was unable to operate. In addition, all glider sensors generated useful data, with particularly interesting initial results relating to subsurface chlorophyll maxima and numerous fish/cetacean detections within the water column. The broader implications of this study for marine ecosystem monitoring with submarine gliders are discussed