scholarly journals Impact of heat and moisture stress on crop productivity: Evidence from the Langgewens Research Farm

2021 ◽  
Vol 117 (9/10) ◽  
Author(s):  
Beatrice Conradie ◽  
Jenifer Piesse ◽  
Johann Strauss
Keyword(s):  
Heat Stress ◽  
Growing Season ◽  
Moisture Stress ◽  
Crop Productivity ◽  
Model Specification ◽  
Maximum Temperature ◽  
Total Rainfall ◽  
Crop Farming ◽  
Heat And Moisture

We investigated the effect of heat and moisture stress on total factor productivity in crop farming under experimental farm conditions. Heat stress is the number of days during the growing season during which the maximum temperature exceeds 24.9 °C. Total rainfall is treated as a basic factor of production and periodic moisture stress, or lack thereof, is the number of rainfall days during the growing season. All models controlled for the cumulative soil benefits arising from minimum tillage, which is the main objective of the experiment. Model specification was evaluated using likelihood ratio tests and three are worthy of note. The study site received 329 mm of rainfall on average on 22 rainy days per season during the period 2002–2015, while the maximum temperature typically rose above 24.9 °C on 33 days per growing season. The average efficiency of the plots in the long-term crop rotation experiment increased at 3.4% per year from a base of 60% to the most recent level of 78%. Neither heat nor moisture stress changed significantly over the study period. Heat stress was found to reduce efficiency by 1.75% per hot day and rainfall increased efficiency by 1.45% for each additional rainy day. However, the interaction of heat and moisture stress lowered productivity overall.

scholarly journals Growth and development of soybean varieties of the northern ecotype depending on the influence of limiting factors of the growing season

2020 ◽  
pp. 4-9
Author(s):  
Marina Evgenievna Belyshkina ◽  
Tamara Petrovna Kobozeva ◽  
Elena Vasilevna Gureyeva
Keyword(s):  
Growth And Development ◽  
Growing Season ◽  
Vegetation Period ◽  
Limiting Factors ◽  
Limiting Factor ◽  
Temperature And Precipitation ◽  
Average Annual Temperature ◽  
Favorable Conditions ◽  
Heat And Moisture

Based on long-term data, the article considers the peculiarities of growth and development of soybean varieties of the Northern ecotype depending on the conditions of the growing season and the influence of limiting factors. The need of soy plants for heat and moisture increases from seed germination to germination, then to the phases of flowering and bean formation, while their uniform distribution is important. In the absence of abnormal periods of drought or waterlogging, soybean varieties of the Northern ecotype Mature in August – early September. The purpose of the research was to determine the degree of influence of variability of agrometeorological conditions of the vegetation period in different years on the production process of soybean varieties of the Northern ecotype and to assess the possibility of their cultivation in the Ryazan and other regions of the Central district of the Non-Chernozem zone. The experiments were carried out in 2009–2019 years with varieties of soya of Northern ecotype Mahewa, Bright and the Whale. The limiting factor in some years of research in the conditions of the Ryazan region was the lack of moisture, while the biological minimum temperatures were maintained at all stages of growth and development. As a result of the analysis of the average annual temperature and precipitation data, the most favorable conditions for the cultivation of all the studied soybean varieties for seeds are formed in the Bryansk, Oryol and Ryazan regions. For Vladimir, Ivanovo, Kaluga, Moscow, Smolensk and Tula regions, the varieties Kasatka and Mageva are recommended, for Kostroma, Tver, and Yaroslavl – Kasatka. In all areas of the Central region of the Non-Chernozem zone, these varieties can be used to obtain green mass, silage and haylage.

scholarly journals Performance of Sorghum Varieties under Variable Rainfall in Central Tanzania

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Barnabas M. Msongaleli ◽  
S. D. Tumbo ◽  
N. I. Kihupi ◽  
Filbert B. Rwehumbiza
Keyword(s):  
Crop Production ◽  
Rainfall Variability ◽  
Growing Season ◽  
Moisture Stress ◽  
Crop Failure ◽  
Rainfall Distribution ◽  
Cropping Season ◽  
Dry Spells ◽  
Semiarid Areas

Rainfall variability has a significant impact on crop production with manifestations in frequent crop failure in semiarid areas. This study used the parameterized APSIM crop model to investigate how rainfall variability may affect yields of improved sorghum varieties based on long-term historical rainfall and projected climate. Analyses of historical rainfall indicate a mix of nonsignificant and significant trends on the onset, cessation, and length of the growing season. The study confirmed that rainfall variability indeed affects yields of improved sorghum varieties. Further analyses of simulated sorghum yields based on seasonal rainfall distribution indicate the concurrence of lower grain yields with the 10-day dry spells during the cropping season. Simulation results for future sorghum response, however, show that impacts of rainfall variability on sorghum will be overridden by temperature increase. We conclude that, in the event where harms imposed by moisture stress in the study area are not abated, even improved sorghum varieties are likely to perform poorly.

scholarly journals Rainfall and temperatures during the 1991/92 drought in the Kruger National Park

Koedoe ◽  
1995 ◽  
Vol 38 (1) ◽  
Author(s):  
N. Zambatis ◽  
H.C. Biggs
Keyword(s):  
National Park ◽  
Kruger National Park ◽  
Maximum Temperature ◽  
Daily Maximum ◽  
Total Rainfall ◽  
Temperature Range ◽  
History Of ◽  
Annual Total ◽  
Maximum Minimum

Rainfall and temperatures during the 1991/92 drought, the severest in the recorded history of the Kruger National Park (KNP), are described. Mean total rainfall for the KNP was 235.6 mm (44.1 of the long- term mean), with a median of 239.9 mm. The num- ber of days on which rain occurred also decreased significantly from a mean annual total of 48.3 to a mean of 24.2 in 1991/92. Daily maximum, minimum and average temperatures for some months increased significantly, as did the number of days within certain maximum temperature range classes.

Fine-scale variability in growth–climate relationships of Douglas-fir, North Cascade Range, Washington

2005 ◽  
Vol 35 (11) ◽  
pp. 2743-2755 ◽  
Author(s):  
Michael J Case ◽  
David L Peterson
Keyword(s):  
Climatic Variability ◽  
Growing Season ◽  
Moisture Stress ◽  
Elevational Gradient ◽  
High Elevation ◽  
Douglas Fir ◽  
Cascade Range ◽  
Maximum Temperature ◽  
Summer Drought ◽  
The North

Information about the sensitivity to climate of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) is valuable because it will allow forest managers to maximize growth, better understand how carbon sequestration may change over time, and better model and predict future ecosystem responses to climatic change. We examined the effects of climatic variability on the growth of Douglas-fir along an elevational gradient in the North Cascade Range, Washington (USA), at annual timescales during the 20th century. Multivariate analysis and correlation analysis were used to identify climate-growth relationships. Mid-elevation chronologies were negatively correlated with growing season maximum temperature and positively correlated with growing season precipitation. In contrast, high-elevation chronologies were positively correlated with annual temperatures and negatively correlated with previous-year winter Pacific Decadal Oscillation index. Projected increases in summer temperatures will likely cause greater soil moisture stress in many forested ecosystems. The potential of extended summer drought periods over decades may significantly alter spatial patterns of productivity, thus impacting carbon storage. It is likely that the productivity of Douglas-fir in the Cascade Range will decrease at sites with shallow, excessively drained soils, south- and west-facing aspects, and steep slopes and will increase at high-elevation sites.

Long-term marketable yields of horticultural crops in southern Ontario in relation to seasonal climate

2005 ◽  
Vol 85 (2) ◽  
pp. 431-438 ◽  
Author(s):  
Alan McKeown ◽  
Jon Warland ◽  
Mary Ruth McDonald
Keyword(s):  
Growing Season ◽  
Maximum Temperature ◽  
Vegetable Crops ◽  
Vegetable Crop ◽  
Cool Season ◽  
Horticultural Crops ◽  
Field Crops ◽  
Hot Days ◽  
Before And After

In Ontario, Canada, marketable yields of certain annual horticultural crops increased steadily from 1940 to the mid-1980s, then dramatically decreased and became highly variable. This was not seen in field crops such as soybean and corn. Standard climatological variables showed little correlation with yields of vegetable crops such as tomatoes, cabbage, cauliflower, onions and rutabagas. The number of hot days (defined as days with maximum temperature greater than 30°C) and number of days with precipitation were better correlated with cool-season vegetable crop yield. With these climate measures we identified a period of milder growing season climate, from 1961 to 1986, and there was a greater frequency of hot days before and after this period. This analysis shows that horticultural crops are more sensitive to specific synoptic events, such as periods of hot days, than to overall growing season climate, and their yields may provide an indicator of a changing climate. Key words: Horticultural yields, historical climate, weather

Connecting Crop Nutrient Use Efficiency to Future Soil Productivity

2018 ◽  
Vol 102 (4) ◽  
pp. 8-10
Author(s):  
Fernando García ◽  
Andrés Grasso ◽  
María González Sanjuan ◽  
Adrián Correndo ◽  
Fernando Salvagiotti
Keyword(s):  
Nutrient Management ◽  
Nutrient Use Efficiency ◽  
Management Strategies ◽  
Crop Productivity ◽  
Soil Productivity ◽  
Nutrient Use ◽  
Grain Crop ◽  
Wide Scale ◽  
Use Efficiency

Trends over the past 25 years indicate that Argentina’s growth in its grain crop productivity has largely been supported by the depletion of the extensive fertility of its Pampean soils. Long-term research provides insight into sustainable nutrient management strategies ready for wide-scale adoption.

Influence of long-term fertilization on soil microbial biomass and dehydrogenase activity in relation to crop productivity in an acid Inceptisols

2019 ◽  
Vol 56 (3) ◽  
pp. 305-311
Author(s):  
Debasis Purohit ◽  
Mitali Mandal ◽  
Avisek Dash ◽  
Kumbha Karna Rout ◽  
Narayan Panda ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Dehydrogenase Activity ◽  
Nutrient Content ◽  
Crop Productivity ◽  
Maturity Stage ◽  
Microbial Biomass Nitrogen ◽  
Biological Potential ◽  
Initiation Stage ◽  
The Impact

An effective approach for improving nutrient use efficiency and crop productivity simultaneously through exploitation of biological potential for efficient acquisition and utilization of nutrients by crops is very much needed in this current era. Thus, an attempt is made here to investigate the impact of long term fertilization in the soil ecology in rice-rice cropping system in post kharif - 2015 in flooded tropical rice (Oryza sativa L.) in an acidic sandy soil. The experiment was laid out in a randomized block design with quadruplicated treatments. Soil samples at different growth stages of rice were collected from long term fertilizer experiment.The studied long-term manured treatments included 100 % N, 100% NP, 100 % NPK, 150 % NPK and 100 % NPK+FYM (5 t ha-1) and an unmanured control. Soil fertility status like SOC content and other available nutrient content has decreased continuously towards the crop growth period. Comparing the results of different treatments, it was found that the application of 100% NPK + FYM exhibited highest nutrient content in soils. With regards to microbial properties it was also observed that the amount of microbial biomass carbon (MBC) and microbial biomass nitrogen ( MBN) showed highest accumulation in 100 % NPK + FYM at maximum tillering stage of the rice. The results further reveal that dehydrogenase activity was maximum at panicle initiation stage and thereafter it decreases. Soil organic carbon content, MBC, MBN and dehydrogenase activity were significantly correlated with each other. Significant correlations were observed between rice yield and MBC at maturity stage( R2 = 0.94**) and panicle initiation stage( R2 = 0.92**) and available nitrogen content at maturity stage( R2 = 0.91**).

Soil and ecological division into districts of the Baikal region

2018 ◽  
Vol 940 (10) ◽  
pp. 54-64 ◽  
Author(s):  
I.A. Belozertseva ◽  
A.A. Sorokovoj
Keyword(s):  
Baikal Region ◽  
Soil Cover ◽  
Soil Formation ◽  
Forest Steppe ◽  
Leading Role ◽  
Soil Cover Structure ◽  
Reflecting Surface ◽  
Heat And Moisture ◽  
Made In

On the basis of long-term researches of soils in the territory of Russia and Mongolia soil and ecological division into districts of the Baikal region is carried out. At division into districts the whole set of an environment of soil formation was considered. On the map of soil and ecological division into districts 13 mountain, mid-mountain, low-mountain taiga, foothill, hollow-valley, forest-steppe and steppe provinces reflecting surface device originality as the ratio of balance of heat and moisture forming a basis to zoning is shown against the background of difficult orography are allocated. In total 42 districts on lithologic-geomorphological features are allocated. In formation of distinctions of a soil cover of these provinces the leading role is played by bioclimatic factors and inside them the lithologic-geomorphological ones. In the view of structural approach of the district they are considered as territories with a certain natural change of several types of the soil cover structure caused by features of a relief and the parent rock. The map is made in the MapInfo program. It is revealed that on ill-defined width zoning of soils the vertical one which has a greater influence on soils of this region is imposed. Soils of the Baikal region are not similar to the soils located at the same latitude of the flat European territory of Russia. Zone soils of this territory are specific and original.

scholarly journals Linking population size structure, heat stress and bleaching responses in a subtropical endemic coral

Coral Reefs ◽  
2021 ◽  
Author(s):  
Liam Lachs ◽  
Brigitte Sommer ◽  
James Cant ◽  
Jessica M. Hodge ◽  
Hamish A. Malcolm ◽  
...  
Keyword(s):  
Heat Stress ◽  
Size Structure ◽  
Temporal Trends ◽  
Early Recovery ◽  
Size Frequency Distribution ◽  
Frequency Distributions ◽  
Community Organisation ◽  
Size Frequency ◽  
Eastern Australia

AbstractAnthropocene coral reefs are faced with increasingly severe marine heatwaves and mass coral bleaching mortality events. The ensuing demographic changes to coral assemblages can have long-term impacts on reef community organisation. Thus, understanding the dynamics of subtropical scleractinian coral populations is essential to predict their recovery or extinction post-disturbance. Here we present a 10-yr demographic assessment of a subtropical endemic coral, Pocillopora aliciae (Schmidt-Roach et al. in Zootaxa 3626:576–582, 2013) from the Solitary Islands Marine Park, eastern Australia, paired with long-term temperature records. These coral populations are regularly affected by storms, undergo seasonal thermal variability, and are increasingly impacted by severe marine heatwaves. We examined the demographic processes governing the persistence of these populations using inference from size-frequency distributions based on log-transformed planar area measurements of 7196 coral colonies. Specifically, the size-frequency distribution mean, coefficient of variation, skewness, kurtosis, and coral density were applied to describe population dynamics. Generalised Linear Mixed Effects Models were used to determine temporal trends and test demographic responses to heat stress. Temporal variation in size-frequency distributions revealed various population processes, from recruitment pulses and cohort growth, to bleaching impacts and temperature dependencies. Sporadic recruitment pulses likely support population persistence, illustrated in 2010 by strong positively skewed size-frequency distributions and the highest density of juvenile corals measured during the study. Increasing mean colony size over the following 6 yr indicates further cohort growth of these recruits. Severe heat stress in 2016 resulted in mass bleaching mortality and a 51% decline in coral density. Moderate heat stress in the following years was associated with suppressed P. aliciae recruitment and a lack of early recovery, marked by an exponential decrease of juvenile density (i.e. recruitment) with increasing heat stress. Here, population reliance on sporadic recruitment and susceptibility to heat stress underpin the vulnerability of subtropical coral assemblages to climate change.

Short- and long-term dynamics of the physiological and behavioral response to heat stress and thymol supplementation in Japanese quail

2021 ◽  
pp. 102876
Author(s):  
Maria Emilia Fernandez ◽  
Maria Carla Labaque ◽  
Gabriel Orso ◽  
Raúl Hector Marin ◽  
Jackelyn Melissa Kembro
Keyword(s):  
Heat Stress ◽  
Japanese Quail ◽  
Behavioral Response ◽  
Short And Long Term
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