INFLUENCE OF WEATHER CONDITIONS ON THE NITROGEN CONTENT OF WHEAT

1935 ◽  
Vol 12 (2) ◽  
pp. 228-237 ◽  
Author(s):  
J. W. Hopkins

A statistical study of results from experimental plots of Marquis wheat grown annually (though not on the same soil) at five points in Saskatchewan and Alberta indicates that there was a significant negative correlation between the amount of rainfall during the growing season and the nitrogen content of wheat. The main effect of rainfall was exerted during May and June. The data do not justify the conclusion that the amount of rain falling in July or August, or the amount of pre-seasonal precipitation, modified the nitrogen content significantly. Mean maximum temperature for July or August failed to show a significant correlation with nitrogen content, but may not be a satisfactory measure of the temperature conditions actually experienced by the crop.It is suggested that the preponderating effect of early rainfall may be due to the fact that it stimulates tillering and vegetative development generally. The available nitrogen must thus be distributed amongst an increased number of culms, whilst at the same time the total leaf area devoted to the production of carbohydrates is augmented.

1935 ◽  
Vol 13c (3) ◽  
pp. 127-133
Author(s):  
J. W. Hopkins

Supplementing a previous statistical study, coefficients designed to weight observed temperatures in proportion to their assumed effect on respiration were computed from the daily observations for three 3-week periods extending from July 1 to September 1. After allowing for the effect of May and June rainfall there was a moderate but significant partial correlation (r = +0.33) between nitrogen content and the sum of the temperature coefficients for the last two periods.There was a positive correlation (r = +0.74) between height of crop and yield of grain, and a negative correlation (r = −0.50) between height and nitrogen content. The partial correlation between nitrogen content and yield, after eliminating variations in both associated with height, was negligible (r = −0.07), suggesting that reductions in yield due to restriction of the later stages of translocation did not result in significant modification of the nitrogen content of the grain.Results of the investigation as a whole are briefly discussed.


2020 ◽  
Vol 0 (6) ◽  
pp. 13-19
Author(s):  
Guzel Gumerova ◽  
Georgiy Gulyuk ◽  
Dmitry Kucher ◽  
Anatoly Shuravilin ◽  
Elena Piven

Data of long-term researches (2015–2018) in southern forest-steppe zone of the Republic of Bashkortostan, is justified theoretically and experimentally the mode of irrigation of potatoes on leached chernozems of unsatisfactory, satisfactory and good ameliorative condition of irrigated lands. For the growing periods of potatoes with different heat and moisture supply, the number of watering, the timing of their implementation, irrigation and irrigation norms are established. On lands with unsatisfactory meliorative state the number of irrigation depending on weather conditions of potato vegetation period varied from 0 to 3 (1.5 on average) with average irrigation norm – 990 m3/ha. With satisfactory meliorative state of lands the number of irrigation on average increased from 0 to 4 (2.3 on average) with irrigation norm – 1305 m3/ha. On lands with good meliorative state the number of irrigation was the highest – from 1 to 5 (3 on average) with average irrigation irrigation norm is 1653 m3/ha. It was noted that in the dry periods of potato vegetation the greatest number of watering was carried out (3–5 watering), and in the wet periods (2017) watering was not carried out except for the area with a good reclamation state, where only one irrigation was carried out by the norm of 550 m3/ha. Water consumption of potato was studied in dynamics as a whole during the growing season and the months of the growing season depending on weather conditions of vegetation period and land reclamation condition of irrigated lands, as well as in the control (without irrigation). The lowest total water consumption was in the area without irrigation and averaged 226.8 mm. In irrigated areas, its values increased to 319-353.4 mm. The average daily water consumption varied from 2.12 to 3.3 mm. The highest rates of potato water consumption were observed in June and July, and the lowest – in May and August. In the total water consumption of potatoes on the site without irrigation, the largest share was occupied by atmospheric precipitation and in addition to them the arrival of moisture from the soil. Irrigation water was used in irrigated areas along with precipitation, the share of which was 30.2–46.1 %.


2020 ◽  
Vol 66 (No. 9) ◽  
pp. 468-476
Author(s):  
Miroslav Jursík ◽  
Martin Kočárek ◽  
Michaela Kolářová ◽  
Lukáš Tichý

Six sunflower herbicides were tested at two application rates (1N and 2N) on three locations (with different soil types) within three years (2015–2017). Efficacy of the tested herbicides on Chenopodium album increased with an increasing cation exchange capacity (CEC) of the soil. Efficacy of pendimethalin was 95%, flurochloridone and aclonifen 94%, dimethenamid-P 72%, pethoxamid 49% and S-metolachlor 47%. All tested herbicides injured sunflower on sandy soil (Regosol) which had the lowest CEC, especially in wet conditions (phytotoxicity 27% after 1N application rate). The highest phytotoxicity was recorded after the application of dimethenamid-P (19% at 1N and 45% at 2N application rate). Main symptoms of phytotoxicity were leaf deformations and necroses and the damage of growing tips, which led to destruction of some plants. Aclonifen, pethoxamid and S-metolachlor at 1N did not injure sunflower on the soil with the highest CEC (Chernozem) in any of the experimental years. Persistence of tested herbicides was significantly longer in Fluvisol (medium CEC) compared to Regosol and Chernozem. Dimethenamid-P showed the shortest persistence in Regosol and Chernozem. The majority of herbicides was detected in the soil layer 0–5 cm in all tested soils. Vertical transport of herbicides in soil was affected by the herbicide used, soil type and weather conditions. The highest vertical transport was recorded for dimethenamid-P and pethoxamid (4, resp. 6% of applied rate) in Regosol in the growing season with high precipitation.  


2021 ◽  
Vol 13 (4) ◽  
pp. 739
Author(s):  
Jiale Jiang ◽  
Jie Zhu ◽  
Xue Wang ◽  
Tao Cheng ◽  
Yongchao Tian ◽  
...  

Real-time and accurate monitoring of nitrogen content in crops is crucial for precision agriculture. Proximal sensing is the most common technique for monitoring crop traits, but it is often influenced by soil background and shadow effects. However, few studies have investigated the classification of different components of crop canopy, and the performance of spectral and textural indices from different components on estimating leaf nitrogen content (LNC) of wheat remains unexplored. This study aims to investigate a new feature extracted from near-ground hyperspectral imaging data to estimate precisely the LNC of wheat. In field experiments conducted over two years, we collected hyperspectral images at different rates of nitrogen and planting densities for several varieties of wheat throughout the growing season. We used traditional methods of classification (one unsupervised and one supervised method), spectral analysis (SA), textural analysis (TA), and integrated spectral and textural analysis (S-TA) to classify the images obtained as those of soil, panicles, sunlit leaves (SL), and shadowed leaves (SHL). The results show that the S-TA can provide a reasonable compromise between accuracy and efficiency (overall accuracy = 97.8%, Kappa coefficient = 0.971, and run time = 14 min), so the comparative results from S-TA were used to generate four target objects: the whole image (WI), all leaves (AL), SL, and SHL. Then, those objects were used to determine the relationships between the LNC and three types of indices: spectral indices (SIs), textural indices (TIs), and spectral and textural indices (STIs). All AL-derived indices achieved more stable relationships with the LNC than the WI-, SL-, and SHL-derived indices, and the AL-derived STI was the best index for estimating the LNC in terms of both calibration (Rc2 = 0.78, relative root mean-squared error (RRMSEc) = 13.5%) and validation (Rv2 = 0.83, RRMSEv = 10.9%). It suggests that extracting the spectral and textural features of all leaves from near-ground hyperspectral images can precisely estimate the LNC of wheat throughout the growing season. The workflow is promising for the LNC estimation of other crops and could be helpful for precision agriculture.


2021 ◽  
Vol 11 (11) ◽  
pp. 4757
Author(s):  
Aleksandra Bączkiewicz ◽  
Jarosław Wątróbski ◽  
Wojciech Sałabun ◽  
Joanna Kołodziejczyk

Artificial Neural Networks (ANNs) have proven to be a powerful tool for solving a wide variety of real-life problems. The possibility of using them for forecasting phenomena occurring in nature, especially weather indicators, has been widely discussed. However, the various areas of the world differ in terms of their difficulty and ability in preparing accurate weather forecasts. Poland lies in a zone with a moderate transition climate, which is characterized by seasonality and the inflow of many types of air masses from different directions, which, combined with the compound terrain, causes climate variability and makes it difficult to accurately predict the weather. For this reason, it is necessary to adapt the model to the prediction of weather conditions and verify its effectiveness on real data. The principal aim of this study is to present the use of a regressive model based on a unidirectional multilayer neural network, also called a Multilayer Perceptron (MLP), to predict selected weather indicators for the city of Szczecin in Poland. The forecast of the model we implemented was effective in determining the daily parameters at 96% compliance with the actual measurements for the prediction of the minimum and maximum temperature for the next day and 83.27% for the prediction of atmospheric pressure.


2021 ◽  
Vol 13 (12) ◽  
pp. 2249
Author(s):  
Sadia Alam Shammi ◽  
Qingmin Meng

Climate change and its impact on agriculture are challenging issues regarding food production and food security. Many researchers have been trying to show the direct and indirect impacts of climate change on agriculture using different methods. In this study, we used linear regression models to assess the impact of climate on crop yield spatially and temporally by managing irrigated and non-irrigated crop fields. The climate data used in this study are Tmax (maximum temperature), Tmean (mean temperature), Tmin (minimum temperature), precipitation, and soybean annual yields, at county scale for Mississippi, USA, from 1980 to 2019. We fit a series of linear models that were evaluated based on statistical measurements of adjusted R-square, Akaike Information Criterion (AIC), and Bayesian Information Criterion (BIC). According to the statistical model evaluation, the 1980–1992 model Y[Tmax,Tmin,Precipitation]92i (BIC = 120.2) for irrigated zones and the 1993–2002 model Y[Tmax,Tmean,Precipitation]02ni (BIC = 1128.9) for non-irrigated zones showed the best fit for the 10-year period of climatic impacts on crop yields. These models showed about 2 to 7% significant negative impact of Tmax increase on the crop yield for irrigated and non-irrigated regions. Besides, the models for different agricultural districts also explained the changes of Tmax, Tmean, Tmin, and precipitation in the irrigated (adjusted R-square: 13–28%) and non-irrigated zones (adjusted R-square: 8–73%). About 2–10% negative impact of Tmax was estimated across different agricultural districts, whereas about −2 to +17% impacts of precipitation were observed for different districts. The modeling of 40-year periods of the whole state of Mississippi estimated a negative impact of Tmax (about 2.7 to 8.34%) but a positive impact of Tmean (+8.9%) on crop yield during the crop growing season, for both irrigated and non-irrigated regions. Overall, we assessed that crop yields were negatively affected (about 2–8%) by the increase of Tmax during the growing season, for both irrigated and non-irrigated zones. Both positive and negative impacts on crop yields were observed for the increases of Tmean, Tmin, and precipitation, respectively, for irrigated and non-irrigated zones. This study showed the pattern and extent of Tmax, Tmean, Tmin, and precipitation and their impacts on soybean yield at local and regional scales. The methods and the models proposed in this study could be helpful to quantify the climate change impacts on crop yields by considering irrigation conditions for different regions and periods.


2000 ◽  
Vol 78 (10) ◽  
pp. 1831-1839 ◽  
Author(s):  
P Sound ◽  
M Veith

Daily activity patterns of male western green lizards, Lacerta bilineata (Daudin, 1802), at the edge of their northern distribution range in western Germany after the breeding season from June to October were recorded using implanted radio transmitters. Different activity indices discriminating between stimulation, duration, and length of movement were correlated with actual weather conditions (d0) and with weather conditions on the 2 previous days (d-1 and d-2). The lizards' dependence on weather showed two different phases throughout the study period. During the first period and in the period preceding a drastic change of weather in midsummer, weather had no significant influence on movement parameters. After that event, temperatures dropped and a strong dependence on weather of all movement parameters except those indicating displacements became apparent. Thresholds for 50% activity during this second phase were a maximum temperature of 17°C and a minimum humidity of 35%. Two days after periods of bad weather, the influence of weather conditions increased again. This can be explained by physiological deficits that require compensation during the period of marginal weather conditions prior to hibernation. Displacement movements were significantly longer than home-range movements and were neither triggered nor modulated by the weather. They must therefore represent activities such as patrolling territory boundaries.


2021 ◽  
Vol 5 (1) ◽  
pp. 13-22
Author(s):  
V. V. Gamayunova ◽  
L. H. Khonenko ◽  
M. I. Fedorchuk ◽  
O. A. Kovalenko

The cultivation expediency of more drought-resistant crops, in particular sorghum, millet, false flax, safflower and others, instead of sunflower in the area of the Southern Steppe of Ukraine is substantiated. This is, first of all, required by climate change both in Ukraine and in the world. Since 2004, researches of field crops were carried out in the conditions of the Educational and Scientific Practical Center of the Mykolaiv National Agrarian University. Soil phase is the southern chernozem with humus content in the 0–30 cm soil layer which consist of 2.96–3.21 %, with medium and high level of availability of mobile phosphorus and potassium and low – mobile nitrogen. Experiments with soriz (Oksamyt hybrid) were conducted during 2004–2006, millet (Tavriiske, Kostantynivske, Skhidnevarieties) in 2008–2010, grain sorghum (Stepovyi 5 hybrid) in 2014–2016, safflower dye (Lahidnyi variety) in 2017–2019. The years of research differed significantly in temperature and even more in the amount of precipitation before sowing and during the growing season of crops. However, the weather conditions were typical of the Southern Steppe zone of Ukraine. It is established that all studied drought-resistant crops respond positively to nutrition optimization – the level of yield and quality of grain or seeds increases. It was found that the soriz productivity depending on the application of fertilizers and sowing dates increased by 37.6–39.2 %, millet –by 33.3–41.6 %, grain sorghum depending on the background of nutrition and growing conditions – by 8.2–33.2 %, dye safflower – by 11.1–64.6 %. It was determined that the optimization of nutrition of cultivated crops allows to increase their resistance to adverse conditions and productivity in the case of application of low doses of the mineral fertilizers before sowing, pre-sowing treatment of seeds, and growth-regulating chemical application of plants on the main stages of the growing season. Key words: drought-resistant plants, climatic conditions, nutrition optimization, yield, crop quality, varieties, sowing dates.


Author(s):  
П.А. Котяк

Представлены результаты исследования уровня общей токсичности и микробного токсикоза дерново-подзолистой глееватой почвы при антропогенной нагрузке. Изучение токсичности почвы особенно актуально в агроценозах, где человек в значительной мере регулирует условия произрастания растений. Использование показателей токсичности при оценке агротехнических приёмов позволяет усовершенствовать существующие технологии, чтобы избежать нежелательных сопутствующих эффектов при агрогенном воздействии на агроэкосистемы. Сравнительный анализ полученных результатов показал, что почва опытного участка в начале вегетации имела класс средней и низкой токсичности (индекс токсичности фактора (ИТФ) от 0,63 до 0,82), а в конце вегетации – класс высокой и средней токсичности (ИТФ от 0,35 до 0,55). Оценка микробиологической токсичности почвы исследуемых вариантов опыта по всхожести семян тест-культуры показала в основном средний уровень микробного токсикоза: 69,75% – на индуцированных образцах, 60,97% – на контрольных образцах. Урожайность зелёной массы ярового рапса находилась на невысоком уровне, что могло быть связано с неблагоприятными погодными условиями вегетационного периода и варьировала в пределах от 76 до 218 ц/га. Проведённые исследования по установлению влияния антропогенной нагрузки на токсический статус дерново-подзолистой почвы в условиях Ярославской области показали, что лучшими характеристиками обладают варианты: система отвальной обработки почвы, фон «Органо-минеральный субстрат + NPK» как с внесением гербицида, так и без его применения при возделывании ярового рапса. В этих условиях снижается общая токсичность почвы, статус микробного токсикоза не меняется, что позволяет сохранять почвенное плодородие, иметь оптимальное фитосанитарное состояние и получать качественный урожай выращиваемых культур. The results of the research of general toxicity level and microbial toxicosis of soddy podzolic gleyic soil at man-caused load are presented. The study of soil toxicity is especially important in agrocenoses, where a person largely regulates the conditions of plant growth. The use of toxicity indicators in assessing agricultural practices allows improving existing technologies in order to avoid undesirable concomitant effects during agrogenic effects on agroecosystems. A comparative analysis of the obtained results showed that the soil of the test area at the beginning of the growing season had a medium and low toxicity class (factor toxicity index (FTI) from 0.63 to 0.82) and at the end of the growing season it had a high and medium toxicity class (FTI from 0.35 to 0.55). Assessment of the microbiological toxicity of the soil of test variants under investigation by seed germination of the test-crop showed mainly the average level of microbial toxicosis: 69.75% on the induced samples, 60.97% on the control samples. The yield of green mass of spring rape was at a low level, which could be associated with unfavorable weather conditions of the growing season and varied from 76 to 218 hkg / ha. Researches conducted to establish influence of man's activities on the toxic status of soddy podzolic soil in the conditions of the Yaroslavl region showed that the best characteristics are options: a system of moldboard tillage, background "Organic-mineral substrate + NPK" both with the herbicide application and without its use in the cultivation of spring rape. Under these conditions the general toxicity of the soil decreases, the status of microbial toxicosis does not change which allows maintaining soil fertility, having an optimal phytosanitary condition and obtaining a quality yield of crops grown.


2020 ◽  
Vol 4 (1) ◽  
pp. 15-22
Author(s):  
Muhammad Taqui ◽  
Jabir Hussain Syed ◽  
Ghulam Hassan Askari

Pakistan’s largest city, Karachi, which is industrial centre and economic hub needs focus in research and development of every field of Engineering, Science and Technology. Urbanization and industrialization is resulting bad weather conditions which prolongs until a climate change. Since, Meteorology serves as interdisciplinary field of study, an analytical study of real and region-specific meteorological data is conducted which focuses on routine, extreme and engineering meteorology of metropolitan city Karachi. Results of study endorse the meteorological parameters relationship and establish the variability of those parameters for Karachi Coastal Area. The rise of temperature, decreasing trend of atmospheric pressure, increment in precipitation and fall in relative humidity depict the effects of urbanization and industrialization. The recorded extreme maximum temperature of 45.50C (on June 11, 1988) and the extreme minimum temperature of 4.5 0C(on January 1, 2007) is observed at Karachi south meteorological station. The estimated temperature rise in 32 years is 0.9 0C, which is crossing the Intergovernmental Panel on Climate Change (IPCC) predicted/estimated limit of 2oC rise per century. The maximum annual precipitation of 487.0mm appearing in 1994 and the minimum annual precipitation of 2.5mm appearing in 1987 is observed at same station which is representative meteorological station for Karachi Coast. Further Engineering meteorological parameters for heating ventilation air condition (HVAC) system design for industrial purpose are deduced as supporting data for coastal area site study for industrial as well as any follow-up engineering work in the specified region.


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