scholarly journals Comparison of hydrological and vegetation remote sensing datasets as proxies for rainfed maize yield in Malawi

2022 ◽  
Vol 262 ◽  
pp. 107375
Author(s):  
Daniela Anghileri ◽  
Veronica Bozzini ◽  
Peter Molnar ◽  
Justin Sheffield
Keyword(s):  
2019 ◽  
Vol 108 ◽  
pp. 11-26 ◽  
Author(s):  
Louise Leroux ◽  
Mathieu Castets ◽  
Christian Baron ◽  
Maria-Jose Escorihuela ◽  
Agnès Bégué ◽  
...  

2020 ◽  
Vol 12 (4) ◽  
pp. 1313
Author(s):  
Leah M. Mungai ◽  
Joseph P. Messina ◽  
Sieglinde Snapp

This study aims to assess spatial patterns of Malawian agricultural productivity trends to elucidate the influence of weather and edaphic properties on Moderate Resolution Imaging Spectroradiometer (MODIS)-Normalized Difference Vegetation Index (NDVI) seasonal time series data over a decade (2006–2017). Spatially-located positive trends in the time series that can’t otherwise be accounted for are considered as evidence of farmer management and agricultural intensification. A second set of data provides further insights, using spatial distribution of farmer reported maize yield, inorganic and organic inputs use, and farmer reported soil quality information from the Malawi Integrated Household Survey (IHS3) and (IHS4), implemented between 2010–2011 and 2016–2017, respectively. Overall, remote-sensing identified areas of intensifying agriculture as not fully explained by biophysical drivers. Further, productivity trends for maize crop across Malawi show a decreasing trend over a decade (2006–2017). This is consistent with survey data, as national farmer reported yields showed low yields across Malawi, where 61% (2010–11) and 69% (2016–17) reported yields as being less than 1000 Kilograms/Hectare. Yields were markedly low in the southern region of Malawi, similar to remote sensing observations. Our generalized models provide contextual information for stakeholders on sustainability of productivity and can assist in targeting resources in needed areas. More in-depth research would improve detection of drivers of agricultural variability.


2016 ◽  
Vol 7 ◽  
Author(s):  
Omar Vergara-Díaz ◽  
Mainassara A. Zaman-Allah ◽  
Benhildah Masuka ◽  
Alberto Hornero ◽  
Pablo Zarco-Tejada ◽  
...  

2021 ◽  
Vol 13 (6) ◽  
pp. 1094
Author(s):  
Xingshuo Peng ◽  
Wenting Han ◽  
Jianyi Ao ◽  
Yi Wang

In this study, we develop a method to estimate corn yield based on remote sensing data and ground monitoring data under different water treatments. Spatially explicit information on crop yields is essential for farmers and agricultural agencies to make well-informed decisions. One approach to estimate crop yield with remote sensing is data assimilation, which integrates sequential observations of canopy development from remote sensing into model simulations of crop growth processes. We found that leaf area index (LAI) inversion based on unmanned aerial vehicle (UAV) vegetation index has a high accuracy, with R2 and root mean square error (RMSE) values of 0.877 and 0.609, respectively. Maize yield estimation based on UAV remote sensing data and simple algorithm for yield (SAFY) crop model data assimilation has different yield estimation accuracy under different water treatments. This method can be used to estimate corn yield, where R2 is 0.855 and RMSE is 692.8kg/ha. Generally, the higher the water stress, the lower the estimation accuracy. Furthermore, we perform the yield estimate mapping at 2 m spatial resolution, which has a higher spatial resolution and accuracy than satellite remote sensing. The great potential of incorporating UAV observations with crop data to monitor crop yield, and improve agricultural management is therefore indicated.


2021 ◽  
Vol 9 (1) ◽  
pp. 36
Author(s):  
Agathos Filintas

The effects of three drip irrigation (IR1: Farmer’s, IR2:Full (100%ETc), IR3:Deficit (80%ETc) irrigation), and two fertilization (Ft1, Ft2) treatments were studied on maize yield and biomass by applying new agro-technologies (TDR—sensors for soil moisture (SM) measurements, Precision Agriculture, Remote Sensing—NDVI (Sentinel-2 satellite sensor), soil-hydraulic analyses and Geostatistical models, SM-rootzone modelling-2D-GIS mapping). A daily soil moisture depletion (SMDp) model was developed. The two-way-ANOVA statistical analysis results revealed that irrigation (IR3 = best) and fertilization treatments (Ft1 = best) significantly affect yield and biomass. Deficit irrigation and proper fertilization based on new agro-technologies for improved management decisions can result in substantial improvement on yield (+116.10%) and biomass (+119.71%) with less net water use (−7.49%) and reduced drainage water losses (−41.02%).


1998 ◽  
Vol 8 (2) ◽  
pp. 161-167
Author(s):  
Zhaoli Liu ◽  
Tieqing Huang ◽  
Enpu Wan ◽  
Yangzhen Zhang
Keyword(s):  

2021 ◽  
Author(s):  
Dereje Biru ◽  
Jemal Tefera .

Abstract Background: Policy makers, government planners and agriculturalist in Ethiopia require accurate and timely information about maize yield and production. Kaffa zone is by far the most important maize producing zone in the country. The manual collection of field data and data processing for crop forecasting by the CSA requires significant amounts of time before official reports are released. Several studies have shown that maize yield can be effectively forecast using satellite remote sensing data. The objectives of this study were to develop a maize yield forecast model in kaffa Zone derived from time series data of eMODIS_NDVI, actual and potential evapotranspiration and CHIRPS for the years 2008-2017.Official grain yield data from the Central statistical Agency of Ethiopia was used to validate the strength of the indices in explaining the yield. Crop masking at crop land area was applied and refined by using agro ecological zones suitable for the crop of interest. Correlation analyses were used to determine associations among crop yield, spectral indices and agro meteorological variables for maize crop of the long rainy season (kiremt). Indices with high correlation with maize yield were identified. Results: Average Normalized Difference Vegetation Index and rainfall have high correlation of maize yield with 84% and 89%, respectively. That means their variables are positively strong related with maize yield. The generated spectro-agro meteorological yield model was successfully tested against the Central Statistical Agency's expected Zone level yields (r2= 0.89, RMSE = 1.54qha1, and 16.7% coefficient of variation).Conclusions: Thus, remote sensing and geographical information system based maize yield forecast improved quality and timelines of the data besides distinguishing yield production levels/areas and making intervention very easy for the decision makers there by proving the clear potential of spectro-agro meteorological factors for maize yield forecasting, particularly for Ethiopia.


Agronomy ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 719 ◽  
Author(s):  
Vijaya R. Joshi ◽  
Kelly R. Thorp ◽  
Jeffrey A. Coulter ◽  
Gregg A. Johnson ◽  
Paul M. Porter ◽  
...  

Integrating remote sensing data into crop models offers opportunities for improved crop yield estimation. To compare site-specific yield estimation accuracy of a stand-alone crop model with a data-integration approach, a study was conducted in 2016–2017 with nitrogen (N)-fertilized and unfertilized treatments across a heterogeneous 7-ha maize field. For each treatment, yield data were grouped into five classes resulting in 109 spatial zones. In each zone, the Crop Environment Resource Synthesis (CERES)-Maize model was run using the GeoSim plugin within Quantum GIS. In the data integration approach, maize biomass values estimated using satellite imagery at the five (V5) and ten (V10) leaf collar stages were used to optimize the total soil nitrogen concentration (SLNI) and soil fertility factor (SLPF) in CERES-Maize. Without integration, maize yield was simulated with root mean square error (RMSE) of 1264 kg ha−1. Optimization of SLNI improved yield simulations at both V5 and V10. However, better simulations were obtained from optimization at V10 (RMSE 1026 kg ha−1) as compared to V5 (RMSE 1158 kg ha−1). Optimization of SLPF together with SLNI did not further improve the yield simulations. This study shows that integrating remote sensing data into a crop model can improve site-specific maize yield estimations as compared to the stand-alone crop modeling approach.


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