Effect of superphosphate addition on N mineralization in some Australian forest soils

Pinus radiata stands are reported to accumulate increased N on addition of phosphatic fertilizers. Field and laboratory studies were initiated to determine if addition of superphoshate increases soil N mineralization in forest soils. In a field experiment, application of 200 kg P ha-1 as superphosphate to trenched plots in a Pinus radiata stand increased accumulated soil mineral-N contents by 122% and 82% above the control on two occasions. Application of 500 kg P ha-1 as superphosphate either alone or in combination with lime (10 Mg ha-1) increased in situ soil net N mineralization in a dry sclerophyll eucalypt forest from 20.7 (control) to 28.3 (+P) and 30.2 (+P+lime) kg N ha-1 yr-1 20 cm-1. Uptake by the vegetation accounted for all of the mineralized nitrogen. In a 180 day laboratory incubation using undisturbed soil columns (0-20 cm) from nine forest sites, seven soils showed a positive response to superphosphate (100 kg P ha-1) addition, with increases in N mineralization ranging from 14% to 117%. The response of N mineralization to superphosphate addition was not related to initial soil organic C, total N or P content in the 0-20 cm layer. However, soil pH and organic C combined to account for 76% of the variation in N mineralization response (P < 0.01). In the 0-5 cm layer of untreated soils, soil organic P content could explain 71% of the variation in net N mineralization. Addition of superphosphate appears to increase N mineralization in several Australian forest soils and the improved availability of N will enhance tree growth rates. The mechanisms underlying the response are still poorly understood and thus also our ability to predict its significance for tree nutrition on specific forest sites.

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Nitrogen transformations in the rhizosphere of different tree types in a seasonally flooded soil

Plant Soil and Environment ◽

10.17221/878/2013-pse ◽

2014 ◽

Vol 60 (No. 6) ◽

pp. 249-254 ◽

Cited By ~ 8

Author(s):

D. Liu ◽

S. Fang ◽

Y. Tian ◽

Chang SX

Keyword(s):

Tree Species ◽

N Mineralization ◽

Rhizosphere Soil ◽

Net N Mineralization ◽

Flooded Soil ◽

N Transformations ◽

Total N ◽

Organic C ◽

Rhizosphere Effects ◽

Seasonally Flooded

Plant roots strongly influence C and N availability in the rhizosphere via rhizodeposition and uptake of nutrients. An in situ rhizobox approach was used to compare rhizosphere effects of different tree species and clones on N cycling under seasonally flooded soil. We examined N mineralization and nitrification rates, inorganic N, and microbial biomass C (MBC) and N (MBN) in rhizosphere and bulk soils of three poplar clones, alder, and willow plantations in southeast China. Significant differences in soil pH, total N, soil organic C, MBC, MBN, and MBC/MBN were found between bulk and rhizosphere soils except alder. Compared to bulk soil, the net N mineralization and nitrification rates in rhizosphere soil across all tree species and clones increased by 124–228% and 108–216%, respectively. However, NO<sub>3</sub><sup>–</sup>-N was depleted in the rhizosphere soil mainly owing to the root uptake and rhizosphere microbial immobilization. The magnitude of rhizosphere effects on N transformations was considerably different among the tree species studied. Of the tested ones, alder had the greatest rhizosphere effect on N transformation, indicating different capacities of tree species to facilitate N turnover in the rhizosphere.

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Nitrogen mineralization and nitrification in upland and peatland forest soils in two Canadian Shield catchments

Canadian Journal of Forest Research ◽

10.1139/x99-148 ◽

1999 ◽

Vol 29 (11) ◽

pp. 1793-1804 ◽

Cited By ~ 42

Author(s):

Kevin J Devito ◽

Cherie J Westbrook ◽

Sherry L Schiff

Keyword(s):

Forest Soils ◽

N Mineralization ◽

Organic N ◽

Net N Mineralization ◽

Forest Stands ◽

Mixed Stands ◽

N Transformations ◽

Total N ◽

Soil C ◽

Net Mineralization

Net mineralization and nitrification in surface forest soils were measured in upland forest stands and valley peatlands using in situ soil incubations at two headwater catchments of Harp Lake, Ontario from July 1995 to October 1996. No difference in either net N mineralization or nitrification was observed between the two adjacent catchments despite differences in catchment N export. Annual rates of net N mineralization in surface 10 cm were higher in forest soils of the deciduous (11.5 ± 3.1 g/m2; mean ± SE) and conifer-mixed (conifer-hardwoods) (13.9 ± 2.3 g/m2) stands than in peatland soils (1.6 ± 0.6 g/m2). Mean annual nitrification rates were higher in deciduous soils (6.6 ± 0.7 g N/m2) than in mixed stands (1.9 ± 0.6 g N/m2) and peatland soils (0.1 ± 0.2 g N/m2). Annual net N mineralization and nitrification were correlated with variations in soil C and N content and moisture associated with different forest stands. Frequent winter incubations indicate that net mineralization and nitrification under snow cover in upland surface soils can contribute as much as 49 and 23% of the annual net production, respectively. The importance of forest vegetation patterns, winter N transformations, and dissolved organic N pools to total N and NO3- cycling and leaching in these catchments is discussed.

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Effect of compaction on microbial activity and carbon and nitrogen transformations in two oxisols with different mineralogy

Revista Brasileira de Ciência do Solo ◽

10.1590/s0100-06832011000400007 ◽

2011 ◽

Vol 35 (4) ◽

pp. 1141-1149 ◽

Cited By ~ 10

Author(s):

Sérgio Ricardo Silva ◽

Ivo Ribeiro da Silva ◽

Nairam Félix de Barros ◽

Eduardo de Sá Mendonça

Keyword(s):

Organic Matter ◽

Microbial Activity ◽

Soil Compaction ◽

N Mineralization ◽

Organic N ◽

Net N Mineralization ◽

Mineral N ◽

Organic C ◽

Soil Microbial ◽

Controlled Conditions

The use of machinery in agricultural and forest management activities frequently increases soil compaction, resulting in greater soil density and microporosity, which in turn reduces hydraulic conductivity and O2 and CO2 diffusion rates, among other negative effects. Thus, soil compaction has the potential to affect soil microbial activity and the processes involved in organic matter decomposition and nutrient cycling. This study was carried out under controlled conditions to evaluate the effect of soil compaction on microbial activity and carbon (C) and nitrogen (N) mineralization. Two Oxisols with different mineralogy were utilized: a clayey oxidic-gibbsitic Typic Acrustox and a clayey kaolinitic Xantic Haplustox (Latossolo Vermelho-Amarelo ácrico - LVA, and Latossolo Amarelo distrófico - LA, respectively, in the Brazil Soil Classification System). Eight treatments (compaction levels) were assessed for each soil type in a complete block design, with six repetitions. The experimental unit consisted of PVC rings (height 6 cm, internal diameter 4.55 cm, volume 97.6 cm³). The PVC rings were filled with enough soil mass to reach a final density of 1.05 and 1.10 kg dm-3, respectively, in the LVA and LA. Then the soil samples were wetted (0.20 kg kg-1 = 80 % of field capacity) and compacted by a hydraulic press at pressures of 0, 60, 120, 240, 360, 540, 720 and 900 kPa. After soil compression the new bulk density was calculated according to the new volume occupied by the soil. Subsequently each PVC ring was placed within a 1 L plastic pot which was then tightly closed. The soils were incubated under aerobic conditions for 35 days and the basal respiration rate (CO2-C production) was estimated in the last two weeks. After the incubation period, the following soil chemical and microbiological properties were detremined: soil microbial biomass C (C MIC), total soil organic C (TOC), total N, and mineral N (NH4+-N and NO3--N). After that, mineral N, organic N and the rate of net N mineralization was calculated. Soil compaction increased NH4+-N and net N mineralization in both, LVA and LA, and NO3--N in the LVA; diminished the rate of TOC loss in both soils and the concentration of NO3--N in the LA and CO2-C in the LVA. It also decreased the C MIC at higher compaction levels in the LA. Thus, soil compaction decreases the TOC turnover probably due to increased physical protection of soil organic matter and lower aerobic microbial activity. Therefore, it is possible to conclude that under controlled conditions, the oxidic-gibbsitic Oxisol (LVA) was more susceptible to the effects of high compaction than the kaolinitic (LA) as far as organic matter cycling is concerned; and compaction pressures above 540 kPa reduced the total and organic nitrogen in the kaolinitic soil (LA), which was attributed to gaseous N losses.

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Mineral nitrogen in tropical forest soils

The Journal of Agricultural Science ◽

10.1017/s0021859600015288 ◽

1962 ◽

Vol 59 (2) ◽

pp. 257-262 ◽

Cited By ~ 9

Author(s):

R. K. Cunningham

Keyword(s):

Organic Matter ◽

Tropical Forest ◽

Forest Soils ◽

Mineral Nitrogen ◽

Surface Layers ◽

Mineral N ◽

Total N ◽

Organic C ◽

Mineralizable N ◽

Temperate Soils

1. Δmin-Nad is the most satisfactory measurement for assessing mineralizable-N in the tropical forest soils used; values are treble those for Δmin-Nf and then increase even further on storage. Comparisons of Δmin-Nad are pointless unless methods of sampling, drying, storing and incubating are standardized.2. Δmin-Nad is correlated with total N and organic C but not pH.3. Undisturbed tropical forest soils can produce very large quantities of mineral N, particularly in their surface layers. This probably accounts for the lack of N responses in these soils. More intensive cultivation of these soils is only possible when organic matter is preserved by protecting cleared soils.4. Added nitrogen was leached more rapidly in these soils than in comparable temperate soils but was not fast enough to prevent absorption by plants.

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Effects of green-manure and tillage management on soil microbial community composition, nutrients and tree growth in a walnut orchard

Scientific Reports ◽

10.1038/s41598-021-96472-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Ningguang Dong ◽

Guanglong Hu ◽

Yunqi Zhang ◽

Jianxun Qi ◽

Yonghao Chen ◽

...

Keyword(s):

Microbial Community ◽

Green Manure ◽

Rhizosphere Soil ◽

Green Manures ◽

Hairy Vetch ◽

Mineral N ◽

Total N ◽

Organic C ◽

Nutrient Contents ◽

Walnut Tree

AbstractThis study characterized the effect of green manures (February orchid, hairy vetch, rattail fescue and a no-green-manure control) and the termination method (flail or disk) on nutrient contents, enzyme activities, microbial biomass, microbial community structure of rhizosphere soil and vegetative growth of walnut tree. All three selected green manures significantly enhanced the water content, organic C, total N and available P. The rattail fescue significantly decreased the mineral N. Total organic C, total N, mineral N and available P were significantly greater under flail than under disk. Hairy vetch and February orchid significantly improved levels of soil β-glucosidase, N-acetyl-glucosaminidase and acid phosphatase activity, whereas rattail fescue improved only β-glucosidase activity. All of the green manures significantly decreased phenoloxidase activity. β-glucosidase, N-acetyl-glucosaminidase and acid phosphatase activities were significantly greater under flail relative to disk. The termination method had no significant effect on phenoloxidase activity. The different types of green manures and termination methods significantly altered the soil microbial biomass and microbial community structure. The green-manure treatments were characterized by a significantly greater abundance of Gram-positive (Gram +) bacteria, total bacteria and saprophytic fungi compared to the control. Hairy vetch significantly decreased the abundance of arbuscular mycorrhizal fungi (AMF) while February orchid and rattail fescue increased their abundance compared to the no-green-manure treatment. The abundance rates of Gram+ bacteria, actinomycetes, saprophytic fungi and AMF were significantly greater in soils under flail than under disk. In terms of vegetative growth of walnut tree, hairy vetch showed the greatest positive effects. The growth of walnut tree was significantly greater under flail relative to disk. Our results indicate that green-manure application benefits the rhizosphere soil micro-ecology, rhizosphere soil nutrient contents and tree growth. Overall, the hairy vetch and flail combined treatment is recommended for walnut orchards in northern China.

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

Soil Research ◽

10.1071/sr00026 ◽

2001 ◽

Vol 39 (3) ◽

pp. 519 ◽

Cited By ~ 25

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.

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Impact of the addition of different plant residues on carbon–nitrogen content and nitrogen mineralization–immobilization turnover in a soil incubated under laboratory conditions

Solid Earth Discussions ◽

10.5194/sed-6-3051-2014 ◽

2014 ◽

Vol 6 (2) ◽

pp. 3051-3074 ◽

Cited By ~ 1

Author(s):

M. K. Abbasi ◽

M. M. Tahir ◽

N. Sabir ◽

M. Khurshid

Keyword(s):

Nitrogen Mineralization ◽

Biochemical Composition ◽

N Mineralization ◽

Growth Promotion ◽

Lignin Content ◽

Leguminous Plant ◽

Plant Residues ◽

Net N Mineralization ◽

N Transformations ◽

Total N

Abstract. Application of plant residues as soil amendment may represent a valuable recycling strategy that affects on carbon (C) and nitrogen (N) cycling, soil properties improvement and plant growth promotion. The amount and rate of nutrient release from plant residues depend on their quality characteristics and biochemical composition. A laboratory incubation experiment was conducted for 120 days under controlled conditions (25 °C and 58% water filled pore space (WFPS)) to quantify initial biochemical composition and N mineralization of leguminous and non-leguminous plant residues i.e. the roots, shoots and leaves of Glycine max, Trifolium repens, Zea mays, Poplus euramericana, Rubinia pseudoacacia and Elagnus umbellate incorporated into the soil at the rate of 200 mg residue N kg−1 soil. The diverse plant residues showed wide variation in total N, carbon, lignin, polyphenols and C/N ratio with higher polyphenol content in the leaves and higher lignin content in the roots. The shoot of G. max and the shoot and root of T. repens displayed continuous mineralization by releasing a maximum of 109.8, 74.8 and 72.5 mg N kg−1 and representing a 55, 37 and 36% of added N being released from these resources. The roots of G. max and Z. mays and the shoot of Z. mays showed continuous negative values throughout the incubation showing net immobilization. After an initial immobilization, leaves of P. euramericana, R. pseudoacacia and E. umbellate exhibited net mineralization by releasing a maximum of 31.8, 63.1 and 65.1 mg N kg−1, respectively and representing a 16, 32 and 33% of added N being released. Nitrogen mineralization from all the treatments was positively correlated with the initial residue N contents (r = 0.89; p ≤ 0.01), and negatively correlated with lignin content (r = −0.84; p ≤ 0.01), C/N ratio (r = −0.69; p ≤ 0.05), lignin/N ratio (r = −0.68; p ≤ 0.05), polyphenol/N ratio (r = −0.73; p ≤ 0.05) and ligin + polyphenol/N ratio (r = −0.70; p ≤ 0.05) indicating a significant role of residue chemical composition and quality in regulating N transformations and cycling in soil. The present study indicates that incorporation of plant residues strongly modify the mineralization-immobilization turnover (MIT) of soil that can be taken into account to develop synchronization between net N mineralization and crop demand in order to maximize N delivery and minimize N losses.

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Mid-Term Effects of Forest Thinning on N Mineralization in a Semi-Arid Aleppo Pine Forest

Forests ◽

10.3390/f12111470 ◽

2021 ◽

Vol 12 (11) ◽

pp. 1470

Author(s):

Inmaculada Bautista ◽

Luis Lado-Monserrat ◽

Cristina Lull ◽

Antonio Lidón

Keyword(s):

N Mineralization ◽

Nutrient Dynamics ◽

Pinus Halepensis ◽

Block Design ◽

Plant Cover ◽

Basal Area ◽

Net N Mineralization ◽

Mineral N ◽

Silvicultural Treatments ◽

Randomized Block Design

In order to assess the sustainability of silvicultural treatments in semiarid forests, it is necessary to know how they affect the nutrient dynamics in the forest. The objective of this paper is to study the effects of silvicultural treatments on the net N mineralization and the available mineral N content in the soil after 13 years following forest clearings. The treatments were carried out following a randomized block design, with four treatments and two blocks. The distance between the two blocks was less than 3 km; they were located in Chelva (CH) and Tuéjar (TU) in Valencia, Spain. Within each block, four experimental clearing treatments were carried out in 1998: T0 control; and T60, T75 and T100 where 60%, 75% and 100 of basal area was eliminated, respectively. Nitrogen dynamics were measured using the resin tube technique, with disturbed samples due to the high stoniness of the plots. Thirteen years after the experimental clearings, T100, T75 and T60 treatments showed a twofold increase in the net mineralization and nitrification rates with respect to T0 in both blocks (TU and CH). Within the plots, the highest mineralization was found in sites with no plant cover followed by those covered by undergrowth. These results can be explained in terms of the different litterfall qualities, which in turn are the result of the proportion of material originating from Pinus halepensis Mill. vs. more decomposable undergrowth residues.

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

International Journal of Agronomy ◽

10.1155/2012/120429 ◽

2012 ◽

Vol 2012 ◽

pp. 1-12 ◽

Cited By ~ 4

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.

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Nitrogen Availability in Biochar-Amended Soils with Excessive Compost Application

Agronomy ◽

10.3390/agronomy10030444 ◽

2020 ◽

Vol 10 (3) ◽

pp. 444 ◽

Cited By ~ 3

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.

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