MF2242

Daniel O'Brien et al., Economic comparison of SDI and center pivots for various field sizes, Kansas State University, October 1997

Where did all the irrigators go? Trends in irrigation and demographics in Kansas

Presented at the 2006 Central Plains irrigation conference on February 21-22 in Colby, Kansas.The 2000 United States Census indicated that Kansas had grown by 8.51 percent in population since 1990, compared to the national average growth rate of 13.15 percent. Only nine (9) of 105 counties in Kansas experienced growth equal to or greater than the national average growth rate. From 2000-2004 only 8 counties grew at or above the national average growth rate. In 1990, Kansans were 1.00 percent of the U.S. population, in 2004 only 0.94% of the population. The 2004 population estimates had 56 of 105 counties in Kansas declining in population since 2000. Of the 54 counties overlying the High Plains aquifer, only three (3) counties had equal or greater growth than the national average. In addition the census also indicated a cultural transition as many counties experienced domestic out-migration and foreign immigration. Agricultural Census data document a 5.26 percent decrease in the total market value of agricultural products from 1997 to 2002, while the total number of farms increased 4.58 percent in Kansas during the same period. The number of Irrigated farms decreased by 3.58 percent with total irrigated acres declining by only 1.07 percent to 2.678 million acres over the same five year period. Total acreage in crop production declined 1.59 percent, while the market value of crops sold decreasing 24.9% from $3.22 billion in 1997 to$2.42 billion in 2002. Since 1990, irrigation technology has dramatically changed to more efficient low pressure pivot and SDI (subsurface drip irrigation) systems. With more efficient water use, irrigators have been able to grow significantly more corn and other water intensive crops. Given the 3.5 percent decrease in the number of irrigated farms since 1997, the resulting 1.08 percent decline in irrigated acres indicates increased acreage efficiency by remaining irrigators. This presentation intends to demonstrate spatial and temporal trends in irrigation and demographics for Kansas, with focus on the 54 counties overlying the High Plains Aquifer

MF2587

Danny Rogers, et al, Fuel cost - an irrigation fuel cost evaluator, Kansas State University, August 2006

MIL evaluation of center pivot irrigation systems

Presented at the 2006 Central Plains irrigation conference on February 21-22 in Colby, Kansas.Includes bibliographical references

Do body condition and plumage during fuelling predict northwards departure dates of Great Knots Calidris tenuirostris from north-west Australia?

It is often assumed that strong selection pressures give rise to trade-offs between body condition and time in long-distance migrating birds. Birds that are 'behind schedule' in fuel deposition or moult should delay departure, and this should result in a negative correlation between initial condition and departure date. We tested this hypothesis in the Great Knot Calidris tenuirostris migrating from north-west Australia to eastern Asia en route to Siberia. Great Knot gain mass and moult into breeding plumage before leaving northern Australia in late March and early April, and fly 5400-6000 km to eastern China and Korea. We radiotracked 27 individuals (17 males and ten females) to determine departure dates; 23 migrated and four remained in Australia. We characterized body condition at capture using body mass, predicted pectoral muscle mass (based on ultrasound estimates of the size of the pectoral muscles) and breeding plumage scores. Residual condition indices were uncorrelated, indicating that at the individual level, variation in one fuelling component was not strongly associated with variation in the other components. Birds that did not depart had lower residual body mass and breeding plumage indices than those that did migrate; these four birds may have been subadults. Neither sex, size nor the condition indices explained variation in departure date of migrants. Reasons for this are explored. Departure dates for northward migrating waders indicate that the migration window (span over which birds depart) decreases with proximity to the northern breeding grounds. We suggest that migration schedules become tighter as birds get nearer to the breeding grounds. Thus the lack of a relationship between condition and departure date in Great Knots may reflect the fact that the departure episode under study is the first one in sequence and is still 4-8 weeks before breeding

Irrigation and drainage in the new millennium

Presented at the 2000 USCID international conference, Challenges facing irrigation and drainage in the new millennium on June 20-24 in Fort Collins, Colorado.Irrigation scheduling has been promoted as management tool to minimize irrigation water application, however, few irrigators regularly followed any rigorous scheduling methodology. Kansas State University Research and Extension in conjunction with an irrigation association, Water PACK, began a long-term project to promote ET based irrigation scheduling and other management technology. Area irrigators serve as the focal point of the project and over time have been asked to assume responsibility of scheduling the project fields. A long-term commitment and on-farm activities such as variable water application tests and center pivot uniformity tests seems to have generated confidence and acceptance of ET-based irrigation scheduling

Using livestock wastewater with SDI: a status report after three seasons

Presented at the Central Plains irrigation short course and exposition on February 5-6, 2001 at the Holiday Inn in Kearney, Nebraska.Using subsurface drip irrigation (SDI) with lagoon wastewater has many potential advantages. The challenge is to design and manage the SDI system to prevent emitter clogging. A study was initiated in 1998 to test the performance of five types of driplines (with emitter flow rates of 0.15, 0.24, 0.40, 0.60, and 0.92 gal/hr-emitter) with lagoon wastewater. A disk filter (200 mesh, with openings of 0.003 inches) was used and shock treatments of chlorine and acid were injected periodically. Over the course of three seasons (1998-2000) a total of approximately 52 inches of irrigation water has been applied through the SDI system. The flow rates of the two smallest emitter sizes, 0.15 gal/hr-emitter and 0.24 gal/hr-emitter have decreased approximately 30% during the three seasons, indicating some emitter clogging. The three largest driplines (0.40, 0.60, and 0.92 gal/hr-emitters) have had less than 5% reduction in flow rate. The disk filter and automatic backflush controller have performed adequately with the beef livestock wastewater in all three years. Based on these results, the use of SDI with beef lagoon wastewater shows promise. However, the smaller emitter sizes normally used with groundwater sources in western Kansas may be risky for use with lagoon wastewater and the long-term (> 3 growing seasons) effects are untested

Prenatal Hypoxia–Ischemia Induces Abnormalities in CA3 Microstructure, Potassium Chloride Co-Transporter 2 Expression and Inhibitory Tone

Infants who suffer perinatal brain injury, including those with encephalopathy of prematurity, are prone to chronic neurological deficits, including epilepsy, cognitive impairment, and behavioral problems, such as anxiety, inattention, and poor social interaction. These deficits, especially in combination, pose the greatest hindrance to these children becoming independent adults. Cerebral function depends on adequate development of essential inhibitory neural circuits and the appropriate amount of excitation and inhibition at specific stages of maturation. Early neuronal synaptic responses to γ-amino butyric acid (GABA) are initially excitatory. During the early postnatal period, GABAAR responses switch to inhibitory with the upregulation of potassium-chloride co-transporter KCC2. With extrusion of chloride by KCC2, the Cl− reversal potential shifts and GABA and glycine responses become inhibitory. We hypothesized that prenatal hypoxic–ischemic brain injury chronically impairs the developmental upregulation of KCC2 that is essential for cerebral circuit formation. Following late gestation hypoxia–ischemia (HI), diffusion tensor imaging in juvenile rats shows poor microstructural integrity in the hippocampal CA3 subfield, with reduced fractional anisotropy and elevated radial diffusivity. The loss of microstructure correlates with early reduced KCC2 expression on NeuN-positive pyramidal neurons, and decreased monomeric and oligomeric KCC2 protein expression in the CA3 subfield. Together with decreased inhibitory post-synaptic currents during a critical window of development, we document for the first time that prenatal transient systemic HI in rats impairs hippocampal CA3 inhibitory tone. Failure of timely development of inhibitory tone likely contributes to a lower seizure threshold and impaired cognitive function in children who suffer perinatal brain injury

Rapid population decline in migratory shorebirds relying on Yellow Sea tidal mudflats as stopover sites

Migratory animals are threatened by human-induced global change. However, little is known about how stopover habitat, essential for refuelling during migration, affects the population dynamics of migratory species. Using 20 years of continent-wide citizen science data, we assess population trends of ten shorebird taxa that refuel on Yellow Sea tidal mudflats, a threatened ecosystem that has shrunk by >65% in recent decades. Seven of the taxa declined at rates of up to 8% per year. Taxa with the greatest reliance on the Yellow Sea as a stopover site showed the greatest declines, whereas those that stop primarily in other regions had slowly declining or stable populations. Decline rate was unaffected by shared evolutionary history among taxa and was not predicted by migration distance, breeding range size, non-breeding location, generation time or body size. These results suggest that changes in stopover habitat can severely limit migratory populations