Biosolids differently affect seed yield, nodule growth, nodule-specific activity, and symbiotic nitrogen fixation of field bean

2017 ◽  
Vol 68 (8) ◽  
pp. 735 ◽  
Author(s):  
S. Pampana ◽  
A. Scartazza ◽  
R. Cardelli ◽  
A. Saviozzi ◽  
L. Guglielminetti ◽  
...  

The main aim of this research was to verify whether mineral nitrogen (N) continuously released by organic fertilisers during the field bean growth cycle may be sufficiently high to enhance plant growth and seed yield but sufficiently low that it does not negatively affect nodulation and symbiotic N2 fixation. Plants were grown without N fertilisation, and with mineral and organic N (biosolids) fertilisation. All plant parts were collected and dry matter, N content, %Ndfa, and N2 fixed were measured at 8th node, flowering, and maturity stages. Nodule specific activity, N derived from soil, and N remobilisation were estimated. The nitrate concentration of soil was also determined. Biosolids reduced nodule growth, nodule fixation activity, and N2 fixation during the vegetative but not the reproductive phase. During seed filling, nodule fixation activity increased and N2 fixation was roughly twice that of the Control plants. Biosolids increased seed yield by removing the imbalance between N demand and N supply for pod growth. This may be related to an increase in nodule-specific activity due to the reduction in mineral N in the soil.

Agriculture ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 678
Author(s):  
Getenesh Genetu ◽  
Markku Yli-Halla ◽  
Mekonnen Asrat ◽  
Mihiret Alemayehu

The productivity of the faba bean has declined in Ethiopia, owing to poor management practices, such as blanket fertilisation. In 2018, a field experiment was conducted in a Nitisol soil during the main cropping season in Northwestern Ethiopia, to determine the amount of chemical fertiliser and Rhizobium inoculant to be used for the optimum yield within economic feasibility. The experiment consisted of a factorial combination of five rates of blended NPSZnB fertiliser (0, 60, 121, 180 and 240 kg ha−1) and three rates of inoculant (0, 500 and 750 g ha−1). Sole chemical fertilisation, as well as inoculation, individually produced a seed yield of 2.3–2.5 t ha−1, about 1.0–1.2 t ha−1 more than the control. However, the maximum seed yield (3.3 t ha−1) was recorded from the combined application of both the chemical fertiliser and the inoculant. The seed yield correlated closely with the number of active nodules (R2 = 0.78 **), suggesting a substantial contribution of symbiotic N2 fixation. Inoculation increased the N content of the seed yield by at least 30 kg ha−1. Chemical fertilisation, containing at least 44 kg ha−1 of mineral N does not appear to have an adverse effect on N2 fixation. The combined use of 180 kg ha−1 blended fertiliser with 750 g ha−1 inoculant, producing a maximum net profit of 72,918 birr ha−1 (EUR 2232), is recommended for the study area. This study emphasises that (1) inoculation alone can produce as much seed as the maximum rate of chemical fertilisation, but (2) the maximum yield was produced with a combined use of inoculant and chemical fertiliser, by promoting the vigour of the nodules and N2 fixation.


1998 ◽  
Vol 49 (5) ◽  
pp. 811 ◽  
Author(s):  
Qifu Ma ◽  
Nancy Longnecker ◽  
Neil Emery ◽  
Craig Atkins

Yield and harvest index of narrow-leafed lupin (Lupinus angustifolius L.) are variable, and factors affecting their reliability have not been clearly identified. In this study, plants were grown in sand culture and were non-nodulated and supplied with mineral nitrogen (N) or acquired N through symbiotic N2 fixation. Transient N deficiency was imposed a number of times during development in nodulated plants by flushing pure O2 to the roots to suppress N2 fixation and in non-nodulated plants by changing the rate of N addition. Low N supply (0·4 mM) before floral initiation or for 2 weeks during floral initiation caused a reduction in seed yield. Transient N deficiency induced by O2 flush during early growth (Weeks 6 and 7 after sowing) had a marked effect on vegetative growth, the number of main stem flowers, pod set, and seed yield. The early N deficiency also affected shoot and root N concentrations and total cytokinin concentrations in root exudate. Compared with N2-fixing plants, those supplied with adequate mineral N had a greater flower number and greater branch growth and biomass, but not higher pod set and seed yield, resulting in lower harvest index. Seed N concentrations were also decreased by transient N deficiencies at early (floral initiation), mid (flowering), and late (grain filling) stages. These findings indicate that any field conditions which transiently reduce N2 fixation (e.g. temporary waterlogging or drought) are likely to result in lower grain yield and quality of lupin crops.


1994 ◽  
Vol 45 (7) ◽  
pp. 1455 ◽  
Author(s):  
MJ Bell ◽  
GC Wright

The contribution of symbiotic N2 fixation to the total N budget of irrigated crops of peanut (Arachis hypogaea L.) during vegetative and reproductive growth was investigated using four peanut cultivars with differing patterns of dry matter (DM) partitioning to developing pods. Estimates of NZ fixation were obtained with the 15N natural abundance procedure by using a non-nodulating peanut genotype as a non-N2-fixing reference plant. Partitioning was assessed on the basis of vegetative DM equivalents, with adjustments to pod DM based on relative synthesis costs of vegetative and pod DM. Cultivars differed in crop duration, DM production and yield of pods and kernels. Despite large differences in derived DM partitioning coefficients among cultivars (0.68 to 1.03), both total crop N and fixed N increased as a constant proportion of accumulated, energy-adjusted DM. Crop duration was the primary factor determining both total crop N and fixed N. In addition to fixation, all cultivars continued to accumulate soil mineral N throughout the season. However, in all cultivars except TMV-2, crop N uptake during reproductive growth was insufficient to meet the demands of developing pods and N was renlobilized from vegetative plant parts. Remobilized N was almost exclusively N derived originally from N2 fixation. Despite relatively high levels of N2 fixation (from 140 to 210 kg N ha-1, depending on crop duration), all cultivars except Virginia Bunch showed a negative apparent N balance when the amounts of N2 fixed were compared to N removed in pods at final harvest. This was primarily due to high N harvest indices (0.62 to 0.73), and is likely to be a feature of many recently released, high yielding cultivars.


Author(s):  
Subin Kalu ◽  
Gboyega Nathaniel Oyekoya ◽  
Per Ambus ◽  
Priit Tammeorg ◽  
Asko Simojoki ◽  
...  

AbstractA 15N tracing pot experiment was conducted using two types of wood-based biochars: a regular biochar and a Kon-Tiki-produced nutrient-enriched biochar, at two application rates (1% and 5% (w/w)), in addition to a fertilizer only and a control treatment. Ryegrass was sown in pots, all of which except controls received 15N-labelled fertilizer as either 15NH4NO3 or NH415NO3. We quantified the effect of biochar application on soil N2O emissions, as well as the fate of fertilizer-derived ammonium (NH4+) and nitrate (NO3−) in terms of their leaching from the soil, uptake into plant biomass, and recovery in the soil. We found that application of biochars reduced soil mineral N leaching and N2O emissions. Similarly, the higher biochar application rate of 5% significantly increased aboveground ryegrass biomass yield. However, no differences in N2O emissions and ryegrass biomass yields were observed between regular and nutrient-enriched biochar treatments, although mineral N leaching tended to be lower in the nutrient-enriched biochar treatment than in the regular biochar treatment. The 15N analysis revealed that biochar application increased the plant uptake of added nitrate, but reduced the plant uptake of added ammonium compared to the fertilizer only treatment. Thus, the uptake of total N derived from added NH4NO3 fertilizer was not affected by the biochar addition, and cannot explain the increase in plant biomass in biochar treatments. Instead, the increased plant biomass at the higher biochar application rate was attributed to the enhanced uptake of N derived from soil. This suggests that the interactions between biochar and native soil organic N may be important determinants of the availability of soil N to plant growth.


Agronomy ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 921
Author(s):  
Rania M. A. Nassar ◽  
Engy A. Seleem ◽  
Gianluca Caruso ◽  
Agnieszka Sekara ◽  
Magdi T. Abdelhamid

Egyptian henbane (Hyoscyamus muticus L.) plants are rich sources of alkaloids used in pharmaceutical products. Recently, rising efforts have been devoted to reducing mineral fertilizer supply, production cost, and environmental pollution via decreasing the doses of nitrogenous fertilizers and adopting biofertilizer farming systems. Two field experiments were conducted to examine the potential role of N fixing bacteria Azotobacter spp. and Azospirillum spp. on the growth, mineral status, tropane alkaloids, leaf anatomy, and seed yield of Egyptian henbane grown with different levels of mineral nitrogen fertilizer, i.e., 25%, 50%, and 100% of the recommended dose, equal to 30, 60, and 120 kg N ha−1. N fertilizer improved growth, mineral elements, tropane alkaloids, seed yield, and yield components of Egyptian henbane, which showed a gradually rising trend as the rate of N fertilizer increased. High doses of N fertilizer presumably elicited favorable changes in the anatomical structure of Egyptian henbane leaves. The application of 50% N dose plus N fixing bacteria affected Egyptian henbane trials similarly to 100% of recommended N dose. In conclusion, the N fixing bacteria proved to be a sustainable tool for a two-fold reduction in the recommended dose of mineral N fertilizer and the sustainable management of Egyptian henbane nutrition.


Revista CERES ◽  
2012 ◽  
Vol 59 (5) ◽  
pp. 689-694 ◽  
Author(s):  
Thiago de Oliveira Vargas ◽  
Ellen Rúbia Diniz ◽  
Ricardo Henrique Silva Santos ◽  
Alysson Roberto de Almeida ◽  
Segundo Urquiaga ◽  
...  

Roots effect is not generally considered in studies assessing the performance of crops in response to green manuring. However, such effect can contribute to a better understanding of crop rotation. The aim of this study was to assess the effect of root and shoot of two legumes on the production of cabbage. The experiment was conducted in pots of 10 liters containing substrate of 2:1 soil/sand. The experiment was arranged in a factorial scheme (2x3 + 2) in a randomized block design with five replicates using two legume species (Crotalaria juncea L. and Canavalia ensiformis L), three plant parts (root, shoot, or whole plant), and two additional treatments (mineral fertilization with 100% and 50% of the recommended dose of N for growing cabbage). Pots with legume treatments received mineral fertilizer with 50% of the recommended dose of N for growing cabbage. The experimental plot consisted of a pot containing one plant of cabbage. Legumes were grown in pots and harvested at 78 days. The root biomass was determined in extra pots. Production was assessed using head fresh and dry weight. The application of the whole plant of both legume species reduced cabbage production. However, root or shoot of both legume species was equivalent to 50% of mineral N fertilization required for the cultivation of cabbage.


2016 ◽  
Vol 13 (16) ◽  
pp. 4645-4657 ◽  
Author(s):  
Angela N. Knapp ◽  
Sarah E. Fawcett ◽  
Alfredo Martínez-Garcia ◽  
Nathalie Leblond ◽  
Thierry Moutin ◽  
...  

Abstract. In a coastal lagoon with a shallow, 25 m water column off the southwest coast of New Caledonia, large-volume ( ∼  50 m3) mesocosm experiments were undertaken to track the fate of newly fixed nitrogen (N). The mesocosms were intentionally fertilized with 0.8 µM dissolved inorganic phosphorus to stimulate diazotrophy. N isotopic evidence indicates that the dominant source of N fueling export production shifted from subsurface nitrate (NO3−) assimilated prior to the start of the 23-day experiments to N2 fixation by the end of the experiments. While the δ15N of the sinking particulate N (PNsink) flux changed during the experiments, the δ15N of the suspended PN (PNsusp) and dissolved organic N (DON) pools did not. This is consistent with previous observations that the δ15N of surface ocean N pools is less responsive than that of PNsink to changes in the dominant source of new N to surface waters. In spite of the absence of detectable NO3− in the mesocosms, the δ15N of PNsink indicated that NO3− continued to fuel a significant fraction of export production (20 to 60 %) throughout the 23-day experiments, with N2 fixation dominating export after about 2 weeks. The low rates of organic N export during the first 14 days were largely supported by NO3−, and phytoplankton abundance data suggest that sinking material primarily comprised large diatoms. Concurrent molecular and taxonomic studies indicate that the diazotroph community was dominated by diatom–diazotroph assemblages (DDAs) at this time. However, these DDAs represented a minor fraction (< 5 %) of the total diatom community and contributed very little new N via N2 fixation; they were thus not important for driving export production, either directly or indirectly. The unicellular cyanobacterial diazotroph, a Cyanothece-like UCYN-C, proliferated during the last phase of the experiments when N2 fixation, primary production, and the flux of PNsink increased significantly, and δ15N budgets reflected a predominantly diazotrophic source of N fueling export. At this time, the export flux itself was likely dominated by the non-diazotrophic diatom, Cylindrotheca closterium, along with lesser contributions from other eukaryotic phytoplankton and aggregated UCYN-C cells, as well as fecal pellets from zooplankton. Despite comprising a small fraction of the total biomass, UCYN-C was largely responsible for driving export production during the last  ∼  10 days of the experiments both directly ( ∼  5 to 22 % of PNsink) and through the rapid transfer of its newly fixed N to other phytoplankton; we infer that this newly fixed N was transferred rapidly through the dissolved N (including DON) and PNsusp pools. This inference reconciles previous observations of invariant oligotrophic surface ocean DON concentrations and δ15N with incubation studies showing that diazotrophs can release a significant fraction of their newly fixed N as some form of DON.


1994 ◽  
Vol 74 (1) ◽  
pp. 99-107 ◽  
Author(s):  
D. C. Jans-Hammermeister ◽  
W. B. McGill ◽  
T. L. Jensen

The distribution and dynamics of 15N following green manuring of 15N-labelled 10% bloom and full bloom field pea (Pisum sativum ’Sirius’) were investigated in the soil mineral N, microbial N and non-microbial organic N (NMO-N) fractions and in a subsequent barley crop at two contrasting field sites in central Alberta: one on a Chernozemic (Dark Brown) soil near Provost and the other on a Luvisolic (Gray Luvisol) soil near Rimbey. Soils and plants were sampled four times during a 1-yr period. The 10% bloom and full bloom pea shoots were similar in dry matter production and N and C content. More N was, however, released from the younger pea residues directly following soil incorporation, which we attributed to a larger proportion of labile components. Barley yield, N content and 15N recovery in the grain were not influenced by legume bloom stage at incorporation, although significantly more 15N was recovered in the barley straw and roots of the full bloom treatment. Incorporation of full bloom legumes resulted in closer synchrony between the appearance of legume-derived mineral 15N and early N demand by the barley crop. The decay rate constants for the recalcitrant fraction of the legume residues were not significantly influenced by bloom stage or site over the time intervals of our observations and are, thus, consistent with the theory that decomposition of the recalcitrant fraction of plant residues can be described by a single exponential equation. Key words:15N, legume green manuring, Pisum sativum, decomposition


Author(s):  
Syed Azam Shah ◽  
Wisal Mohammad ◽  
Haroon Haroon ◽  
Adnan Anwar Khan

The study was designed to asses the residual effect of organic N (Poultry Manure) and mineral N on maize crop in field experiments carried out on silty clay loam soil at NIFA, Tarnab, Peshawar, Khyber Pakhtunkhwa (KP) Pakistan during 2014-15. Combined dose of N from both sources were 120 kg ha-1 applied to wheat crop alone and in different combination making six treatments. Maize variety (Azam) was sown in Randomized complete block (RCB) design with four replications. Agronomic data, grains ear-1, 1000 grain weight, biomass grain yield data, N-uptake in maize grain and straw were recorded. Results showed that maximum grain ear−1, 1000 grain weight, biomass and grain yield was obtained from treatment where 25% N applied from poultry manure + 75% from mineral N source applied to previous wheat crop. Agronomic efficiency and nitrogen use efficiency were also found maximum in treatment where 75% poultry manure + 25% mineral N was applied. It was concluded from the study that residual effect of organic manure with mineral N in different ratios enhances crop productivity and soil fertility.


1989 ◽  
Vol 69 (3) ◽  
pp. 551-565
Author(s):  
F. SELLES ◽  
A. J. LEYSHON ◽  
C. A. CAMPBELL

Prairie farmers are interested in applying nitrogen (N) in the fall or winter to reduce fertilizer costs and allow a better distribution of labor and machinery use. Two studies were conducted in southwestern Saskatchewan to determine the consequences of applying N in late fall. In the laboratory, fertilizer N barely penetrated into the snow at constant subzero temperatures, but under freeze-thaw conditions, urea and ammonium nitrate descended 27 cm in 3 d. In the field, ammonium nitrate and urea were applied to snow-covered and bare microplots of grass sod and cereal stubble (1981–1982) and grass sod only (1985–1986). Nitrogen from ammonium nitrate penetrated deeper into the snow than N from urea. Nitrogen recovery in April 1982 was 55–59% from ammonium nitrate and 39–51% from urea, but was near 100% for both sources on bare soil treatments in April 1986. More N was recovered when fertilizer was applied to bare than to snow-covered soil, especially during 1985–1986 when all the applied fertilizer was blown off the snow-covered plots. Mineral N generally declined from fall to spring in all treatments, probably because of denitrification and immobilization. In 1985–1986, a period of extremely low temperatures in late fall resulted in no movement or transformation of N until after early December. By late January, periods of above-zero soil temperatures resulted in substantial mineralization of soil organic N, in the fertilized plots. This apparent priming effect was attributed to perturbations in the organic matter and microbial biomass due to fertilizer application and freezing and thawing. Following this period there was a general decrease in mineral N towards spring, as observed in 1981–1982. Producers must consider the benefits of using labor and equipment more efficiently and of lower fertilizer cost in the fall against the risk of large potential N losses over winter. Key words: Urea, ammonium nitrate, N recovery, frozen soils, fertilizing in winter


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