Soil Changes and Tree Seedling Response Associated with Site Preparation in Northern Idaho

Abstract Conifer regeneration in western North America is often hampered by low soil moisture, poor soil nutrient status, and competing vegetation. Three site preparation techniques were evaluated at two different elevations in northern Idaho as potential remedies for these problems: (1) soil mounds without control of competing vegetation, (2) soil mounds with herbicidal control of competing vegetation, and (3) scalping (removal of soil surface organic horizons and mineral topsoil). Treatments were evaluated for effects on soil nutrient levels, soil physical properties, and the growth of Douglas-fir (Pseudotsuga menziesii var. glauca) and western white pine (Pinus monticola) seedlings. Both species generally grew best when planted in the mounded treatment with competing vegetation removed and worst after scalping. Mounding with herbicide application resulted in the lowest bulk density, best seedling growth, and increased water availability. Mounding may be a viable site preparation method in the Inland Northwest on less productive sites that have severe competition. Scalping, especially when competition was not a problem, generally did not produce favorable seedling growth responses. Scalping may also reduce longer term seedling growth by removing surface organic matter. West. J. Appl. For. 12(3):81-88.

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The effects of soil mixing on soil nutrient status, recovery of competing vegetation and conifer growth on cedar-hemlock cutovers in coastal British Columbia

New Forests ◽

10.1007/bf00035485 ◽

1995 ◽

Vol 9 (3) ◽

pp. 163-179 ◽

Cited By ~ 8

Author(s):

Christian Messier ◽

Rodney Keenan ◽

James P. (Hamish) Kimmins

Keyword(s):

British Columbia ◽

Soil Nutrient ◽

Nutrient Status ◽

Soil Nutrient Status ◽

Competing Vegetation ◽

Soil Mixing ◽

Coastal British Columbia

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Charge characteristics of soil in a lowland tropical moist forest in Panama in response to dry-season irrigation

Soil Research ◽

10.1071/sr00061 ◽

2002 ◽

Vol 40 (2) ◽

pp. 269 ◽

Cited By ~ 8

Author(s):

Joseph B. Yavitt ◽

S. Joseph Wright

Keyword(s):

Surface Charge ◽

Surface Soil ◽

Soil Nutrient ◽

Soil Surface ◽

Nutrient Status ◽

Dry Season ◽

Soil Nutrient Status ◽

Variable Charge ◽

Subsurface Soil ◽

Moist Forest

Although the hot, moist tropics in the Republic of Panama receive more than 2000 mm of rain per year, soils dry considerably during the 4-month dry season. We examined the effect of seasonal drought by irrigating two 2.25-ha plots of lowland tropical moist forest on Barro Colorado Island (BCI) for 5 consecutive dry seasons. Irrigation decreased soil permeability and improved soil nutrient status, which prompted this study of soil charge characteristics in the irrigated and control plots. Soil was an Alfisol, and thus it was not clear a prioriwhether variable-charge or permanent-charge components dominated. Surface soil (0–15 cm) had a pH(H2O) of 5.5 and pH(KCl) of 4.8. Subsurface soil (30–45 cm) had a pH(H2O) of 4.8 and a pH(KCl) of 3.5. The point of zero salt effect (PZSE), measured by titration, varied from 3.7 to 5.0 in surface soil and from 3.5 to 4.2 in subsurface soil. Variable charge of surface soil was 2.6 cmolc/kg.pH unit after the dry season in April versus 3.2 cmolc/kg.pH unit after the wet season in December in both control and dry-season irrigated plots, reflecting seasonal differences in pH and PZSE. The point of zero net charge (PZNC), measured by ion retention, was at pH <2.0, indicating that permanent-charge components dominated the soil surface charge. Five years of dry-season irrigation resulted in pH(H2O) increasing by 0.6 units and pH(KCl) increasing by 0.2 units. As well, irrigation increased the amount of permanent charge and cation retention, leading to less sorption of phosphate and sulfate. The results have important ecological implications, showing mechanistically how wetter conditions affected soil surface charge leading to improved soil nutrient status. permanent charge, soil pH, tropical forest soil, variable charge, water regime.

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Impacts of soil compaction and tree stump removal on soil properties and outplanted seedlings in northern Idaho, USA

Canadian Journal of Soil Science ◽

10.4141/s97-022 ◽

1998 ◽

Vol 78 (1) ◽

pp. 29-34 ◽

Cited By ~ 33

Author(s):

Deborah S. Page-Dumroese ◽

Alan E. Harvey ◽

Martin F. Jurgensen ◽

Michael P. Amaranthus

Keyword(s):

Bulk Density ◽

Soil Compaction ◽

Site Preparation ◽

Douglas Fir ◽

Pinus Monticola ◽

White Pine ◽

Total N ◽

Western White Pine ◽

Northern Idaho ◽

Site Disturbance

Intensive timber harvesting and site preparation are becoming more common as demand for timber-based products increases. On some harvested sites in the western United Staes of America and Canada, stump removal is used to ameliorate root disease problems. Soil compaction and nutrient loss could become a problem on some sites after harvesting, site preparation, or stump removal. In a non-replicated, randomized block experiment, two levels of soil compaction (none and severe) and a stump extraction treatment were examined on an ash-cap soil in northern Idaho. These treatments were planted with Douglas-fir (Pseudotsuga menziesii var. glauca [Beissn.] Franco) and western white pine (Pinus monticola Dougl. ex D. Don) seedlings. Soil compaction increased post-harvest bulk density 15–20% to a depth of 30 cm. Stump removal decreased surface soil bulk density, but it increased at the 30- to 45-cm depth to levels equal to the soil compaction treatment. One year after outplanting, seedling top weights were similar among treatments, but root volume was significantly reduced in the soil compaction treatment. Soil compaction and stump removal treatments also reduced the numbers and morphological types of ectomycorrhizae and non-ectomycorrhizal short roots on Douglas-fir. Western white pine seedlings had reduced numbers of non-ectomycorrhizal short roots in the same treatments. Three years after outplanting, stump removal resulted in smaller root collar diameters and less total N content for both seedling species. Severe site disturbance, with associated soil compaction and mixing, may decrease productivity of ash-cap sites by reducing pore space and root and ectomycorrhizal activity. Managers must weigh short-term benefits of intensive site disturbance with possible long-term loss of soil productivity. Key words: Bulk density, compaction, ectomycorrhizae, stumping, site preparation, Douglas-fir, western white pine

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Tropical tree seedling growth responses to nitrogen, phosphorus and potassium addition

Journal of Ecology ◽

10.1111/j.1365-2745.2011.01904.x ◽

2011 ◽

Vol 100 (2) ◽

pp. 309-316 ◽

Cited By ~ 150

Author(s):

Louis S. Santiago ◽

S. Joseph Wright ◽

Kyle E. Harms ◽

Joseph B. Yavitt ◽

Carmi Korine ◽

...

Keyword(s):

Seedling Growth ◽

Tropical Tree ◽

Growth Responses ◽

Tree Seedling ◽

Phosphorus And Potassium ◽

Nitrogen Phosphorus ◽

Potassium Addition ◽

Tree Seedling Growth

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Conservation Agriculture Mitigates the Effects of Climate Change

Journal of Nepal Agricultural Research Council ◽

10.3126/jnarc.v7i1.36934 ◽

2021 ◽

Vol 7 ◽

pp. 122-132

Author(s):

Tika Bahadur Karki ◽

Pankaj Gyawaly

Keyword(s):

Agricultural Research ◽

Cropping Systems ◽

Soil Nutrient ◽

Soil Surface ◽

Conservation Agriculture ◽

Nutrient Status ◽

Policy Support ◽

Conventional Agriculture ◽

Agricultural Research Council ◽

Public And Private Sector

Intensive tillage based conventional agriculture have high global warming potential. Alternative to this, conservation agriculture (CA) systems utilize soils for the production of crops by reducing excessive tillage, maintaining crop residue on the soil surface, and adoption of crop rotations. The paper attempts to review the findings of CA based experiments under different cropping systems within and outside of the country. It has been found that CA increases and sustains the crop productivities, mitigates green house gas emissions from agriculture by enhancing soil carbon sequestration, improving soil nutrient status and water use efficiencies, and reducing fuel consumption. Mainstreaming of CA systems in Nepal is hindered by its knowledge gap, inadequate farm machineries and tools, small holdings, poor infrastructures, and lack of CA friendly policy support. Therefore, there is an urgent need to test, verify and scale-out the CA based technologies by Nepal Agricultural Research Council (NARC) across the different agro-ecologies through farmer-centered partnership among the international institutions, public and private sector of Nepal.

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