Variability of δ15N in soil and plants at a New Zealand hill country site: correlations with soil chemistry and nutrient inputs

Soil Research ◽  
2001 ◽  
Vol 39 (2) ◽  
pp. 373 ◽  
Author(s):  
D. J. Hawke
Keyword(s):  
Soil Chemistry ◽  
Parent Material ◽  
Nutrient Inputs ◽  
Available N ◽  
Hill Country ◽  
15N Enrichment ◽  
A Site ◽  
Soil Δ15n ◽  
Total Soil N ◽  
Total P

This study investigated 15N enrichment and nutrient cycling in hill country used for semi-extensive pastoral agriculture, at a site where pre-European seabird breeding occurred. Soil (0–15 cm) and plant samples were taken from 18 ridgeline and sideslope transects. Three stock camps (locations which grazing animals frequent) were identified within the study area, two on the ridgeline and one on the sideslope. Soil 15N enrichment was greatest at stock camps, and lowest where stock input was minimal. Soil natural abundance 15N (δ15N) was therefore an index of stock nutrient inputs. Soil δ15N increased with decreasing C: N ratio, consistent with N loss through volatilisation and/or nitrate leaching from net mineralisation. Plant δ15N from stock camps was lower than its associated soil, implying that 15N enrichment of plant-available N was lower than that of total soil N. However, the correlation between plant δ15N and soil δ15N varied between stock camps, indicating differences in N cycling. Olsen P was higher at stock camps, although again differences were found between stock camps. Total P and N were correlated neither with stock camps nor topography, but were higher than expected from parent material concentrations and literature results, respectively. It is postulated that significant contributions of both elements from former seabird breeding remain in the soil.

Soil Physical and Chemical Properties under Four Densities of Hybrid Larch Plantations

2012 ◽  
Vol 524-527 ◽  
pp. 2139-2142
Author(s):  
Shu Li Wang ◽  
Chao Ma ◽  
Wei Bin Yuan
Keyword(s):  
Chemical Properties ◽  
Soil Bulk Density ◽  
Physical And Chemical Properties ◽  
Larix Olgensis ◽  
Hybrid Larch ◽  
Total N ◽  
Available N ◽  
Physical And Chemical ◽  
Total P ◽  
And Chemical Properties

The soil physical and chemical properties of four densities (A:2500/hm2，B:3300/hm2，C:4400/hm2，D:6600/hm2) of hybrid Larch plantations, Larix olgensis plantation(E) and Quercus mandsurica forest(F) were studied in Jiangshanjiao forest farm of Heilongjiang province of China. Soil bulk density, soil porosity, total N, total P, available N and available P were affected significantly by plantation density in hybrid Larch plantations. The lowest surface soil bulk density was in density 2500/hm2. Soil porosity of density 2500/hm2and 3300/hm2was bigger than that of density 4400/hm2and density 6600/hm2. Total N, total P and available N of density 4400/hm2and 3300/hm2were higher than that of density 6600/hm2and density 2500/hm2. Total N, total P, available N and available P of hybrid Larch plantations were not lower than that of Larix olgensis plantation. The results of the soil physical and chemical properties under different densities of hybrid Larch plantations and different types of forest seems to confirm that hybrid Larch plantation did not decreased the soil fertility, and the hybrid Larch plantation with densities of 3300/hm2and 4400/hm2could be conductive to improving the soil quality. The results would provide the theories basis for manage the hybrid Larch plantations.

Indices of soil nitrogen availability in five Tasmanian Eucalyptus nitens plantations

Soil Research ◽  
2004 ◽  
Vol 42 (7) ◽  
pp. 719 ◽  
Author(s):  
M. T. Moroni ◽  
P. J. Smethurst ◽  
G. K. Holz
Keyword(s):  
Soil Solution ◽  
Nitrogen Availability ◽  
Native Forest ◽  
N Availability ◽  
Eucalyptus Nitens ◽  
Soil Nitrogen Availability ◽  
Mineral N ◽  
Total N ◽  
Available N ◽  
Total P

Several soil analyses were used to estimate available N in surface soils (0–10 cm) over a 2-year period at 5 sites that supported 1- to 4-year-old Eucalyptus nitens plantations, and once in subsoils (10–120 cm) at 3 of these sites. Soils were derived from basalt (1 site previously pasture, 1 Pinus radiate, and 2 native forest) or siltstone (previously native forest). Soil analyses examined were total N, total P, total C, anaerobically mineralisable N (AMN), hot KCl-extractable N (hot KCl-N), and NH4+ and NO3– in soil solution and KCl extracts. AMN, KCl-extractable NH4+ and NO3–, and soil solution NH4+ and NO3– varied considerably with time, whereas hot KCl-N, total N, total P, and total C were temporally stable except for a gradual decline in total C with time at one site. Only total P was correlated with net N mineralisation (NNM) across all sites (r2 = 0.91, P < 0.05, n = 5). At 2–3 years after planting, soil solution and KCl-extractable NO3– dropped below 0.1 mm N and 1 μg N/g soil, respectively, at sites with NNM ≤24 kg N/ha.year (n = 3). Sites with NNM ≤24 kg N/ha.year also had ≤0.8 Mg P/ha. Although concentrations of indices of soil N availability decreased with depth, the contribution of subsoil (10–120 cm depth) to total profile N availability was estimated to be at least twice that of the top 10 cm. At an ex-pasture site, high concentrations of mineral N were found at 75–105 cm depths (KCl-extractable N, 289.3 μg N/g soil; 2.8 mm mineral N in soil solution), which may have become available to plantations as their root systems developed.

Amounts and sources of phosphate in hill country rocks, south-eastern North Island, New Zealand

Soil Research ◽  
1992 ◽  
Vol 30 (3) ◽  
pp. 357 ◽  
Author(s):  
DN Eden ◽  
RL Parfitt
Keyword(s):  
New Zealand ◽  
Plant Growth ◽  
Heavy Fraction ◽  
Soil Environment ◽  
Size Fractions ◽  
Hill Country ◽  
South Eastern ◽  
Parent Rocks ◽  
Reactive Surfaces ◽  
Total P

The phosphate (P) present in a range of parent rocks for hill country soils in Wairarapa region, New Zealand, has been studied. In general the highest P concentrations occur in the mudstones which contain 50% more P than the fine to medium sandstones, and at least 10 times more P than the coarse sandstones. Most of the P is in the 20-2 �m and <2 �m size fractions of the rocks. The P is present both in apatite and calcite mineral grains. Although the highest P concentrations occur in the heavy fraction (containing apatite), most of the total P is held in the light fraction in which calcite is abundant and where some apatite also occurs within aggregates. Since both calcite and apatite are relatively soluble in this soil environment, and since both have large reactive surfaces, they may readily release P for plant growth.

Precipitation nutrients in the open and under two forests in Minnesota

1977 ◽  
Vol 7 (1) ◽  
pp. 112-119 ◽  
Author(s):  
Elon S. Verry ◽  
D. R. Timmons
Keyword(s):  
Forest Floor ◽  
Black Spruce ◽  
Inorganic Nitrogen ◽  
Annual Precipitation ◽  
Nutrient Inputs ◽  
Nutrient Input ◽  
Forest Canopies ◽  
North Central ◽  
Annual Amount ◽  
Total P

Concentrations of N, P, K, Ca, Mg, and Na were measured in rain and snow in the open, and in throughfall and stemflow under black spruce and aspen forests in north-central Minnesota. Concentrations of total P in rain and black spruce throughfall were inversely related to storm size. Annual precipitation nutrient inputs to the forest floor were calculated for each site. In general, nutrient contributions from snow were less than 10% of the annual nutrient input from precipitation at each site, and differences in snow nutrient input between sites were minimal. Rainfall nutrient input differed significantly between sites. Rain and snow passing through both forest canopies were enriched with nutrients except inorganic nitrogen. Total annual nutrients added to the forest floor under the black spruce stand averaged 1.7 times that added in the open; the annual amount added under the aspen stand averaged 5.2 times that added in the open.

Impact of Soil Nutrient Contents and Spatial Variability in Different Sampling Schemes under the Conservation Tillage

2013 ◽  
Vol 718-720 ◽  
pp. 316-320
Author(s):  
Si Jia Li ◽  
Yan Nan Sun ◽  
Hong Bin Wang ◽  
Zhi Wen Chen
Keyword(s):  
Conservation Tillage ◽  
Cropping System ◽  
Soil Nutrient ◽  
Parent Material ◽  
Available P ◽  
Moderate Intensity ◽  
Structural Factors ◽  
Available N ◽  
Nutrient Contents ◽  
Sampling Schemes

According to the 40×40m mesh, taking the 180 soil samples in both strains and ridges of the demonstration fields under the stalk mulching conservation tillage for 5 consecutive years in Gaojia country, which the area covers 15 hm2 in Li Shu town, Jilin Province. The available N, available P, available K and other nutrition of soil in different sampling schemes have been tested. Based on the platform of GIS and the method of geostatistical analyst, the space distribution's characteristics of the three kinds of soil's nutrients have been researched, which demonstrate each variable corresponds normal distribution, the contents of available N and available K in different sampling schemes vary so much, but the content of available P has shown much more similarity than difference. Through the analysis of semivariogram, the soil nutrients in every different sampling schemes have revealed a moderate intensity autocorrelation and a relative strong spatial heterogeneity, which are affected by structural factors such as soil types, parent material, terrain, climate, hydrological conditions and so on, and they are also affected by random factors, for example, fertilization, cropping system, tillage operation and management. Analyzing the three nutrients in different sampling schemes, which are affected by random factors. Through applying the semivariogram and kriging to analyze the impacts factors of spatial variable in the soil, there are the differences between the two methods.

scholarly journals Controls on heterotrophic soil respiration and carbon cycling in geochemically distinct African tropical forest soils

2021 ◽  
Author(s):  
Benjamin Bukombe ◽  
Peter Fiener ◽  
Alison M. Hoyt ◽  
Sebastian Doetterl
Keyword(s):  
Soil Respiration ◽  
Tropical Forest ◽  
Forest Soils ◽  
Soil Chemistry ◽  
Poor Quality ◽  
Parent Material ◽  
Soil C ◽  
Soil Parent Material ◽  
C Stocks ◽  
Heterotrophic Soil Respiration

Abstract. Heterotrophic soil respiration is an important component of the global terrestrial carbon (C) cycle, driven by environmental factors acting from local to continental scales. For tropical Africa, these factors and their interactions remain largely unknown. Here, using samples collected along strong topographic and geochemical gradients in the East African Rift Valley, we study how soil chemistry and soil fertility, derived from the geochemical composition of soil parent material, can drive soil respiration even after many millennia of weathering and soil development. To address the drivers of soil respiration, we incubated soils from three regions with contrasting geochemistry (mafic, felsic, and mixed sedimentary) sampled along slope gradients. For three soil depths, we measured the potential maximum heterotrophic respiration under stable environmental conditions as well as the radiocarbon content (Δ14C) of the bulk soil and respired CO2. We found that soil microbial communities were able to mineralize C from fossil as well as other poor quality C sources under laboratory conditions representative of tropical topsoils. Furthermore, despite similarities in terms of climate, vegetation, and the size of soil C stocks, soil respiration showed distinct patterns with soil depth and parent material geochemistry. The topographic origin of our samples was not a main determinant of the observed respiration rates and Δ14C. In situ, however, soil hydrological conditions likely influence soil C stability by inhibiting decomposition in valley subsoils. Our study shows that soil fertility conditions are the main determinant of C stability in tropical forest soils. Further, in the presence of organic carbon sources of poor quality or the presence of strong mineral related C stabilization, microorganisms tend to discriminate against these sources in favor of more accessible forms of soil organic matter as energy sources, resulting in a slower rate of C cycling. Our results demonstrate that even in deeply weathered tropical soils, parent material has a long-lasting effect on soil chemistry that can influence and control microbial activity, the size of subsoil C stocks, and the turnover of C in soil. Soil parent material and its lasting control on soil chemistry need to be taken into account to understand and predict C stabilization and rates of C cycling in tropical forest soils.

Cadmium distribution and inventories at a pre-European seabird breeding site on agricultural land, Banks Peninsula, New Zealand

Soil Research ◽  
2003 ◽  
Vol 41 (1) ◽  
pp. 19 ◽  
Author(s):  
D. J. Hawke
Keyword(s):  
New Zealand ◽  
Agricultural Land ◽  
Surface Soil ◽  
Agricultural Soils ◽  
Soil Depth ◽  
Breeding Site ◽  
Parent Material ◽  
Agricultural Activity ◽  
Hill Country ◽  
Agricultural Site

Cadmium distribution was determined at a hill country agricultural site with no history of fertiliser application, but where pre-European seabird breeding occurred. Total Cd concentrations were measured in 2 depth profiles on the ridgeline, and in surface soil (0–15 cm; 15 ridgeline and 7 sideslope transects). Concentrations were low (range 0.04–0.13 mg/kg) for New Zealand agricultural soils. Concentrations were independent of stock camps (locations frequented by grazing animals), altitude, soil depth, organic matter, and N and P concentrations. Surface Cd concentrations on the sideslope were significantly higher than the ridgeline. Inventories from the 2 ridgeline profiles (29.9 ± 2.4 mg/m2; 18.4 ± 1.5 mg/m2) were higher than the 16 mg/m2 and 7 mg/m2, respectively, predicted from the loess and basalt parent material concentrations; surface soil concentrations also exceeded those predicted from parent materials. Together, these results suggest that agricultural activity has not significantly redistributed Cd, and that external sources have contributed a large proportion of soil Cd. Atmospheric input was too low to explain all of the observed enrichment. Instead, Cd distribution was consistent with seabird input concentrated in the deeper soils of the sideslope rather than the relatively thin soils of the ridgeline.

Soil selenium in a forested seabird colony: distribution, sources, uptake by plants, and comparison with non-seabird sites

Soil Research ◽  
2012 ◽  
Vol 50 (7) ◽  
pp. 588 ◽  
Author(s):  
David J. Hawke ◽  
Jun-Ru Wu
Keyword(s):  
Terrestrial Ecosystems ◽  
Breeding Site ◽  
Control Site ◽  
Parent Material ◽  
Median Surface ◽  
Breeding Colony ◽  
Model Soil ◽  
Soil Parent Material ◽  
Plant Foliage ◽  
A Site

Seabirds vector selenium (Se) into terrestrial ecosystems in Antarctica and on tropical coral islands, but factors controlling distribution within affected soils are unknown, especially in temperate regions. At a Westland petrel (Procellaria westlandica) breeding colony on mainland New Zealand, the concentration of Se in petrel guano (3.6 mg kg–1) exceeded soil parent material (0.8 mg kg–1) and in all but two soil samples (range 1.2–4.2 mg kg–1; n = 52). External Se (Se not derived from parent material) accounted for 64 ± 9% (mean ± s.d.) of soil Se. Measurements were also made at a former seabird breeding site, and at a site with no Holocene seabird breeding. Median surface-soil Se concentrations (mg kg–1) were in the order burrow soil (2.6) > adjacent forest floor (2.2) > former breeding site (1.0) > control site (0.2), with significant differences between burrow soil and (1) the former breeding site and (2) the control site. In a linear regression model, soil pH, and δ15N were the only significant predictors of external Se in colony soil. The correlations are consistent with seabird input driving both the Se supply and increased sorptive uptake in an environment acidified by seabird guano. Despite the enhanced Se in colony soil, median foliage concentrations (tree fern 0.05 mg kg–1, nikau 0.08 mg kg–1) were close to the accepted minimum for herbivore nutrition. Seabirds therefore contribute significant Se to breeding colony soils in temperate areas, but this is not necessarily transferred to plant foliage.

scholarly journals Soil Phosphorus Speciation and Availability in Meadows and Forests in Alpine Lake Watersheds With Different Parent Materials

2021 ◽  
Vol 3 ◽  
Author(s):  
Thomas Heron ◽  
Daniel G. Strawn ◽  
Mariana Dobre ◽  
Barbara J. Cade-Menun ◽  
Chinmay Deval ◽  
...  
Keyword(s):  
Forest Soils ◽  
Management Practices ◽  
Lake Tahoe ◽  
Parent Material ◽  
P Availability ◽  
Organic P ◽  
Lake Tahoe Basin ◽  
Parent Materials ◽  
Tahoe Basin ◽  
Total P

In the Lake Tahoe Basin in California and Nevada (USA), managing nutrient export from watersheds into streams and the lake is a significant challenge that needs to be addressed to improve water quality. Leaching and runoff of phosphorus (P) from soils is a major nutrient source to the lake, and P loading potential from different watersheds varies as a function of landscape and ecosystem properties, and how the watershed is managed. In this research, P availability and speciation in forest and meadow soils in the Lake Tahoe Basin were measured at two watersheds with different parent material types. Soils developed on andesitic parent materials had approximately twice as much total P compared to those developed on granitic parent materials. Regardless of parent material, organic P was 79–92% of the total P in the meadow soils, and only 13–47% in the forest soils. Most of the soil organic P consisted of monoester P compounds, but a significant amount, especially in meadow soils, was diester P compounds (up to 30% of total extracted P). Water extractable P (WEP) concentrations were ~10 times greater in the granitic forest soils compared to the andesitic forest soils, which had more poorly crystalline aluminosilicates and iron oxides that retain P and thus restrict WEP export. In the meadow soils, microbial biomass P was approximately seven times greater than the forest soils, which may be an important sink for P leached from upland forests. Results show that ecosystem and parent material are important attributes that control P speciation and availability in the Lake Tahoe Basin, and that organic P compounds are a major component of the soil P and are available for leaching from the soils. These factors can be used to develop accurate predictions of P availability and more precise forest management practices to reduce P export into Lake Tahoe.

The Effects of N and P Addition on the Soil Properties of a Eucalyptus urophylla Stand

2014 ◽  
Vol 700 ◽  
pp. 314-322
Author(s):  
Qiu Jing Li ◽  
Li Xue ◽  
Hong Yue Chen
Keyword(s):  
Organic Matter ◽  
Soil Bacteria ◽  
Eucalyptus Urophylla ◽  
N Addition ◽  
N Content ◽  
Total N ◽  
Available N ◽  
Biochemical Indices ◽  
P Addition ◽  
Total P

The effects of N and P addition on soil organic matter and nutrients, microbe and enzyme were investigated in a Eucalyptus urophylla stand to provide basis for soil management. Contents of organic matter, available P of N, P and N + P addition was significantly greater than the control, total N content of N and N+P addition was significant greater than the control, contents of total P, total K and available K of P and N + P addition was significantly greater than the control, available N content of N addition was significantly greater than the control, whereas that of P addition was significantly smaller than the control. N addition significantly increased the soil actinomyces number and urease activity, but had no significant effect on the number of soil bacteria and fungus, activities of phosphatase and catalase. Number of soil bacteria, fungus and actinomyces, activities of urease, phosphatase and catalase significantly increased after P addition, and biochemical indices except for bacteria number significantly increased after N + P addition.

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