Nitrogen Balance of Field Pea Crops in South Western Australia, Studied Using the 15N Natural Abundance Technique

1994 ◽  
Vol 21 (4) ◽  
pp. 533 ◽  
Author(s):  
EL Armstrong ◽  
JS Pate ◽  
MJ Unkovich
Keyword(s):  
Western Australia ◽  
N Uptake ◽  
15N Natural Abundance ◽  
Natural Abundance ◽  
Field Pea ◽  
N Balance ◽  
Total N ◽  
Peak Biomass ◽  
Biomass N ◽  
Total Plant

The nitrogen economies of six contrasting field pea (Pisum sativum L.) genotypes were examined at three widely separated sites in south Western Australia, using the 15N natural abundance technique to asssess proportional dependence on fixed N, harvests at peak biomass to assess total N yields and harvests at crop maturity to examine partitioning of N between seed and non harvested crop residues. The budgets for one site (Wongan Hills) included N of nodulated roots which on average comprised 12% of total plant N at peak crop biomass and 25% of recoverable plant N after harvest of seed. At this site maximum potential (residual) benefits to a following crop (peak total plant biomass N - N uptake from soil and N taken off as harvested seed) varied between genotypes from 8 to 41 g N ha-1 (mean 26; n = 6). Data for the other two sites, based solely on N budgets of above-ground parts, provided evidence of substantial site- and genotype-specific differences in N balance in terms of shoot residues (i.e. + 7 to - 24 kg N ha-1 (mean - 5) at Avondale, + 40 to - 29 (mean + 3) at Mt Barker). The results collectively indicated a general relationship between peak biomass N of a crop and its potential or otherwise to effect a net input of residue N to the ecosystem. There were, however, considerable variations between genotypes and sites due to differences in proportional dependence on fixation (range across all sites and genotypes 60-91%) and crop harvest indices for N (corresponding range 53-90%). Correlation plots were constructed from the data for N2 fixed against crop dry matter yield and residual nitrogen benefit against nitrogen harvest index. Results are discussed in relation to values for N balance of field pea and other grain legumes obtained elsewhere by other investigators.

Nitrogen use efficiency, economic return and yield performance of Pigeonpea [Cajanus cajan (L.) Millsp.] as influenced by nipping and fertility levels

2019 ◽  
Author(s):  
A.K. Dhaka ◽  
Satish Kumar ◽  
Bhagat Singh ◽  
Karmal Singh ◽  
Amit Kumar ◽  
...  
Keyword(s):  
Nitrogen Use Efficiency ◽  
N Uptake ◽  
Utilization Efficiency ◽  
N Balance ◽  
Flower Initiation ◽  
Recovery Efficiency ◽  
Nitrogen Use ◽  
Total N ◽  
Yield Attributes ◽  
Use Efficiency

An experiment was conducted to study nitrogen use efficiency in pigeonpea at Research farm, CCS Haryana Agricultural University, Hisar, India having three nipping treatments (no nipping, nipping at just start of branching and nipping at flower initiation) and five fertility levels (control, 20 kg N + 40 kg P2O5/ha, 30 kg N + 40 kg P2O5 /ha, 40 kg N + 40 kg P2O5/ha and 20 kg N + 40 kg P2O5/ha + foliar spray of 2% N immediately after nipping) replicated thrice in split plot design during growing seasons of 2016 and 2017. Nipping at start of branching reduced the plant height, while increased primary and secondary branches, pods/plant and yield over no nipping. Significantly higher total N uptake, protein content, net return, B: C, agronomical NUE, physiologic NUE, agro-physiologic NUE, apparent recovery efficiency, utilization efficiency of N and partial N balance were improved with nipping at start of branching. Among fertility levels, 40 kg N + 40 kg P2O5 / ha recorded significantly higher yield attributes with 39.7 per cent higher seed yield over control. Significantly higher agronomic NUE, physiologic NUE, agro-physiological NUE, apparent recovery efficiency, utilization efficiency of N, partial N balance and NER were recorded with 20 kg/ha as compared to higher nitrogen doses.

scholarly journals Isotopic and Nonisotopic Estimation of Nitrogen Uptake Efficiency in Container-grown Woody Ornamentals

HortScience ◽  
2005 ◽  
Vol 40 (3) ◽  
pp. 665-669 ◽  
Author(s):  
David R. Sandrock ◽  
Timothy L. Righetti ◽  
Anita N. Azarenko
Keyword(s):  
N Uptake ◽  
Regression Line ◽  
Dry Weight ◽  
Fertilizer N ◽  
Tracer Method ◽  
Total N ◽  
Uptake Efficiency ◽  
N Uptake Efficiency ◽  
Total Plant ◽  
Fertilizer N Uptake

Cornus sericea L., Weigela florida (Bunge) A. DC., and Euonymus alatus (Thunb.) Sieb were grown outside in 3.8-L plastic containers for 345 days (1 Apr. 2001 to 11 Mar. 2002). Nitrogen (N) was applied at rates (NAR) of 25, 50, 100, 200, and 300 mg·L–1 and delivered as aqueous double-labeled 15N depleted NH4NO3 (min 99.95% atom 14N). In all species, root, shoot, and total plant dry weight increased with increasing NARs while root to shoot ratios decreased. Similarly, root, shoot, and total plant N increased with NAR for each species, and at each NAR more N was stored in the roots than in the shoots. Estimation of fertilizer N uptake determined by the total N method was higher for all species and at each NAR than estimation of N uptake determined by the fertilizer 15N tracer method. Fertilizer N uptake efficiency determined by the total N method was highest at 25 mg·L–1 and decreased as NARs increased. In contrast fertilizer N uptake efficiency determined by the fertilizer 15N tracer method was lowest at 25 mg·L–1 and increased or remained relatively constant as NARs increased. Differences in N uptake and N uptake efficiency can be attributed to overestimation by the total N method due to the inclusion of nonfertilizer N and underestimation by the fertilizer 15N tracer method due to pool substitution. Corrected N uptake efficiency values can be calculated by adjusting the original data (total N or 15N uptake) by the distance between the origin and the y intercept of the regression line representing the data.

Temporal dynamics of nitrogen rhizodeposition in field pea as determined by 15N labeling

2013 ◽  
Vol 93 (5) ◽  
pp. 941-950 ◽  
Author(s):  
Melissa M. Arcand ◽  
J. Diane Knight ◽  
Richard E. Farrell
Keyword(s):  
Temporal Dynamics ◽  
Field Pea ◽  
N Balance ◽  
Vegetative Stage ◽  
Root Turnover ◽  
Seed Harvest ◽  
15N Labeling ◽  
Below Ground ◽  
Total Plant ◽  
Intact Roots

Arcand, M. M., Knight, J. D. and Farrell, R. E. 2013. Temporal dynamics of nitrogen rhizodeposition in field pea as determined by 15 N labeling. Can. J. Plant Sci. 93: 941–950. Assessing the contribution of symbiotically fixed N2 to soil from pulse crops necessitates a full accounting of the total crop residue N remaining in the field after seed harvest. Below-ground N, including root and rhizodeposit N, comprises an important component of this total plant N balance – without it the N input to soil is underestimated. Under controlled conditions in a greenhouse, N in intact roots and N rhizodeposition were quantified in field pea (Pisum sativum L.) using the cotton-wick 15N labeling technique. Plants were supplied with 15N on a continuous basis and harvested at the vegetative stage (nine leaves unfolded), flowering, and maturity. As the plants aged, the 15N enrichment in the rhizosphere soil decreased, whereas that in the bulk soil increased, suggesting that N released as root exudates comprised a more important proportion of N rhizodeposition in plants at the early vegetative stage compared with mature plants. In mature plants, N rhizodeposition was comprised predominantly of N associated with root turnover. The contribution of N rhizodeposition recovered in soil to the total plant N balance decreased from 17.8% at the vegetative stage harvest, to 12.3% at flowering, and finally to 7.5% at maturity. However, the total amount of root-derived N released to soil by pea increased with plant development. Below-ground N, including N rhizodeposition and N in intact roots contributed 11.3% to the total plant N balance of mature pea.

scholarly journals Comparison of inorganic nitrogen uptake dynamics following snowmelt and at peak biomass in subalpine grasslands

2013 ◽  
Vol 10 (11) ◽  
pp. 7631-7645 ◽  
Author(s):  
N. Legay ◽  
F. Grassein ◽  
T. M. Robson ◽  
E. Personeni ◽  
M.-P. Bataillé ◽  
...  
Keyword(s):  
Land Use ◽  
Microbial Biomass ◽  
Plant Communities ◽  
Inorganic Nitrogen ◽  
N Uptake ◽  
Microbial Biomass N ◽  
Inorganic N ◽  
Peak Biomass ◽  
Biomass N ◽  
Subalpine Grasslands

Abstract. Subalpine grasslands are highly seasonal environments and likely subject to strong variability in nitrogen (N) dynamics. Plants and microbes typically compete for N acquisition during the growing season and particularly at plant peak biomass. During snowmelt, plants could potentially benefit from a decrease in competition by microbes, leading to greater plant N uptake associated with active growth and freeze-thaw cycles restricting microbial growth. In managed subalpine grasslands, we expect these interactions to be influenced by recent changes in agricultural land use, and associated modifications in plant and microbial communities. At several subalpine grasslands in the French Alps, we added pulses of 15N to the soil at the end of snowmelt, allowing us to compare the dynamics of inorganic N uptake in plants and microbes during this period with that previously reported at the peak biomass in July. In all grasslands, while specific shoot N translocation (per g of biomass) of dissolved inorganic nitrogen (DIN) was two to five times greater at snowmelt than at peak biomass, specific microbial DIN uptakes were similar between the two sampling dates. On an area basis, plant communities took more DIN than microbial communities at the end of snowmelt when aboveground plant biomasses were at least two times lower than at peak biomass. Consequently, inorganic N partitioning after snowmelt switches in favor of plant communities, allowing them to support their growing capacities at this period of the year. Seasonal differences in microbial and plant inorganic N-related dynamics were also affected by past (terraced vs. unterraced) rather than current (mown vs. unmown) land use. In terraced grasslands, microbial biomass N remained similar across seasons, whereas in unterraced grasslands, microbial biomass N was higher and microbial C : N lower at the end of snowmelt as compared to peak biomass. Further investigations on microbial community composition and their organic N uptake dynamics are required to better understand the decrease in microbial DIN uptake.

Selection of reference plants for 15N natural abundance assessment of N2 fixation by crop and pasture legumes in south-west Australia

1994 ◽  
Vol 45 (1) ◽  
pp. 133 ◽  
Author(s):  
JS Pate ◽  
MJ Unkovich ◽  
EL Armstrong ◽  
P Sanford
Keyword(s):  
N2 Fixation ◽  
Subterranean Clover ◽  
15N Natural Abundance ◽  
Natural Abundance ◽  
Field Pea ◽  
Legume Species ◽  
Reference Species ◽  
Rooting Zone ◽  
South West ◽  
Reference Plants

The 15N natural abundance (S15N) of the shoot total N of a range of non-N2 fixing potential reference species was compared with that of nodulated field pea (Pisum sativum L.), narrow leafed lupin (Lupinus angustijolius L.) or subterranean clover (Trijolium subterraneum L.) across a range of field sites, to which N fertilizers had not been applied in the season of study. Shoot S15N values of reference species lay mostly within the range from +3 to +5%o and there was some evidence of lower S15N values in gramineaceous than dicotyledonous non-legume species. Continuous sampling within crops of each legume showed S15N values to differ consistently between and within potential reference species through the season. The S15N values of seedlings of four non legume species in a lupin crop were closer to that of soil N03-N (S15N = 4.2%o) than soil NH4-N (S15N = 7.9%0). Shoot S15N values of non-nodulated pea, lupin and subterranean clover, and a range of possible reference species all sand-cultured on a defined nitrate source (S15N = 7.5%), suggested little or no discrimination during utilization of nitrate. However, when four candidate reference species were sand cultured with nodulated actively fixing subterranean clover on the same nitrate source, the S15N of the ryegrass was lowered significantly below that of the NO3. Field plot comparisons of nine potential reference species with nodulated field pea showed certain species to resemble field pea more closely than others in terms of the S15N value of their shoots. Reference plants sampled within or well outside the rooting zone of an actively fixing legume (subterranean clover, field pea or lupin) showed significantly lower shoot S15N of mixed grass components when harvested in root contact with, as opposed to well distant from, subterranean clover. A similar effect was observed for barley within v. outside the rooting zone of pea, but no such effects were observed between capeweed and subterranean clover, pea and radish, or for any of five reference plants matched with lupin. The data are utilized to select appropriate reference plants for field assessments of N2 fixation under south-west Australian conditions.

scholarly journals Comparison of inorganic nitrogen uptake dynamics following snowmelt and at peak biomass in subalpine grasslands

2013 ◽  
Vol 10 (5) ◽  
pp. 8887-8917 ◽  
Author(s):  
N. Legay ◽  
F. Grassein ◽  
T. M. Robson ◽  
E. Personeni ◽  
M.-P. Bataillé ◽  
...  
Keyword(s):  
Land Use ◽  
Microbial Biomass ◽  
Microbial Communities ◽  
Plant Communities ◽  
N Uptake ◽  
Microbial Biomass N ◽  
Inorganic N ◽  
Peak Biomass ◽  
Biomass N ◽  
Subalpine Grasslands

Abstract. Subalpine grasslands are highly seasonal environments and likely subject to strong variability in nitrogen (N) dynamics. Plants and microbes typically compete for N acquisition during the growing season and particularly at plant peak biomass. During snowmelt, plants could potentially benefit from a decrease in competition by microbes because of greater plant N uptake associated with active growth and freeze-thaw cycles restricting microbial growth. In managed subalpine grasslands, we expect these interactions to be influenced by recent changes in agricultural land-use, and associated modifications in plant and microbial communities. At a subalpine grassland site in the Central French Alps, a pulse of 15N was added to the soil at the end of snowmelt, allowing us to compare the dynamics of inorganic N uptake in plants and microbes during this period with that previously reported at the peak biomass in July. In all grasslands, specific plant (per g of biomass) dissolved inorganic N (DIN) uptake was two to five times greater at snow-melt than at peak biomass, whereas the specific microbial DIN uptakes were similar between the two sampling dates. On an area basis, plant communities took more DIN than microbial communities at the end of snowmelt, and the intensity of this DIN uptake by plants differed across land use types. Consequently, N partitioning after snowmelt switches in favor of plant communities allowing them to support their growing capacities at this period of the year. Seasonal differences in microbial and plant N-related dynamics were also affected by past (terraced vs. unterraced) rather than current (mown vs. unmown) land use. In terraced grasslands, microbial biomass N remained similar across seasons, whereas in unterraced grasslands, microbial biomass N was higher and microbial C : N lower at the end of snowmelt as compared to peak biomass. Further investigations on microbial community composition and their organic N uptake dynamics are required to better understand the decrease in microbial DIN uptake.

RELATIONS BETWEEN NITRATE REDUCTASE ACTIVITY AND NITROGEN ACCUMULATION IN SOYBEANS

1976 ◽  
Vol 56 (2) ◽  
pp. 377-384 ◽  
Author(s):  
MIR HATAM ◽  
D. J. HUME
Keyword(s):  
Nitrate Reductase ◽  
Nitrate Reduction ◽  
Nitrate Uptake ◽  
Reductase Activity ◽  
N Uptake ◽  
Nitrogen Accumulation ◽  
Total N ◽  
Total Plant ◽  
Nr Activity

An in vivo assay for nitrate reductase (NR) activity was adapted to measure total NR activity in soybean [Glycine max (L.) Merr.] plants grown for a 29-day period indoors. Disappearance of nitrate from the nutrient solution, plant nitrate and total plant nitrogen (N) also were measured. Under the conditions of this experiment, nitrate reduction estimated from NR activities agreed closely with actual nitrate reduction. The same assay was used to measure leaf NR activities of field-grown soybeans throughout the 1971 growing season. Leaf NR activities accounted for 77 and 72% of the total N uptake in plants receiving 0 and 280 kg N as NH4NO3/ha, respectively. Measurements of nitrate and ammonium losses from soil under soybeans and under adjacent bare soil at three stages of plant development suggested that in plots receiving no fertilizer N, 86% of N uptake from the soil was in the form of nitrate. The NR activity of field-grown plants agreed well with total plant N derived from soil nitrates. Results indicated that leaf NR activities were proportional to nitrate uptake and might be used to determine amounts and seasonal patterns of nitrate uptake by soybean plants.

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