Water relations of Pinus radiata under plantation conditions

1964 ◽  
Vol 12 (2) ◽  
pp. 111 ◽  
Author(s):  
RD Johnston
Keyword(s):  
Soil Moisture ◽  
Late Summer ◽  
Soil Surface ◽  
Experimental Period ◽  
Mean Value ◽  
Soil Conditions ◽  
Dry Period ◽  
Autumn Leaf ◽  
Leaf Water Deficit ◽  
Old Trees

Two groups of four 9-year-old trees of P. radiata were isolated "droughted" by lining trenches, and covering the soil surface, with plastic film. Two similar groups served as controls. Soils in the control plots dried out to above pF 4.2 during a 6 weeks' drought in late summer, and again in a shorter dry period in autumn. Leaf water deficit (L.W.D.) was correlated with soil moisture tension (S.M.T.) while there was available soil moisture, and rose during the drought to a maximum of 22.8. Autumn rain which wet the upper part of the soil profile reduced the L.W.D. to a mean value of 12. In the droughted plots, S.M.T. rose to above pF 4.2 in the first six weeks and remained high for the rest of the experimental period. During normal weather with occasional light falls of rain, L.W.D. was maintained at about 17-significantly higher than the corresponding values for the control plots. With the onset of dry weather, L.W.D. in the droughted plots rose further, but not significantly higher than in the controls. L.W.D. decreased when rain occurred, although less than in the control plots. P. radiata is able to maintain moderate turgidity in its needles, even under very dry soil conditions, as long as there is frequent precipitation sufficient to wet the foliage.

scholarly journals Detection of Changes in Arable Chernozemic Soil Health Based on Landsat TM Archive Data

2021 ◽  
Vol 13 (12) ◽  
pp. 2411
Author(s):  
Igor Savin ◽  
Elena Prudnikova ◽  
Yury Chendev ◽  
Anastasia Bek ◽  
Dmitry Kucher ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Satellite Data ◽  
Survey Methods ◽  
Humus Content ◽  
Arable Land ◽  
Soil Health ◽  
Soil Surface ◽  
Soil Conditions ◽  
Moisture Regime ◽  
Arable Soils

When soils are used for a long period of time as arable land, their properties change. This can lead to soil degradation and loss of fertility, as well as other important soil biosphere functions. Obtaining data on the trends in arable soil conditions over large areas using traditional field survey methods is expensive and time-consuming. Currently, there are large archives of satellite data that can be used to monitor the status of arable soils. The analysis of changes in the color of the surface of arable chernozem soils of the Belgorod region, for the period from 1985 to the present, has been carried out based on the analysis of Landsat TM5 satellite data and information about the spectral reflectance of the soils of the region. It is found that, on most parts of arable lands of the region, the color of the soil surface has not changed significantly since 1985. Color changes were revealed on 11% of the analyzed area. The greatest changes are connected with the humus content and moisture content of soils. The three most probable reasons for the change of humus content in an arable horizon of soils are as follows: the dehumidification of soils during plowing; the reduction of the humus content due to water erosion; and the increase in humus content due to changes in the land-use system of the region in recent years. The change in soil moisture regime has mainly been found in arable lands in river valleys, most likely conditioned by the natural evolution of soils. Trends of increasing soil moisture are prevalent. The revealed regularities testify to the high stability of arable soils in the region during the last few decades.

Rainfall Conservation and The Yields Of Sorghum and Groundnuts in Northern Nigeria

1966 ◽  
Vol 2 (2) ◽  
pp. 139-146 ◽  
Author(s):  
D. A. Lawes
Keyword(s):  
Soil Moisture ◽  
Field Experiments ◽  
Soil Surface ◽  
Infiltration Rate ◽  
Soil Conditions ◽  
Northern Nigeria ◽  
Seed Cotton ◽  
High Yields ◽  
Cultivation Techniques ◽  
Poor Soil

SummaryThe use of cultivation techniques to conserve rainfall, by preventing runoff, and to improve the soil surface infiltration rate, has produced spectacular increases in the yield of cotton on the Loess Plain soils of Northern Nigeria, where yields of the order of 2000 lb seed cotton per acre can now be produced regularly irrespective of the rainfall pattern. As yields of this level had not been obtained previously, it has been concluded that lack of soil moisture and poor soil aeration have in the past set a ceiling to seed cotton yields. The effects of these cultivation treatments on the two other major crops of the area, sorghum and groundnuts, have now been examined, and results from a series of field experiments over six seasons indicate that adequate soil moisture is essential to the production of high yields, but that the other soil conditions which are alleviated by these cultivations are not so critical for these two crops as they are for cotton. Reasons are suggested why spectacular increases in yield in response to the treatments are not generally to be expected with sorghum and groundnuts.

Stemflow infiltration areas into forest soils around American beech trees

2020 ◽  
Author(s):  
Pilar Llorens ◽  
Jérôme Latron ◽  
Darryl E. Carlyle-Moses ◽  
Kerstin Näthe ◽  
Jeff L. Chang ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Preferential Flow ◽  
Mean Value ◽  
Fagus Grandifolia ◽  
Soil Conditions ◽  
Nutrient Inputs ◽  
American Beech ◽  
Management Area ◽  
Loam Soil ◽  
Moisture Conditions

<p>Despite the fact that stemflow is often a small percentage of precipitation, it is a concentrated flux of water, solutes, and particulates to near-trunk soils. As a consequence, per unit area, near-trunk soils receive water and nutrient inputs that largely exceed those received by soils in the distal zone via throughfall. This funnelling effect of trees can contribute to preferential flow and groundwater recharge and can have important biogeochemical implications. However, to evaluate the importance of this flux for near-trunk soils is necessary to quantify the magnitude of the stemflow infiltration area.</p><p>This study presents a stemflow simulation experiment with the objective of determining the stemflow infiltration area in near-trunk soils.  The experiment was conducted at the Fair Hill Natural Resources Management area in northeastern Maryland (USA). We selected four American beech (Fagus grandifolia Ehrh.) trees with a DBH of ~29 cm, growing in a loam soil. Each tree was equipped with a collar, built with a tube with small holes, and installed around the tree. This tube was connected with a hose to a 36.5 L container positioned ~ 1 m above the collar. The hose had two stopcocks to regulate the water rate. Before starting the simulations, litterfall was removed.</p><p>A total of thirteen simulations were run with differing simulated stemflow rates (from 30 to 290 L/h) and differing initial soil moisture conditions (mean soil moisture from 25 to 43 m<sup>3</sup>m<sup>-3</sup>). Soil moisture was measured around the trees before each simulation with a TDR device. To further increase soil moisture between simulations, 40 L of water were carefully applied circumferentially around the trunk, at a maximum distance of 35 cm. Each simulation was performed with different colour dye tracer to enable accurate measurements of the stemflow infiltration area. After each simulation, the infiltration area was measured using a mesh grid of known area. At the end of the last simulations soil samples were taken around each tree.</p><p>The results show that in all cases the infiltration area is < 0.1 m<sup>2</sup>, with a mean value of about 0.03 m<sup>2</sup>. Likewise, there is a tendency to decrease the area of infiltration by increasing soil moisture. This trend seems to be modified for saturated conditions or when the stemflow rate is extreme. These small stemflow infiltration areas are explained by both the high infiltration rates of near-trunk soils in forests and the macroporosity produced by living or decaying roots. Moreover, these trees have slight buttressing that increase the perimeter of contact between the stem and the soil (with respect to the basal perimeter (calculated at breast height)), thus further promoting infiltration. Results suggest the importance of measuring the infiltration areas for different species and soil conditions to better evaluate the relevance of stemflow.</p>

scholarly journals Testing the Effects of Experimental Snow Removal on Soil Moisture and Plant Responses in Montane Meadows

2008 ◽  
Vol 31 ◽  
pp. 81-87
Author(s):  
Diane Debinski ◽  
Matthew Germino ◽  
Dennis Demshar
Keyword(s):  
Soil Moisture ◽  
Water Potential ◽  
Soil Water ◽  
Global Climate ◽  
Late Summer ◽  
Soil Conditions ◽  
Plant Responses ◽  
Snow Removal ◽  
Northern Rocky Mountains ◽  
Set Up

Regional models of global climate change for the northern Rocky Mountains predict warmer temperatures and western states have shown a recent trend towards increases in the fraction of precipitation falling as rain rather than snow. Thus, the amount of soil moisture available to plants during the growing season may already be varying significantly from historical conditions. In order to simulate drier summer soil conditions and test soil moisture and plant responses, we set up a pilot snow removal experiment in Grand Teton National Park, WY in 2008. Because most of the precipitation comes in the form of snow, and spring snowpack is about 50% water by volume, removing all snow present in early May can reduce the annual precipitation by approximately half. Snow was removed from three ~9x15 m experimental plots using a Thiokol in early May. These experimental sites were paired with adjacent control sites and the pairs were established along a hydrological gradient of meadow types representing hydric, mesic, and xeric sites. Dataloggers were installed in June and soil moisture was monitored at 5, 20, and 50 cm depths through August. Water potential was measured in Bromus and Carex during mid-July. Over the summer season, there were differences in soil water between the snow removal and control plots, as well as across the hydrological gradient. Decreases in soil water content and water potential of Carex showed strongest responses in the mesic site, whereas Bromus showed the strongest response in the hydric site. This is the first study to reveal that variability in spring snowpack can lead to measurable impacts on the vegetation community, even into mid-late summer when soil water is fairly scarce throughout the landscape. Furthermore, changes in snow depth are not likely to have equivalent impacts on the different community types within a region; the effects will vary predictably as a function of soil and plant community characteristics.

THE METHODOLOGY OF MONITORING THE TWO-WAY REGULATION OF SOIL MOISTURE DURING THE OPERATION OF ENGINEERING RECLAMATION SYSTEMS

2021 ◽  
pp. 23-30
Author(s):  
K. S. SEMENOVA ◽  
◽  
O. V. KABLUKOV
Keyword(s):  
Soil Moisture ◽  
Fire Safety ◽  
Meteorological Data ◽  
Field Studies ◽  
Soil Conditions ◽  
Representative Point ◽  
Peat Bogs ◽  
Sampling Point ◽  
Soil Morphology ◽  
Dry Period

The purpose of the performed research is, based on the analysis of field studies, to select a well (point) for the selection of averaged moisture in the inter-drainage space for monitoring reclamation systems, to justify the construction of drainage-humidification systems to regulate moisture in a fire-hazardous peat bog. To solve the problem, a scheme has been developed for organizing monitoring on engineering reclamation systems that provide a two-way regulation of the water regime in the root layer of the soil in the zone of unstable moisture, as well as for monitoring and ensuring fire safety of the entire peat profile. The article discusses measuring equipment for determining the dynamics of soil moisture which must be used to monitor reclamation systems. There are given the results of field studies on peat bogs of the floodplain of the Dubna River, Moscow region, namely: meteorological data and data on soil moisture. On the basis of the research carried out, a representative point of moisture sampling for monitoring of reclamation systems has been substantiated. The sampling point should be located on a typical plot with the same relief, the soil profile should be uniform with the properties and soil morphology characteristic of the entire field. Wells for sampling checks the value of the distance in ¼E (E is the distance between drains), in this case the measured value is close to the average value in relation to the entire section of the drainage-humidified system. For the soil conditions of the experimental site, the humidity in the selected well during the locking of the canal in the dry period of summer increased by 1.5 times reaching the fireproof one. It is noted that when supplying and maintaining a propped water level in a channel up to 85 cm deep for 5 or more hours, the humidity in the interdrains space rises to the value of the fire safety norm in the dry period.

scholarly journals Root Response to Soil Water Status via Interaction of Crop Genotype and Environment

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 708
Author(s):  
Phanthasin Khanthavong ◽  
Shin Yabuta ◽  
Hidetoshi Asai ◽  
Md. Amzad Hossain ◽  
Isao Akagi ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Soil Water ◽  
Root Distribution ◽  
Water Status ◽  
Soil Layer ◽  
Shoot Biomass ◽  
Soil Conditions ◽  
Crop Adaptation ◽  
Soil Moisture Status ◽  
Root Distributions

Flooding and drought are major causes of reductions in crop productivity. Root distribution indicates crop adaptation to water stress. Therefore, we aimed to identify crop roots response based on root distribution under various soil conditions. The root distribution of four crops—maize, millet, sorghum, and rice—was evaluated under continuous soil waterlogging (CSW), moderate soil moisture (MSM), and gradual soil drying (GSD) conditions. Roots extended largely to the shallow soil layer in CSW and grew longer to the deeper soil layer in GSD in maize and sorghum. GSD tended to promote the root and shoot biomass across soil moisture status regardless of the crop species. The change of specific root density in rice and millet was small compared with maize and sorghum between different soil moisture statuses. Crop response in shoot and root biomass to various soil moisture status was highest in maize and lowest in rice among the tested crops as per the regression coefficient. Thus, we describe different root distributions associated with crop plasticity, which signify root spread changes, depending on soil water conditions in different crop genotypes as well as root distributions that vary depending on crop adaptation from anaerobic to aerobic conditions.

scholarly journals Impacts of soil moisture level and organic matter content on growth of two Juncus species and Poa pratensis grown under acid soil conditions

Weed Research ◽  
2019 ◽  
Vol 59 (6) ◽  
pp. 490-500
Author(s):  
W Kaczmarek‐Derda ◽  
M Helgheim ◽  
J Netland ◽  
H Riley ◽  
K Wærnhus ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Moisture ◽  
Poa Pratensis ◽  
Acid Soil ◽  
Organic Matter Content ◽  
Matter Content ◽  
Moisture Level ◽  
Soil Conditions ◽  
Soil Moisture Level

Seasonal activity and estivation of lumbricid earthworms in the midlands of Tasmania

Soil Research ◽  
1994 ◽  
Vol 32 (6) ◽  
pp. 1355 ◽  
Author(s):  
RB Garnsey
Keyword(s):  
Soil Moisture ◽  
Adult Development ◽  
Survival Rates ◽  
Soil Surface ◽  
Early Spring ◽  
Lumbricus Rubellus ◽  
Late Winter ◽  
Cocoon Production ◽  
Density And Biomass ◽  
Earthworm Activity

Earthworms have the ability to alleviate many soil degradational problems in Australia. An attempt to optimize this resource requires fundamental understanding of earthworm ecology. This study reports the seasonal changes in earthworm populations in the Midlands of Tasmania (<600 mm rainfall p.a.), and examines, for the first time in Australia, the behaviour and survival rates of aestivating earthworms. Earthworms were sampled from 14 permanent pastures in the Midlands from May 1992 to February 1994. Earthworm activity was significantly correlated with soil moisture; maximum earthworm activity in the surface soil was evident during the wetter months of winter and early spring, followed by aestivation in the surface and subsoils during the drier summer months. The two most abundant earthworm species found in the Midlands were Aporrectodea caliginosa (maximum of 174.8 m-2 or 55.06 g m-2) and A. trapezoides (86 m-2 or 52.03 g m-2), with low numbers of Octolasion cyaneum, Lumbricus rubellus and A. rosea. The phenology of A. caliginosa relating to rainfall contrasted with that of A. trapezoides in this study. A caliginosa was particularly dependent upon rainfall in the Midlands: population density, cocoon production and adult development of A. caliginosa were reduced as rainfall reduced from 600 to 425 mm p.a. In contrast, the density and biomass of A. trapezoides were unaffected by rainfall over the same range: cocoon production and adult development continued regardless of rainfall. The depth of earthworm aestivation during the summers of 1992-94 was similar in each year. Most individuals were in aestivation at a depth of 150-200 mm, regardless of species, soil moisture or texture. Smaller aestivating individuals were located nearer the soil surface, as was shown by an increase in mean mass of aestivating individuals with depth. There was a high mortality associated with summer aestivation of up to 60% for juvenile, and 63% for adult earthworms in 1993 in the Midlands. Cocoons did not survive during the summers of 1992 or 1994, but were recovered in 1993, possibly due to the influence of rainfall during late winter and early spring.

Seasonal Photosynthesis and Partitioning of Nonstructural Carbohydrates in Leafy Spurge (Euphorbia esula)

Weed Science ◽  
2007 ◽  
Vol 55 (4) ◽  
pp. 346-351 ◽  
Author(s):  
Russ W. Gesch ◽  
Debra Palmquist ◽  
James V. Anderson
Keyword(s):  
Late Summer ◽  
Leafy Spurge ◽  
Adventitious Bud ◽  
Adventitious Buds ◽  
Continuous Increase ◽  
Carbohydrate Partitioning ◽  
Growing Seasons ◽  
Autumn Leaf ◽  
Carbohydrate Status ◽  
New Strategies

Previous evidence indicates that changes in well-defined phases of dormancy in underground adventitious buds of leafy spurge in late summer and autumn are regulated by complex sensing and signaling pathways involving aboveground sugar signals. However, little information exists concerning seasonal photosynthesis and carbohydrate partitioning of leafy spurge, although such information would help to elucidate the involvement of sugar in controlling bud dormancy. An outdoor study was conducted over two growing seasons to determine and model seasonal patterns of photosynthesis and aboveground carbohydrate partitioning and their relationship to underground adventitious bud carbohydrate status. Photosynthesis and total nonstructural carbohydrate (TNC) content of aboveground tissues was greatest during vegetative growth. Photosynthesis gradually declined over the growing season, whereas TNC decreased sharply during flowering, followed by a gradual decline between midsummer and autumn. Leaf starch increased dramatically to midsummer before declining sharply throughout late summer and early autumn, whereas sucrose content responded inversely, indicating a mobilization of starch reserves and export of sugars to overwintering belowground sink tissues. Because newly formed underground adventitious buds showed a continuous increase in TNC from midsummer through autumn, export of sugars from aboveground tissues likely contributed to the increase in TNC. These results may facilitate new strategies for biological control of leafy spurge.

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