November - December 2004: Volume 59, Number 6
Table of Contents
Features
The human dimension of resource management programs
By P.J. Nowak and P.E. Cabot
Is crop residue a waste?
By R. Lai
Research
- Manure management in urbanizing settings
P.E. Cabot, S.K. Bowen, and P.J. Nowak
- Linkages between phosphorus index estimates and environmental quality indicators
E.K. Schendel, H. Schreier, and L.M. Lavkulich
- Streambank stabilization: An economic analysis from the landowner's perspective
J.R. Williams, P.M. Clark, and P.G. Balch
- Profit, yield, and soil quality effects of tillage systems in corn - soybean rotations
R.A. Buman, B.A. Alesii, J.L. Hatfield, and D.L. Karlen
- Tracing the fate of 15N in a small-grain potato rotation to improve accountability of nitrogen budgets
J.A. Delgado, M.A. Dillon, R.T. Sparks, and R.F. Follett
- Ridge and contour tillage effects on soil erosion from steep hillslopes in the Sichuan Basin, China
J.H. Zhang, M. Frielinghaus, G. Tian, and D.A. Lobb
Departments
- Home Front
Viewpoint
- Raise Your Voice
- Notebook
- Conservogram
Manure management in urbanizing settings
(Full text appears in the Journal of Soil and Water Conservation, Vol.59, No. 6)
P.E. Cabot, S.K. Bowen, and P.J. Nowak
ABSTRACT: The management of manure in urbanizing settings is a critical issue, due to the frequent nature of manure placement to scattered fields in areas where land is fragmented by development. Results suggest that exurban developments exert a strong influence on manure management routines of livestock producers. This influence is very local. Farmers in an urbanizing setting were more likely to encounter problems during manure hauling when the fields they were accessing were in close proximity to urban developments, regardless of their proximity to the urban core. The distances and times required to haul manure between the farm and the most distant field increased in the last five years. Land rental rates steadily increased at the same time that lease lengths shortened. Cash grain land tends to be sparse as livestock producers compete with developers for tracts on which to distribute manure. Manure brokering is a possible strategy to monitor land availability and coordinate manure placement between farms.
Keywords: Exurban development, manure management, urbanization
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Linkages between phosphorus index estimates and environmental quality indicators
(Full text appears in the Journal of Soil and Water Conservation, Vol.59, No. 6)
E.K. Schendel, H. Schreier, and L.M. Lavkulich
ABSTRACT: A growing concern over water quality in agricultural areas highlights phosphorus (P) as a key constituent in eutrophication and degrading water quality. A preliminary analysis is presented that tests the effectiveness of P index predictions using linkages to sediment and surface water P concentrations. The field P status in the Elk Creek watershed is described according to P inputs by land managers, soil characteristics, and sediment and water quality analyses. The watershed is partitioned into contributing areas, and the available P in soils shows an increase in concentration in the downstream direction. The P index ratings also show an increase in vulnerability for P loss from soil to surface waters in the lower part of the watershed. The rankings are in agreement with the intensity of land use, and this is reflected in the increase in predominance of the source factors as the main contributor to the P index ratings. In spite of complex process interaction associated with sediment movement, the stream sediment showed similar trends to the soils and P index ratings. Increases in total P in wet-season stream water at the outlet of the watershed may indicate the downstream cumulative effects predicted by the P index ratings.
Keywords: British Columbia, land use, phosphorus index, sediment, soil, water quality
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Streambank stabilization: An economic analysis from the landowner's perspective
(Full text appears in the Journal of Soil and Water Conservation, Vol.59, No. 6)
J.R. Williams, P.M. Clark, and P.G. Balch
ABSTRACT: This research conducts an economic analysis of streambank stabilization projects on the Little Blue River in Washington County, Kansas. The results show each project has a positive net present value to the landowner. Annualized net present values (ANPV) over the 15-year life of the projects range from $126 to $1,760 with an average of $781. Cost share payments are important for the landowner to benefit from the projects. Only two of the projects studied will have a positive net present value without cost share payments specifically targeted for streambank stabilization. Gains are also realized from the value of hectares not lost to erosion, income from being able to crop the preserved hectares not in the stabilization project, and payments received for the hectares enrolled in Continuous Conservation Reserve Program (CRP) as part of the project. The net present value (NPV) increases in proportion to the annual erosion rate relative to the number of hectares required in the stabilization project.
Keywords: CRP, economics, net present value, riparian areas, stabilization, streambank
© 2004 Soil and Water Conservation Society
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Profit, yield, and soil quality effects of tillage systems in corn - soybean rotations
(Full text appears in the Journal of Soil and Water Conservation, Vol.59, No. 6)
R.A. Buman, B.A. Alesii, J.L. Hatfield, and D.L. Karlen
ABSTRACT: Adoption of conservation tillage for corn (Zea mays L.) and soybean (Glycine max L.) rotations, has stagnated over the past several years despite the evidence of the benefits to erosion control, soil health, and associated natural resources derived from conservation tillage. The Monsanto Centers of Excellence were established to evaluate the potential benefits of conservation tillage across a range of soils and climates. Our objective is to summarize the results from field-scale studies conducted at 13 Monsanto Centers of Excellence sites in nine states from 1998 through 2002. Strip-tillage, no-tillage, and conventional corn production, and narrow- and wide-row, no-tillage and conventional tillage soybean production were evaluated in this study. Nine of the 13 sites included a stale seedbed “fast start” corn treatment by which the seedbed is prepared in the fall by conventional tillage and a spring herbicide burndown if needed. Neither soil bulk density nor crop emergence showed any significant differences among tillage systems for either crop throughout the five-year study. Earthworm populations were higher with no-tillage than conventional tillage. Soil quality indicators were not significantly different among the tillage systems. Soil temperature at the 5 cm depth was similar for strip- and conventional-tillage, with both being higher than no-tillage Yield differences among tillage systems within years were not significant for either crop, but profit for no-tillage and strip-tillage corn was the highest in four of five years. The five-year average profit for soybean was also highest for the no-tillage, narrow-row system. Rotating corn and soybean using no-tillage systems resulted in $130 to $145 ha-1 ($53 to $59 ac-1) more profit than the other practices. Farmers, crop consultants, and others should carefully consider overall profit rather than just crop yield when evaluating alternative tillage practices.
Keywords: Centers of Excellence, conservation tillage, corn, no-tillage, soil quality indicators, soybeans
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Tracing the fate of 15N in a small-grain potato rotation to improve accountability
(Full text appears in the Journal of Soil and Water Conservation, Vol.59, No. 6)
J.A. Delgado, M.A. Dillon, R.T. Sparks, and R.F. Follett
ABSTRACT: Nitrogen (N) is difficult to manage because of its dynamic nature and mobility. Improving N use efficiency in agricultural production requires better accounting of N sources and sinks. In small grain [barley (Hordeum vulgare L) and wheat (Triticum aestivum L)]-potato (Solanum tuberosum L) systems, N cycling from small grain crop residue into potato crops is poorly understood. We used 15N labeled fertilizer to trace N from the small grain crop residue into a potato crop. We found that the 15N recovery by these small grains averaged about 46 percent. When we factored in the soil 15N recovery, the average 15N recovery in the system was about 70 percent. The cycling of N from the crop residue into the potato averaged about 2.6 kg N ha-1 for wheat and 4.4 kg N ha-1 for barley. We estimate that the total N cycling from the above ground and below ground compartments was about 4 to 9 kg N ha-1 and that total N released from the crop exchange residue, including the unaccounted N, was about 9 kg N ha-1. About 82 to 86 percent of the N that was incorporated with the crop residue was still in the system (soil-crop) after one year of cycling, which suggests that considerable N is sequestered in the soil over that time period. Results highlight the importance of crop residue in N cycling and identify opportunities to improve the assessment of N budgets for commercial small grain-potato operations.
Keywords: 15N, barley, crop residue, exchange, nitrogen cycling
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Ridge and contour tillage effects on soil erosion from steep hillslopes in the Sichuan Basin, China
(Full text appears in the Journal of Soil and Water Conservation, Vol.59, No. 6)
J.H. Zhang, M. Frielinghaus, G. Tian, and D.A. Lobb
ABSTRACT: Little is known about the impact of tillage methods on soil movement resulting from hoeing tillage operations in the Sichuan Basin, China. Effects of tiered ridge and contour tillage on soil movement (translocation and erosion) were examined in the steep hillslopes of this basin using a physical tracer method. Stone chips were used as tracers, having a contrasting color from the surrounding soil, and were incorporated into each experimental plot. Net mean downslope displacement distance by contour tillage was much shorter (P<0.0001) than that by downslope tillage (5 times for tiered ridge tillage, 3 times for flat tillage). Soil displacement distance was positively correlated to slope gradient for downslope tillage (R2 = 0.6303-0.8282, P = 0.0002 - <0.0001), whereas slope gradient was not significantly correlated to soil downslope displacement by contour tillage (R2 = 0.2421-0.3142, P = 0.0529-0.0239). Tillage transport coefficients were 25.5 and 30.7 kg m-1 tillage pass-1 for k3-values and 153.0 and 141.3 kg m-1 tillage pass-1 for k4-values, respectively for downslope ridge and downslope flat tillage. For a typical downslope length of 15 m and two tillages per year, tillage erosion rates by downslope tillage reached 42.0 - 129.1 t ha-1 yr-1 and 49.0 - 122.1 t ha-1 yr-1 for slopes ranging from 0.04-0.47 m m-1 and from 0.04-0.43 m m-1 respectively for downslope ridge and downslope flat tillage. Tillage erosion rates by contour tillage were reduced by 84% and 77%, compared to downslope tillage respectively for ridge and flat treatments. No significant differences in soil translocation and erosion rates existed between downslope ridge and downslope flat tillage. Contour ridge tillage was more effective than contour flat tillage with respect to controlling tillage translocation and erosion.
Keywords: Hoeing tillage, Sichuan Basin, soil translocation, tiered ridge, tillage erosion
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