Patterns and controls of ecosystem function in longleaf pine - wiregrass savannas. II. Nitrogen dynamics

1999 ◽  
Vol 29 (6) ◽  
pp. 752-760 ◽  
Author(s):  
Carlos A Wilson ◽  
Robert J Mitchell ◽  
Joseph J Hendricks ◽  
Lindsay R Boring
Keyword(s):  
Soil Moisture ◽  
N Mineralization ◽  
Longleaf Pine ◽  
Pinus Palustris ◽  
First Year ◽  
N Availability ◽  
Net N Mineralization ◽  
Ecological Gradient ◽  
N Losses ◽  
In Fire

The productivity of many temperate forests is nitrogen limited. Controls on N availability are particularly important in fire-maintained ecosystems such as longleaf pine - wiregrass (Pinus palustris Mill. - Aristida stricta Michx.) forests of the Coastal Plain of the southeastern United States, where periodic burning can result in substantial N losses. This study quantifies variation in net N mineralization across a complex ecological gradient for longleaf pine - wiregrass forests, from dry sandhills to wet-mesic sites adjacent to wetlands, for the first year after burning. Net N mineralization was consistently higher for the xeric site and declined as soil moisture status increased. Higher N availability was primarily due to higher rates of net nitrification in these plots, suggesting possible substrate-induced influences. Temperature was positively related to net N mineralization, while percent soil moisture was inversely correlated to net N mineralization. The greater N availability on dry sites may reflect greater quality organic matter inputs resulting from a significant hardwood (Quercus laevis Walt. predominately) component, and (or) it may reflect microclimate differences (warmer soil) that accelerate decomposition of detritus in soil.

Patterns and controls of ecosystem function in longleaf pine - wiregrass savannas. I. Aboveground net primary productivity

1999 ◽  
Vol 29 (6) ◽  
pp. 743-751 ◽  
Author(s):  
Robert J Mitchell ◽  
L Katherine Kirkman ◽  
Stephen D Pecot ◽  
Carlos A Wilson ◽  
Brian J Palik ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Primary Productivity ◽  
N Mineralization ◽  
Environmental Gradient ◽  
Net Primary Productivity ◽  
Longleaf Pine ◽  
Pinus Palustris ◽  
Individual Species ◽  
Aboveground Net Primary Productivity ◽  
Resource Limitations

Longleaf pine - wiregrass (Pinus palustris Mill. - Aristida stricta Michx.) woodlands occupy sites ranging from deep, xeric sandhills to the edge of wetlands in the southeastern United States. Aboveground net primary productivity (ANPP) of the overstory and understory were determined for three replicate sites of three site types (xeric, intermediate, and wet-mesic) that span a wide environmental gradient. In addition, soil moisture (at 30 and 90 cm) and N mineralization (in situ buried bag incubations) were measured through an annual cycle. Longleaf pine - wiregrass ecosystems varied by nearly twofold in ANPP across complex gradients. Overstory and understory and total (overstory and understory) ANPP were positively correlated to soil moisture at 30 and 90 cm. The proportion of understory ANPP relative to the total ANPP did not increase across the environmental gradient as predicted by hypotheses that invoke niche differentiation in rooting habits of grasses and trees. Contrary to expectations, cumulative net N mineralization was negatively related to soil moisture. All ANPP estimates were significantly and negatively related to cumulative N-mineralization. Further work is needed to explore the mechanisms by which soil moisture regulates productivity across space, time, and for individual species. Additional experimentation through resource addition would allow for investigations into multiple resource limitations and how resource limitations vary depending on gradient position.

Factors controlling N mineralization, nitrification, and nitrogen losses in an Oxisol amended with sewage sludge

Soil Research ◽  
2001 ◽  
Vol 39 (3) ◽  
pp. 519 ◽  
Author(s):  
J. Sierra ◽  
S. Fontaine ◽  
L. Desfontaines
Keyword(s):  
Sewage Sludge ◽  
Field Experiment ◽  
Water Content ◽  
N Mineralization ◽  
Initial Period ◽  
Factorial Experiment ◽  
Net N Mineralization ◽  
N Losses ◽  
Mineral N ◽  
The Difference

Laboratory incubations and a field experiment were carried out to determine the factors controlling N mineralization and nitrification, and to estimate the N losses (leaching and volatilization) in a sewage-sludge-amended Oxisol. Aerobically digested sludge was applied at a rate equivalent to 625 kg N/ha. The incubations were conducted as a factorial experiment of temperature (20˚C, 30˚C, and 40˚C) soil water (–30 kPa and –1500 kPa) sludge type [fresh (FS) water content 6230 g/kg; dry (DS) water content 50 g/kg]. The amount of nitrifiers was determined at the beginning and at the end of the experiment. The incubation lasted 24 weeks. The field study was conducted using bare microplots (4 m) and consisted of a factorial experiment of sludge type (FS and DS) sludge placement (subsurface, I+; surface, I–). Ammonia volatilization and the profile (0–0.90 m) of mineral N concentration were measured during 6 and 29 weeks after sludge application, respectively. After 24 weeks of incubation at 40˚C and –30 kPa, net N mineralization represented 52% (FS) and 71% (DS) of the applied N. The difference between sludges was due to an initial period of N immobilization in FS. Nitrification was more sensitive than N mineralization to changes in water potential and it was fully inhibited at –1500 kPa. The introduction of a large amount of nitrifiers with FS did not modify the rate of nitrification, which was principally limited by soil acidity (pH 4.9). Although N mineralization was greatest at 30˚C, nitrification increased continuously with temperature. Nitrogen mineralization from DS was well described by the double-exponential equation. For FS, the equation was modified to take into account an immobilization-remineralization period. Sludge placement significantly affected the soil NO-3/NH+4 ratio in the field: 16 for I+ and 1.5 for I–, after 11 weeks. In the I– treatment, nitrification of the released NH+4 was limited by soil moisture because of the dry soil mulch formed a few hours after rain. At the end of the field experiment, the estimated losses of N by leaching were 432 kg N/ha for I+ and 356 kg N/ha for I–. Volatilization was not detectable in the I+ microplots and it represented only 0.5% of the applied N in the I– microplots. The results showed that placement of sludge may be a valuable tool to decrease NO-3 leaching by placing the sludge under unfavourable conditions for nitrification.

scholarly journals A Comparison of the Attributes of Pine Straw from Southern Pine Species

2021 ◽  
Vol 39 (3) ◽  
pp. 115-122
Author(s):  
Zachary Singh ◽  
Adam Maggard ◽  
Rebecca Barlow ◽  
John Kush
Keyword(s):  
Soil Moisture ◽  
Soil Temperature ◽  
Soil Properties ◽  
Soil Nutrients ◽  
Longleaf Pine ◽  
Pinus Palustris ◽  
Pinus Elliottii ◽  
Slash Pine ◽  
Weed Growth ◽  
Pine Straw

Abstract Longleaf pine (Pinus palustris Mill.), and slash pine (Pinus elliottii Engelm.) are two southern pine species that are popular for producing pine straw for landscaping. The objective of this research was to determine the response of soil properties and weed growth to the application of pine straw. Longleaf pine, slash pine, and two non-mulched controls (with and without chemical weed control) were tested. Volumetric soil water content, soil nutrients, soil temperature, weed biomass, and seedling growth were measured. Compared to non-mulched controls, both longleaf and slash pine plots had a greater soil moisture during extended periods without rainfall in the full sun environment. When soil temperatures increased, mulched plots had lower soil temperature relative to non-mulched plots. Soil pH and soil nutrients were generally similar between pine straw types with few significant differences in measured variables. Both pine straw treatments reduced weed growth and longleaf pine maintained a greater straw depth over the study period compared to slash pine, but no differences were observed for decomposition. These results indicate that longleaf pine straw and slash pine straw perform equally as well in terms of increasing soil moisture, moderating soil temperature, and reducing weed growth compared to not using mulch. Index words: Pinus elliottii, Pinus palustris, organic mulch, soil properties, landscaping. Species used in this study: Shumard oak, Quercus shumardii Buckl., Eastern redbud, Cercis canadensis L.

Empirical relationships between temperature and nitrogen availability across North American forests

1992 ◽  
Vol 22 (5) ◽  
pp. 707-712 ◽  
Author(s):  
Xiwei Yin
Keyword(s):  
N Mineralization ◽  
Regional Scale ◽  
Mineral Soil ◽  
Published Data ◽  
N Availability ◽  
Net N Mineralization ◽  
Soil N ◽  
Litter Fall ◽  
Available N ◽  
N Pool

Published data were analyzed to examine whether nitrogen (N) availability varies along macroclimatic gradients in North America. Extractable N produced during 8-week aerobic laboratory incubation was used as an index of potential net N mineralization. Mean extractable N during the growing season in the forest floor plus top mineral soil was used as an index of the available N pool. Using multiple regression, potential net N mineralization was shown to increase with available N and with litter-fall N (R2 = 0.722). Available N increased with increasing total soil N and with decreasing mean January and July air temperatures (R2 = 0.770). These relationships appeared to hold also for deciduous and coniferous forests separately across regions. Results suggest that net N mineralization output under uniform temperature and moisture conditions can be generally expressed by variations of N input (litter fall) and the available soil N pool, and that the available soil N pool is predictable along a temperature gradient at a regional scale.

scholarly journals Reviews and syntheses: measuring ecosystem nitrogen status – a comparison of proxies

2016 ◽  
Vol 13 (18) ◽  
pp. 5395-5403 ◽  
Author(s):  
Maya Almaraz ◽  
Stephen Porder
Keyword(s):  
N Mineralization ◽  
Nitrogen Availability ◽  
N Availability ◽  
Net N Mineralization ◽  
Tropical Regions ◽  
Net Nitrification ◽  
Kendall’S Τ ◽  
Soil Δ15n ◽  
N Status

Abstract. There are many proxies used to measure nitrogen (N) availability in watersheds, but the degree to which they do (or do not) correlate within a watershed has not been systematically addressed. We surveyed the literature for intact forest or grassland watersheds globally, in which several metrics of nitrogen availability have been measured. Our metrics included the following: foliar δ15N, soil δ15N, net nitrification, net N mineralization, and the ratio of dissolved inorganic to organic nitrogen (DIN : DON) in soil solution and streams. We were particularly interested in whether terrestrial and stream based proxies for N availability were correlated where they were measured in the same place. Not surprisingly, the strongest correlation (Kendall's τ) was between net nitrification and N mineralization (τ  =  0.71, p < 0.0001). Net nitrification and N mineralization were each correlated with foliar and soil δ15N (p < 0.05). Foliar and soil δ15N were more tightly correlated in tropical sites (τ  =  0.68, p < 0.0001), than in temperate sites (τ  =  0.23, p  =  0.02). The only significant correlations between terrestrial- and water-based metrics were those of net nitrification (τ  =  0.48, p  =  0.01) and N mineralization (τ  =  0.69, p  =  0.0001) with stream DIN : DON. The relationship between stream DIN : DON with both net nitrification and N mineralization was significant only in temperate, but not tropical regions. To our surprise, we did not find a significant correlation between soil δ15N and stream DIN : DON, despite the fact that both have been used to infer spatially or temporally integrated N status. Given that both soil δ15N and stream DIN : DON are used to infer long-term N status, their lack of correlation in watersheds merits further investigation.

scholarly journals Nitrogen Availability and Uptake by Sugarbeet in Years Following a Manure Application

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Rodrick D. Lentz ◽  
Gary A. Lehrsch
Keyword(s):  
N Mineralization ◽  
Dairy Manure ◽  
High Rate ◽  
N Availability ◽  
Net N Mineralization ◽  
Soil N ◽  
Manure Application ◽  
Total N ◽  
Urea Fertilizer ◽  
Low Rate

The use of solid dairy manure for sugarbeet production is problematic because beet yield and quality are sensitive to deficiencies or excesses in soil N, and soil N availability from manure varies substantially depending on the year of application. Experimental treatments included combinations of two manure rates (0.33 and 0.97 Mg total N ha−1) and three application times, and non-manure treatments (control and urea fertilizer). We measured soil net N mineralization and biomass, N uptake, and yields for sprinkler-irrigated sugarbeet. On average, the 1-year-old, low-rate manure, and 1- and 2-year-old, high-rate manure treatments produced 1.2-fold greater yields, 1.1-fold greater estimated recoverable sugar, and 1.5-fold greater gross margins than that of fertilizer alone. As a group the 1-year-old, low-rate manure, and 2- and 3-year-old, high-rate-manure treatments produced similar cumulative net N mineralization as urea fertilizer; whereas the 1-year-old, high-rate manure treatment provided nearly 1.5-fold more N than either group. With appropriate manure application rates and attention to residual N and timing of sugarbeet planting, growers can best exploit the N mineralized from manure, while simultaneously maximizing sugar yields and profits.

Pensacola Bahiagrass Can Be Used to Improve the Forage Resource when Regenerating Southern Pines

1985 ◽  
Vol 9 (4) ◽  
pp. 254-259 ◽  
Author(s):  
Clifford E. Lewis ◽  
Warren G. Manson ◽  
Richard J. Bonyata
Keyword(s):  
Longleaf Pine ◽  
Pinus Palustris ◽  
Site Preparation ◽  
Paspalum Notatum ◽  
First Year ◽  
Forage Plants ◽  
Southern Pines ◽  
Pine Seedlings ◽  
Nutritional Qualities ◽  
Grass Stage

Abstract Many native forage plants in the South are low quality, poor producers, and unpalatable to cattle. Replacement of these plants with more desirable species would improve the forage resource. One approach is to seed grasses during site preparation when regenerating southern pines. Following site preparation by shearing and strip-disking, Pensacola bahiagrass (Paspalum notatum) was seeded at 15 pounds per acre in the spring and longleaf pine (Pinus palustris) was row-seeded on 12-foot centers in December of the next year. The bahiagrass became established among the residual native plants and was heavily utilized by cattle grazing yearlong. A light application of fertilizer after 3 years tripled bahiagrass yields the first year and doubled it the next year compared to unfertilized plots. Fertilizer improved some nutritional qualities of bahiagrass but digestibility was lowered. Longleaf pine seedlings came out of the grass stage more rapidly and were 50% taller at age 9 with grazing than without it; and in spite of heavier mortality with grazing (36% vs. 21%), stocking was 967 trees per acre at age 11.

scholarly journals Nitrogen Availability in Biochar-Amended Soils with Excessive Compost Application

Agronomy ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 444 ◽  
Author(s):  
Chen-Chi Tsai ◽  
Yu-Fang Chang
Keyword(s):  
N Mineralization ◽  
Nitrogen Availability ◽  
Agricultural Soils ◽  
Inorganic Nitrogen ◽  
Clay Content ◽  
N Availability ◽  
Net N Mineralization ◽  
Mineral N ◽  
Mineralization Potential ◽  
The Impact

Adding biochar to excessive compost amendments may affect compost mineralization rate and nitrogen (N) availability. The objective of this 371-day incubation study was to evaluate the effects of four proportions of woody biochar (0%, 0.5%, 1.0%, and 2.0%) from lead tree (Leucaena leucocephala (Lam.) de. Wit) biochar produced at 750 °C through dynamic mineral N and N mineralization rates in three rural soils (one Oxisol and two Inceptisols). In each treatment, 5% poultry–livestock manure compost was added to serve as an excessive application. The results indicated that the biochar decreased available total inorganic nitrogen (TIN) (NO3−-N+NH4+-N) by on average 6%, 9% and 19% for 0.5%, 1.0% and 2.0% treatments, respectively. The soil type strongly influenced the impact of the biochar addition on the soil nitrogen mineralization potential, especially the soil pH and clay content. This study showed that the co-application of biochar and excessive compost benefited the agricultural soils by improving NO3−-N retention in agroecosystems. The application of biochar to these soils to combine it with excessive compost appeared to be an effective method of utilizing these soil amendments, as it diminished the net N mineralization potential and reduced the nitrate loss of the excessive added compost.

Foliar litter position and decomposition in a fire-maintained longleaf pine – wiregrass ecosystem

2002 ◽  
Vol 32 (6) ◽  
pp. 928-941 ◽  
Author(s):  
Joseph J Hendricks ◽  
Carlos A Wilson ◽  
Lindsay R Boring
Keyword(s):  
Mass Loss ◽  
Longleaf Pine ◽  
Pinus Palustris ◽  
Soil Surface ◽  
Fire Regimes ◽  
Pine Forests ◽  
N Losses ◽  
Surface Mass ◽  
Decay Constants ◽  
P Immobilization

Foliar litter position and decomposition were assessed in longleaf pine (Pinus palustris Mill.) - wiregrass (Aristida beyrichiana Trin. & Rupr.) woodlands during a 3-year burn interval. Position assessments revealed 57.7 and 67.4% of foliar litter was elevated in wiregrass crowns 1 and 2 years, respectively, following burning. Decomposition assessments revealed soil-surface mass loss decay constants (range 0.097–0.282) similar to those measured in comparable pine forests. However, elevated longleaf pine and wiregrass litter exhibited decay constants (0.052 and 0.074, respectively) 50% lower than corresponding soil-surface rates and among the lowest values in the literature. With the exception of wiregrass, which did not exhibit an immobilization of the nutrients (N, P, Ca, K, and Mg) assessed, foliar litter exhibited either extensive P immobilization with minimal N immobilization or minimal, short-lived immobilization of N, P, or both N and P. The percentage of original N and P remaining after 3 years varied widely among the soil surface (N range 6.3–56.3%; P range 3.4–204.7%) and elevated (N range 76.8–94.9%; P range 52.0–99.2%) litter. These results suggest that fire regimes typically employed in longleaf pine – wiregrass woodlands may balance N losses via volatilization with P limitations via litter immobilization.

Gaps in a gappy forest: plant resources, longleaf pine regeneration, and understory response to tree removal in longleaf pine savannas

2001 ◽  
Vol 31 (5) ◽  
pp. 765-778 ◽  
Author(s):  
John P McGuire ◽  
Robert J Mitchell ◽  
E Barry Moser ◽  
Stephen D Pecot ◽  
Dean H Gjerstad ◽  
...  
Keyword(s):  
Seedling Survival ◽  
Longleaf Pine ◽  
Light Availability ◽  
Pinus Palustris ◽  
Understory Vegetation ◽  
Net N Mineralization ◽  
Plant Resources ◽  
Pine Seedlings ◽  
Pine Regeneration ◽  
Tree Removal

Resource availability and planted longleaf pine (Pinus palustris Mill.) seedling and understory vegetation response within and among three sizes of experimentally created canopy gaps (0.11, 0.41, 1.63 ha) in a mature longleaf pine savanna were investigated for 2 years. Longleaf pine seedlings and understory vegetation showed increased growth in gaps created by tree removal. Longleaf pine seedling growth within gaps was maximized approximately 18 m from the uncut savanna. Increased longleaf pine seedling survival under the uncut savanna canopy observed after the first year suggests that the overstory may facilitate establishment of longleaf pine seedlings rather than reduce survival through competition. Despite the relative openness of the uncut longleaf pine forest, light quantity was increased by tree removal. Light was also the resource most strongly correlated with seedling and understory vegetation growth. Although net N mineralization was correlated to seedling response, the amount of variation explained was low relative to light. Belowground (root) gaps were not strong, in part because of non-pine understory roots increasing in biomass following tree removal. These results suggest that regeneration of longleaf pine may be maximized within gap sizes as small as approximately 0.10 ha, due largely to increases in light availability.

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