scholarly journals Development and evaluation of a new Canadian spring wheat sub-model for DNDC

2011 ◽  
Vol 91 (4) ◽  
pp. 503-520 ◽  
Author(s):  
R. Kröbel ◽  
W. Smith ◽  
B. Grant ◽  
R. Desjardins ◽  
C. Campbell ◽  
...  

Kröbel, R., Smith, W. N., Grant, B. B., Desjardins, R. L., Campbell, C. A., Tremblay, N., Li, C. S., Zentner, R. P. and McConkey, B. G. 2011. Development and evaluation of a new Canadian spring wheat sub-model for DNDC. Can. J. Soil Sci. 91: 503–520. In this paper, the ability of the DNDC model (version 93) to predict biomass production, grain yield and plant nitrogen content was assessed using data from experiments at Swift Current, Saskatchewan, and St-Blaise, Quebec, Canada. While predicting wheat grain yields reasonably well, the model overestimated the growth of above-ground plant biomass and nitrogen uptake during the first half of the growing season. A new spring wheat sub-model (DNDC-CSW) was introduced with a modified plant biomass growth curve, dynamic plant C/N ratios and modified plant biomass fractioning curves. DNDC-CSW performed considerably better in simulating plant biomass [modeling efficiency (EF): 0.75, average relative error (ARE): 6.0%] and plant nitrogen content (EF: 0.61, ARE: −2.7%) at Swift Current and St-Blaise (EF of 0.75 and ARE of 2.3%), compared with DNDC 93 (biomass SC: EF 0.49, ARE 17.1%, SB: EF 0.02 ARE 33.4%). In comparison with DNDC 93, DNDC-CSW better captured inter-annual variations in crop growth for a range of wheat rotations, increasing the EF from 0.32 to 0.52 for grain and from 0.35 to 0.39 for straw yields. DNDC-CSW also performed considerably better than DNDC 93 in estimating soil carbon changes at Swift Current. Hence, DNDC-CSW has the potential to improve the performance of DNDC 93 in simulating wheat biomass, plant nitrogen, yield and soil carbon at various Canadian sites.

2000 ◽  
Vol 80 (3) ◽  
pp. 395-400 ◽  
Author(s):  
W. A. Rice ◽  
G. W. Clayton ◽  
P. E. Olsen ◽  
N. Z. Lupwayi

Crop production systems that include field pea (Pisum sativum L.) in rotation are important for sustainable agriculture on acid soils in northwestern Canada. Greenhouse experiments were conducted to compare the ability of liquid inoculant applied to the seed, powdered peat inoculant applied to the seed, and granular inoculant applied in a band with the seed to establish effective nodulation on field pea grown at soil pH(H2O) 4.4, 5.4 and 6.6. Plants were grown to the flat pod stage, and then total plant biomass dry weight, dry weight of nodules, number of nodules, plant nitrogen content, and proportion of plant nitrogen derived from the atmosphere (%Ndfa) were measured. Granular and powdered peat inoculants produced greater nodule numbers and weight, plant nitrogen content, %Ndfa and total biomass than liquid inoculant in at least two of the three experiments. Only granular inoculant was effective in establishing nodules at soil pH 4.4, but granular and powdered peat inoculants were effective at pH 5.4, and all three formulations were effective at pH 6.6. The results showed that granular inoculant has potential for effective nodulation of field pea grown on acid soil. Key words: Rhizobium, inoculant formulations, field pea, nodulation, acid soil


2021 ◽  
Author(s):  
◽  
Yia Yang

Soybean [Glycine max (L.) Merr] cultivars have low genetic variation due to domestication, founder events, and selection strategies for modern plant breeding. There is a need to introduce genetic diversity into soybean cultivars for long-term improvement of agronomic and seed compositional traits. In both public and private soybean breeding programs, the introgression of wild soybean (Glycine soja Siebold and Zucc.) genes has been utilized to incorporate novel genetic diversity. In our study, 3,015 single F[subscript 4:9] soybean plants were genotyped for nine genotype-by-sequencing markers from a previous genetic mapping study on recombinant inbred lines (La, 2018) to create two residual heterozygotes derived near isogenic lines (RHD-NIL) populations. The first RHD-NIL population was selected for a novel oil quantitative trait loci (QTL) on chromosome 8 and the second RHD-NIL population was selected for a novel protein QTL on chromosome 14. Both novel QTL derived from the wild soybean accession PI 593983. The objective of this research is to validate these QTL, reduce the QTL interval, and fine map the two novel QTL for candidate gene identification. Single marker analysis and linkage analysis was conducted using SoySNP6K BeadChip markers for QTL validation. The chromosome 8 oil QTL was not advanced for fine mapping because the QTL was not validated in a subsequent field and greenhouse study. Whole genome resequencing was leveraged to reduce the QTL from 16.5 Mbp to approximately 4.6 Mbp and to fine map 50 high protein RHD-NIL, which have segregated for the validated chromosome 14 QTL to permit candidate gene identification. A total of 55 potential candidates was identified in a physical interval of 8,059,955 to 12,648,760 bp. Our results provide a better insight of utilizing wild soybean as a source of genetic diversity for soybean cultivar improvement. In addition to the fine mapping and candidate gene identification study, we conducted linkage analysis for a recombinant inbred line (RIL) mapping population for plant biomass content, whole plant carbon content, whole plant nitrogen content, seed oil content, and seed protein content. Soybean seeds require a large amount of nitrogen because of its high protein content. Through a symbiotic association between soil microorganisms and soybean root nodules, soybean is able to fix atmospheric dinitrogen for nitrogen uptake. Plant biomass was collected by bulking five soybean shoot samples per plot from 262 plots in four locations and bulking three soybean shoots samples per plot from 262 plots in one location. Plant materials were dried and weighed for whole plant biomass weight. Whole plant carbon content, whole plant nitrogen content, seed oil content, and seed protein content was analyzed via near infrared spectroscopy. The objective of this study was to examine nitrogen mobilization from a mapping population from the cross PI 361103 (contains high shoot N content and low seed N content) x PI 567572B (contains high seed N content and low shoot N content), identify QTL for plant biomass, whole plant carbon content, whole plant nitrogen content, and seed composition, and study maternal effects of cytoplasmic inheritance of the five traits from the reciprocal parental cross. Linkage analysis was conducted using BARCSoySNP50K markers. We identified six QTL for plant biomass, two QTL for whole plant carbon content, three QTL for whole plant nitrogen content, three QTL for seed oil content, and five QTL for seed protein content, with multiple traits having overlapping QTL intervals. Our results indicate QTL associated with multiple traits demonstrating the potential of pleiotropic effect in our mapping population.


2020 ◽  
Vol 65 (6) ◽  
pp. 1219-1229
Author(s):  
В.А. Четырбоцкий ◽  
◽  
А.Н. Четырбоцкий ◽  
Б.В. Левин ◽  
◽  
...  

A numerical simulation of the spatial-temporal dynamics of a multi-parameter system is developed. The components of this system are plant biomass, mobile and stationary forms of mineral nutrition elements, rhizosphere microorganisms and environmental parameters (temperature, humidity, acidity). Parametric identification and verification of the adequacy of the model were carried out based on the experimental data on the growth of spring wheat «Krasnoufimskaya-100» on peat lowland soil. The results are represented by temporal distributions of biomass from agricultural crop under study and the findings on the content of main nutrition elements within the plant (nitrogen, phosphorus, potassium). An agronomic assessment and interpretation of the obtained results are given.


Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 126
Author(s):  
Judit Barroso ◽  
Nicholas G. Genna

Russian thistle (Salsola tragus L.) is a persistent post-harvest issue in the Pacific Northwest (PNW). Farmers need more integrated management strategies to control it. Russian thistle emergence, mortality, plant biomass, seed production, and crop yield were evaluated in spring wheat and spring barley planted in 18- or 36-cm row spacing and seeded at 73 or 140 kg ha−1 in Pendleton and Moro, Oregon, during 2018 and 2019. Russian thistle emergence was lower and mortality was higher in spring barley than in spring wheat. However, little to no effect of row spacing or seeding rate was observed on Russian thistle emergence or mortality. Russian thistle seed production and plant biomass followed crop productivity; higher crop yield produced higher Russian thistle biomass and seed production and lower crop yield produced lower weed biomass and seed production. Crop yield with Russian thistle pressure was improved in 2018 with 18-cm rows or by seeding at 140 kg ha−1 while no effect was observed in 2019. Increasing seeding rates or planting spring crops in narrow rows may be effective at increasing yield in low rainfall years of the PNW, such as in 2018. No effect may be observed in years with higher rainfall than normal, such as in 2019.


2003 ◽  
Vol 56 (2) ◽  
pp. 323-335 ◽  
Author(s):  
Paul D. Groves

Transfer alignment is the process of initialising and calibrating a weapon INS using data from the host aircraft's navigation system. To determine which transfer alignment technique performs best, different design options have been assessed, supported by simulation work. The dependence of transfer alignment performance on environmental factors, such as manoeuvres, alignment duration, lever arm and inertial sensor quality has also been studied. ‘Rapid’ alignment, using attitude as well as velocity measurements was found to perform better than ‘conventional’ techniques using only velocity. Innovative developments include the estimation of additional acceleration and gyro states and estimation of force dependent relative orientation, which has enabled robust alignment using wing rock manoeuvres, which do not require the pilot to change trajectory. Transfer alignment has been verified in real-time by flight trials on a Tornado aircraft. In addition, techniques have been developed to prevent transients in the aircraft integrated navigation solution following GPS re-acquisition after an outage of several minutes from disrupting the transfer alignment process.


2017 ◽  
Author(s):  
Javier López-Solano ◽  
Alberto Redondas ◽  
Thomas Carlund ◽  
Juan J. Rodriguez-Franco ◽  
Henri Diémoz ◽  
...  

Abstract. The high spatial and temporal variability of aerosols make networks capable of measuring their properties in near real time of high scientific interest. In this work we present and discuss results of an aerosol optical depth algorithm to be used in the European Brewer Network, which provides data in near real time of more than 30 spectrophotometers located from Tamanrasset (Algeria) to Kangerlussuaq (Greenland). Using data from the Brewer Intercomparison Campaigns in the years 2013 and 2015, and the period in between, plus comparisons with Cimel sunphotometers and UVPFR instruments, we check the precision, stability, and uncertainty of the Brewer AOD in the ultraviolet range from 300 to 320 nm. Our results show a precision better than 0.01, an uncertainty of less than 0.05, and a stability similar to that of the ozone measurements for well-maintained instruments. We also discuss future improvements to our algorithm with respect to the input data, their processing, and the characterization of the Brewer instruments for the measurement of aerosols.


2001 ◽  
Vol 44 (11-12) ◽  
pp. 61-67 ◽  
Author(s):  
S-Y. Kim ◽  
P.M. Geary

Two species of macrophytes, Baumea articulata and Schoenoplectus mucronatus, were examined for their capacity to remove phosphorus under nutrient-rich conditions. Forty large bucket systems with the two different species growing in two types of substrate received artificial wastewaters for nine months, simulating a constructed wetland (CW) under high loading conditions. Half of the plants growing in the topsoil and gravel substrates were periodically harvested whereas the other half remained intact. Plant tissue and substrate samples were regularly analysed to determine their phosphorus concentrations. With respect to phosphorus uptake and removal, the Schoenoplectus in the topsoil medium performed better than the Baumea. Biomass harvesting enhanced P uptake in the Schoenoplectus, however the effect was not significant enough to make an improvement on the overall P removal, due to the slow recovery of plants and regrowth of biomass after harvesting. From P partitioning, it was found that the topsoil medium was the major P pool, storing most of total P present in the system. Plant parts contributed only minor storage with approximately half of that P stored below ground in the plant roots. The overall net effect of harvesting plant biomass was to only remove less than 5% of total phosphorus present in the system.


2016 ◽  
Vol 9 (1) ◽  
pp. 1
Author(s):  
YUDI RINANTO ◽  
UMI FATMAWATI

<p class="5abstrak">The aim of this research is to identify the effectiveness of Local Isolate Bacteria from Boyolali (ILB) to decompose organic materials from wasted vegetable and slurry. The result of decomposition were compared to EM4 for control. The laboratory result indicates that Local isolate bacteria from Boyolali were more effective than EM4 to increase N (Nitrogen) content. The ability of Local isolate bacteria from Boyolali was better than EM4 in degrading organic materials of slurry, particularly, towards P (Phosphate). The best concentration of ILB decomposition is 30 %. Liquid fertilizer produced from Slurry with decomposition ILB 30% that applied towards cabbage  increased the weight of cabbage and the length of circumference by 0.5525 gram and 12.67 cm respectively. From the experimental results that it can be concluded that ILB has better capability in decomposing organic material than EM4. ILB has a good potential as <em>decomposter</em> to produces liquid organic fertilizer.</p><p class="5abstrak"> </p><strong>Keywords</strong>:     Local isolate, decomposter, EM4, Slurry, cabbage


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