Estimating dry-matter accumulation in soybean

1977 ◽  
Vol 55 (16) ◽  
pp. 2196-2201 ◽  
Author(s):  
J. L. Heilman ◽  
E. T. Kanemasu ◽  
G. M. Paulsen
Keyword(s):  
Solar Radiation ◽  
Photosynthetically Active Radiation ◽  
Dry Matter ◽  
Dark Respiration ◽  
Field Measurements ◽  
Dry Matter Accumulation ◽  
Soil Water Depletion ◽  
Area Index ◽  
Active Radiation ◽  
Gross Photosynthesis

Equations to estimate gross photosynthesis, respiration, and dry-matter accumulation for soybean from daily estimates of intercepted, photosynthetically active radiation (PAR) were developed from field measurements. We found that gross photosynthesis was a function of intercepted PAR and that 24-h dark respiration was a function of gross photosynthesis. In addition, we developed equations relating intercepted PAR to leaf area index (LAI) and solar radiation. We assumed that gross photosynthesis was reduced when soil-water depletion was greater than 65%. The growth model predicted accumulated dry matter for soybean in 1974, 1975, and 1976 to within 2.7 mg cm−2 of observed values.

scholarly journals Upscaling from Instantaneous to Daily Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) for Satellite Products

2020 ◽  
Vol 12 (13) ◽  
pp. 2083
Author(s):  
Siyuan Chen ◽  
Liangyun Liu ◽  
Xue He ◽  
Zhigang Liu ◽  
Dailiang Peng
Keyword(s):  
Zenith Angle ◽  
Photosynthetically Active Radiation ◽  
Solar Zenith Angle ◽  
Field Measurements ◽  
Area Index ◽  
Active Radiation ◽  
Sensing Applications ◽  
Typical Satellite ◽  
Absorbed Photosynthetically Active Radiation ◽  
Local Noon

The fraction of absorbed photosynthetically active radiation (FAPAR) is an essential climate variable (ECV) widely used for various ecological and climate models. However, all the current FAPAR satellite products correspond to instantaneous FAPAR values acquired at the satellite transit time only, which cannot represent the variations in photosynthetic processes over the diurnal period. Most studies have directly used the instantaneous FAPAR as a reasonable approximation of the daily integrated value. However, clearly, FAPAR varies a lot according to the weather conditions and amount of incoming radiation. In this paper, a temporal upscaling method based on the cosine of the solar zenith angle (SZA) at local noon ( c o s ( S Z A n o o n ) ) is proposed for converting instantaneous FAPAR to daily integrated FAPAR. First, the diurnal variations in FAPAR were investigated using PROSAIL (a model of Leaf Optical Properties Spectra (PROSPECT) integrating a canopy radiative transfer model (Scattering from Arbitrarily Inclined Leaves, SAIL)) simulations with different leaf area index (LAI) values corresponding to different latitudes. It was found that the instantaneous black sky FAPAR at 09:30 AM provided a good approximation for the daily integrated black sky FAPAR; this gave the highest correlation (R2 = 0.995) and lowest Root Mean Square Error (RMSE = 0.013) among the instantaneous black sky FAPAR values observed at different times. Secondly, the difference between the instantaneous black sky FAPAR values acquired at different times and the daily integrated black sky FAPAR was analyzed; this could be accurately modelled using the cosine value of solar zenith angle at local noon ( c o s ( S Z A n o o n ) ) for a given vegetation scene. Therefore, a temporal upscaling method for typical satellite products was proposed using a cos(SZA)-based upscaling model. Finally, the proposed cos(SZA)-based upscaling model was validated using both the PROSAIL simulated data and the field measurements. The validated results indicated that the upscaled daily black sky FAPAR was highly consistent with the daily integrated black sky FAPAR, giving very high mean R2 values (0.998, 0.972), low RMSEs (0.007, 0.014), and low rMAEs (0.596%, 1.378%) for the simulations and the field measurements, respectively. Consequently, the cos(SZA)-based method performs well for upscaling the instantaneous black sky FAPAR to its daily value, which is a simple but extremely important approach for satellite remote sensing applications related to FAPAR.

Influence of primed seed and varying seed rate on growth and productivity of soybean (Glycine max L.) under different planting techniques

2018 ◽  
Author(s):  
Rupinder Kaur Jassal ◽  
Harmeet Singh
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Plant Height ◽  
Seed Yield ◽  
Dry Matter ◽  
Seed Priming ◽  
Dry Matter Accumulation ◽  
Area Index ◽  
Active Radiation ◽  
Seed Rate

An experiment was conducted at Punjab Agricultural University, Ludhiana during 2015 and 2016 to study the effect of priming, different seed rate on growth and seed yield of soybean planted under bed and flat method. The study was planned in factorial split plot design, keeping two planting techniques (flat sowing and bed sowing) and two seed priming treatments ( non primed seeds and 100 ppm GA3 primed seeds) in main plot and three seed levels ( 50, 62.5 and 75 kg ha-1) in sub plot. The objective of the study was to evaluate the effect of seed priming on growth and productivity under different planting techniques with the use of varying seed rates. The results revealed that growth attributes viz. emergence count, plant height, dry matter accumulation, leaf area index and photosynthetic active radiation interception (%) was significantly higher under bed planting technique as compared to flat sowing method. The pooled seed yield was increased by 15.6 % in bed planted soybean crop as compared to flat planted crop. Soybean seeds primed with 100 ppm GA3 recorded significant results in all the growth parameters. Primed seed recorded increase in yield 15.3 % than non primed seeds. Seed rate of 62.5 kg ha-1 recorded significantly higher emergence count, plant height, dry matter accumulation, leaf area index and photosynthetic active radiation interception (%) which was statistically similar in results with 75 kg ha-1 seed rate in both the two years. Pooled seed yield of 62.5 kg ha-1seed rate was 4.61 % higher than 75 kg ha-1 and 12.6 % than 50 kg ha-1 seed rate.

scholarly journals Interception of solar radiation by the productive structures of spring canola hybrids

2016 ◽  
Vol 46 (10) ◽  
pp. 1790-1796 ◽  
Author(s):  
Elizandro Fochesatto ◽  
Astor Henrique Nied ◽  
Homero Bergamaschi ◽  
Genei Antonio Dalmago ◽  
Daniele Gutterres Pinto ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Extinction Coefficient ◽  
Photosynthetically Active Radiation ◽  
Field Experiments ◽  
Area Index ◽  
Active Radiation ◽  
Nitrogen Levels ◽  
Reproductive Structures ◽  
Spring Canola ◽  
Sowing Dates

ABSTRACT: The objective of this study was to adjust parameters related to the interception of photosynthetically active radiation (PAR) by reproductive structures of spring canola, with different nitrogen levels and hybrids. Two field experiments were conducted, being one with different sowing dates and hybrids (Hyola 61 and Hyola 432) and another with doses of 10, 20, 40, 80, 160kg ha-1 of N, applied in top dressing. They were conducted in Passo Fundo and Coxilha, RS, Brazil, in 2011 and 2014, respectively.The evaluated variables were: area index of reproductive structures, interception efficiency and extinction coefficient of these structures for PAR. PAR interception increased by increasing the reproductive structures volume. Interception efficiency of PAR by reproductive structures ranged from 45 to 80%. It was higher in the Hyola 61 hybrid and at the highest dose of N. The extinction coefficient of reproductive structures for PAR was 0.44 in non-limiting doses of N.

scholarly journals Conversion Efficiency of Photosynthetically Active Radiation for Soybean Cultivations in Spatial Arrangements

2019 ◽  
Vol 11 (9) ◽  
pp. 213
Author(s):  
Braulio Otomar Caron ◽  
Ana Paula Rockenbach ◽  
Denise Schmidt ◽  
Thaise Dieminger Engroff ◽  
Felipe Schwerz ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Conversion Efficiency ◽  
Photosynthetically Active Radiation ◽  
Area Index ◽  
Active Radiation ◽  
Soybean Cultivars ◽  
Growth Habits ◽  
Conversion Efficiencies

The objective of this paper was to assess the efficiency of photosynthetically active radiation (PAR) intercepted in dried phytomass of soybean cultivars of determinate and indeterminate growth habits in different spatial arrangements. All experiments were carried out during the 2013/2014 crop year, two soybean cultivars (BMX Ativa RR/determinate and BMX Turbo RR/indeterminate) in a spatial arrangements (45, crossed, 20, 20 × 40, 20 × 60, 20 × 80 cm). Starting from first emergence up to the point of maturation, 14 phytomass assessment were evaluated with seven days interval, in which one plant was sampled per repetition. Greater conversion efficiencies of solar radiation were obtained in paired arrangements. Paired arrangements, and 20 cm, lead to a greater leaf area index, and possibly a greater interception of the diffused radiation and an increase of conversion efficiency and the overall cultivation productivity of BMX Ativa RR and BMX Turbo RR.

scholarly journals The nitrogen topdressing mode of indica-japonica and indica hybrid rice are different after side-deep fertilization with machine transplanting

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiaodan Wang ◽  
Yaliang Wang ◽  
Yuping Zhang ◽  
Jing Xiang ◽  
Yikai Zhang ◽  
...  
Keyword(s):  
Single Dose ◽  
Controlled Release ◽  
Nitrogen Uptake ◽  
Dry Matter ◽  
Hybrid Rice ◽  
Dry Matter Accumulation ◽  
Area Index ◽  
Quick Release ◽  
Significant Difference ◽  
Spikelets Per Panicle

AbstractDetermination of the optimal fertilization method is crucial to maximize nitrogen use efficiency and yield of different rice cultivars. Side-deep fertilization with controlled-release nitrogen, in conjunction with machine transplanting and subsequent topdressing, was applied to Indica–japonica hybrid rice ‘Yongyou1540’ (YY1540) and indica hybrid rice ‘Tianyouhuazhan’ (TYHZ). Four nitrogen treatments were applied in 2018 and 2019: traditional nitrogen application with quick-release nitrogen (T1), single-dose deep fertilization at transplanting with 100% controlled-release nitrogen (T2), and deep fertilization of 70% controlled-release nitrogen and topdressing of 30% quick nitrogen at tillering (T3), or at panicle initiation (T4). Side-deep fertilization reduced the fertilizer application frequency without causing yield loss, T4 enhanced the yield of YY1540 by increasing the number of productive tillers and number of spikelets per panicle compared with T1, T2 and T3. The yield of TYHZ showed no significant difference among treatments. The T4 treatment decreased the number of tillers at the tilling peak stage and increased the percentage productive tillers and number of differentiated spikelets. Compared with the other treatments, T4 increased dry matter accumulation and leaf area index during panicle initiation and grain ripening, and contributed to enhanced nitrogen uptake and nitrogen utilization in YY1540. On average, nitrogen uptake and utilization in YY1540 were highest in T4, but no significant differences among treatments were observed in TYHZ. Dry matter accumulation and nitrogen uptake from panicle initiation to heading of YY1540 were correlated with number of spikelets per panicle, but no significant correlations were observed for TYHZ. Supplementary topdressing with quick-release nitrogen at the panicle initiation stage was required to increase yield of indica–japonica hybrid rice, whereas single-dose deep fertilization with controlled-release nitrogen is satisfactory for the indica hybrid cultivar.

scholarly journals Radiación fotosintéticamente activa evaluada en la ciudad de Zacatecas

2020 ◽  
pp. 1-11
Author(s):  
Mónica Montserrat Escobedo-Sánchez ◽  
Ricardo Conejo-Flores ◽  
Sergio Miguel Durón-Torres ◽  
Juan Manuel García-González
Keyword(s):  
Decision Making ◽  
Solar Radiation ◽  
Production Planning ◽  
Photosynthetically Active Radiation ◽  
Detailed Knowledge ◽  
Active Radiation ◽  
Incident Solar Radiation ◽  
Daily Average ◽  
Life On Earth

The present investigation is related to one of the most important processes for the development of life on Earth; photosynthesis, an essential process in the cycle and development of living beings, centered on solar radiation that is useful for plants to carry out this process, Photosynthetically Active Radiation (PAR). The objective of this work is to generate information on the PAR through a database to collaborate in the decision-making of farmers in the area. For this purpose, a quantum sensor installed in building 6 of the UAZ Siglo XXI Campus was used. According to Abal (2013), in agricultural and production planning, it is especially important to have a detailed knowledge of incident solar radiation on the earth's surface (Abal and Durañona, 2013). When collecting, treating and analyzing the data, it was found that the daily average PAR is 819.52 μmol of photons m-2 s-1 (179.47 W m-2), if only the sunny hours are taken into account. It can be concluded that according to the PAR received in the evaluation region and the type of nutrients in the soil, other crop alternatives to those traditionally used can be sought.

scholarly journals Effects of UV-B Radiation on Oxalate Content of Silver Beet Leaves

2012 ◽  
Vol 1 (4) ◽  
pp. 1 ◽  
Author(s):  
H. A. Presswood ◽  
R. Hofmann ◽  
G. P. Savage
Keyword(s):  
New Zealand ◽  
Photosynthetically Active Radiation ◽  
Dry Matter ◽  
Active Radiation ◽  
Silver Beet

Silver beet (<em>Beta vulgaricus </em>var. <em>cicla</em>) a common vegetable in New Zealand is known to contain high levels of oxalates in the leaves. Silver beet plants were grown in afield trial under glass and perspex sheets which filtered sunlight reaching the plants. After eight weeks of growth, the plants were harvested and the total, soluble and insoluble oxalate content of the leaves of the plants grown under the two filter treatments and a no-frame control were measured. Perspex allowed the transmission of UV-A, UV-B and photosynthetically active radiation (PAR), whereas glass excluded UV-B radiation. No significant differences between the perspex treatment and the no-frame control were observed when the data was compared on a wet matter (WM) or dry matter (DM) basis Shielding the growing plants with glass significantly reduced the total oxalate and soluble oxalates to 83 and 84% respectively when compared to the perspexand no-frame treatments.

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