Summary Globally, coastal cultivation regions (CCRs) are facing irrigation water shortages due to the impacts of climate change (ICV). CCRs have repeatedly suffered from saline irrigation water, increases in temperature, and reduced rainfall, resulting in irrigation water shortages. The aim of this study was, therefore, to evaluate the impacts of weather variables on the rice water requirement (RWR) in CCRs in Kien Giang Province. The response of rice grain yield to weather variables was estimated by simulating the AquaCrop model under different crop cultivation schedules (CCSs). These schedules involved advancing or delaying the sowing date by 30 days compared to the current common sowing date (baseline) for winter-spring (WS) and summer-fall (SF) vegetation seasons. The AquaCrop model demonstrated accurate simulation capabilities, as indicated by the high correlation values of statistical error indexes during the validation and calibration procedures. The findings revealed that rice grain yields would enhance up to 7.8% and 5.6% compared to the baseline when CCSs involve sowing 20 days earlier for WS vegetation season and are advanced by 20 days for SF vegetation season. Overall, modifying CCSs for coastal rice paddies in the study area, while considering weather variables, would have a positive contribution by mitigating the adverse effects of ICV.
{"title":"Adapting to climate variability for rice cultivation paddies in the lowland coastal regions of Kien Giang Province, Vietnam","authors":"Thai D. Phung, Truong A. Dang","doi":"10.2478/boku-2023-0003","DOIUrl":"https://doi.org/10.2478/boku-2023-0003","url":null,"abstract":"Summary Globally, coastal cultivation regions (CCRs) are facing irrigation water shortages due to the impacts of climate change (ICV). CCRs have repeatedly suffered from saline irrigation water, increases in temperature, and reduced rainfall, resulting in irrigation water shortages. The aim of this study was, therefore, to evaluate the impacts of weather variables on the rice water requirement (RWR) in CCRs in Kien Giang Province. The response of rice grain yield to weather variables was estimated by simulating the AquaCrop model under different crop cultivation schedules (CCSs). These schedules involved advancing or delaying the sowing date by 30 days compared to the current common sowing date (baseline) for winter-spring (WS) and summer-fall (SF) vegetation seasons. The AquaCrop model demonstrated accurate simulation capabilities, as indicated by the high correlation values of statistical error indexes during the validation and calibration procedures. The findings revealed that rice grain yields would enhance up to 7.8% and 5.6% compared to the baseline when CCSs involve sowing 20 days earlier for WS vegetation season and are advanced by 20 days for SF vegetation season. Overall, modifying CCSs for coastal rice paddies in the study area, while considering weather variables, would have a positive contribution by mitigating the adverse effects of ICV.","PeriodicalId":35538,"journal":{"name":"Bodenkultur","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135532500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Summary Lake Chad, situated in the semi-arid region of African Sahel, plays a vital role in hydrogeological balance of regional ecosystems. It presents an essential water source and provides a habitat for rare wildlife species including migrating waterbirds. However, the lake has shrunk significantly since the 1960s and has continued to reduce in size and extent during recent decades. Trends in drying and shrinking of Lake Chad are caused by environmental factors and changed climate. The desiccation of the lake is threatening environmental sustainability. This study focused on identification of changes in the Chad Lake area, wetland extent, and associated land cover types. The methods include the Geographic Resources Analysis Support System (GRASS) Geographic Information System (GIS) for remote sensing data classification. The maximum likelihood discriminant analysis classifier was applied for analysis of multispectral Landsat 8–9 OLI/TIRS images in 2013, 2017, and 2022. Detected changes in land cover types reflect variations in water balance and wetland area and extent around Lake Chad over recent decades. Cartographic scripting tools of GRASS GIS provide an efficient method of digital image processing for monitoring endorheic lakes of Central Africa. GRASS GIS methods provide an opportunity to automatically classify Earth observation data with cartographic scripts for environmental monitoring.
{"title":"Using open-source software GRASS GIS for analysis of the environmental patterns in Lake Chad, Central Africa","authors":"Polina Lemenkova","doi":"10.2478/boku-2023-0005","DOIUrl":"https://doi.org/10.2478/boku-2023-0005","url":null,"abstract":"Summary Lake Chad, situated in the semi-arid region of African Sahel, plays a vital role in hydrogeological balance of regional ecosystems. It presents an essential water source and provides a habitat for rare wildlife species including migrating waterbirds. However, the lake has shrunk significantly since the 1960s and has continued to reduce in size and extent during recent decades. Trends in drying and shrinking of Lake Chad are caused by environmental factors and changed climate. The desiccation of the lake is threatening environmental sustainability. This study focused on identification of changes in the Chad Lake area, wetland extent, and associated land cover types. The methods include the Geographic Resources Analysis Support System (GRASS) Geographic Information System (GIS) for remote sensing data classification. The maximum likelihood discriminant analysis classifier was applied for analysis of multispectral Landsat 8–9 OLI/TIRS images in 2013, 2017, and 2022. Detected changes in land cover types reflect variations in water balance and wetland area and extent around Lake Chad over recent decades. Cartographic scripting tools of GRASS GIS provide an efficient method of digital image processing for monitoring endorheic lakes of Central Africa. GRASS GIS methods provide an opportunity to automatically classify Earth observation data with cartographic scripts for environmental monitoring.","PeriodicalId":35538,"journal":{"name":"Bodenkultur","volume":"202 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135533613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Andrea Watzinger, Judith Prommer, Andreea Spiridon, Weronika Kisielinska, Rebecca Hood-Nowotny, Herbert Formayer, Anna Wawra, Johannes Hösch, Julia Miloczki
Summary Climate change scenarios predict more frequent and intense drought periods for 2071–2100 in the most important and intensively used agricultural region of Austria, the Marchfeld. Current and predicted lower precipitation scenarios were simulated at a lysimeter station for 9 years. Plant biomass, nitrogen (N) and carbon (C) content, and δ 13 C and δ 15 N values of plant compartments were monitored in years 7–9. Aboveground biomass of cereals and grain yield decreased under the predicted scenario, while the quality of grain (% N) was unaffected. Weed and catch crops grown in winter were not affected or were even positively affected, possibly due to the accumulation of nutrients in the soil following the lower plant uptake in summer. Accordingly, low plant δ 15 N values were mainly attributed to the presence of higher proportion of mineral fertilizer in the predicted precipitation scenario. As expected, water stress significantly increased δ 13 C values in plants grown over summer, while this was not seen for plants growing over winter. Fertile agricultural soil might ameliorate but cannot outbalance the negative impact of more frequent and intense drought periods.
{"title":"More extreme and frequent drought periods reduced crop production and altered stable isotope ratios of C and N in plants","authors":"Andrea Watzinger, Judith Prommer, Andreea Spiridon, Weronika Kisielinska, Rebecca Hood-Nowotny, Herbert Formayer, Anna Wawra, Johannes Hösch, Julia Miloczki","doi":"10.2478/boku-2023-0004","DOIUrl":"https://doi.org/10.2478/boku-2023-0004","url":null,"abstract":"Summary Climate change scenarios predict more frequent and intense drought periods for 2071–2100 in the most important and intensively used agricultural region of Austria, the Marchfeld. Current and predicted lower precipitation scenarios were simulated at a lysimeter station for 9 years. Plant biomass, nitrogen (N) and carbon (C) content, and δ 13 C and δ 15 N values of plant compartments were monitored in years 7–9. Aboveground biomass of cereals and grain yield decreased under the predicted scenario, while the quality of grain (% N) was unaffected. Weed and catch crops grown in winter were not affected or were even positively affected, possibly due to the accumulation of nutrients in the soil following the lower plant uptake in summer. Accordingly, low plant δ 15 N values were mainly attributed to the presence of higher proportion of mineral fertilizer in the predicted precipitation scenario. As expected, water stress significantly increased δ 13 C values in plants grown over summer, while this was not seen for plants growing over winter. Fertile agricultural soil might ameliorate but cannot outbalance the negative impact of more frequent and intense drought periods.","PeriodicalId":35538,"journal":{"name":"Bodenkultur","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135532254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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