scholarly journals Retrieval of Grassland Aboveground Biomass through Inversion of the PROSAIL Model with MODIS Imagery

2019 ◽  
Vol 11 (13) ◽  
pp. 1597 ◽  
Author(s):  
Li He ◽  
Ainong Li ◽  
Gaofei Yin ◽  
Xi Nan ◽  
Jinhu Bian
Keyword(s):  
Aboveground Biomass ◽  
Physical Nature ◽  
Field Measurements ◽  
Matter Content ◽  
Lookup Table ◽  
Dry Matter Content ◽  
Area Index ◽  
Important Indicator ◽  
Physically Based ◽  
Modis Imagery

The estimation of aboveground biomass (AGB), an important indicator of grassland production, is crucial for evaluating livestock carrying capacity, understanding the response and feedback to climate change, and achieving sustainable development. Most existing grassland AGB estimation studies were based on empirical methods, in which field measurements are indispensable, hindering their operational use. This study proposed a novel physically-based grassland AGB retrieval method through the inversion of PROSAIL model against MCD43A4 imagery. This method relies on the basic understanding that grassland is herbaceous, and therefore AGB can be represented as the product of leaf dry matter content (Cm) and leaf area index (LAI), i.e., AGB = Cm × LAI. First, the PROSAIL model was parameterized according to the literature regarding grassland parameters retrieval, then Cm and LAI were retrieved using a lookup table (LUT) algorithm, finally, the retrieved Cm and LAI were multiplied to obtain the AGB. The method was assessed in Zoige Plateau, China. Results show that it could reproduce the reference AGB map, which is generated by upscaling the field measurements, in terms of magnitude (with RMSE and R-RMSE of 60.06 g·m−2 and 18.1%, respectively) and spatial distribution. The estimated AGB time series also agreed reasonably well with the expected temporal dynamic trends of the grassland in our study area. The greatest advantage of our method is its fully physical nature, i.e., no field measurement is needed. Our method has the potential for operational monitoring of grassland AGB at regional and even larger scales.

Persistence of modern varieties and hybrids of carrots and its dependence on the biochemical composition

2020 ◽  
pp. 16-19
Author(s):  
Е.В. Янченко
Keyword(s):  
Botrytis Cinerea ◽  
Sclerotinia Sclerotiorum ◽  
Dry Matter ◽  
Inverse Correlation ◽  
Dry Weight ◽  
Matter Content ◽  
White Rot ◽  
Dry Matter Content ◽  
Important Indicator ◽  
Modern Varieties

Цель исследований – дать оценку сохраняемости и болезнеустойчивости современных сортов и гибридов моркови столовой и определить корреляционные зависимости влияния биохимических показателей качества на сохраняемость и степень поражения моркови столовой различными видами болезней в процессе хранения. Исследования проводились в 2011–2016 годах во ВНИИО – филиале ФГБНУ ФНЦО по общепринятым методикам. В биохимической лаборатории отдела земледелия и агрохимии содержание сухого вещества определяли высушиванием до абсолютно сухого веса, общего сахара – по Бертрану, аскорбиновой кислоты – по Мурри, нитраты – ионоселективным методом. При характеристике моркови столовой важнейший показатель, определяющий его качество – количество сухого вещества и сахаров. В процессе хранения были выявлены следующие болезни моркови: серая гниль (Botrytis cinerea Pers. ex Fr.), белая гниль (Sclerotinia sclerotiorum (Lib.)), белая парша (Rhizoctonia carotae Rad.), альтернариоз (Alternaria radicina M., Dr. et E.). В большей степени сортообразцы моркови столовой поражались серой гнилью. Лучшими по сохраняемости сортообразцами были Корсар (94,6%), F1Берлин (94,5%), Берликум Роял (94,1%) и F1 Звезда (94%). Сохраняемость у зарубежных сортов и гибридов моркови столовой была немного выше, чем у отечественных (на 0,4%) как за счет меньшей величины убыли массы (6,3% против 6,4%), так и потерь от болезней (1,6% против 1,9%). Сохраняемость корнеплодов моркови находится в прямой корреляционной зависимости от содержания сухого вещества (r=+0,41), каротиноидов (r=+0,39), моносахаров (r­=+0,30) и суммы сахаров (r=+0,27). Проявление серой гнили находится в обратной корреляционной связи с содержанием сухого вещества и каротиноидов (r=-0,37 и r=-0,35 соответственно), белой парши – в прямой корреляции с содержанием сухого вещества , моносахаров и дисахаров (r= +0,21; r= +0,39; r= -0,41 соответственно), белой гнили в обратной корреляционной связи с содержанием сухого вещества, моносахаров и дисахаров. The purpose of the research is to assess the persistence and disease resistance of modern varieties and hybrids of carrots and to determine the correlation between the influence of biochemical quality indicators on the persistence and degree of damage to carrots by various types of diseases during storage. The research was conducted in 2011–2016 at ARRIVG – branch of FSBSI FSVC, according to generally accepted methods. In the biochemical laboratory of the Department of Agriculture and Agrochemistry, the dry matter content was determined by drying to absolutely dry weight, total sugar – by Bertran, ascorbic acid – by Murri, nitrates – by the ion-selective method. When describing carrots, the most important indicator that determines its quality is the amount of dry matter and sugars. During storage, the following diseases of carrots were detected: gray rot (Botrytis cinerea Pers. ex Fr.), white rot (Sclerotinia sclerotiorum (Lib.), white scab (Rhizoctonia carotae Rad.), alternariasis (Alternaria radicina M., Dr. et E.). To a greater extent, varieties of table carrots were affected by gray rot. The best preserved varieties were Corsar (94.6%), F1 Berlin (94.5%), Berlicum Royal (94.1%) and F1 Zvezda (94%). The persistence of foreign varieties and hybrids of table carrots was slightly higher than that of domestic ones by 0.4%. both due to a smaller amount of weight loss (6.3% vs. 6.4%) and losses from diseases (1.6% vs. 1.9%). The persistence of carrot root crops is directly correlated with the content of dry matter (r=+0.41), carotenoids (r=+0.39), monosaccharides (r=+0.30) and the amount of sugars (r=+0.27). The manifestation of gray rot is in inverse correlation with the content of dry matter and carotenoids (r=-0.37 and r=-0.35, respectively), white scab is in direct correlation with the content of dry matter (r= +0.21; r= +0.39; r= –0.41, respectively), white rot is in inverse correlation with the content of dry matter, monosaccharides and disaccharides.

Prediction of aboveground biomass and dry‐matter content in brachiaria pastures by combining meteorological data and satellite imagery

2021 ◽  
Author(s):  
Igor L. Bretas ◽  
Domingos S.M. Valente ◽  
Fabyano F. Silva ◽  
Mario L. Chizzotti ◽  
Mário F. Paulino ◽  
...  
Keyword(s):  
Satellite Imagery ◽  
Aboveground Biomass ◽  
Dry Matter ◽  
Meteorological Data ◽  
Matter Content ◽  
Dry Matter Content ◽  
Brachiaria Pastures

scholarly journals Características morfométricas e rendimento da palma forrageira ‘Gigante’ sob diferentes adubações e configurações de plantio

2016 ◽  
Vol 11 (1) ◽  
pp. 67 ◽  
Author(s):  
M. C. Padilha Junior ◽  
S. L. R. Donato ◽  
J. A. Silva ◽  
P. E. R. Donato ◽  
E. S. Souza
Keyword(s):  
Dry Matter ◽  
Block Design ◽  
Matter Content ◽  
Mineral Fertilizers ◽  
Organic Chemical ◽  
Dry Matter Content ◽  
Morphometric Characteristics ◽  
Morphometric Traits ◽  
Area Index ◽  
Organic Mineral

<p>Objetivou-se com o presente trabalho avaliar as características morfométricas e de rendimento da palma forrageira 'Gigante' submetida a diferentes tipos de adubação orgânica, química e organomineral e configurações de plantio<em>. </em>O experimento foi instalado em LATOSSOLO Vermelho-Amarelo distrófico, num delineamento em blocos casualizados, em esquema de parcelas subdivididas, com três repetições. As parcelas constituídas por duas configurações de plantio: 1) 24.0000 plantas ha<sup>-1</sup>, dispostas em fileira tripla, no espaçamento 3,00 x 1,00 x 0,25 m; 2) 26.666 plantas ha<sup>-1</sup>, dispostas em fileira quádrupla, no espaçamento 3,00 x 1,00 x 0,25 m; as subparcelas compostas por 12 tipos de adubação orgânica, química e organomineral. Aos 650 DAP mensuraram-se altura da planta, número, comprimento, largura e índice de área de cladódios, produção de matéria verde e seca e teor de matéria seca. As características morfométricas, o teor de matéria seca e a produção de massa verde e matéria seca foram influenciadas pelas adubações (P&lt;0,05), independentemente da configuração utilizada. Das características morfométricas apenas a largura e área do cladódio não foram influenciadas pelas adubações. A ausência de adubação ou apenas 30 Mg ha<sup>-1</sup> ano<sup>-1</sup> de esterco bovino são insuficientes para obter resultados satisfatórios com palma forrageira ‘Gigante’.</p><p><strong><em>Morphometric traits and yield of forage cactus 'Gigante' under different fertilization and planting settings</em></strong></p><p><strong>Abstract</strong><strong>: </strong>The objective of this study was to evaluate the morphometric characteristics and yield of 'Gigante' forage cactus subjected to different types of organic, chemical, and organic mineral fertilizers and planting configurations. The experiment was installed in a dystrophic Red-Yellow LATOSOL (Oxisol), in a randomized block design, in a split plot design parcel, with three replications. The plots consist of two plant configurations: 1) 24.0000 pl ha<sup>-1</sup>, arranged in triple row, spaced 3.00 x 1.00 x 0.25 m; 2) 26,666 pl ha<sup>-1</sup>, arranged in quadruple row, spaced 3.00 x 1.00 x 0.25 m. The subplots are composed of types of organic, chemical, and organic mineral fertilizers. On the 650th DAP were measured the plant height, number, length, width, cladode area index, fresh and dry matter yield and dry matter content. Morphometric characteristics, the dry matter content and the green mass and dry matter production were influenced by fertilization (P &lt;0.05), regardless the configuration. From the morphometric features, only the width and cladode area were not affected by fertilization. The absence of fertilization or just 30 Mg ha<sup>-1</sup> yr<sup>-1</sup> of cattle manure is not enough to achieve satisfactory results with 'Gigante' forage cactus.</p>

The growth of maize

1978 ◽  
Vol 90 (3) ◽  
pp. 569-577 ◽  
Author(s):  
G. O. Iremiren ◽  
G. M. Milbourn
Keyword(s):  
Leaf Area ◽  
Dry Matter ◽  
Matter Content ◽  
Net Assimilation Rate ◽  
Dry Matter Content ◽  
Dry Matter Yield ◽  
Assimilation Rate ◽  
Maize Silage ◽  
Area Index ◽  
Net Assimilation

SummaryTotal dry-matter yield of maize silage rose asymptotically as density was increased up to 17 plants/m2. Over the range 11–17 plants/m2, which is generally higher than is used in the U.K., the increase in yield was 1–1·6 t dry matter/ha which can justify the higher seed cost and although there was no adverse affect on time of maturity the risk of lodging increased at the highest density. During the harvest period whilst whole crop dry-matter percentage was rising from 23 to 28%, the ear dry-matter content rose steadily from 29 to 35%, whereas the leaf and stem dry-matter content remained essentially constant and only dried out at a later stage after a frost.Caldera 535 had a higher leaf area index and net assimilation rate than the earlier variety Julia which it outyielded by 15%. The additional yield was mainly stem tissue and the greater vegetative production caused an 11-day delay in reaching the silage stage of maturity (25% crop D.M.). NO differences occurred between density treatments and varieties in the forage quality components considered, namely percentage drymatter digestibility, modified acid-detergent fibre, crude protein and ash. Thus in U.K. conditions, total dry-matter yield exerts an overriding influence on the yields per unit area of these quality constituents. This contrasts with reports from the U.S.A. in which a reduced grain/stover ratio adversely influences silage quality.Removal of the whole ear (including husk and rachis) at an early stage in ear development resulted in a 50% reduction in the final dry-matter yield. In the earless plants, leaf area and net assimilation rate was lower, but the dry-matter content of the leaves and stem was considerably higher, and a marked purple coloration developed indicative of excess starch concentration. These results emphasize the need in maize silage not only for an adequate leaf canopy, best obtained early in the growing season by using high planting density and subsequently by using late maturing varieties, but also for sufficient sink capacity in the ear as well as in the stem fraction.

scholarly journals Estimación de variables esenciales de la vegetación en un ecosistema de dehesa utilizando factores de reflectividad simulados estacionalmente

2020 ◽  
pp. 31
Author(s):  
M. P. Martín ◽  
J. Pacheco-Labrador ◽  
R. González-Cascón ◽  
G. Moreno ◽  
M. Migliavacca ◽  
...  
Keyword(s):  
Structural Characteristics ◽  
Vegetation Indices ◽  
Matter Content ◽  
Tree Cover ◽  
Dry Matter Content ◽  
Least Squares Regression ◽  
Area Index ◽  
Remote Sensors ◽  
Spectral Bands ◽  
The Relationship

<p>Mixed vegetation systems such as wood pastures and shrubby pastures are vital for extensive and sustainable livestock production as well as for the conservation of biodiversity and provision of ecosystem services, and are mostly located in areas that are expected to be more strongly affected by climate change. However, the structural characteristics, phenology, and the optical properties of the vegetation in these mixed -ecosystems such as savanna-like ecosystems in the Iberian Peninsula which combines herbaceous and/or shrubby understory with a low density tree cover, constitute a serious challenge for the remote sensing studies. This work combines physical and empirical methods to improve the estimation of essential vegetation variables: leaf area index (<em>LAI</em>, m<sup>2</sup> / m<sup>2</sup> ), leaf (C<sub>ab,leaf</sub>, μg / cm<sup>2</sup> ) and canopy(C<sub>ab,canopy</sub>, g / m<sup>2 </sup>) chlorophyll content, and leaf (C<sub>m, leaf</sub>, g / cm<sup>2</sup> ) and canopy (C<sub>m,canopy</sub>, g / m<sup>2</sup> ) dry matter content in a dehesa ecosystem. For this purpose, a spectral simulated database for the four main phenological stages of the highly dynamic herbaceous layer (summer senescence, autumn regrowth, greenness peak and beginning of senescence), was built by coupling PROSAIL and FLIGHT radiative transfer models. This database was used to calibrate different predictive models based on vegetation indices (VI) proposed in the literature which combine different spectral bands; as well as Partial Least Squares Regression (PLSR) using all bands in the simulated spectral range (400-2500 nm). PLSR models offered greater predictive power (<em>R<sup>2</sup></em> ≥ 0.93, <em>RRMSE</em> ≤ 10.77 %) both for the leaf and canopy- level variables. The results suggest that directional and geometric effects control the relationships between simulated reflectance factors and the foliar parameters. High seasonal variability is observed in the relationship between biophysical variables and IVs, especially for <em>LAI</em> and <em>C<sub>ab</sub></em>, which is confirmed in the PLSR analysis. The models developed need to be validated with spectral data obtained either with proximal or remote sensors.</p>

scholarly journals Effect of Different Planting Material on Physiological Parameters and Cassava Mosaic Incidence in Cassava (Manihot esculenta Crantz.)

2021 ◽  
pp. 20-25
Author(s):  
S. Nanthakumar ◽  
K. Krithika ◽  
M. Prabhu
Keyword(s):  
Disease Incidence ◽  
Block Design ◽  
Maximum Yield ◽  
Matter Content ◽  
Mosaic Disease ◽  
Physiological Parameters ◽  
Dry Matter Content ◽  
Vegetable Crops ◽  
Manihot Esculenta Crantz ◽  
Area Index

An investigation was carried out to assess the effect of planting materials on physiological parameters, cassava mosaic incidence and yield of Cassava varieties viz. H-226 and CO.2 at the Department of Vegetable crops, Horticultural College and Research Institute, TNAU, Coimbatore during September 2010 to June 2011. The experiments were laid out in Factorial Randomized Block Design with four treatments and three replications in two varieties. The results revealed that the tissue culture plants were found be the best in virtue of its high leaf area index, net assimilation rate, dry matter content, tuber yield (26.33 t ha-1) and least incidence of cassava mosaic virus. Among the varieties, CO.2 showed less incidence of CMD. The tissue cultured plants may be recommended to farmers to reduce mosaic disease incidence and get maximum yield in cassava.

A simplified method for characterising agronomic services provided by species-rich grasslands

2010 ◽  
Vol 61 (5) ◽  
pp. 420 ◽  
Author(s):  
Michel Duru ◽  
Pablo Cruz ◽  
Jean Pierre Theau
Keyword(s):  
Diversity Index ◽  
Field Measurements ◽  
Matter Content ◽  
Functional Ecology ◽  
Grass Species ◽  
Dry Matter Content ◽  
Functional Convergence ◽  
Trade Offs ◽  
Simplified Method ◽  
The Difference

In order to encourage farmers and their advisors to promote species-rich grasslands, the agronomic services they can provide should be demonstrated. Methods based on functional ecology are promising, but difficult to use in an applied context. Thus, we aimed to construct a simplified method, tailored for non-researchers, for assessing grassland agronomic services. We assess them by focusing on the grass species that was coupled to a leaf dry matter content (LDMC) database. These simplifications are supported by several hypotheses tested in our paper: (i) trade-offs between agronomic properties; (ii) mass ratio hypothesis; and (iii) functional convergence and divergence between grass and dicotyledonous species. The results were based on 37 vegetation records taken in the south of France (central Pyrenees, from 650 to 1250 m. a.s.l.) for calculating the proportion of grass species and the aggregated LDMC of grass species (LDMCgw), weighting species values by their abundance. LDMC of grass species was taken from field measurements and from a database. The two methods were compared. The latter avoids tedious field measurements, and we found that it was at least as good as the former for assessing agronomic productivity and quality, and the same was true for a LDMC diversity index. Reducing the list of grass species to the two dominant ones did not significantly alter the LDMCgw. There were significant differences between the grass and dicotyledonous components coexisting within a plant community for the digestibility of the plant components (higher for dicots) and in the date at which ceiling yield occurred (earlier for dicots), but no significant effect for productivity. For assessing agronomic services, we proposed corrections based on the grass : dicotyledon ratio. The hypotheses used for designing the method were verified. Finally, agronomic services such as herbage productivity and quality provided by species-rich grasslands can be evaluated by recording dominant grass species and the proportion of grass in the herbage. However, taking account of the difference in sensitivity to the environment for agronomic properties and plant species composition, the main use of the method is for ranking plant communities within a given area and a given year, rather than for providing absolute values of these agronomic properties.

scholarly journals Evaluation of cropsyst model for yield and water productivity of chickpea

2019 ◽  
Author(s):  
Ramesh Kumar ◽  
R. S. Yadav ◽  
Amit Kumawat ◽  
V. S. Rathore ◽  
N. D. Yadava ◽  
...  
Keyword(s):  
Soil Depth ◽  
Water Productivity ◽  
Organic Matter Content ◽  
Field Measurements ◽  
Matter Content ◽  
Residual Soil ◽  
Total Water ◽  
Deep Drainage ◽  
Area Index ◽  
Soil Organic Matter Content

An experiment entitled “Evaluation of CropSyst model for yield and water productivity of chickpea” was conducted on farmers field during rabi2012-13 at village Mainawali in Hanumangarh district of Rajasthan. The soils of the area are alluvial and calcareous in nature formed under arid and semi arid climate. The soils of site are brown to grayish brown and dark gray in colour, besides being calcareous and slightly alkaline in reaction having 67.7, 11.1 and 21.0 % of sand, clay and silt, respectively in 0-15 cm soil depth with pH 8.09 and low soil organic matter content. The simulated and observed green area index differs with field measurements at all stages. The simulate yield of chickpea were closer to the observed yield. The total water applied in chickpea was 415 mm out of this 356.5 mm consumed in ET. Thus, ET constituted 86% of total water applied and deep drainage constituted 12% and rest 2% stored as residual soil moisture.

scholarly journals Organic Mulch Effects on High Tunnel Lettuce in Southern New England

2018 ◽  
Vol 28 (4) ◽  
pp. 485-491
Author(s):  
Rahmatallah Gheshm ◽  
Rebecca Nelson Brown
Keyword(s):  
Soil Temperature ◽  
Rank Order ◽  
Canopy Cover ◽  
Matter Content ◽  
Economic Feasibility ◽  
Weed Suppression ◽  
Dry Matter Content ◽  
Romaine Lettuce ◽  
Area Index ◽  
Fall Experiment

Lettuce (Lactuca sativa L.) is a popular crop for spring and fall high tunnels among direct-market vegetable producers. Common practices include the use of compost as a soil amendment, and reliance on cultivation for weed control. This study examined the impacts of using compost as a surface mulch to control weeds in spring and fall romaine lettuce, with data collected on soil temperature, weed suppression, and lettuce yields. Costs of all inputs, including labor, were tracked to assess economic feasibility of using mulch. Compost mulch was compared with bare ground with cultivation across four cultivars of romaine lettuce: Ridgeline, Coastal Star, Green Forest, and Shushan. In the fall experiment, mulching increased average soil temperature by 1 °C and canopy cover, leaf area index (LAI), and fresh and dry weights were significantly higher in mulched plots. Mulching decreased daily variation in soil temperature in the spring experiment but had no effect on average soil temperature. Canopy cover, LAI, and fresh and dry weights were not significantly affected by mulching in the spring experiment. Compost mulch affected all cultivars similarly in both experiments, with no significant interaction effects. Yields were greater and leaves were larger in the spring experiment than in the fall for all cultivars. Fresh weight yields in the spring experiment averaged 3.22 kg·m−2 and heads had a LAI of 7.9 as compared with 1.02 kg·m−2 and 1.6 for the fall experiment. Dry matter content (DMC) was significantly higher in the fall lettuce (113 g·kg−1) than in the spring lettuce (43 g·kg−1). Cultivar rank order was consistent across experiments, with ‘Ridgeline’ having the best performance and ‘Green Forest’ the worst. ‘Coastal Star’ and ‘Shoshone’ were intermediate and very similar to each other. Although the use of compost as a mulch increased yields of all cultivars in the fall experiment, only the top cultivar, Ridgeline, produced enough additional yield to offset the increased costs of the compost mulch used in this study. The use of a less-expensive compost or a higher retail price for romaine lettuce would have made the economics more favorable for the other cultivars.

scholarly journals Assessment of Yellow-fleshed Kiwifruit (Actinidia chinensis ‘Hort16A’) Quality in Pre- and Post-harvest Conditions Using a Portable Near-infrared Spectrometer

HortScience ◽  
2011 ◽  
Vol 46 (1) ◽  
pp. 57-63 ◽  
Author(s):  
Jinquan Feng ◽  
Andrew V. McGlone ◽  
Mike Currie ◽  
Chris J. Clark ◽  
Bob R. Jordan
Keyword(s):  
Near Infrared ◽  
Field Measurements ◽  
Quality Attributes ◽  
Matter Content ◽  
Soluble Solids ◽  
Dry Matter Content ◽  
Actinidia Chinensis ◽  
Short Period ◽  
Infrared Spectrometer ◽  
Near Infrared Spectrometer

Dry matter content (DM), soluble solids content (SSC), and flesh hue (FH) are important quality attributes of yellow-fleshed kiwifruit (Actinidia chinensis ‘Hort16A’). Rapid non-destructive measurement tools enable effective assessment of quality attributes in the field or in packhouses and offer the potential for selective harvesting and differential postharvest treatments. This study investigates a few practical issues for use of one such tool, a portable near-infrared spectrometer, the FANTEC™ FQA-NIRGUN. Experimental results indicated that the precision of the NIRGUN in predicting the DM, SSC and FH of ‘Hort16A’ kiwifruit, given as the root mean square error of calibration (RMSEC), is 0.6%, 0.9% and 1.4°, respectively, and is similar to that reported for standard laboratory benchtop spectrometers. These levels of precision are good enough to distinguish differences in fruit quality between fruit from different vines. However, this is only possible when measurements are carried out under similar conditions either within a short period of time in the field when fruit temperature is stable or in a temperature-controlled laboratory. The calibration developed on one instrument could be transferred to another instrument, but bias correction is necessary after the calibration transfer. Hence, the absolute accuracy of predictions from the NIRGUN is limited by significant and variable bias offset issues, particularly for field measurements when fruit are on the vine.

Sign in / Sign up

Export Citation Format

Share Document