First Quarter 2001 Table of Contents
Features
- Soil of the Intensive Agriculture Biome of Biosphere 2
H. Allen Torbert and Hyrum B. Johnson
Research
- Animal Powered Tillage Translocated Soil Affects Nutrient Dynamics and Soil Properties at Claveria, Philippines
B.B. Thapa, D.K. Cassel, and D.P. Garrity
- Dairy Diet Effects on Phosphorous Cycles of Cropland
J.M. Powell, Z. Wu, and L.D. Satter
- Pasture Management Influences on Soil Properties in the Northern Great Plains
B.J. Wienhold, J.R. Hendrickson, and J.F. Karn
- Water-Quality Effects of Infiltration Rate and Manure Application Rate for Soils Receiving Swine Manure
D.H. Pote, B.A. Reed, T.C. Daniel, D.J. Nichols, P.A. Moore, Jr., D.R. Edwards, and S. Formica
- Influence of Thermal Gradients on the Rates of Heating and Cooling of Streams
L.L. Larson and P.A. Larson
- Land Management at the Major Watershed---Agroecoregion Intersection
L.K. Hatch, A. Mallawatantri, D. Wheeler, A. Gleason, D. Mulla, J. Perry, K.W. Easter, R. Smith, L. Gerlach, and P. Brezonik
- Comparison of Profit Maximization and Multiple Criteria Models for Selecting Farming Systems
T. Prato and S. Hajkowicz
- Winter Wheat and Grain Sorghum Production as Influenced by Depth of Soil Water, Tillage and Cropping System
C.A. Thompson
- Coupling Use-Dependent and Use-Invariant Data for Soil Quality Evaluation in the United States
R.B. Grossman, D.S. Harms, C.A. Seybold, and J.E. Herrick
- Organizational Factors Affecting the Strength of Missouri's Soil and Water Conservation Districts
A.H. Raedeke, J.S. Rikoon, and C. Rich
Departments
Animal Powered Tillage Translocated Soil Affects Nutrient Dynamics and Soil Properties at Claveria, Philippines
(Full text appears in the Journal of Soil and Water Conservation, Vol.56, No.1)
B.B. Thapa, D.K. Cassel, and D.P. Garrity
ABSTRACT: Intensive tillage in a humid tropical setting on uplands in Claveria, Philippines moves soil downslope, often creating unfavorable soil conditions for crop production. This field study, conducted on Oxisols with slope gradients ranging from 16–22%, evaluated nutrient dynamics for four ox-powered contour tillage systems: 1.) contour moldboard plowing (CMP); 2.) contour ridge tillage (CRT); 3.) contour natural grass barrier strips plus contour moldboard plowing (GCMP); and 4.) contour natural grass barrier strips plus contour ridge tillage (GCRT). The four management systems (treatments) were replicated three times on two sites. Eight corn (Zea mays L) crops were grown from 1992 to 1996. Corn residues, vegetative materials, and inorganic fertilizers (80 kg N, 30 kg P, and 30 kg K ha-1) were applied uniformly to all systems. Lime at 3 Mg ha-1 was applied in 1992. Soil sampling was conducted within plots initially, and in 1996, was systematic at equally divided compartments along transects. Overall, from 1992 to 1996, the concentration of total C slightly increased, total N slightly decreased, and extractable Ca, K, P, Cu, and Zn increased significantly in all systems. During the four year period, generally, the concentration gradients of extractable P, K, and Ca within treatments became steeper, with the higher concentrations occurring at the lower elevation of the CRT and CMP plots and at the lower elevation of individual terraces of GCMP and GCRT plots. In contrast, concentration gradients for Cu and Zn increased linearly from the lower to higher elevation. Soil pH immediately downslope from the grass strips was significantly lower compared to pH in the grass strips. The changes in pH and chemical concentration gradients across the plots and terraces are attributed primarily to tillage translocated soil downslope due to moldboard plowing. Installation of contour grass barrier strips in conjunction with ridge tillage reduced the rate of soil translocation and, thus, the rate of chemical gradient change.
Keywords: Concentration gradients, divided compartments, intensive tillage, translocated soil
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Dairy Diet Effects on Phosphorus Cycles of Cropland
(Full text appears in the Journal of Soil and Water Conservation, Vol.56, No.1)
J.M. Powell, Z. Wu, and L.D. Satter
ABSTRACT: The long term importation of feed and fertilizer has resulted in soil nutrient accumulation and subsequent loss from many dairy farms. This study examines how excessive supplementation of dairy cow diets with inorganic P affects the land required for recycling manure P through crops and the ability of dairy farms to recycle manure P in view of new federal guidelines that limit land application of manure based on crop P requirements. Approximately 0.71 ha of cropland is required to recycle manure P excreted by a lactating cow fed a P adequate diet. Addition of supplemental P to raise dietary P from 3.8 g kg-1 of diet dry matter, a level adequate for lactating cows, to 4.8 g kg-1, typical of diets currently fed in North America, increases the area of cropland needed for recycling manure by 39%. For a representative Wisconsin dairy farm having 78.3 ha of tillable land, 9.5 ha of which already has excessive P, the annual addition of 8.1 kg P per cow to increase dietary P from 3.8 to 4.8 g kg-1 for a 90 cow herd would create excessive soil test P levels in all fields within 11 years. More strategies for integrating feed, manure, fertilizer, and land management are needed to decrease environmental risks while maintaining farm profits.
Keywords: Dairy diet, manure, P cycling, phosphorus, P supplementation, soil P
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Pasture Management Influences on Soil Properties in the Northern Great Plains
(Full text appears in the Journal of Soil and Water Conservation, Vol.56, No.1)
B.J. Wienhold, J.R. Hendrickson, and J.F. Karn
ABSTRACT: The effect of management practices associated with livestock grazing on soil properties are largely unknown. Several physical, chemical, and biological soil properties were compared for soil from a native vegetation exclosure, a moderately grazed native vegetation pasture stocked at 2.6 ha (6.4 ac) steer-1, a heavily grazed native vegetation pasture stocked at 0.9 ha steer-1, and a fertilized crested wheatgrass (Agropyron cristatum L. Gaertn.) pasture stocked at 0.9 ha steer-1 near Mandan, North Dakota. The three native vegetation pastures were established in 1916 and the crested wheatgrass pasture was seeded in 1932. Soil properties varied in sensitivity to the management practices. Measures of vegetation and animal production, combined with assessment of soil properties suggest that moderate grazing and fertilization of crested wheatgrass are viable management options that appear to be sustainable while providing goods and services needed by society. Range and pasture assessment should include soil assessment to more completely determine management effects on pastoral ecosystems.
Keywords: Grazing management, microbe numbers, mixed grass prairie, N mineralization, North Dakota, organic C, soil quality
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Water-Quality Effects of Infiltration Rate and Manure Application Rate for Soils Receiving Swine Manure
(Full text appears in the Journal of Soil and Water Conservation, Vol.56, No.1)
D.H. Pote, B.A. Reed, T.C. Daniel, D.J. Nichols, P.A. Moore, Jr., D.R. Edwards, and S. Formica
ABSTRACT: We investigated the effects of rain infiltration rate and manure application rate on the quality of leachate and runoff from four soils. Tall fescue (Festuca arundinacea Schreber) plots received swine (Sus scrofa L) manure slurry at 1 or 2 Mg (dry weight) ha-1 to provide N at 78.4 or 156.8 kg ha-1. Simulated rain (75 mm hr-1) applied 24 hr after slurry application produced 30 min of runoff from each plot. Mean infiltration rates ranged from 7.7 to 60.6 mm hr-1. Concentrations and mass losses of total Kjeldahl nitrogen (TKN), NH4-N, dissolved reactive P (DRP), and total P in runoff increased significantly (a = 0.05) following slurry applications, and doubled when slurry application doubled. High infiltration rates reduced runoff volumes and runoff concentrations of Cl, total dissolved solids, DRP, TKN, and NH4-N. Concentrations of NO3-N and NH4-N in leachate water, collected at 0.4 m depth by suction cup lysimeters, did not increase following slurry applications.
Keywords: Runoff, swine manure, water quality
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Influence of Thermal Gradients on the Rates of Heating and Cooling of Streams
(Full text appears in the Journal of Soil and Water Conservation, Vol.56, No.1)
L.L. Larson and P.A. Larson
ABSTRACT: Field studies were undertaken to study the influence of thermal gradients on rates of stream heating and cooling. Results from the study on four watersheds suggest that the rates of stream heating and cooling are strongly influenced by exposure to the surrounding thermal environment. Air temperature, when used as an index of the thermal environment, provided a mechanism for estimating the rate of stream heating or cooling in different thermal environments. Rates were tested for significant difference and summarized to provide a framework for anticipating rates of heating and cooling given thermal environment conditions. Monitoring water temperature for watershed assessments determines how much thermal pollution is in a stream. Collecting temperature data between two established monitoring sites, and using air or soil temperatures as an indicator of the watershed’s thermal response to climatic factors can help describe why, as well as where, the pollution is occurring. This study evaluates a means of quantifying and evaluating rates of water heating through the application of scientific principles.
Keywords: Stream temperature, thermal gradients
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Land Management at the Major Watershed—Agroecoregion Intersection
(Full text appears in the Journal of Soil and Water Conservation, Vol.56, No.1)
L.K. Hatch, A. Mallawatantri, D. Wheeler, A. Gleason, D. Mulla, J. Perry, K.W. Easter, R. Smith, L. Gerlach, and P. Brezonik
ABSTRACT: The watershed natural resources management framework is prevalent today because land use in watersheds is presumed to be reflected in receiving stream water quality. However, landscape characteristics affecting soil erosion and water quality (e.g., precipitation, geomorphology, slope, soil internal drainage, cropping system) often vary significantly within a single large watershed (> 200,000 ha). A uniform watershed best management practice would not account for this variability and would not be satisfactory for soil conservation, water quality, or socioeconomic returns. It is highly unlikely that stream water quality monitoring will take place on enough small streams within a large watershed to capture the landscape variation. We have developed "agroecoregions" to quantify this variation, based on empirical data from the Minnesota River Basin (MRB). This approach is needed to help target cleanup efforts to the most sensitive soils and landscapes within the most critical watersheds. Our work shows that soil erodibility index variability and stream biotic habitat scores were better represented by agroecoregions than by watersheds. Stakeholder characterization and economic analysis reveal a large variance in attitudes and beliefs about pollution issues and mitigation costs in the MRB, due in part to problems of scale perception (e.g., entire basin, major watershed, county, city, farm). We suggest that watershed management in highly agricultural watersheds will be most effective when hydrologic watersheds are used as a framework that is complemented by agroecoregions to identify and target regions where specific combinations of best management practices for agricultural sediment and phosphorus abatement are most appropriate.
Keywords: Ecoregions, Minnesota River, nonpoint source pollution, water quality, watershed management
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Comparison of Profit Maximization and Multiple Criteria Models for Selecting Farming Systems
(Full text appears in the Journal of Soil and Water Conservation, Vol.56, No.1)
T. Prato and S. Hajkowicz
ABSTRACT: The rationale for subsidizing soil and water conservation practices is that farmers would not adopt farming systems incorporating these practices to the extent desired by society without cost sharing subsidies. Premises underlying this rationale are that profit maximization is the sole criterion for selecting farming systems and farming systems incorporating soil and water conservation practices are less profitable than systems that exclude these practices. Validity of the profit maximization model is evaluated by comparing the selection of farming systems based on profit maximization and a general multiple criteria decision-making (MCDM) model. Preferences for criteria were obtained from a survey of 20 farmers in Missouri’s Goodwater Creek watershed. The MCDM model was used to evaluate five farming systems in terms of five economic and environmental criteria: increasing net return (profit), reducing economic risk, reducing soil erosion, improving drinking water quality, and enhancing aquatic ecosystems. Three methods were used to estimate the weights for the criteria: fixed point scoring, paired comparisons, and judgment analysis. Weights represent farmers’ preferences for the five criteria. Values of the five criteria are determined using a watershed simulation model. Weights and values for the criteria are used to calculate utility scores, which are then used to rank the five farming systems. The top ranked and most profitable farming systems are different. Three possible interpretations of this discrepancy and their implications for conservation subsidies are discussed.
Keywords: Conservation-based farming, cost sharing, profit maximization, multiple criteria models
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Winter Wheat and Grain Sorghum Production as Influenced by Depth of Soil Water, Tillage and Cropping System
(Full text appears in the Journal of Soil and Water Conservation, Vol.56, No.1)
C.A. Thompson
ABSTRACT: A 24 year study of five cropping systems was conducted to determine how 1.) cropping systems, 2.) depth of soil water at planting, and 3.) tillage systems affected yields and economic returns. The study involved two crops, winter wheat (Triticum aestivum L.) and grain sorghum (Sorghum biocolor L Moench), in systems of continuous wheat (WWW), continuous sorghum (SSS), wheat/sorghum/fallow (WSF), wheat/fallow (WF), and sorghum/fallow (SF). These systems were farmed under reduced-till (RT) and no-till (NT) on a nearly level, high fertility, Crete silty clay loam soil (fine, smectitic, mesic Pachic Argiustolls) at the Kansas State University Agricultural Research Center-Hays. Depth of soil water at planting had significant effects on yields of all cropping/tillage systems. Tillage systems had limited effects on wheat yields, but significant effects on sorghum yields. Considering all factors, SSS with RT had the highest economic return on this upland fertile soil in the central Great Plains.
Keywords: Cropping system, dryland wheat, economic return, soil moisture, sorghum, tillage system
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Coupling Use-Dependent and Use-Invariant Data for Soil Quality Evaluation in the United States
(Full text appears in the Journal of Soil and Water Conservation, Vol.56, No.1)
R.B. Grossman, D.S. Harms, C.A. Seybold, and J.E. Herrick
ABSTRACT: The estimated properties for soil survey map units typically are only for major soil use. Users are provided only one set of soil properties. We consider the combination of use-invariant and use-dependent databases to produce composite records. The use-invariant data is determined by soil origin and genesis and is at most only slightly subject to change with use. The use-dependent data is readily subject to change by use. Near-surface properties are particularly subject to change with use. Each use-invariant property is assigned a surficial exclusion zone within which the property is considered use-dependent and hence the standard interpretive record is not applicable. Both use-dependent and use-invariant properties are placed in one of five classes. Numerical rankings for quality evaluation are obtained by combining the placements for the several properties concerned.
Keywords: Near-surface, quality class placements, soil interpretations, soil properties, soil quality, soil survey, use-dependency, use-invariance
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Organizational Factors Affecting the Strength of Missouri’s Soil and Water Conservation Districts
(Full text appears in the Journal of Soil and Water Conservation, Vol.56, No.1)
A.H. Raedeke, J.S. Rikoon, and C. Rich
ABSTRACT: In this study we develop an index to measure "district strength" in Missouri. By district strength we refer to the ability or capacity of districts to promote and meet their conservation goals. Using data from a statewide mail survey of SWCD supervisors and SWCD employees, we examine how various organizational factors influence district strength, including such internal variables as supervisor leadership and perceptions of the adequacy of employee salaries, and external variables, including district relations with the Missouri Soil and Water Districts Commission, and Natural Resources Conservation Service. Our findings reveal that supervisor leadership, districts linkages to the state Commission, and, to a lesser extent, external relations with NRCS, influence district strength.
Keywords: Conservation, organizations, organizational effectiveness, soil and water conservation districts
