Atmospheric moisture contribution to the growing season in the Amazon arc of deforestation

The daily, in situ gross photosynthetic patterns of Cladonia stellaris (Opiz.) Pouz. & Vězda. and Cladonia rangiferina (L.) Wigg. were monitored during portions of the 1977, 1978, and 1979 growing seasons at Anaktuvuk Pass, Alaska. Photosynthetic activity in both species closely paralleled atmospheric moisture status, where peak photosynthetic rates were attained during or following sporadic summer rain. In addition, thallus absorption of moisture during extended periods of high atmospheric water vapor content gave rise to short periods of minimal photosynthetic activity. During late evening and early morning hours moistened thalli exhibited minimal or no photosynthetic activity, coinciding with consistent attenuation in solar radiation during these periods. Photosynthetic activity was not homogeneous throughout the thallus. The greatest activity occurred in the apical regions and decreased progressively into the basal regions. The apical 10-mm regions of C. stellaris and C. rangiferina thalli accounted for approximately 50% of their photosynthetic capabilities. The potential gross CO2 assimilation of the apical 10-mm regions over 72 days of the 1978 growing season was estimated at approximately 35 g CO2∙m−2 and 16 g CO2∙m−2 for C. stellaris and C. rangiferina, respectively.

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Increase in Near-Surface Atmospheric Moisture Content due to Land Use Changes: Evidence from the Observed Dewpoint Temperature Data

Monthly Weather Review ◽

10.1175/2007mwr2040.1 ◽

2008 ◽

Vol 136 (4) ◽

pp. 1554-1561 ◽

Cited By ~ 32

Author(s):

Rezaul Mahmood ◽

Kenneth G. Hubbard ◽

Ronnie D. Leeper ◽

Stuart A. Foster

Keyword(s):

Land Use ◽

Land Use Change ◽

Moisture Content ◽

Great Plains ◽

Growing Season ◽

Atmospheric Moisture ◽

Near Surface ◽

Dewpoint Temperature ◽

Atmospheric Moisture Content

Abstract Land use change can significantly affect root zone soil moisture, surface energy balance, and near-surface atmospheric temperature and moisture content. During the second half of the twentieth century, portions of the North American Great Plains have experienced extensive introduction of irrigated agriculture. It is expected that land use change from natural grass to irrigated land use would significantly increase near-surface atmospheric moisture content. Modeling studies have already shown an enhanced rate of evapotranspiration from the irrigated areas. The present study analyzes observed dewpoint temperature (Td) to assess the affect of irrigated land use on near-surface atmospheric moisture content. This investigation provides a unique opportunity to use long-term (1982–2003) mesoscale Td data from the Automated Weather Data Network of the high plains. Long-term daily Td data from 6 nonirrigated and 11 irrigated locations have been analyzed. Daily time series were developed from the hourly data. The length of time series was the primary factor in selection of these stations. Results suggest increase in growing-season Td over irrigated areas. For example, average growing-season Td due to irrigation can be up to 1.56°C higher relative to nonirrigated land uses. It is also found that Td for individual growing-season month at irrigated locations can be increased up to 2.17°C by irrigation. Based on the results, it is concluded that the land use change in the Great Plains has modified near-surface moistness.

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Methods of tilling under conditions of insufficient and unstable moistening during winter wheat cultivation

E3S Web of Conferences ◽

10.1051/e3sconf/202017509008 ◽

2020 ◽

Vol 175 ◽

pp. 09008

Author(s):

Julia Semenikhina ◽

Sergey Kambulov ◽

Galina Parkhomenko ◽

Andrey Boyko ◽

Svetlana Ponomareva ◽

...

Keyword(s):

Winter Wheat ◽

Soil Structure ◽

Growing Season ◽

Climatic Conditions ◽

Atmospheric Moisture ◽

Wheat Cultivation ◽

Leguminous Crop ◽

Cultivation Technology ◽

Direct Sowing ◽

Tillage Methods

Acute deficit of soil moisture during the growing season of crops negatively affects the yield. Various tillage methods that are part of the technology (traditional and zero) of winter wheat cultivation affect the soil structure in the topsoil, forming the soil structure in such a way that it acquires the properties of accumulation and preservation of atmospheric moisture. Purpose of the study is to determine the method of soil cultivation that contributes into increase in winter wheat productivity and moisture preservation in the soil. The study of various tillage methods was carried out under the conditions of many years of stationary experience in leguminous crop rotation. Soil and climatic conditions over the years of research were taken into account. The researched processing methods that form the basis of the traditional cultivation technology and implement their tillage tools are: surface - disc harrow B7T; small combined unit KUM 4; dump plow PN5-35. And cultivation of winter wheat by seeder of direct sowing WINTERSTEIGER Plotseed according to zero technology was studied, i.e. the main tillage was absent.

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Variability of moisture recycling using a precipitationshed framework

Hydrology and Earth System Sciences Discussions ◽

10.5194/hessd-11-5143-2014 ◽

2014 ◽

Vol 11 (5) ◽

pp. 5143-5178 ◽

Cited By ~ 1

Author(s):

P. W. Keys ◽

E. A. Barnes ◽

R. J. van der Ent ◽

L. J. Gordon

Keyword(s):

Land Use ◽

Land Surface ◽

Transport Model ◽

Land Use Changes ◽

Growing Season ◽

Northern China ◽

Atmospheric Moisture ◽

Moisture Recycling ◽

The Core ◽

Western Sahel

Abstract. Recent research has revealed that upwind land-use changes can significantly influence downwind precipitation. The precipitationshed (the upwind ocean and land surface that contributes evaporation to a specific location's precipitation) may provide a boundary for coordination and governance of these upwind-downwind water linkages. We aim to quantify the variability of the precipitationshed boundary to determine whether there are persistent and significant sources of evaporation for a given region's precipitation. We identify the precipitationsheds for three regions (i.e. Western Sahel, Northern China, and La Plata) by tracking atmospheric moisture with a numerical water transport model (WAM-2layers) using gridded fields from both the ERA-Interim and MERRA reanalyses. Precipitationshed variability is examined first by diagnosing the persistence of the evaporation contribution and second with an analysis of the spatial variability of the evaporation contribution. The analysis leads to three key conclusions: (1) a core precipitationshed exists; (2) most of the variance in the precipitationshed is explained by a pulsing of more or less evaporation from the core precipitationshed; and, (3) the reanalysis datasets agree reasonably well, although the degree of agreement is regionally dependent. Given that much of the growing season evaporation arises from within a core precipitationshed that is largely persistent in time, we conclude that the precipitationshed can potentially provide a useful boundary for governing land-use change on downwind precipitation.

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The influence of water table depth on evapotranspiration in the Amazon arc of deforestation

Hydrology and Earth System Sciences ◽

10.5194/hess-23-3917-2019 ◽

2019 ◽

Vol 23 (9) ◽

pp. 3917-3931 ◽

Cited By ~ 1

Author(s):

John O'Connor ◽

Maria J. Santos ◽

Karin T. Rebel ◽

Stefan C. Dekker

Keyword(s):

Soil Moisture ◽

Water Stress ◽

Growing Season ◽

Dry Season ◽

Rooting Depth ◽

Recycling System ◽

Moisture Recycling ◽

Arc Of Deforestation ◽

Dry Seasons ◽

Wet And Dry Seasons

Abstract. The Amazon rainforest evapotranspiration (ET) flux provides climate-regulating and moisture-provisioning ecosystem services through a moisture recycling system. The dense complex canopy and deep root system creates an optimum structure to provide large ET fluxes to the atmosphere, forming the source of precipitation. Extensive land use and land cover change (LULCC) from forest to agriculture in the arc of deforestation breaks this moisture recycling system. Crops such as soybean are planted in large homogeneous monocultures and the maximum rooting depth of these crops is far shallower than forest. This difference in rooting depth is key as forests can access deep soil moisture and show no signs of water stress during the dry season, while in contrast crops are highly seasonal with a growing season dependent on rainfall. As access to soil moisture is a limiting factor in vegetation growth, we hypothesised that if crops could access soil moisture, they would undergo less water stress and therefore would have higher evapotranspiration rates than crops which could not access soil moisture. We combined remote-sensing data with modelled groundwater table depth (WTD) to assess whether vegetation in areas with a shallow WTD had higher ET than vegetation in deep WTD areas. We randomly selected areas of forest, savanna, and crop with deep and shallow WTD and examined whether they differ on MODIS Evapotranspiration (ET), Land Surface Temperature (LST), and Enhanced Vegetation Index (EVI), from 2001 to 2012, annually and during transition periods between the wet and dry seasons. As expected, we found no differences in ET, LST, and EVI for forest vegetation between deep and shallow WTD, which because of their deep roots could access water and maintain evapotranspiration for moisture recycling during the entire year. We found significantly higher ET and lower LST in shallow WTD crop areas than in deep WTD during the dry season transition, suggesting that crops in deep WTD undergo higher water stress than crops in shallow WTD areas. The differences found between crop in deep and shallow WTD, however, are of low significance with regards to the moisture recycling system, as the difference resulting from conversion of forest to crop has an overwhelming influence (ET in forest is ≈2 mm d−1 higher than that in crops) and has the strongest impact on energy balance and ET. However, access to water during the transition between wet and dry seasons may positively influence growing season length in crop areas.

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The influence of water table depth on evapotranspiration in the Amazon arc of deforestation

10.5194/hess-2019-47 ◽

2019 ◽

Author(s):

John O'Connor ◽

Maria J. Santos ◽

Karin T. Rebel ◽

Stefan C. Dekker

Keyword(s):

Soil Moisture ◽

Water Stress ◽

Growing Season ◽

Dry Season ◽

Rooting Depth ◽

Limiting Factor ◽

Recycling System ◽

Moisture Recycling ◽

Growing Season Length ◽

Arc Of Deforestation

Abstract. The Amazon rainforest evapotranspiration (ET) flux provides climate regulating and moisture provisioning ecosystem services through a moisture recycling system. The dense complex canopy and deep root system creates an optimum structure to provide large ET fluxes to the atmosphere forming the source for precipitation. Extensive land use and land cover change (LULCC) from forest to agriculture in the arc of deforestation breaks this moisture recycling system. Crops such as soybean are planted in large homogeneous monocultures and the maximum rooting depth of these crops is far shallower than forest. This difference in rooting depth is key as forests can access deep soil moisture and show no signs of water stress during the dry season while in contrast crops are highly seasonal with a growing season dependant on rainfall. As access to soil moisture is a limiting factor in vegetation growth, we hypothesised that if crops could access soil moisture they would undergo less water stress and therefore would have higher evapotranspiration rates than crops which could not access soil moisture. We combined remote sensing data with modelled groundwater table depth (WTD) to assess whether vegetation in areas with a shallow WTD had higher ET than vegetation in deep WTD areas. We randomly selected areas of forest, savanna and crop with deep and shallow WTD and examined whether they differ on MODIS Evapotranspiration (ET), Land Surface Temperature (LST) and Enhanced Vegetation Index (EVI), from 2001 to 2012, annually and during transition periods between the wet and dry season. As expected, we found no differences in ET, LST, and EVI for forest vegetation between deep and shallow WTD, which because of their deep roots could access water and maintain evapotranspiration for moisture recycling during the entire year. We found significantly higher ET and lower LST in shallow WTD crop areas than in deep WTD during the dry season transition, suggesting that crops in deep WTD undergo higher water stress than crops in shallow WTD areas. The differences found between crop in deep and shallow WTD, however, are of low significance with regards the moisture recycling system as the difference resulting from conversion of forest to crop has an overwhelming influence (ET in forest is ≈ 2 mm day−1 higher than that in crops) and has the strongest impact on energy balance and ET. However, access to water during the transition between wet and dry seasons may positively influence growing season length in crop areas.

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Growing season

PsycEXTRA Dataset ◽

10.1037/e541672004-001 ◽

1992 ◽

Author(s):

Nicholas Wellington

Keyword(s):

Growing Season

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Irrigation regime and water consumption of potatoes in the Republic of Bashkortostan, depending on the reclamation condition of lands

Melioration and Water Management ◽

10.32962/0235-2524-2019-6-13-19 ◽

2020 ◽

Vol 0 (6) ◽

pp. 13-19

Author(s):

Guzel Gumerova ◽

Georgiy Gulyuk ◽

Dmitry Kucher ◽

Anatoly Shuravilin ◽

Elena Piven

Keyword(s):

Water Consumption ◽

Weather Conditions ◽

Growing Season ◽

Vegetation Period ◽

Forest Steppe ◽

Total Water ◽

Total Water Consumption ◽

Republic Of Bashkortostan ◽

Irrigated Lands ◽

The Republic

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 %.

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Dynamics of CO2 emission from chernozems under agricultural use

Agricultural science and practice ◽

10.15407/agrisp4.03.043 ◽

2017 ◽

Vol 4 (3) ◽

pp. 43-49

Author(s):

M. Miroshnychenko ◽

O. Siabruk

Keyword(s):

Carbon Dioxide ◽

Agricultural Practices ◽

Growing Season ◽

Warm Period ◽

Direct Seeding ◽

Soil Tillage ◽

Plant Residues ◽

Hydrothermal Conditions ◽

Organic Mineral ◽

Mineral System

Aim. The comparison of the effect of hydrothermal conditions and various agricultural practices on the emission of CO 2 from chernozems in the Left-Bank Forest-Steppe of Ukraine. Methods. The dynamics of the intensity of carbon dioxide emissions from chernozem calcic (typical chernozem – in Ukrainian classifi cation) was studied during the growing season of 2011–2012. The observations were based on two fi eld experiments with various methods of soil till- age (6–7 years from the beginning of the experiment) and fertilization systems (21–22 years from the beginning of the experiment). Particularly, plowing at 20–22 cm, disking at 10–12 cm, cultivation at 6–8 cm and direct seeding using Great Plains drill were studied among the soil tillage methods. Mineral system (N 45 P 50 K 45 ), organic system (manure 8 t/ha) and combined organic-mineral system (manure 8 t/ha + N 45 P 50 K 45 ) were studied among fertilization systems. The intensity of CO 2 fl ux was determined using the non-stationary respiratory chambers by the alkaline absorption method, with averaging of the results during the day and the frequency of once a month. Results. During the warm period, the emission of carbon dioxide from the soil changes dynamically depending on temperature and humidity. The maximum of emission coincides with the periods of warm summer showers in June-July, the minimum values are characteristic for the late autumn period. The total emission losses of carbon in chernozems over the vegetation period ranged from 480 to 910 kg/ha and varied depending on the methods of tillage ± (4.0–6.0) % and fertilization systems ± (3.8–7.1) %. The changes in the intensity of CO 2 emission from the soil under different methods of soil tillage are associated with hydrothermal regime and the depth of crop residues location. The biggest difference is observed im- mediately after tillage, but in the spring period the differences are only 12–25 %, and after drying of the top layer of soil become even less. Direct seeding technology provides the greatest emission of CO 2 from chernozem, which is fa- cilitated by better water regime and more complete mineralization of plant residues on the soil surface. Annual losses of carbon are the least under disking of soil at 10–12 cm. The changes in the intensity of CO 2 emission from the soil under different fertilization systems are associated with the involvement of the additional organic matter from plant residues and manure to the microbiological decomposition. The greatest emission was observed under the organic- mineral fertilization system, which increased the loss of carbon by 7–8 % in comparison with the mineral system in the unfavorable hydrothermal year and by 11–15 % in the more favorable year. These differences are observed mainly during the fi rst half of the growing season when there is a clear tendency to increase the intensity of soil respiration. Conclusions. The hydrothermal conditions of the warm period of the year are decisive in the formation of the CO 2 emission fl ow from chernozems. Due to the improvement of agricultural practices, emissions might be reduced but not more that by 15 % of natural factor contribution.

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Irrigation scheduling and water requirements for cowpea using evaporation pan at middle of Iraq

Journal of Aridland Agriculture ◽

10.25081/jaa.2018.v4.3445 ◽

1970 ◽

pp. 13-17

Author(s):

Saifuldeen A. Salim ◽

Isam Kudhier Hamza ◽

Laith Farhan Jar

Keyword(s):

Water Productivity ◽

Irrigation Treatment ◽

Growing Season ◽

Irrigation Scheduling ◽

Water Requirements ◽

Applied Water ◽

Fresh Seed ◽

Irrigation Interval ◽

Biological Yield ◽

Evaporation Pan

The present study was conducted to find out the water requirements and most suitable irrigation frequencies for cowpea (Vigna unguiculata L.) var grown under drip irrigation. The treatments were based on the IW:CPE ratio at different empirical pan factors 0.6 , 0.8, 1.0, 1.,1.4 , and 1.6 Ef (where Ef = IW/CPE). It was observed that the irrigation interval was variable values decreased by increasing Ef value and with the progress of the growing season. The 1.2 and 1.0 IW: CPE treatments with approximately 4 days irrigation interval were achieved the best results. The total amount of applied water during Cowpea growing season was varied between 247.7 and 266.5mm with 254.8mm as a mean. Irrigation treatment with Ef1.2 was superior over the rest of other treatments in fresh seed yield (5.13 ton.hec.-1), crop water productivity (2.14 kg.m-3), biological yield (6.88 ton.hec.-1) , fresh pod yield (7.33 ton.hec.-1), weight of 100 seed (31.28gm), number of seed/pod (9.34) and netting percentage (37.1). The lowest values of the most parameters used in this study were obtained by Ef 0.6 irrigation treatment.

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