Modeling and Forecasting Brazilian Crop Yields Using Meteorological Data

Author(s):  
Fernando Silveira da Mota ◽  
Marisa Oliveira de Oliveira Agendes ◽  
José Luiz da Costa Rosskoff ◽  
João Baptista da Silva
2020 ◽  
Vol 15 (2) ◽  
pp. 123-133
Author(s):  
Ruslan M. Bischokov

Using computer fuzzy-logical models based on empirical values of climatic characteristics (rainfall, temperature and humidity) of long-term observations (1955-2018) from meteorological stations in the Kabardino-Balkarian Republic (Nalchik, Baksan, Prokhladny and Terek) and crop yields (winter wheat, spring wheat, corn, sunflower, millet, oats), dependence of crop yields on variations of climatic factors were analyzed and a specific forecast was given. Setting expected values of climatic characteristics in computer model, we received possible values of productivity for the next season. Uniformity assessment (Dixon and Smirnov - Grabbsas criterion), stability (Student and Fischers criterion), statistical importance of parameters of distribution and accidental errors were determined. Originality of the method is in the fact that in the form of input parameters of the model predictors, the previously calculated forecast values of the meteorological parameters for the next agricultural year were used, and at the output, the predicted values of crop productivity were obtained as predictants. Furthermore, recommendations on adoption of management decisions were developed.


2015 ◽  
Vol 51 (4) ◽  
pp. 615-634 ◽  
Author(s):  
BOUBA TRAORE ◽  
MARK T. VAN WIJK ◽  
KATRIEN DESCHEEMAEKER ◽  
MARC CORBEELS ◽  
MARIANA C. RUFINO ◽  
...  

SUMMARYAgricultural production in the Sudano–Sahelian zone of west Africa is highly vulnerable to the impacts of climate variability and climate change. The present study aimed to understand farmers’ perceptions of climate variability and change and to evaluate adaptation options together with farmers, including tactical management of planting date in combination with the use of mineral fertilizer. Farmers perceived an increase in annual rainfall variability, an increase in the occurrence of dry spells during the rainy season, and an increase in temperature. Overall, this is in line with the observed meteorological data. Drought tolerant, short maturing crop varieties and appropriate planting dates were the commonly preferred adaptation strategies to deal with climate variability. On-farm trials confirmed that planting delays significantly reduce crop yields. The use of mineral fertilizer is often promoted, but risky for smallholders: although larger fertilizer applications increased the yield of maize (Zea mays) and millet (Pennisetum glaucum) significantly, a gross margin analysis indicated that it did not lead to more profit for all farmers. We conclude that integrating management of nutrients and planting time with improved farmer access to timely weather information, especially on the onset of the rains, is critical to enhancing adaptive capacity to increased climate variability and change.


1981 ◽  
Vol 61 (2) ◽  
pp. 425-435 ◽  
Author(s):  
C. S. TAN ◽  
J. M. FULTON

Several years of daily evapotranspiration (ET) data for irrigated early potatoes, corn and processing tomatoes, grown on Fox sandy loam measured by floating lysimeters and estimated by meteorological data were used to evaluate an equilibrium evapotranspiration (ETeq) model. A reasonable relationship was obtained between values estimated by the model and those measured by floating lysimeters. The ETeq model can be used to estimate daily ET over a wide range of soil moisture and foliage cover conditions. ETeq can be estimated from readily available climatic data in the form: ETeq = (0.48 + 0.01 Ta) [(0.114 + 0.365n/N) K↓a − 0.039]; where Ta is the mean daily air temperature (°C); n is sunshine duration (h); N is maximum hours of bright sunshine (h); K↓a is solar energy received at the top of the atmosphere (mm/day). At high soil water storage in the root zone, the ET/ETeq remained constant, whereas, at low soil water storage, the ET/ETeq decreased linearly with decreasing soil water storage. The total crop yields were directly related to growing season accumulated ET.


2018 ◽  
Vol 10 (3) ◽  
pp. 435-452 ◽  
Author(s):  
Msafiri Yusuph Mkonda ◽  
Xinhua He ◽  
Emma Sandell Festin

Abstract This paper examines and compares smallholder farmers’ perceptions of climate change with the collected meteorological data (1980–2015) across the seven agroecological zones (AEZs) of Tanzania. Systematic and simple random sampling procedures were employed in the selection of districts and villages, respectively. This study used both quantitative and qualitative datasets. Quantitative data were derived from climatic records and questionnaires, while the qualitative data were widely derived from interviews and discussions. The Mann–Kendall test (software) and theme content (method) were used for data analyses. The results showed that rain has experienced a significant change in terms of patterns, frequency, and intensity, while temperature was locally increasing in all the AEZs. Moreover, the farmers’ responses to both closed and open questions indicated that most of them (>70%) noticed these alterations. Comparatively, the farmers residing in the most vulnerable AEZs, that is, arid and semiarid lands, were more responsive and sensitive to climatic impacts than those in the least vulnerable zones, such as alluvial regions. The increase in temperature and change in the rain patterns led to the decrease in crop yields. As a response to this, farmers have adopted new strategies such as early planting and the use of shorter growing crops cultivars. This study concludes that, although farmers’ perceptions were correct and echoed the meteorological/measured data in all the AEZs, adaptation and mitigation strategies are inadequate.


Land ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 999
Author(s):  
Kaiza R. Kaganzi ◽  
Aida Cuni-Sanchez ◽  
Fatuma Mcharazo ◽  
Emanuel H. Martin ◽  
Robert A. Marchant ◽  
...  

Mountain environments and communities are disproportionately impacted by climate change. Changes in temperature are greater than at lower elevations, which affect the height of the cloud base and local rainfall patterns. While our knowledge of the biophysical nature of climate change in East Africa has increased in the past few years, research on Indigenous farmers’ perceptions and adaptation responses is still lacking, particularly in mountains regions. Semi-structured interviews were administered to 300 farmers on Mount Kilimanjaro (n = 150) and the Udzungwa Mountains (n = 150) in Tanzania across gender and wealth groups. Respondents in both mountains reported not only changes in rainfall and temperature, corresponding with meteorological data, but also a greater incidence of fog, wind, frost, and hailstorms—with impacts on decreased crop yields and increased outbreaks of pests. The most common adaptation strategies used were improved crop varieties and inputs. Wealthier households diversified into horticulture or animal rearing, while poorer households of Hehe ethnicity diversified to labour and selling firewood. Despite being climate change literate and having access to radios, most respondents used Indigenous knowledge to decide on planting dates. Our findings highlight how context and culture are important when designing adaptation options and argue for greater involvement of local stakeholders in adaptation planning using a science-with-society approach. Place-based results offer generalisable insights that have application for other mountains in the Global South.


Author(s):  
A. P. Likhatsevich

The programming (simulation) of yield in the area of “risky farming” that Belarus belongs to according to data from a single-factor experiment considering only the food mode, can lead to unacceptably large errors in the calculations. These errors can easily be avoided by increasing the factorality of agronomic experiment by using standard meteorological data processed using mathematical model of crop yields. A mathematical model of environmental factors effect on crop yields is proposed and tested. It is shown that the accuracy of yield simulation (calculation) increases with the growing number of crop-forming factors taken into account. The possibilities of mathematical simulation allowing to switch from one-factor to multifactorial agronomic research are demonstrated, involving meteorological data characterizing the moisture and heat availability of the vegetation period when analyzing the results of the experiment as additional information. The moisture supply conditions can be characterized quite accurately by atmospheric precipitation during the vegetation period, and the heat supply – by the maximum daily air temperatures in the same period. Inclusion in analysis of additional water and heat factors of yield makes it possible not only to increase the factorality of field experiment, but also to substantially increase the conclusions validity according to the results based on the proposed mathematical model. 


Author(s):  
Andrey ilinsky ◽  
Alexander Nefedov ◽  
Konstantin Evsenkin

Global climatic changes, technogenic pollution by pollutants, violations of technologies of exploitation of reclaimed land lead to a decrease in fertility and soil degradation of agricultural land. Adverse weather conditions, resulting in a lack of adequate flood water, and economic difficulties in agriculture make it difficult to fill the deficit of organic matter and macronutrients in reclaimed alluvial soils. The monitoring of agrochemical properties of alluvial meadow medium-loamy soil of the stationary site (reclaimed lands of JSC «Moskovskoye» of Ryazan region), located in the floodplain of the Oka river, conducted by the Meshchersky branch of Vniigim, showed the presence and intensification of degradation changes in the soil. Thus, comparing the agrochemical indicators in the layer 0–20 cm, carried out in 1995, with the indicators of 2019, it should be noted a decrease in soil fertility. The decrease in soil quality was expressed in a decrease in the amount of mobile phosphorus by 37.6 %, mobile potassium by 53.3 %. Also, during this time there was a decrease in organic matter by 9.1 %, and an increase in soil acidity was 0.6 pH. As a result of such changes, soils lose ecological stability and become more vulnerable to adverse weather and negative anthropogenic impacts. In such a situation, advanced agricultural techniques should be actively used to obtain guaranteed, environmentally safe crop yields and restore the fertility of degraded reclaimed soils. In this regard, there is a need to develop innovative methods of fertility restoration of degraded alluvial soils in reclaimed lands using multi-component organic-mineral ameliorants. Meshchersky branch performs research work in addressing this issue.


2020 ◽  
pp. 67-79
Author(s):  
Yu. Kravchenko

In Ukraine 57.5 % of agricultural land is subjected to erosion with 10–24 million tons of humus, 0.3–0.96 million tons of nitrogen, 0.7–0.9 million tons of phosphorus and 6–12 million tons of potassium lost annually. Degradation processes are also common on chernozems, which cover about 60 % of the Ukrainian territory. The aim of the research is to defi ne the most eff ective soil conservation practices and legislative decisions aimed to conservation/recovering the Ukrainian chernozem fertility. The experimental data of the agrochemical certifi cation of Ukrainian lands, data from scientifi c papers, stock and instructional materials as well as our own fi eld and laboratory studies were used. It has been established that the long-term use of deep subsurface tillage on typical chernozem increases, compared with plowing, the content of 10–0.25 mm of air-dry and water-resistant aggregates, the bulk density, soil water storages, water infi ltration rates, the content of mobile phosphorus and exchangeable potassium, pHH2O, CaCO3 stocks, the contents of humic and fulvic acids, molecular weights of humic acids – by 5.5 and 3.06 %; 0.05 g/cm3; 25.5 mm; 22.6 mm/h; 0.1 and 3 mg/100 g of soil; 0.03 pHH2O; 18 t/ha, 0.02 and 0.04 %, 91195 kDa, respectively. Fertilizers may contribute to the crop yields increase from by 60% in the Polissya, by 40 % – in the Forest Steppe, by 15 % – in the Wet Steppe, by 10 % – in the Dry Steppe and by 40 % – in the Irrigated Steppe areas. In soil-conservation rotations, the crop placement and alternation are advisable to combine with strips or hills sowing, taking into account the local relief features; soil alkalinization, applying anti-erosion structures. Ukrainian agriculture will receive additional 10–12 million tons of forage units or 20–22 % from all fodder in a fi eld agriculture under increasing 8–10 % of arable lands for intercrops. It is advisable to mulch the eroded chernozems of Ukraine depending on their texture composition: 1.3 t/ha of mulch for sandy and loamy soils, 1.9 t/ha – for sandy and 1.1 t/ha – for loamy soils. The implementation of soil conservation agriculture can minimize some soil degradation processes and improve eff ective soil properties required to realize the biological potential of cultivated plants. Key words: chernozem, degradation, fertility, soil conservation technologies, agriculture policy.


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