scholarly journals Foliar N:P Stoichiometry in Aralia elata Distributed on Different Slope Degrees

Author(s):  
Hongxu WEI ◽  
Hengtian ZHAO ◽  
Xin CHEN

Plant nitrogen (N) to phosphorus (P) stoichiometry is of essentially ecological meaning to non-wood forest production (NWFP) plant community in the temperate forest ecosystem. In this study, natural Aralia elata (Miq.) Seem. communities in montane areas of southern Heilongjiang Province, Northeast China were investigated for plant density, vegetative growth, and soil and leaf parameters on slopes in 5°, 9°, and 14° degrees. We found that individual height was greater in sites on 5°- (1.6 m) and 9°-degree slopes (1.9 m) than on the 14°-degree slope (0.8 m), but soil available P content was highest on the steepest slope (5.5, 4.0, and 16 mg kg-1, respectively). The foliar N:P ratio ranged 6–13. Nitrogen availability tended to promote community density and individual growth; while P availability tended to depress density but promote foliar biomass accumulation. By the diagnosis of plant nutritional monogram, the better growth and high foliar N:P ratio of about 13:1 in A. elata individuals on 9°-degree slope were generated by both deficiency-driving N uptake and excessive P depletion. We recommend the 9°-degree slope to develop A. elata community which can be fed by higher N availability if higher density was achieved.   ********* In press - Online First. Article has been peer reviewed, accepted for publication and published online without pagination. It will receive pagination when the issue will be ready for publishing as a complete number (Volume 47, Issue 3, 2019). The article is searchable and citable by Digital Object Identifier (DOI). DOI link will become active after the article will be included in the complete issue. *********

1998 ◽  
Vol 78 (3) ◽  
pp. 563-572 ◽  
Author(s):  
V. Jowkin ◽  
J. J. Schoenau

Nitrogen availability to a spring wheat crop was examined in the cropping season in a side-by-side comparison of no-till (first year) and tillage fallow in an undulating farm field in the Brown soil zone in southwestern Saskatchewan. Thirty different sampling points along a grid in each tillage landscape were randomly selected, representing 10 each of shoulder, footslope and level landscape positions. Nitrogen availability was studied i) by profile inorganic N content ii) by crop N uptake and yield of spring wheat (Triticum aestivum L.) and iii) by 15N tracer technique and in situ burial of anion exchange resin membranes (AEM).Pre-seeding available moisture content of the surface soil samples was significantly higher under no-till compared with tillage fallow. However, no significant differences in pre-seeding profile total inorganic N, crop N uptake and yield were observed between the treatments. At the landform scale, shoulder positions of the respective tillage systems had lower profile inorganic N, crop N uptake and yield compared with other slope positions. Soil N supply power, as determined by 15N tracer and AEM techniques, was not significantly different between the tillage treatments, indicating that N availability is not likely to be greatly affected in initial years by switching to no-till fallow in these soils under normal moisture conditions. Key words: Summerfallow, landscape, nitrogen, wheat


2013 ◽  
Vol 59 (No. 6) ◽  
pp. 235-240 ◽  
Author(s):  
Bordoloi LJ ◽  
Singh AK ◽  
Manoj-Kumar ◽  
Patiram ◽  
S. Hazarika

Plant&rsquo;s nitrogen (N) requirement that is not fulfilled by available N in soil has to be supplied externally through chemical fertilizers. A reliable estimate of soil N-supplying capacity (NSC) is therefore essential for efficient fertilizer use. In this study involving a pot experiment with twenty acidic soils varying widely in properties, we evaluated six chemical indices of soil N-availability viz. organic carbon (C<sub>org</sub>), total N (N<sub>tot</sub>), acid and alkaline-KMnO<sub>4</sub> extractable-N, hot KCl extractable-N (KCl-N) and phosphate-borate buffer extractable-N (PBB-N), based on their strength of correlation with available-N values obtained through aerobic incubation (AI-N) and anaerobic incubation (ANI-N), and also with the dry matter yield (DMY), N percentage and plant (maize) N uptake (PNU). In general, the soils showed large variability in NSC as indicated by variability in PNU which ranged from 598 to 1026 mg/pot. Correlations of the N-availability indices with AI-N and ANI-N decreased in the order: PBB-N (r = 0.784** and 0.901**) &gt; KCl-N (r = 0.773** and 0.743**) &gt; acid KMnO<sub>4</sub>-N (r = 0.575** and 0.651**) &ge; C<sub>org</sub> (r = 0.591** and 0.531**) &ge; alkaline KMnO<sub>4</sub>-N (r = 0.394** and 0.548**) &gt; N<sub>tot</sub> (r = 0.297** and 0.273*). Of all the indices evaluated, PBB-N showed the best correlations with plant parameters as well (r = 0.790** and 0.793** for DMY and PNU, respectively). Based on the highest correlations of PBB-N with biological indices as well as plant responses, we propose PBB-N as an appropriate index of N-availability in the acidic soils of India and other regions with similar soils.


2011 ◽  
Vol 91 (4) ◽  
pp. 493-501 ◽  
Author(s):  
K. Liu ◽  
A. M. Hammermeister ◽  
P. R. Warman ◽  
C. F. Drury ◽  
R. C. Martin

Liu, K., Hammermeister, A. M., Warman, P. R., Drury, C. F. and Martin, R. C. 2011. Assessing soil nitrogen availability in contrasting cropping systems at the end of transition to organic production. Can. J. Soil Sci. 91: 493–501. Quantifying soil nitrogen (N) availability at the end of a transition period for converting conventional fields to organic fields could enhance N management during the subsequent organic crop production phase. Soil total N (Ntot), KCl extractable N (KCl N) and potentially mineralizable N (No) were determined at the end of a 3-yr transition period. A complementary greenhouse ryegrass N bioassay was conducted using soils collected from the treated field plots. The field experiment consisted of six cropping systems comprising two N inputs (legume-based vs. manure-based) and three forage cropping treatments (0, 1 or 2 yr of forage in 4-yr rotations). The N input treatments consisted of alfalfa meal in the legume-based cropping system (LBCS) and composted beef manure in the manure-based cropping system (MBCS). Orthogonal contrasts suggested no differences in Ntot or KCl N either between LBCS and MBCS or between no-forage and forage cropping systems. However, in the greenhouse study, high cumulative N inputs in the MBCS resulted in significantly higher ryegrass N uptake and potentially mineralizable soil N than in the LBCS. Ryegrass N uptake ranged from 101 to 139 kg ha−1, which should be an adequate N supply for the succeeding potato crop. In the greenhouse, a ryegrass N bioassay effectively identified the differences in soil N availability. Ryegrass N uptake was linearly related to cumulative soil amendment N inputs but had no apparent relationship with N o. A systems approach provided a good assessment of N availability at the end of the transition period to organic production.


2020 ◽  
Vol 12 (20) ◽  
pp. 8358
Author(s):  
Gilbert C. Sigua ◽  
Kenneth C. Stone ◽  
Phil J. Bauer ◽  
Ariel A. Szogi

The soil nitrogen (N) availability and urease activity (UA) in a humid ecosystem with variable rainfall distribution and poor soil fertility are not well understood. A complete appreciation of N cycling in the soil–water–plant continuum is needed to better manage N and water in regions that will be strongly affected by climate change. A sorghum (Sorghum bicolor L.) study located in Florence, South Carolina, USA, was conducted using a variable-rate pivot system. We hypothesized that supplemental irrigation (SI) and N would enhance UA and N uptake while minimizing the concentration of N in porewater (TINW). The aim of the study was to assess the impact of SI (0, 50, and 100%) and N fertilization (0, 85, and 170 kg N ha−1) on: UA; total N (TNS); total inorganic N (TINS); TINW; and N uptake of sorghum. Results support our research hypothesis. The greatest UA was from 0% SI and 170 kg ha−1 (18.7 µg N g−1 ha−1). Porewater N (mg L−1), when averaged across SI and N showed a significantly lower concentration at lower soil depth (9.9 ± 0.7) than the upper depth (26.1 ± 2.4). The 100% SI had the greatest biomass N uptake (NUPB) of 67.9 ± 31.1 kg ha−1 and grain N uptake (NUG) of 52.7 ± 20.5 kg ha−1. The greatest NUPB (70.9 ± 30.3 kg ha−1) and NUG (55.3 ± 16.5 kg ha−1) was from the application of 170 kg N ha−1. Overall, results showed that proper use of water and N enhanced soil N dynamics, and improved biomass productivity and N uptake of sorghum.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
B. E. Lapointe ◽  
R. A. Brewton ◽  
L. W. Herren ◽  
M. Wang ◽  
C. Hu ◽  
...  

AbstractThe pelagic brown macroalgae Sargassum spp. have grown for centuries in oligotrophic waters of the North Atlantic Ocean supported by natural nutrient sources, such as excretions from associated fishes and invertebrates, upwelling, and N2 fixation. Using a unique historical baseline, we show that since the 1980s the tissue %N of Sargassum spp. has increased by 35%, while %P has decreased by 44%, resulting in a 111% increase in the N:P ratio (13:1 to 28:1) and increased P limitation. The highest %N and δ15N values occurred in coastal waters influenced by N-rich terrestrial runoff, while lower C:N and C:P ratios occurred in winter and spring during peak river discharges. These findings suggest that increased N availability is supporting blooms of Sargassum and turning a critical nursery habitat into harmful algal blooms with catastrophic impacts on coastal ecosystems, economies, and human health.


2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Craig G. Cogger ◽  
Andy I. Bary ◽  
Elizabeth A. Myhre

As heat-dried biosolids become more widely produced and marketed, it is important to improve estimates of N availability from these materials. Objectives were to compare plant-available N among three different heat-dried biosolids and determine if current guidelines were adequate for estimating application rates. Heat-dried biosolids were surface applied to tall fescue (Festuca arundinaceaSchreb.) in Washington State, USA, and forage yield and N uptake measured for two growing seasons following application. Three rates of urea and a zero-N control were used to calculate N fertilizer efficiency regressions. Application year plant-available N (estimated as urea N equivalent) for two biosolids exceeded 60% of total N applied, while urea N equivalent for the third biosolids was 45%. Residual (second-year) urea N equivalent ranged from 5 to 10%. Guidelines for the Pacific Northwest USA recommend mineralization estimates of 35 to 40% for heat-dried biosolids, but this research shows that some heat-dried materials fall well above that range.


Agronomy ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 781
Author(s):  
Mauricio Schoebitz ◽  
Dalma Castillo ◽  
Milko Jorquera ◽  
Antonio Roldan

Intercropping could increase the capacity of crops to use soil resources. The aim of this study was to investigate the effects of lupin/wheat intercropping on soil properties, grain yield and nutrient uptake at different plant densities. Lupin and wheat were grown under field conditions as monocrops and intercrops. Soil nutrient availability and relative abundance of functional genes (acdS, phoD, phoC and nifH) were evaluated. The results obtained indicate that the cropping system had a significant effect (p < 0.001) on N and P availability. Lupin monocrop led to significantly higher N availability compared to intercrop. Intercropping resulted in significantly lower Olsen-P and K in soil concentrations compared to monocropping. No significant differences were observed in enzyme activity, except for phosphatase, which was 152% greater in the treatments at high plant density. Foliar nutrients were significantly higher in intercropping compared to monocropping. Acid phosphatase gene phoC was more abundant than the alkaline phosphatase gene phoD, which plays a more relevant role in acidic Andisols. The results confirm that N and P mobilization can improve nutrient absorption on wheat. When intercropped, lupin had positive effects on wheat due to its P mobilization capacity, while no effects were observed on lupin.


Agronomy ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 582 ◽  
Author(s):  
Anita Ierna ◽  
Giovanni Mauromicale

Nitrogen fertilization is indispensable to improving potato crop productivity, but there is a need to manage it suitably by looking at environmental sustainability. In a three-season experiment, we studied the effects of five nitrogen (N) fertilization rates: 0 (N0), 100 (N100), 200 (N200), 300 (N300) and 400 (N400) kg N ha−1 on crop N uptake, apparent nitrogen recovery efficiency (ANRE), tuber yield, nitrogen use efficiency (NUE), nitrogen uptake efficiency (NUpE), nitrogen utilization efficiency (NUtE) and agronomic nitrogen use efficiency (AgNUE) of five different potato cultivars: Daytona, Ninfa, Rubino, Sieglinde and Spunta. The economically optimum N fertilizer rates (EONFR) were also calculated. In seasons with high soil nitrogen availability for the crop (about 85 kg ha−1 of N), tuber yield increased only up to N100 and ANRE was about 50%; in seasons with medium (from 50 to 60 kg ha−1 of N) soil N availability, tuber yield increased up to N200 and ANRE was about 45%. Rubino and Sieglinde (early cultivars) responded for tuber yield only up to N100; Daytona, Ninfa, Spunta (late cultivars) up to N200, showing the highest values of NUE, NUpE, NUtE and AgNUE at N100. EONFR ranged from 176 to 268 kg ha−1 in relation to cultivar and season, but the reduction by 50% led to a tuber yield decrease of only around 16%. The adoption of cultivars characterized by high AgNUE at a low N rate and a soil nitrate test prior to planting, are effective tools to achieve a more sustainable and cost-effective nitrogen fertilization management.


1993 ◽  
Vol 73 (2) ◽  
pp. 197-208 ◽  
Author(s):  
J. E. Richards ◽  
J.-Y. Daigle ◽  
P. LeBlanc ◽  
R. Paulin ◽  
I. Ghanem

Greenhouse, field and laboratory studies were conducted to determine if N availability to corn (Zea mays L.) and NO3 leaching were affected by encapsulating conventional granular fertilizer within peat pellets (organo-mineral fertilizers or OMF). In the greenhouse, total N uptake by three 6-wk crops of corn from soil fertilized with NH4NO3 was 9.1% higher than the mean from soils fertilized with OMF made with urea (OMF-urea) or with NH4NO3 (OMF-AN). Total N uptake was 5.1% higher from soils fertilized with OMF-AN than OMF-urea. Differences in total N uptake among the fertilizers were constant across crops. In two field trials, total N uptake was slightly higher (4%) from soil fertilized with commercial NH4NO3 than with OMF-AN. In a laboratory experiment, NO3 from commercial NH4NO3 fertilizer leached more readily from soil than NO3 from OMF-AN. Approximately 95% of the NO3 from commercial NH4NO3 fertilizer leached from 3-cm soil cores in the first 50 mL of leachate whereas only 26% of the NO3 contained in OMF-AN leached. In another trial, NO3 from commercial NH4NO3 fertilizer leached more deeply than NO3 from OMF-AN after application of 2.5 cm irrigation water to soil in 63-cm leaching columns. Virtually no NO3 was retained within the OMF-AN pellet after leaching, suggesting that the retention of NO3 by OMF-AN used in our work is of limited duration. The OMF is an effective source of N to crops and is less prone to NO3 leaching losses than commercial NH4NO3 fertilizer when rain occurs soon after application. More work is required to determine the effect of pellet size and composition on NO3 retention, NO3 leaching losses and crop availability of N. Key words: Nitrate leaching, corn, organo-mineral fertilizers


1994 ◽  
Vol 74 (2) ◽  
pp. 147-155 ◽  
Author(s):  
J. W. Paul ◽  
E. G. Beauchamp

The amount of available nitrogen in fresh and composted manures is required to adjust inorganic fertilizer applications for crops when using manures and composts. Corn (Zea mays L.) plants were grown for 8 wk at temperatures of 17–27 °C and 12–18 °C in soil amended with two rates of fresh and composted solid beef cattle manure. Apparent N uptake of corn grown in soil amended with fresh solid beef cattle manure, composted beef cattle manure and (NH4)2SO4 at the higher temperature was 2, 8, and 36%, respectively, during this 8-wk period. Nitrogen uptake by corn in fresh solid beef cattle manure-amended soil at low temperature was affected by factors other than N availability. A 12-wk laboratory experiment was performed in which 15NH4+ was added to fresh and composted manure-amended soil to determine the fate of the inorganic N in the manure and to measure N mineralization rates. Net immobilization of inorganic N occurred with all manures; however, after 3 wk, net mineralization occurred with the solid and composted beef cattle manure. Immobilization of 15N continued with all manure amendments as a result of mineralization-immobilization turnover. The amount of unrecovered 15N after 12 wk was 10.5, 2 and 1% of the added 15N in soil amended with solid beef cattle manure, composted beef cattle manure and manure composted with bark, respectively. Key words: Composted manure, nitrogen availability, 15N, immobilization, remineralization, temperature


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