Chemical and pedogenetic effects of simulated acid precipitation on two eastern Canadian forest soils. I. Nonmetals

1985 ◽  
Vol 15 (5) ◽  
pp. 839-847 ◽  
Author(s):  
J. A. Hern ◽  
G. K. Rutherford ◽  
G. W. vanLoon

An experiment involving the addition of simulated acid rain to two Canadian Shield orthic humo-ferric podzolic forest soils was carried out in the field and in the laboratory. Soils were subjected to treatments of pH 5.7, 3.5, and 2.0 water containing added nitric and sulphuric acids in a 1:2 molar ratio. Pore-water concentrations of H+, [Formula: see text], [Formula: see text], [Formula: see text], and Cl− were monitored at depths of 15–60 cm for up to 2 years. Some of the laboratory columns were dismantled after 1 year and total soil N, S, soil pH, and S adsorption characteristics were measured. Half the columns were sterilized in an attempt to assess the relative importance of microbial processes. Considerable H+ buffering by the soils was indicated, with soil pH unchanged even under the most acidic treatment. Nitrate but not ammonium production was suppressed under highly acid treatment conditions in the laboratory, while in the field only small concentrations of both nitrogen species were detected in pore water. No change in total soil N was detected. Sulphur retention was assessed, with major amounts retained by the soil just below the Ae horizon where iron and aluminum oxides along with organic matter accumulate. Sterile column data indicates microbial processes are also of considerable importance in the immobilization of S inputs.

1987 ◽  
Vol 108 (3) ◽  
pp. 609-615 ◽  
Author(s):  
I. Papastylianou ◽  
Th. Samios

SummaryUsing data from rotation studies in which barley or woollypod vetch were included, both cut for hay and preceding barley for grain, it is shown that forage barley gave higher dry-matter yield than woollypod vetch (3·74 v. 2·92 t/ha per year). However, the latter gave feedingstuff of higher nitrogen concentration and yield (86 kg N/ha per year for vetch v. 55 kg N/ha per year for barley). Rainfall was an important factor in controlling the yield of the two forages and the comparison between them in different years and sites. Barley following woollypod vetch gave higher grain yield than when following forage barley (2·36 v. 1·91 t/ha). Rotation sequences which included woollypod vetch had higher output of nitrogen (N) than input of fertilizer N with a positive value of 44–60 kg N/ha per year. In rotations where forage barley was followed by barley for grain the N balance between output and input was 5–6 kg N/ha. Total soil N was similar in the different rotations at the end of a 7-year period.


1996 ◽  
Vol 127 (3) ◽  
pp. 347-363 ◽  
Author(s):  
M. J. Glendining ◽  
D. S. Powlson ◽  
P. R. Poulton ◽  
N. J. Bradbury ◽  
D. Palazzo ◽  
...  

SUMMARYThe Broadbalk Wheat Experiment at Rothamsted (UK) includes plots given the same annual applications of inorganic nitrogen (N) fertilizer each year since 1852 (48, 96 and 144 kg N/ha, termed N1 N2 and N3 respectively). These very long-term N treatments have increased total soil N content, relative to the plot never receiving fertilizer N (N0), due to the greater return of organic N to the soil in roots, root exudates, stubble, etc (the straw is not incorporated). The application of 144 kg N/ha for 135 years has increased total soil N content by 21%, or 570 kg/ha (0–23 cm). Other plots given smaller applications of N for the same time show smaller increases; these differences were established within 30 years. Increases in total soil N content have been detected after 20 years in the plot given 192 kg N/ha since 1968 (N4).There was a proportionally greater increase in N mineralization. Crop uptake of mineralized N was typically 12–30 kg N/ha greater from the N3 and N4 treatments than the uptake of c. 30 kg N/ha from the N0 treatment. Results from laboratory incubations show the importance of recently added residues (roots, stubble, etc) on N mineralization. In short-term (2–3 week) incubations, with soil sampled at harvest, N mineralization was up to 60% greater from the N3 treatment than from N0. In long-term incubations, or in soil without recently added residues, differences between long-term fertilizer treatments were much less marked. Inputs of organic N to the soil from weeds (principally Equisetum arvense L.) to the N0–N2 plots over the last few years may have partially obscured any underlying differences in mineralization.The long-term fertilizer treatments appeared to have had no effect on soil microbial biomass N or carbon (C) content, but have increased the specific mineralization rate of the biomass (defined as N mineralized per unit of biomass).Greater N mineralization will also increase losses of N from the system, via leaching and gaseous emissions. In December 1988 the N3 and N4 plots contained respectively 14 and 23 kg/ha more inorganic N in the profile (0–100 cm) than the N0 plot, due to greater N mineralization. These small differences are important as it only requires 23 kg N/ha to be leached from Broadbalk to increase the nitrate concentration of percolating water above the 1980 EC Drinking Water Quality Directive limit of 11·3mgN/l.The use of fertilizer N has increased N mineralization due to the build-up of soil organic N. In addition, much of the organic N in Broadbalk topsoil is now derived from fertilizer N. A computer model of N mineralization on Broadbalk estimated that after applying 144 kg N/ha for 140 years, up to half of the N mineralized each year was originally derived from fertilizer N.In the short-term, the amount of fertilizer N applied usually has little direct effect on losses of N over winter. In most years little fertilizer-derived N remains in Broadbalk soil in inorganic form at harvest from applications of up to 192 kg N/ha. However, in two very dry years (1989 and 1990) large inorganic N residues remained at harvest where 144 and 192 kg N/ha had been applied, even though the crop continued to respond to fertilizer N, up to at least 240 kg N/ha.


HortScience ◽  
2015 ◽  
Vol 50 (7) ◽  
pp. 1055-1063 ◽  
Author(s):  
S. Castro Bustamante ◽  
T.K. Hartz

Organic processing tomato (Solanum lycopersicum L.) production is a significant industry in California, yet little nitrogen (N) fertility research is available to guide N management. A total of 37 certified organic processing tomato fields in the Sacramento Valley of California were monitored during the 2012 and 2013 production seasons, with two objectives: 1) to document current N management practices and 2) to investigate the utility of early-season soil and plant N monitoring techniques in predicting seasonal crop N sufficiency. Between ≈3 and 11 weeks after transplanting (WAT) soil mineral N (SMN), leaf N and petiole NO3-N were determined every other week. In 22 fields, whole plant N concentration at ≈11 WAT was determined as a measure of crop N sufficiency. Growers were surveyed regarding N management practices used and fruit yields achieved. Net N mineralization (Nmin) was measured for 20 fields soils by aerobic laboratory incubation. Carbon mineralization (Cmin) in 24 hours following rewetting of air-dried soil and water extractable organic nitrogen (WEON) and carbon (WEOC) were also determined and evaluated as predictors of Nmin. Nitrogen management was primarily based on the application of manure or manure compost in the fall. Organic fertilizers were applied mainly in spring (pre- and post-transplanting). SMN in the top 60 cm at 3 WAT ranged from 6 to 32 mg·kg−1. About 30% of fields were N deficient by 11 WAT. Sensitivity analysis showed that SMN (whether measured from 0 to 30 or 0 to 60 cm) and leaf N at 5 WAT correctly predicted late-season plant N status in >60% of the fields. Nmin in 28 days ranged from 8 to 31 mg·kg−1, representing an average of 2% of total soil N. Correlation between Nmin and Cmin was weak (r = 0.44, P = 0.051) while stronger correlations were observed between Nmin and WEOC, WEON and total soil N (r = 0.63, 0.61 and 0.51, respectively, all P < 0.03). A multiple linear regression model that used 3 WAT SMN (0–30 cm) and WEON as independent variables improved Nmin prediction (adj. R2 = 0.67). Significant fruit yield increase with sidedress N application of feather meal at 5–6 WAT was observed in 2 of 4 field trials, demonstrating the ability to remedy a soil N limitation identified by early-season N monitoring.


1994 ◽  
Vol 45 (6) ◽  
pp. 1293 ◽  
Author(s):  
PF White ◽  
NK Nersoyan ◽  
S Christiansen

There is a need to quantify the effects on soil N of introducing different legumes into the farming systems of West Asia and North Africa. This paper presents 6 years results from an on-going experiment aimed at examining the productivity of several crop/livestock farming systems in north west Syria. Changes in total soil N and organic matter when either medic pasture (3 stocking rates), vetch, lentil, fallow or watermelon were rotated yearly with wheat were examined. In addition, in the sixth year of the experiment, mineral N levels in the soil and the N content of the wheat and legumes shoots were determined in order to formulate a simple N balance for each rotation. Medic pasture and vetch rotations increased total soil N and the organic matter content of the soil. Lentil had no effect on total soil N or the organic matter content. Total soil N also remained constant in the fallow rotation, but organic matter content of the soil tended to decrease. The changes in soil properties had implications for the long term production from the different rotations, and highlighted the importance of retaining legume residues for maintaining fertility.


1989 ◽  
Vol 69 (4) ◽  
pp. 849-855 ◽  
Author(s):  
S. C. SRIVASTAVA ◽  
A. K. JHA ◽  
J. S. SINGH

Soil biomass C, N and P were determined for a native forest site, an unmined deforested site and an age-series of adjacent coal mine spoils (5, 10, 12, 16 and 20 yr). Biomass C ranged from 209 to 867 μg g−1 soil, biomass N from 20 to 75 μg g−1 soil and biomass P from 7 to 29 μg g−1 soil. Biomass C, N and P were linearly related to each other. Biomass C was also related to the root biomass. Biomass N with a mean C:N ratio of 11.8 accounted for 2.2–4.2% of the total soil N and was positively related to the mineral N of soil. Biomass C:P ratio ranged from 27.6 to 31.0%. The biomass P was significantly related to the bicarbonate soluble soil Pi. Soil microbial biomass was characterized by a mean C:N:P ratio of 29:3:1. Soil microbial C, N and P were positively related with the age of mine spoils, the values for the youngest spoil (5 yr old) being about four times lower compared to native forest soil. Total soil N was also positively related with age of spoil. The data suggest that microbial biomass can be taken as a functional index of soil redevelopment. Key words: Surface coal mining, soil microbial biomass C, biomass N, biomass P, mine spoil


Soil Research ◽  
2004 ◽  
Vol 42 (7) ◽  
pp. 727 ◽  
Author(s):  
S. K. Dong ◽  
Y. Jiang ◽  
M. J. Wei ◽  
R. J. Long ◽  
Z. Z. Hu ◽  
...  

To illustrate the effect of nitrogen (N) application on soil physical and chemical characteristics, herbage yield and quality, and nitrogen and water use efficiency in the alpine region of Qinghai-Tibetan Plateau, a 3-year experiment was conducted on 3 mixtures of 4 perennial grasses commonly cultivated on the Plateau, Bromus inermis (BI) + Elymus nutans (EN), BI + E. sibricus (ES) + Agropyron cristatum (AC), and BI + ES + EN + AC by applying 4 levels of N fertiliser, 0, 115, 230, and 345 kg/ha from 1998 to 2000 in a randomised design. At harvesting time, soil pH and soil dry bulk density at 0–30 cm depth did not vary with N application rate. Soil organic carbon at 0–30 cm was not significantly variable under different N rates. Total soil N at 0–30 cm increased with N application rate and application year. After 3 years’ consecutive N treatment, total soil N reached 13 g/kg at an N application rate of 345 kg/ha. Soluble soil N at 0–30 cm increased with application rate but decreased with application year. At 345 kg N/ha application rate, soluble soil N was >100 mg/kg in 1998, but decreased to around 80 mg/kg in 2000. Herbage DM yields increased linearly with the N application rate. Compared with no fertiliser, 1.5 times more DM yield in 1998 and nearly double the DM yield in 1999 and 2000 were harvested for all grass mixtures at 345 kg N/ha. N concentrations in the herbages were significantly improved by N application. Each N fertiliser rate increased N contents in grass herbages by ≈3 g organic matter/kg. Apparent nitrogen recovery (ANR) decreased with N application rate in the establishment year of 1998, but increased with N application rate in 1999 and 2000. N use efficiency (NUE) decreased with N application throughout the experiment. Precipitation use efficiency (PUE) was significantly improved by N application for each grass mixture. Positive residual N-fertiliser effects were observed on herbage DM yield, ANR, NUE, and PUE in this study. BI + ES + AC showed higher DM yields, ANR, NUE, and PUE than the other 2 grass mixtures, and thus was proposed for N-input grassland systems in the alpine region of the Qinghai-Tibetan Plateau.


2010 ◽  
Vol 40 (2) ◽  
pp. 254-264 ◽  
Author(s):  
Robert A. Slesak ◽  
Timothy B. Harrington ◽  
Stephen H. Schoenholtz

Experimental treatments of logging-debris retention (0%, 40%, or 80% surface coverage) and competing vegetation control (initial or annual applications) were installed at two sites in the Pacific Northwest following clearcutting Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco var. menziesii) stands to assess short-term effects on tree N acquisition, soil N supply, and total soil N. Vegetation control treatments began in the first year after harvest, and logging-debris manipulations were installed 2 years after harvest. Annual vegetation control increased foliar N concentration and content in most years at both sites, which was associated with higher available soil N and increased soil water content. Logging-debris retention treatments had no detectable effect on any of the foliar variables or soil available N at either site. There were no treatment effects on total soil N at the site with relatively high soil N, but total soil N increased with logging-debris retention when annual vegetation control was applied at the site with a low initial soil N pool. Competing vegetation control is an effective means to increase tree N acquisition in the initial years after planting while maintaining soil N pools critical to soil quality. The effect of logging-debris retention on tree N acquisition appears to be limited during early years of stand development, but increased soil N with heavy debris retention at certain sites may be beneficial to tree growth in later years.


1999 ◽  
Vol 79 (2) ◽  
pp. 353-366 ◽  
Author(s):  
F. Selles ◽  
C. A. Campbell ◽  
B. G. McConkey ◽  
S. A. Brandt ◽  
D. Messer

Producers and scientists are seeking more accurate methods for estimating the N-supplying power of soil at the field level. This has become more urgent as new management technologies, such as precision farming, gain popularity on the Canadian Prairies. We characterized the N status of the soil on an 18-ha site on which a new long-term alternative farming experiment was being initiated at Scott, Saskatchewan, by taking 160 cores in a systematic manner in June 1994. In these cores we determined: i) total soil N; and ii) the N-supplying power of the soil by determining mineralizable N by aerobic incubation at optimum temperature and moisture, and by extracting NH4–N with 2 M KCl at 100°C. Because the field had been fertilized shortly before sampling, residual fertilizer N severely affected the quality of determinations of N supplying power at the 0- to 7.5-cm depth. Consequently, we limited our investigation to the 7.5- to 15-cm depth. We also determined pH, bulk density, and particle size distribution. Using geostatistics, simple correlations, and multiple regression analyses, we demonstrated a close association between the biological and chemical measures of N-supplying power of the soil. Semivariograms revealed that the spatial structure of the variance of both variables was similar, with about 70% of the variance resulting from unidentified processes, and the rest explained by spatial structure. Field maps prepared with block-kriged estimates, revealed that these two measures of N-supplying power were similarly distributed throughout the landscape, and followed closely the spatial distribution of total soil N throughout most of the field. However, we identified two areas of the field where the two estimators of N-supplying power had a weak association with total soil N. Multiple regression and cluster analysis indicated that this disparity was a function of differences in soil pH, bulk density, and geometric mean diameter of soil particles, suggesting that soil erosion-transport processes may have altered the nature of organic N in areas of the field. The relationship between N mineralized during a 24-wk incubation and NH4–N extracted with hot KCl was not affected by these differences, suggesting that the biological and chemical procedures tested were accessing similar pools of soil N. We concluded that hot KCl NH4–N should prove useful for quantifying the N supplying power of soils. Key words: Geostatistics, estimation, kriging, spatial variability, mineralizable N


2001 ◽  
Vol 1 ◽  
pp. 673-681 ◽  
Author(s):  
Alan J. Franzluebbers ◽  
John A. Stuedemann

The fate of nitrogen (N) applied in forage-based agricultural systems is important for understanding the long-term production and environmental impacts of a particular management strategy. We evaluated the factorial combination of three types of N fertilization (inorganic, crimson clover [Trifolium incarnatum L.] cover crop plus inorganic, and chicken [Gallus gallus] broiler litter pressure and four types of harvest strategy (unharvested forage, low and high cattle [Bos Taurus] grazing pressure, and monthly haying in summer) on surface residue and soil N pools during the first 5 years of ̒Coastal̓ bermudagrass (Cynodon dactylon [L.] Pers.) management. The type of N fertilization used resulted in small changes in soil N pools, except at a depth of 0 to 2 cm, where total soil N was sequestered at a rate 0.2 g ‧ kg–1‧ year–11 greater with inorganic fertilization than with other fertilization strategies. We could account for more of the applied N under grazed systems (76–82%) than under ungrazed systems (35–71%). As a percentage of applied N, 32 and 48% were sequestered as total soil N at a depth of 0 to 6 cm when averaged across fertilization strategies under low and high grazing pressures, respectively, which was equivalent to 6.8 and 10.3 g ‧ m–2‧ year–1. Sequestration rates of total soil N under the unharvested-forage and haying strategies were negligible. Most of the increase in total soil N was at a depth of 0 to 2 cm and was due to changes in the particulate organic N (PON) pool. The greater cycling of applied N into the soil organic N pool with grazed compared with ungrazed systems suggests an increase in the long-term fertility of soil.


1980 ◽  
Vol 94 (1) ◽  
pp. 247-249 ◽  
Author(s):  
B. R. Singh ◽  
A. P. Uriyo

SummaryThe magnitude of response to fertilizer-N and fertilizer-P decreased with increasing amounts of total soil-N and available soil-P, respectively. Attempts have been made to group the soils into N- and P-fertility classes based on the magnitude of response to applied fertilizers on soils of different fertility with respect to these two nutrient elements.


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