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M.B. Kirkham and B.E. Clothier

In 1992, all governmental resourcing and investment in New Zealand, including that for science, underwent dramatic reform. The global philosophy driving the reform was new public management—a method by which nations could be run more economically by emulating the commercial world. Central to the reform was separation of policy, purchasing (investment), and providers (in the case of research scientists). The reform led to a large reduction in the number of governmental scientists. For example, in 1 year alone, 2001–2002, the Horticultural and Food Research Institute, one of the nine governmental branches of science, lost 51 staff members, 10% of its work force. Over a decade later after the establishment of the reform, in July 2003, the New Zealand government's investment agency announced its budget for the next 6 years. The government-funded science sectors considered to do modern research such as computer technology and biotechnology, and halved funding for land-related sciences. The reduced budget dramatically limited New Zealand's capacity for research in soil and land-use science and ended all research positions in this area (38 jobs). Public outcry through newspaper editorials and from leading businessmen, along with effective leadership from the scientific community, led to the reestablishment of funding in the form of a virtual national center called Sustainable Land Use Research Initiative (SLURI). The elimination of funding for soil and land-use science research in New Zealand was an unexpected and potentially disastrous result of new public management. New Zealand's experience has relevance for the United States, because budgets for agricultural research are being severely reduced or converted to competitive funding. The U.S. President's fiscal year 2006 budget proposed to cut formula funding by 50% and to zero it out in fiscal year 2007. The funds would have been put in competitive grants. In New Zealand, the lack of ability to respond to a scientific problem demonstrated that a balance must be maintained in funding decisions so that scientific capability is retained to solve unforeseen future problems.

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Sharon J.B. Knewtson, Edward E. Carey and M.B. Kirkham

A survey was conducted of 81 growers managing 185 high tunnels in Missouri, Kansas, Nebraska, and Iowa to collect information about their high tunnel management practices. The survey was administered from 2005 to 2007 using internet-based and written forms. The average respondent had 4 years of high tunnel experience. The oldest tunnel still in use was 15 years old. Twenty-five percent of respondents grew crops in their high tunnels year-round. Tomato (Solanum lycopersicum), lettuce (Lactuca sativa), spinach (Spinacia oleracea), cucumber (Cucumis sativus), pepper (Capsicum spp.), leafy greens, and flowers were the most common crops. Organic soil amendments were used exclusively by 35% of growers, and in combination with conventional fertilizers by an additional 50% of growers. The summary of management practices is of interest to growers and the industries and university research and extension scientists who serve them. Growers typically reported satisfaction with their high tunnels. Growers with more than one high tunnel had often added tunnels following the success of crop production in an initial tunnel. Labor for crop maintenance was the main limiting factor reported by growers as preventing expanded high tunnel production.

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Sharon J.B. Knewtson, Rhonda Janke, M.B. Kirkham, Kimberly A. Williams and Edward E. Carey

Growers have indicated that changes in soil quality under production in high tunnels is an important problem, but these have not yet been quantified or critically assessed in the central Great Plains of the United States. We conducted surveys of grower perceptions of soil quality in their tunnels (n = 81) and compared selected soil quality indicators (salinity and particulate organic matter carbon) under high tunnels of varying ages with those of adjacent fields at sites in Kansas, Missouri, Nebraska, and Iowa in the United States. Fourteen percent of growers surveyed considered soil quality to be a problem in their high tunnels, and there were significant correlations between grower perceptions of soil quality problems and reported observations of clod formation and surface crusting and to a lesser extent surface mineral deposition. Grower perception of soil quality and grower observation of soil characteristics were not related to high tunnel age. Soil surface salinity was elevated in some high tunnels compared with adjacent fields but was not related to time under the high tunnel. In the soil upper 5 cm, salinity in fields did not exceed 2 dS·m−1 and was less than 2 dS·m−1 under 74% of high tunnels and less than 4 dS·m−1 in 97% of high tunnels. The particulate organic matter carbon fraction was higher in high tunnels than adjacent fields at 73% of locations sampled. Particulate organic matter carbon measured 0.11 to 0.67 g particulate organic matter per g of the total carbon under high tunnels sampled. Particulate organic matter carbon in the soil was also not correlated to age of high tunnel. Soil quality as measured in this study was not negatively impacted by use of high tunnel structures over time.

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Sharon J.B. Knewtson, M.B. Kirkham, Rhonda R. Janke, Leigh W. Murray and Edward E. Carey

The sustainability of soil quality under high tunnels will influence management of high tunnels currently in use and grower decisions regarding design and management of new high tunnels to be constructed. Soil quality was quantified using measures of soil pH, salinity, total carbon, and particulate organic matter (POM) carbon in a silt loam soil that had been in vegetable production under high tunnels at the research station in Olathe, KS, for eight years. Soil under high tunnels was compared with that in adjacent fields in both a conventional and an organic management system. The eight-year presence of high tunnels under the conventional management system resulted in increased soil pH and salinity but did not affect soil carbon. In the organic management system, high tunnels did not affect soil pH, increased soil salinity, and influenced soil carbon (C) pools with an increase in POM carbon. The increases in soil salinity were not enough to be detrimental to crops. These results indicate that soil quality was not adversely affected by eight years under stationary high tunnels managed with conventionally or organically produced vegetable crops.

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Y. Song, J.M. Ham, M.B. Kirkham and G.J. Kluitenberg

Measurements of soil water content near the soil surface often are required for efficient turfgrass water management. Experiments were conducted in a greenhouse to determine if the dual-probe heat-pulse (DPHP) technique can be used to monitor changes in soil volumetric water content (θv) and turfgrass water use. `Kentucky 31' Tall fescue (Festuca arundinacea Schreb.) was planted in 20-cm-diameter containers packed with Haynie sandy loam (coarse-silty, mixed, calcareous, mesic Typic Udifluvents). Water content was measured with the DPHP sensors that were placed horizontally at different depths between 1.5 and 14.4 cm from the surface in the soil column. Water content also was monitored gravimetrically from changes in container mass. Measurements started when the soil surface was covered completely by tall fescue. Hence, changes in θv could be attributed entirely to water being taken up by roots of tall fescue. Daily measurements were taken over multiple 6- or 7-day drying cycles. Each drying cycle was preceded by an irrigation, and free drainage had ceased before measurements were initiated. Soil water content dropped from ≈0.35 to 0.10 m3·m-3 during each drying cycle. Correlation was excellent between θv and changes in water content determined by the DPHP and gravimetric methods. Comparisons with the gravimetric method showed that the DPHP sensors could measure average container θv within 0.03 m3·m-3 and changes in soil water content within 0.01 m3·m-3.