Comparison of three remotely sensed drought indices for assessing the impact of drought on winter wheat yield

2018 ◽  
Vol 13 (4) ◽  
pp. 504-526 ◽  
Author(s):  
Jianxi Huang ◽  
Wen Zhuo ◽  
Ying Li ◽  
Ran Huang ◽  
Fernando Sedano ◽  
...  
2018 ◽  
Vol 11 (1) ◽  
pp. 33-48 ◽  
Author(s):  
Johannes Möllmann ◽  
Matthias Buchholz ◽  
Oliver Musshoff

Abstract Weather derivatives are considered a promising agricultural risk management tool. Station-based meteorological indices typically provide the data underlying these instruments. However, the main shortcoming of these weather derivatives is an imperfect correlation between the weather index and the yield of the insured crop, called basis risk. This paper considers three available remotely sensed vegetation health (VH) indices, namely, the vegetation condition index (VCI), the temperature condition index (TCI), and the vegetation health index (VHI), as indices for weather derivatives in a German case study. We investigated the correlation and period of highest correlation with winter wheat yield. Moreover, we analyzed whether the use of remotely sensed VH indices for weather derivatives can reduce basis risk and thus improve the performance of weather derivatives. The two commonly used meteorological indices, precipitation and temperature sums, were employed as benchmarks. Quantile regression and index value simulation were used for the design and pricing of the weather derivatives. The analysis for the selected farms and corresponding counties in northeastern Germany revealed that, on average, the VHI resulted in the highest correlation with winter wheat yield, and VHI-based weather derivatives were also superior in terms of the hedging effectiveness. The total periods of the highest correlations ranged from the beginning of April to the end of July. VHI- and VCI-based weather derivatives led to statistically significant reductions of basis risk, compared to the benchmarks. Our results indicate that the VHI-based weather derivatives can be useful alternatives to meteorological indices, especially in regions with sparser weather station networks.


2020 ◽  
Vol 7 (2) ◽  
pp. 44-54
Author(s):  
M. M. Marenych ◽  
V. F. Kaminsky ◽  
C. Yu. Bulygin ◽  
V. V. Hanhur ◽  
I. V. Korotkova ◽  
...  

Aim. To study the impact of complex preparations, containing humic, fulvic and ulmic acids in combination with herbicides and nitrogen fertilizers, on winter wheat yield. Methods. Field, laboratory, statistical methods. Results. The impact of herbicides with different active substances and their mixtures with humic preparations Humifi eld and Foliar concentrate on weed infestation and productivity of Kryzhynka winter variety was investigated. It was determined that the application of herbicide Prima (400 g/ha) and the mixture of preparations Triger (25 g/ha) + Tomigan (0.5 l/ha) in combination with humic preparation Humifi eld in the dose of 200 g/ha had practically no impact on the crop productivity. A considerable increase in the yield, for instance, by 15.6–20.3 %, was observed in case of spraying the fi elds with the same preparation forms of herbicides in the tank mixture with humic stimulator 4R Foliar concentrate in the dose of 2.0 kg/ha. The application of humates in combination with nitrogen fertilizers with the purpose of optimizing the nutrition system for winter wheat via their introduction superfi cially and by spraying the leaf-stem mass of plants was studied. It was demonstrated that the application of the growth regulator 5R SoilBoost in the amount of 11 kg/ha in the mixture with 200 kg/ha of ammonia nitrate led to the increase of productivity for Smuhlianka and Slavna varieties by 11.2 and 8.5 % respectively, and double foliar application of 4R Foliar concentrate (2+2 kg/ha) in the mixture with ammonia nitrate – by 15.5 %. The maximal increase in productivity by 20–23 % was obtained after combined application of humic stimulators 5R SoilBoost (11 kg/ha) and 4R Foliar concentrate (2+2 kg/ha) on the background of ammonia nitrate (200 kg/ha of physical weight). The effi ciency of foliar fertilization for wheat fi elds of Kubus and Mulan varieties using the mixtures of humates and carbamide-ammonia mixture in different phases of crop development was analyzed. The application of such combinations also promoted the productivity increase by 10.0–21.4 %. Conclusions. The increase in productivity of Kryzhynka winter wheat variety by 0.64–0.84 t/ha was determined after spraying crop fi elds with the tank mixture of herbicides and humic stimulator 4R Foliar concentrate in the dose of 2.0 kg/ha. The effi ciency of optimizing the nutrition system of plants via separate or combined application of humic preparations, in particular, granulated 5R SoilBoost (11 kg/ha), superfi cially, and 4R Foliar concentrate (2 kg/ha+2 kg/ ha) in case of foliar fertilization for fi elds in different phases of crop development on the background of early spring introduction of ammonia nitrate (200 kg/ha) to frozen-thawed soil was proven. The increase in wheat productivity was observed in all variants of applying these mixtures. However, the maximal increase in the winter wheat yield was obtained due to the fertilization technology, envisaging the use of humates 5R SoilBoost and 4R Foliar concentrate on the background of ammonia nitrate. There was a noted increase in grain productivity of winter wheat varieties Kubus and Mulan by 0.50–0.94 and 0.41–1.08 t/ha respectively in case of superfi cial introduction of humic preparation 5R SoilBoost (11 kg/ha) and foliar fertilization of wheat fi elds with 4R Foliar concentrate (2+2 kg/ha) in combination with carbamide-ammonia mixture (200 + 100 kg/ha).


2020 ◽  
Vol 12 (7) ◽  
pp. 2801
Author(s):  
Yuan Li ◽  
Yi Dong ◽  
Dongqin Yin ◽  
Diyou Liu ◽  
Pengxin Wang ◽  
...  

Monitoring agricultural drought is important to food security and the sustainable development of human society. In order to improve the accuracy of soil moisture and winter wheat yield estimation, drought monitoring effects of optical drought index data, meteorological drought data, and passive microwave soil moisture data were explored during individual and whole growth periods of winter wheat in 2003–2011, taking Henan Province of China as the research area. The model of drought indices and relative meteorological yield of winter wheat in individual and whole growth periods was constructed based on multiple linear regression. Results showed a higher correlation between Moderate-Resolution Imaging Spectroradiometer (MODIS) drought indices and 10 cm relative soil moisture (RSM10) than 20 cm (RSM20) and 50 cm (RSM50). In the whole growth period, the correlation coefficient (R) between vegetation supply water index (VSWI) and RSM10 had the highest correlation (R = −0.206), while in individual growth periods, the vegetation temperature condition index (VTCI) was superior to the vegetation health index (VHI) and VSWI. Among the meteorological drought indices, the 10-day, 20-day, and 30-day standard precipitation evapotranspiration indices (SPEI1, SPEI2, and SPEI3) were all most relevant to RSM10 during individual and whole growth periods. RSM50 and SPEI3 had a higher correlation, indicating that deep soil moisture was more related to drought on a long time scale. The relationship between Advanced Microwave Scanning Radiometer for EOS soil moisture (AMSR-E SM) and VTCI was stable and significantly positive in individual and whole growth periods, which was better compared to VHI and VSWI. Compared with the drought indices and the relative meteorological yield in the city, VHI had the best monitoring effect during individual and whole growth periods. Results also showed that drought occurring at the jointing–heading stage can reduce winter wheat yield, while a certain degree of drought occurring at the heading–milk ripening stage can increase the yield. In the whole growth period, the combination of SPEI1, SPEI2, and VHI had the best performance, with a coefficient of determination (R2) of 0.282 with the combination of drought indices as the independent variables and relative meteorological yield as the dependent variable. In the individual growth period, the model in the later growth period of winter wheat performed well, especially in the returning green–jointing stage (R2 = 0.212). Results show that the combination of multiple linear drought indices in the whole growth period and the model in the returning green–jointing period could improve the accuracy of winter wheat yield estimation. This study is helpful for effective agricultural drought monitoring of winter wheat in Henan Province.


2017 ◽  
Vol 87 ◽  
pp. 40-49 ◽  
Author(s):  
Joseph P. Lynch ◽  
Deirdre Doyle ◽  
Shauna McAuley ◽  
Fiona McHardy ◽  
Quentin Danneels ◽  
...  

2009 ◽  
Vol 23 (4) ◽  
pp. 564-568 ◽  
Author(s):  
Randy L. Anderson

Improving crop vigor can suppress growth of weeds present in the crop. This study examined the impact of preceding crop and cultural practices on rye growth in winter wheat. Preceding crops were soybean, spring wheat, and an oat/dry pea mixture. Two cultural treatments in winter wheat were also compared, referred to as conventional and competitive canopies. The competitive canopy differed from the conventional in that the seeding rate was 67% higher and starter fertilizer was banded with the seed. The study was conducted at Brookings, SD. Rye seed and biomass production differed fourfold among treatments, with winter wheat following oat/pea being most suppressive of rye growth. Rye produced 63 seeds/plant in winter wheat with a competitive canopy that followed oat/pea, contrasting with 273 seeds/plant in conventional winter wheat following spring wheat. Yield loss in winter wheat due to rye interference increased with rye biomass, but winter wheat was more tolerant of rye interference following oat/pea compared with the other preceding crops. Regression analysis indicated that winter wheat yield loss at the same rye biomass was threefold higher following spring wheat or soybean compared with oat/pea as a preceding crop. Winter wheat competitiveness and tolerance to rye can be improved by increasing the seeding rate, using a starter fertilizer, and growing winter wheat after an oat/pea mixture.


Agronomy ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 50
Author(s):  
Weiwei Liu ◽  
Weiwei Sun ◽  
Jingfeng Huang ◽  
Huayang Wen ◽  
Ran Huang

In the era of global climate change, extreme weather events frequently occur. Many kinds of agro-meteorological disasters that are closely related to environmental conditions (such as sunshine hours, temperature, precipitation, etc.) are witnessed all over the word. However, which factor dominates winter wheat production in the middle and lower reaches of the Yangtze River remains unresolved. Quantifying the key limiting meteorological factor could deepen our understanding of the impact of climate change on crops and then help us to formulate disaster prevention and mitigation measures. However, the relative role of precipitation, sunshine hours and maximum daily temperature in limiting winter wheat yield in the middle and lower reaches of the Yangtze River is not clear and difficult to decouple. In this study, we used statistical methods to quantify the effect of precipitation, maximum temperature and sunshine hours extremes on winter wheat (Triticum aestivum L.) yield based on long time-series, county-level yield data and a daily meteorological dataset. According to the winter wheat growing season period (October of the sowing year to May of the following year), anomaly values of cumulative precipitation, average sunshine hours and average daily maximum temperature are calculated. With the range of −3 σ to 3 σ of anomaly and an interval of 0.5 σ (σ is the corresponding standard deviation of cumulative precipitation, mean maximum temperature and mean sunshine hours, respectively), the corresponding weighted yield loss ratio (WYLR) represents the impact of this kind of climate condition on yield. The results show that excessive rainfall is the key limiting meteorological factor that can reduce winter wheat yield to −18.4% in the middle and lower reaches of the Yangtze River, while it is only −0.24% in extreme dry conditions. Moreover, yield loss under extreme temperature and sunshine hours are negligible (−0.66% for extremely long sunshine hours and −8.29% for extreme cold). More detailed analysis results show that the impact of excessive rainfall on winter wheat yield varies regionally, as it causes severe yield reductions in the Huai River basin and the middle to southern part with low elevation and rainy areas of the study area, while for drier areas in the Hubei province, there is even an increase in yield. Our results disclosed with observational evidence that excessive precipitation is the key meteorological limiting factor leading to the reduction in winter wheat yield in the middle and lower reaches of the Yangtze River. The knowledge of the possible impact of climate change on winter wheat yield in the study area allows policy-makers, agronomists and economists to better forecast a plan that differs from the past. In addition, our results emphasized the need for better understanding and further process-based model simulation of the excessive rainfall impact on crop yield.


2019 ◽  
Vol 56 (2) ◽  
pp. 263-279 ◽  
Author(s):  
Marzena Iwańska ◽  
Michał Stępień

SummaryDrought reduces crop yields not only in areas of arid climate. The impact of droughts depends on the crop growth stage and soil properties. The frequency of droughts will increase due to climate change. It is important to determine the environmental variables that have the strongest effect on wheat yields in dry years. The effect of soil and weather on wheat yield was evaluated in 2018, which was considered a very dry year in Europe. The winter wheat yield data from 19 trial locations of the Research Center of Cultivar Testing (COBORU), Poland, were used. Soil data from the trial locations, mean air temperature (T) and precipitation (P) were considered as environmental factors, as well as the climatic water balance (CWB). The hydrothermal coefficient (HTC), which is based on P and T, was also used. The effect of these factors on winter wheat yield was related to the weather conditions at particular growth stages. The soil had a greater effect than the weather conditions. CWB, P, T and HTC showed a clear relationship with winter wheat yield. Soil data and HTC are the factors most recommended for models predicting crop yields. In the selection of drought-tolerant genotypes, the plants should be subjected to stress especially during the heading and grain filling growth stages.


Author(s):  
Г. П. Довгаль

У статті на прикладі типових аграрних підприємств зони Лісостепу здійснено комплексний аналіз кліматичних факторів і продуктивності агроекосистем. У результаті досліджень встановлено кореляційну залежність урожайності озимої пшениці від окремих кліматичних чинників за 20-річний період (1997–2016 рр.). За визначеними математичними моделями були побудовані графіки функцій, які дають змогу прогнозувати рівень урожайності культури за різного впливу кліматичних факторів. Установлено, що для пшениці озимої найвагомішими метеорологічними факторами є кількість опадів  травня і червня, а також запаси продуктивної вологи в 20 см шарі ґрунту у квітні та травні. In the article the complex analysis of climatic factors and productivity of agro-ecosystems was made by the example of typical Forest-Steppe zones of agricultural enterprises. The studies found the correlation dependence of crop capacity of winter wheat yield of some climatic factors for the 20-year period (1997–2016). By certain mathematical models the graphics features that enable us to predict the level of productivity of various crops by the impact of climate factors were built. It is found that the most significant meteorological factors for winter wheat are rainfalls in May and June, and productive moisture reserves in the soil layer 20 cm in April and May.


2019 ◽  
Vol 102 ◽  
pp. 1-13 ◽  
Author(s):  
Jianxi Huang ◽  
Hongyuan Ma ◽  
Fernando Sedano ◽  
Philip Lewis ◽  
Shunlin Liang ◽  
...  

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