Time-Series of Vegetation Indices (VNIR/SWIR) Derived from Sentinel-2 (A/B) to Assess Turgor Pressure in Kiwifruit

For more than ten years, Central Chile faces drought conditions, which impact crop production and quality, increasing food security risk. Under this scenario, implementing management practices that allow increasing water use efficiency is urgent. The study was carried out in kiwifruit trees, located in the O’Higgins region, Chile; for season 2018-2019 and 2019-2020. We evaluate nine vegetation indices in the VNIR and SWIR regions derived from Sentinel-2 (A/B) satellites to know how much variability in the canopy water status could explain. Over the study's site were installed sensors that continuously measure the leaf's turgor pressure (Yara Water-Sensor). A strong correlation between turgor pressure and vegetation indices was obtained with the Spearman's rho coefficient ($\rho$). However, the NIR range's indices were influenced by the vegetative development of the crop rather than its water status. Red-edge showed better performance as the vegetative growth did not affect it. It is necessary to expand the study to consider higher variability in kiwifruit's water conditions and incorporate the sensitivity of different wavelengths.

Download Full-text

Time-Series of Vegetation Indices (VNIR/SWIR) Derived from Sentinel-2 (A/B) to Assess Turgor Pressure in Kiwifruit

ISPRS International Journal of Geo-Information ◽

10.3390/ijgi9110641 ◽

2020 ◽

Vol 9 (11) ◽

pp. 641

Author(s):

Alberto Jopia ◽

Francisco Zambrano ◽

Waldo Pérez-Martínez ◽

Paulina Vidal-Páez ◽

Julio Molina ◽

...

Keyword(s):

Time Series ◽

Crop Production ◽

Management Practices ◽

Water Status ◽

Vegetation Indices ◽

Turgor Pressure ◽

Security Risk ◽

Vegetative Development ◽

Water Sensor ◽

Sentinel 2

For more than ten years, Central Chile has faced drought conditions, which impact crop production and quality, increasing food security risk. Under this scenario, implementing management practices that allow increasing water use efficiency is urgent. The study was carried out on kiwifruit trees, located in the O’Higgins region, Chile for season 2018–2019 and 2019–2020. We evaluate the time-series of nine vegetation indices in the VNIR and SWIR regions derived from Sentinel-2 (A/B) satellites to establish how much variability in the canopy water status there was. Over the study’s site, eleven sensors were installed in five trees, which continuously measured the leaf’s turgor pressure (Yara Water-Sensor). A strong Spearman’s (ρ) correlation between turgor pressure and vegetation indices was obtained, having −0.88 with EVI and −0.81 with GVMI for season 2018–2019, and lower correlation for season 2019–2020, reaching −0.65 with Rededge1 and −0.66 with EVI. However, the NIR range’s indices were influenced by the vegetative development of the crop rather than its water status. The red-edge showed better performance as the vegetative growth did not affect it. It is necessary to expand the study to consider higher variability in kiwifruit’s water conditions and incorporate the sensitivity of different wavelengths.

Download Full-text

Towards Vine Water Status Monitoring on a Large Scale Using Sentinel-2 Images

Remote Sensing ◽

10.3390/rs13091837 ◽

2021 ◽

Vol 13 (9) ◽

pp. 1837

Author(s):

Eve Laroche-Pinel ◽

Sylvie Duthoit ◽

Mohanad Albughdadi ◽

Anne D. Costard ◽

Jacques Rousseau ◽

...

Keyword(s):

Climate Change ◽

Water Potential ◽

Large Scale ◽

Water Status ◽

Vegetation Indices ◽

Machine Learning Algorithms ◽

Severe Drought ◽

Stem Water Potential ◽

Stem Water ◽

Sentinel 2

Wine growing needs to adapt to confront climate change. In fact, the lack of water becomes more and more important in many regions. Whereas vineyards have been located in dry areas for decades, so they need special resilient varieties and/or a sufficient water supply at key development stages in case of severe drought. With climate change and the decrease of water availability, some vineyard regions face difficulties because of unsuitable variety, wrong vine management or due to the limited water access. Decision support tools are therefore required to optimize water use or to adapt agronomic practices. This study aimed at monitoring vine water status at a large scale with Sentinel-2 images. The goal was to provide a solution that would give spatialized and temporal information throughout the season on the water status of the vines. For this purpose, thirty six plots were monitored in total over three years (2018, 2019 and 2020). Vine water status was measured with stem water potential in field measurements from pea size to ripening stage. Simultaneously Sentinel-2 images were downloaded and processed to extract band reflectance values and compute vegetation indices. In our study, we tested five supervised regression machine learning algorithms to find possible relationships between stem water potential and data acquired from Sentinel-2 images (bands reflectance values and vegetation indices). Regression model using Red, NIR, Red-Edge and SWIR bands gave promising result to predict stem water potential (R2=0.40, RMSE=0.26).

Download Full-text

Effect of Water Regime and Nitrogen Fertilisation on Growth Dynamics, Water Status and Yield of Burley Tobacco (Nicotianatabacum L.)

Beiträge zur Tabakforschung International/Contributions to Tobacco Research ◽

10.2478/cttr-2013-0784 ◽

2004 ◽

Vol 21 (4) ◽

pp. 223-233

Author(s):

C Ruggiero ◽

G Angelino ◽

S Ascione ◽

A Napolitano

Keyword(s):

Plant Growth ◽

Nitrogen Fertilization ◽

Dry Matter ◽

Water Status ◽

Turgor Pressure ◽

Plant Water Status ◽

Plant Water ◽

Nitrogen Fertilisation ◽

Burley Tobacco ◽

Use Efficiency

AbstractThe results of a two-year research project into burley tobacco are reported and discussed. Three irrigation levels (40, 80 and 120% restitution of evapotranspiration (ET)) were factorially combined with four levels of nitrogen fertilisation (0, 80, 160 and 240 kg ha). Leaf area, leaf and stem dry matter and root development were measured. We monitored the water status of the 0-90 cm soil layer, the plants and stomatal resistance. Relations were also studied between leaf turgor pressure and plant growth, between the irrigation regime and plant water status, and between root and shoot development. Finally, water use efficiency (WUE) and quality and quantity of cured leaves yields were evaluated. Nitrogen fertilisation did not affect plant water status, although it promoted plant growth, both in terms of leaf area and leaf and stem dry matter, and induced a yield increase in quantity and quality. Our trial showed little interaction between nitrogen fertilization level and water regime. Under such agronomic condition, the margins for increasing plant growth with nitrogen fertilization are limited, which is why application of nitrogen rates in excess of 160 kg haappear inadvisable. The difference in irrigation volumes led to a different soil water content which affected plant water status, stomatal functioning, plant growth, both in the roots and shoots, yield and quality of the cured leaves. The latter did not vary with the increase in water volume, while yield increased. Water use efficiency increased as the irrigation volume decreased and varied during the cropping cycle, increasing until early bloom, then decreasing. Relations between leaf turgor pressure and plant growth highlighted the different response of plants subjected to water stress compared with non-stressed plants.

Download Full-text

Improving Dryland Crop Simulation by Assimilating Soil Moisture and Vegetation Data

10.5194/egusphere-egu2020-13406 ◽

2020 ◽

Author(s):

Yang Lu ◽

Justin Sheffield

Keyword(s):

Soil Moisture ◽

Crop Production ◽

Management Practices ◽

Water Productivity ◽

Vegetation Indices ◽

Screening Method ◽

Model Performance ◽

State Parameter ◽

Aquacrop Model

<p>Global population is projected to keep increasing rapidly in the next 3 decades, particularly in dryland regions of the developing world, making it a global imperative to enhance crop production. However, improving current crop production in these regions is hampered by yield gaps due to poor soils, lack of irrigation and other management practices. Here we develop a crop modelling capability to help understand gaps, and apply to dryland regions where data for parametrizing and testing models is generally lacking. We present a data assimilation framework to improve simulation capability by assimilating in-situ soil moisture and vegetation data into the FAO AquaCrop model. AquaCrop is a water-driven model that simulates canopy growth, biomass and crop yield as a function of water productivity. The key strength of AquaCrop lies in the low requirement for input data thanks to its simple structure. A global sensitivity analysis is first performed using the Morris screening method and the variance-based Extended Fourier Amplitude Sensitivity Test (EFAST) method to identify the key influential parameters on the model outputs. We begin with state-only updates by assimilating different combinations of soil moisture and vegetation data (vegetation indices, biomass, etc.), and different filtering/smoothing assimilation strategies are tested. Based on the state-only assimilation results, we further evaluate the utility of joint state-parameter (augmented-states) assimilation in improving the model performance. The framework will eventually be extended to assimilate remote sensing estimates of soil moisture and vegetation data to overcome the lack of in-situ data more generally in dryland regions.</p>

Download Full-text

POTENCIAL HÍDRICO FOLIAR E DESENVOLVIMENTO VEGETATIVO DO CAFEEIRO CONILON SOB DIFERENTES LÂMINAS DE IRRIGAÇÃO NA REGIÃO E CAMPOS DOS GOYTACAZES - RJ

Irriga ◽

10.15809/irriga.2021v26n1p13-28 ◽

2021 ◽

Vol 26 (1) ◽

pp. 13-28

Author(s):

Diego Albani Furlan ◽

Elias Fernandes De Sousa ◽

José Carlos Mendonça ◽

Claudio Luiz Melo De Souza ◽

Romildo Domingos Gottardo ◽

...

Keyword(s):

Water Potential ◽

Leaf Water Potential ◽

Water Status ◽

Turgor Pressure ◽

Leaf Water ◽

Vegetative Development ◽

Crown Diameter ◽

Biometric Parameters ◽

The Moment ◽

Water Supplementation

POTENCIAL HÍDRICO FOLIAR E DESENVOLVIMENTO VEGETATIVO DO CAFEEIRO CONILON SOB DIFERENTES LÂMINAS DE IRRIGAÇÃO NA REGIÃO E CAMPOS DOS GOYTACAZES - RJ DIEGO ALBANI FURLAN1; ELIAS FERNANDES DE SOUSA2; JOSÉ CARLOS MENDONÇA3; CLAUDIO LUIZ MELO DE SOUZA4; ROMILDO DOMINGOS GOTTARDO 5 E RODOLLPHO ARTUR DE SOUSA LIMA6 1Laboratório de Engenharia Agrícola – LEAG, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Av. Alberto Laqmedo, 2000, Parque Califórnia, Campos dos Goytacazes, RJ, Brasil, [email protected] 2Laboratório de Engenharia Agrícola – LEAG, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Av. Alberto Laqmedo, 2000, Parque Califórnia, Campos dos Goytacazes, RJ, Brasil, [email protected] 3Laboratório de Engenharia Agrícola – LEAG, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Av. Alberto Laqmedo, 2000, Parque Califórnia, Campos dos Goytacazes, RJ, Brasil, [email protected] 4Laboratório de Engenharia Agrícola – LEAG, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Av. Alberto Laqmedo, 2000, Parque Califórnia, Campos dos Goytacazes, RJ, Brasil, [email protected] 5Laboratório de Engenharia Agrícola – LEAG, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Av. Alberto Laqmedo, 2000, Parque Califórnia, Campos dos Goytacazes, RJ, Brasil, [email protected] 6Laboratório de Engenharia Agrícola – LEAG, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Av. Alberto Laqmedo, 2000, Parque Califórnia, Campos dos Goytacazes, RJ, Brasil, [email protected] 1 RESUMO Na atividade cafeeira, o Brasil se destaca como maior produtor mundial, porém verifica-se que a sua produtividade é afetada de forma negativa pela seca, o que torna a produção dependente de complementação hídrica. Este trabalho tem como objetivo determinar estresse hídrico e o desenvolvimento do café Conilon em diferentes lâminas de irrigação. O delineamento experimental foi constituído de blocos casualizados, com três repetições, distribuídos em cinco tratamentos, sendo estes as lâminas de água de 0, 25, 50, 100 e 125% da ET0. Cada parcela foi constituída de seis plantas, sendo as duas primeiras plantas de cada bloco consideradas bordadura. O potencial hídrico foliar foi determinado pela medição da pressão de turgescência da folha, utilizando a bomba de Scholander, em uma planta por bloco e por tratamento. A altura da planta, secção transversal do caule e diâmetro da copa foram avaliados em três plantas por bloco, utilizando régua e paquímetro graduados. Os valores para o potencial hídrico foliar realizado na antemanhã variaram ente –0,15 a -1,18 MPa e, ao meio dia, de -1,17 a -2,3 MPa. As lâminas de irrigação equivalentes a 100 e 125% da ET0 apresentaram maiores valores ao longo do desenvolvimento da cultura até o momento da avaliação. Palavras-Chave: cafeeiro, bomba de Scholander, status hídrico, parâmetros biométricos. FURLAN, D. A.; SOUSA, E.F.; MENDONÇA, J. C.; SOUZA, C. L. M.; GOTTARDO, R. D. E LIMA, R. A. S. POTENTIAL LEAF WATER AND VEGETATIVE DEVELOPMENT OF COFFEE CONILON UNDER DIFFERENT IRRIGATION DEPTHS IN THE REGION OF CAMPOS DOS GOYTACAZES - RJ 2 ABSTRACT In the coffee production, Brazil stands out as the world's largest producer, but its productivity is negatively affected by drought, which makes production dependent on water supplementation. This work aims to determine water stress and the development of Conilon coffee in different irrigation depths. The experimental design consisted of randomized blocks with three replicates, distributed in five treatments, the irrigation depths of 0, 25, 50, 100 and 125% of ET0 -. Each plot was constituted of six plants, being the first two plants of each block considered border. The leaf water potential was is determined by measuring leaf turgor pressure using the Scholander pump in a plant per block and by treatment. The plant height, stem cross-section and crown diameter were evaluated in three plants per block using a graduated ruler and pachymeter. The values for leaf water potential performed in the morning ranged from -0.15 to -1.18 MPa and, for noon, from -1.17 to -2.3 MPa. The irrigation depths equivalent to 100 and 125% of the ET0 presented higher values throughout the development of the culture until the moment of the evaluation. Keywords: coffee, Scholander pump, water status, biometric parameters.

Download Full-text

Sen2Grass: A Cloud-Based Solution to Generate Field-Specific Grassland Information Derived from Sentinel-2 Imagery

AgriEngineering ◽

10.3390/agriengineering3010008 ◽

2021 ◽

Vol 3 (1) ◽

pp. 118-137

Author(s):

Tom Hardy ◽

Lammert Kooistra ◽

Marston Domingues Franceschini ◽

Sebastiaan Richter ◽

Erwin Vonk ◽

...

Keyword(s):

Vegetation Index ◽

Management Practices ◽

Prediction Models ◽

Vegetation Indices ◽

Weather Conditions ◽

Grassland Management ◽

Time Range ◽

Computing Platform ◽

Robust Prediction ◽

Sentinel 2

Grasslands are important for their ecological values and for agricultural activities such as livestock production worldwide. Efficient grassland management is vital to these values and activities, and remote sensing technologies are increasingly being used to characterize the spatiotemporal variation of grasslands to support those management practices. For this study, Sentinel-2 satellite imagery was used as an input to develop an open-source and automated monitoring system (Sen2Grass) to gain field-specific grassland information on the national and regional level for any given time range as of January 2016. This system was implemented in a cloud-computing platform (StellaSpark Nexus) designed to process large geospatial data streams from a variety of sources and was tested for a number of parcels from the Haus Riswick experimental farm in Germany. Despite outliers due to fluctuating weather conditions, vegetation index time series suggested four distinct growing cycles per growing season. Established relationships between vegetation indices and grassland yield showed poor to moderate positive trends, implying that vegetation indices could be a potential predictor for grassland biomass and chlorophyll content. However, the inclusion of larger and additional datasets such as Sentinel-1 imagery could be beneficial to developing more robust prediction models and for automatic detection of mowing events for grasslands.

Download Full-text

Assessment of Fertilizer Management Strategies Aiming to Increase Nitrogen Use Efficiency of Wheat Grown Under Conservation Agriculture

Agronomy ◽

10.3390/agronomy8120304 ◽

2018 ◽

Vol 8 (12) ◽

pp. 304 ◽

Cited By ~ 1

Author(s):

Jesús Santillano-Cázares ◽

Fidel Núñez-Ramírez ◽

Cristina Ruíz-Alvarado ◽

María Cárdenas-Castañeda ◽

Iván Ortiz-Monasterio

Keyword(s):

Nitrogen Use Efficiency ◽

Crop Production ◽

Management Practices ◽

Production Systems ◽

Conservation Agriculture ◽

Fertilizer Application ◽

Nitrogen Use ◽

Agronomic Efficiency ◽

Use Efficiency ◽

N Management

Sustainable crop production systems can be attained by using inputs efficiently and nitrogen use efficiency (NUE) parameters are indirect measurements of sustainability of production systems. The objective of this study was to investigate the effect of selected nitrogen (N) management treatments on wheat yields, grain and straw N concentration, and NUE parameters, under conservation agriculture (CA). The present study was conducted at the International Maize and Wheat Improvement Center (CIMMYT), in northwest, Mexico. Seventeen treatments were tested which included urea sources, timing, and methods of fertilizer application. Orthogonal contrasts were used to compare groups of treatments and correlation and regression analyses were used to look at the relationships between wheat yields and NUE parameters. Contrasts run to compare wheat yields or agronomic efficiency of N (AEN) performed similarly. Sources of urea or timing of fertilizer application had a significant effect on yields or AEN (p > 0.050). However, methods of application resulted in a highly significant (p < 0.0001) difference on wheat yields and agronomic efficiency of N. NUE parameters recorded in this study were average but the productivity associated to NUE levels was high. Results in this study indicate that wheat grew under non-critically limiting N supply levels, suggesting that N mineralization and reduced N losses from the soil under CA contributed to this favorable nutritional condition, thus minimizing the importance of N management practices under stable, mature CA systems.

Download Full-text

Simultaneous recording of diurnal changes in leaf turgor pressure and stem water status of bread wheat reveal variation in hydraulic mechanisms in response to drought

Functional Plant Biology ◽

10.1071/fp15087 ◽

2015 ◽

Vol 42 (10) ◽

pp. 1001 ◽

Cited By ~ 5

Author(s):

Helen Bramley ◽

Rebecca Bitter ◽

Gertraud Zimmermann ◽

Ulrich Zimmermann

Keyword(s):

Water Status ◽

Flag Leaf ◽

Turgor Pressure ◽

Crop Productivity ◽

Simultaneous Recording ◽

Diurnal Changes ◽

Use Efficiency ◽

Stem Water ◽

The Impact ◽

Kinetics Of

Information about water relations within crop canopies is needed to improve our understanding of canopy resource distribution and crop productivity. In this study, we examined the dehydration/rehydration kinetics of different organs of wheat plants using ZIM-probes that continuously monitor water status non-destructively. ZIM-probes were clamped to the flag leaf and penultimate leaf of the same stem to monitor changes in turgor pressure, and a novel stem probe was clamped to the peduncle (just below the spike of the same stem) to monitor changes in stem water status. All organs behaved similarly under well-watered conditions, dehydrating and recovering at the same times of day. When water was withheld, the behaviour diverged, with the leaves showing gradual dehydration and incomplete recovery in leaf turgor pressure during the night, but the stem was affected to a lesser extent. Penultimate leaves were the most severely affected, reaching turgor loss point before the flag leaf. Upon rewatering, turgor pressure recovered but the output patch-pressure of the probes (Pp) oscillated at ~30 min periods in all organs of most plants (n = 4). Oscillations in Pp were attributed to oscillations in stomatal opening and appear to only occur above a threshold light intensity. The mechanisms identified in this study will be beneficial for crop productivity because the flag leaf is the source of most photoassimilates in developing grains, so the plant’s ability to maintain flag leaf hydration at the expense of older leaves should moderate the impact of drought on yield. Stomatal oscillations could increase water use efficiency as the plant attempts to rehydrate after drought.

Download Full-text

Synergy between a shallow root system with a DRO1 homologue and localized P application improves rice P uptake

10.1101/2020.11.30.405068 ◽

2020 ◽

Author(s):

Aung Zaw Oo ◽

Yasuhiro Tsujimoto ◽

Mana Mukai ◽

Tomohiro Nishigaki ◽

Toshiyuki Takai ◽

...

Keyword(s):

Root System ◽

Crop Production ◽

Management Practices ◽

Soil Layer ◽

P Uptake ◽

The Other ◽

Genetic Traits ◽

P Use Efficiency ◽

Use Efficiency ◽

P Application

ABSTRACTThe development of genotypes and fertilizer management practices that facilitate high phosphorus (P) use efficiency is needed given the depleting phosphorus ore deposits and increasing ecological concerns about its excessive use. Root system architecture (RSA) is important in efficiently capturing immobile P in soils, while agronomically, localized P application near the roots is a potential approach to address this issue. However, the interaction between genetic traits of RSA and localized P application has not been examined. Near-isogenic lines (NILs) and their parent of rice (qsor1-NIL, Dro1-NIL, and IR64, with shallow, deep, and intermediate root growth angles (RGA), respectively) were grown in flooded pots in a uniform and P-sufficient condition (Pinco), and with localized P application by dipping seedling roots into P-enriched slurry at transplanting (P-dipping). The P-dipping created an available P hotspot at the soil surface and substantially improved applied P-use efficiency (equivalent biomass at one fifth of application rate of the Pinco). Further, the qsor1-NIL had significantly greater biomass and P uptake than the other genotypes in the P-dipping. The qsor1-NIL consistently had a greater root biomass and surface area in the 0–3 cm soil layer, despite that there were no genotype differences in total values and that the other genotypes also reduced their RGAs responding to the P hotspot in the P-dipping. The shallow root system of qsor1-NIL facilitated P uptake from the P hotspot. P-use efficiency in crop production can be further increased by combining genetic traits of RSA and localized P application.

Download Full-text

Strategies for improving nitrogen use efficiency: A review

Agricultural Reviews ◽

10.18805/ag.v0iof.7306 ◽

2017 ◽

Cited By ~ 6

Author(s):

M. R. Yadav ◽

Rakesh Kumar ◽

C. M. Parihar ◽

R. K. Yadav ◽

S.L. Jat ◽

...

Keyword(s):

Production System ◽

Crop Production ◽

Management Practices ◽

Plant Management ◽

Management Options ◽

N Losses ◽

Nitrogen Use ◽

Yield Efficiency ◽

Nitrogen Recovery Efficiency ◽

Use Efficiency

Nitrogen (N) is the most critical externally added input for any crop production system. The half of the global population directly or indirectly depends on nitrogenous fertilizers for food supply. Today, Rice, wheat, and maize are consuming more than 90% of total nitrogenous fertilizer used in cereals. Underuse of nitrogen is associated with lower crop production while overuse leads to several soil and environmental related consequences. Therefore, response to applied nitrogen and its use efficiency have to be monitored properly for obtaining the maximum potential and sustainable yield. Efficiency of applied nitrogenous fertilizers is very low due to its various losses i.e. volatilization, leaching, surface runoff and denitrification from soil-plant system. Therefore, the proper understanding of advanced soil and plant management practices which helps in enhancement of nitrogen recovery efficiency is one of the key factors to enhance crop output, decreasing cost of cultivation, and to maintain environmental quality which ultimately adds towards the goal of achieving long term sustainable production system. In this review, an attempt has been made summarize the locally as well as scientific soil and crop management technologies used for improving use efficiency of applied N. This paper also discusses nitrogen cycling in soil-plant systems, various N losses pathways, present status and most possible management options at the farm level for enhancing nitrogen use in crop production system.

Download Full-text