scholarly journals Inhibition of N2 Fixation by N Fertilization of Common Bean (Phaseolus vulgaris L.) Plants Grown on Fields of Farmers in the Eastern Cape of South Africa, Measured Using 15N Natural Abundance and Tissue Ureide Analysis

2021 ◽  
Vol 3 ◽  
Author(s):  
Simon J. Habinshuti ◽  
Sipho T. Maseko ◽  
Felix D. Dakora

Inhibition of N2 fixation in N-fertilized common bean (Phaseolus vulgaris L.) plants growing on the fields of farmers in the Eastern Cape of South Africa was measured using 15N natural abundance and tissue ureide analysis. The N-fertilized bean plants revealed greater soil N uptake, higher concentrations of nitrate in organs, low tissue ureide levels, and much lower percent relative ureide-N abundance when compared with unfertilized plants. In contrast, the unfertilized plants showed greater nodule fresh weight, higher N derived from fixation (e.g., 84.6, 90.4, and 97.1% at Lujecweni fields 2, 3, and 4, respectively), increased amount of N-fixed (e.g., 163.3, 161.3, and 140.3 kg ha−1 at Lujecweni fields 2, 3, and 4, respectively), greater ureide concentration in stems and petioles, higher % relative ureide-N abundance, and low soil N uptake. We also found that the percent N derived from fixation (%Ndfa) was very high for some bean plants receiving a double dose of N fertilizer [e.g., Lujecweni field 1 (51.8%) and Tikitiki field 1 (53.3%], and quite high for others receiving a single dose of N fertilizer [e.g., Tikitiki field 2 (50.1%), Mfabantu fields 1 and 2 (45.5 and 79.9%, respectively), and St. Luthberts field 1 (58.9%)]. Though not assessed in this study, it is likely that the rhizobia that effectively nodulated the N-fertilized bean plants and fixed considerable amounts of symbiotic N had constitutive and/or inducible nitrate reductase genes for reducing nitrate in nodules and bacteroids, hence their ability to form root nodules and derived high %Ndfa in bean with added N. While single- and double-dose N fertilizer applications increased plant growth and grain yield compared to unfertilized bean plants, the single-dose N fertilizer application produced much greater grain yield than the double dose. This indicates that farmers should stop using a double dose of N fertilizers on bean production, as it decreases yields and can potentially pollute the environment. This study has however shown that government supply of free N fertilizers to resource-poor farmers in South Africa increased bean yields for food/nutritional security.

2004 ◽  
Vol 84 (1) ◽  
pp. 133-147 ◽  
Author(s):  
R. H. McKenzie ◽  
A. B. Middleton ◽  
J. DeMulder ◽  
E. Bremer

Barley (Hordeum vulgare L.) silage is the foundation for cattle production on the Canadian prairies, but few studies have evaluated fertilizer requirements for the range of cultivars, soil types and environmental conditions in which it is grown. The objectives of this study were (1) to determine optimum N fertilizer rates for a range of barley cultivars when used for silage in southern and central Alberta and (2) to determine the frequency and impact of P, K and S deficiencies. Thirty-two field experiments were conducted from 1994 to 1996; 20 in southern Alberta under irrigated (8) or dryland (12) conditions and 12 in central Alberta under dryland conditions. Two semi-dwarf (CDC Earl, Tukwa) and three conventional (AC Lacombe, Leduc and Seebe) cultivars were tested. Fertilizer treatments included six rates of N (0 to 200 kg ha-1) and one rate each of P (13 kg ha-1), K (50 kg ha-1) and S (20 or 30 kg ha-1), compared to an appropriate unfertilized control. Optimum rates of N fertilizer ranged from 0 to 172 kg N ha-1. Irrigated sites had the highest N demand but the lowest economic optimum rate of N fertilizer (NFopt) due to high fertilizer N efficiency and high soil N availability. Dryland sites in southern Alberta had a lower N demand than irrigated sites, but NFopt was higher due to lower soil N availability. Sites in central Alberta had the least demand for N, but NFopt was similar to irrigated sites due to low N fertilizer efficiency. Nitrogen fertilizer efficiency frequently exceeded 80% in southern Alberta, particularly under irrigation. Soil N uptake increased with optimum barley yield, indicating that factors that increased crop growth also increased net mineralization and/or efficiency of soil N uptake. A good fit of NFopt was obtained in southern Alberta based on spring soil NO3-N levels and optimum yield. The best estimate of NFopt in central Alberta was the mean due to the lack of a relationship between soil N uptake and spring soil NO3-N. Barley response to P fertilizer was greatest in central Alberta and least in southern Alberta under irrigation. Few responses to K or S fertilizer were observed due to the generally adequate levels of these nutrients in Alberta soils. Fiber concentrations were not strongly affected by fertilizer treatment, while protein concentrations varied with the availability of N relative to demand. Improvements in prediction of fertilizer response for barley silage require better predictors of N fertilizer efficiency and soil N uptake, particularly in central Alberta. Key words: Hordeum vulgare, nitrogen fertilizer use efficiency, protein, fiber


2012 ◽  
Vol 1 (2) ◽  
pp. 257
Author(s):  
Adrien N. Dayegamiye ◽  
Judith Nyiraneza ◽  
Johann K. Whalen ◽  
Michèle Grenier ◽  
Anne Drapeau

<p>Growing soybean (<em>Glycine max L.)</em> prior to corn (<em>Zea mays</em> L) can enhance corn grain and nitrogen (N) use efficiency compared to continuous corn. This two year study (2007-2008) was conducted at 62 sites in Quebec (Eastern Canada) to assess the effect of crop rotations [soybean-corn, soybean-wheat (<em>Triticum aestivum</em> L.,)-corn and corn-corn] on corn yield, N uptake, N fertilizer efficiency (NFE), and the economic optimum N rate (EONR). Plots within each crop rotation received N fertilizer rates from 0 to 250 kg N ha<sup>-1</sup> to assess the N contribution from the preceding soybean crop. Corn grain yields ranged from 8.4 to 10.8 Mg ha<sup>-1</sup> and were lower in continuous corn than in the crop rotations. Corn N uptake and NFE varied from 89 to 164 kg N ha<sup>-1</sup> and from 45 to 80 kg grain per kg N fertilizer, respectively. A significant interaction of crop rotation and year on corn N uptake and NFE was obtained implying that annual variations influenced soil N supply. The EONR for corn was lower under crop rotations than continuous corn in 2008 only. No difference in corn yield, NFE and EONR was observed for soybean-corn and soybean-wheat-corn crop sequences. In conclusion, crop rotations including soybean increased soil N availability and reduced EONR from 32 to 45 kg ha<sup>-1</sup> for corn grown in 2008.</p>


1999 ◽  
Vol 9 (4) ◽  
pp. 598-600 ◽  
Author(s):  
Farbod Youssefi ◽  
Patrick H. Brown ◽  
Steve A. Weinbaum

It has been proposed that a pool of amino N, whose size is determined by aboveground N demand, cycles in the plant and regulates soil N uptake by exerting an inhibitory effect at the root level. Several experiments were carried out to study this hypothesis in almond trees [Prunus dulcis (Mill.) D.A. Webb]. Based on the evidence found, there is an association, at the whole tree level, between sap N content and soil N uptake. The data are consistent with the possibility that increased phloem sap amino acids result in decreased uptake of soil N.


2020 ◽  
Vol 63 (6) ◽  
pp. 2003-2020
Author(s):  
Maria I. Zamora Re ◽  
Sagarika Rath ◽  
Michael D. Dukes ◽  
Wendy Graham

HighlightsDSSAT simulations of final N uptake, biomass, and yield for a maize-peanut rotational field experiment with three irrigation treatments and three N fertilizer rates had good performance for the irrigated treatments (average nRMSE of 9%) but greater error for the rainfed treatments (average nRMSE of 15%).Experiments and DSSAT simulations demonstrated that N fertilizer and irrigation applications were reduced by 26% and 60%, respectively, when using a 247 kg N ha-1 fertilizer rate and a sensor-based irrigation schedule rather than conventional practices of 336 kg N ha-1 and a calendar-based irrigation method, with no impact on yield.Simulations demonstrated that N leaching during the crop rotation was reduced by 37% when an N fertilizer rate of 247 kg N ha-1 and sensor-based irrigation scheduling were used versus conventional practices.Soil N increased (=15 mg kg-1) when maize and peanut residues decayed and then leached during the fallow season. Cover or cash crops planted immediately after the maize and peanut harvests have potential to take up this N and reduce leaching.Abstract. Nitrogen (N) is an essential element for crop growth and yield; however, excessive N applications not taken up by crops can result in N leaching from the root zone, increasing N loads to waterbodies and leading to a host of environmental problems. The main objective of this study was to simulate water and N balances for a maize-peanut (Zea mays L. and Arachis hypogaea L.) rotational field experiment with three irrigation treatments and three N fertilizer rates. The irrigation treatments consisted of mimicking grower irrigation practices in the region (GROW), using soil moisture sensors to schedule irrigation (SMS), and non-irrigated (NON). The N fertilizer rates were low, medium, and high (157, 247, and 336 kg N ha-1, respectively) for maize with a constant 17 kg ha-1 for all peanut treatments. DSSAT maize genetic coefficients were calibrated using the SMS-high treatment combination under the assumption of no water or N stress. The other eight treatment combinations were used as independent data for model validation of the crop coefficients. All soil hydrologic parameters were specified based on measured values, and default DSSAT peanut genetic coefficients were used with no calibration. For the irrigated treatments, DSSAT models had good performance for N uptake, biomass, and yield (average nRMSE of 8%) and moderate performance for soil water content (average nRMSE of 18%). Soil nitrate RMSE was 21% lower than the standard deviation of the observed data (5.8 vs. 7.2 mg kg-1). For the rainfed treatments, DSSAT had greater error (average nRMSE of 15% for N uptake, biomass, and yield, and average nRMSE of 31% for soil water). Soil nitrate RMSE was 11% greater than the standard deviation of the observed data (8.0 vs. 7.2 mg kg-1), and nRMSE was &gt;30% during the crop rotation. Simulations estimated that N leaching over the crop rotation was reduced by 24% on average when using the 247 kg N ha-1 fertilizer rate compared to 336 kg N ha-1 across the irrigation treatments. Furthermore, N leaching was reduced by 37% when using SMS to schedule irrigation and the 247 kg N ha-1 fertilizer rate for maize and 17 kg N ha-1 for peanut compared to conventional practices (GROW and 336 kg N ha-1 for maize and 17 kg N ha-1 for peanut). Moreover, this management practice reduced N fertilizer use by 26% and irrigation water use by up to 60% without negative impacts on yield. Observed and simulated soil N increased during maize and peanut residue decay, with simulations estimating that this soil N would leach below the root zone during the fallow season. This leaching could potentially be reduced if a cover crop or cash crop were planted between the maize and peanut crops to take up the mineralized N. Keywords: Agricultural best management practices, Bare fallow, BMPs, Maize-peanut rotation, N balance, N fertilization, N leaching, Sandy soils, Sensor-based irrigation scheduling, Water balance.


1989 ◽  
Vol 69 (3) ◽  
pp. 695-699 ◽  
Author(s):  
R. M. N. KUCEY

Dinitrogen fixation with field bean (Phaseolus vulgaris L. 'GN1140') and pea (Pisum sativum L. 'Trapper') over the growing season under field conditions was determined using 15N isotope dilution methods. Levels of N2 fixation were low during the early part of the growing season for both bean and pea, and increased later in the growing season. At physiological maturity, GN1140 fixed over 91 kg N ha−1, contributing between 60 and 90% of the N in the bean plants. Pea fixed 117 kg N ha−1, which constituted a maximum of 57% of the pea plant N. More N was contained in the bean and pea pods than was fixed over the growing season. Key words: Bean (field), pea, Phaseolus vulgaris, Pisum sativum, 15N dilution


Agronomy ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2491
Author(s):  
Gabriel Dias Paiao ◽  
Fabián G. Fernández ◽  
Seth L. Naeve

Soil drainage is not considered in the N fertilizer guidelines for corn (Zea mays L.) in the US Midwest. This study investigated the influence of soil drainage on corn grain yield, N requirement, and residual soil N, and evaluated the utility of in-season soil N measurements to guide N application. This 6-year study in Minnesota, US on a corn–soybean (Glycine max [L.] Merr.) rotation had drained and undrained conditions and six at planting (PL) (0–225 in 45 kg N ha−1 increments) and four split (SP) N fertilizer rates (at planting/V6-V8—45/45, 45/90, 45/135, 45/179 kg N ha−1). The drained compared to undrained soil produced 8% more grain yield (12.8 vs. 11.9 Mg ha−1), 12% more N uptake (169 vs. 151 kg N ha−1), 16% lower optimal N rate (ONR) (160 vs. 193 kg N ha−1), 3.1% greater grain yield at ONR (13.5 vs. 13.1 Mg ha−1), and similar in season and residual soil N. Compared to SP, PL lowered ONR (151 vs. 168 kg N ha−1) in drained soils, and the opposite occurred for undrained soils (206 vs. 189 kg N ha−1). These results substantiate the agronomic benefits of artificial drainage and the need to incorporate drainage conditions into N management guidelines.


2016 ◽  
Author(s):  
Stephane Bazot ◽  
Chantal Fresneau ◽  
Claire Damesin ◽  
Laure Barthes

Abstract. The origin of the N which contributes to the synthesis of N reserves of in situ forest trees in autumn, and to the growth of new organs the following spring, is currently poorly documented. To characterize the metabolism of various possible N sources (plant N and soil N), six distinct 20 year-old sessile oaks were 15N labelled by spraying 15NH415NO3: (i) on leaves in May, to label the N pool remobilized in the autumn for synthesis of reserves; (ii) on soil in the autumn, to label the N pool taken up from soil; (iii) on soil at the beginning of the following spring, to label the N pool taken up from soil in the spring. The partitioning of 15N in leaves, twigs, phloem, xylem, fine roots, rhizospheric soil and microbial biomass was followed during two growing seasons. Results showed a significant incorporation of 15N in the soil-tree system; more than 30 % of the administered 15N was recovered. Analysis of the partitioning clearly revealed that in autumn, roots’ N reserves were formed from foliage 15N (73 %) and to a lesser extent from soil 15N (27 %). The following spring, 15N used for the synthesis of new leaves came first from 15N stored during the previous autumn, mainly from 15N reserves formed from foliage (95 %). Thereafter, when leaves were fully expanded, 15N uptake from soil during the previous autumn and before budburst contributed to the formation of new leaves (60 %).


HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 553C-553
Author(s):  
Paula B. Aguirre ◽  
Teryl R. Roper ◽  
Armand R. Krueger

The uptake efficiency of apple scions and rootstocks has not been studied in the field. Using 15N (ammonium nitrate, 1 atom % 15N) we compared nitrogen uptake efficiency of 12 rootstocks grafted to one scion (Gala) and of 20 scions on the same clonal rootstock (M.9 EMLA) in orchards located in northeastern Wisconsin. Trees were treated in either Fall or Spring 1998 with 40 g actual N per tree applied as a liquid to the soil. N uptake was assessed by measuring 15N in leaf and wood tissue taken monthly from June to Oct. 1998. Tissues were oven-dried and analized using a ratio mass spectrometer. Treatment differences were greater among scions with the same rootstocks than among rootstocks with the same scion. Total N and 15N content differences were found between roostocks and these values were inversely related to tree size.


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