scholarly journals The effect of rainfall and extensive use of grasslands on water regime

2011 ◽  
Vol 48 (No. 3) ◽  
pp. 89-95
Author(s):  
R. Duffková
Keyword(s):  
Land Use ◽  
Soil Moisture ◽  
Moisture Content ◽  
Water Regime ◽  
Soil Moisture Content ◽  
Growing Season ◽  
Water Runoff ◽  
Botanical Composition ◽  
Significant Difference ◽  
Determinant Factor

 Water regimes of extensively used grasslands (one cut per year, two cuts per year, no cut, mulching) were determined and compared by drainage lysimeters in 1998–2000. Although the botanical composition and yields of experimental swards were different, there was no statistically significant difference in their water regime (only the soil moisture content of no-cut variant was significantly higher than in other variants). A determinant factor for the water regime of grasslands (GR) is the sum of rainfall over the growing season while the GR water regime is influenced by land use immediately after the cut. Water runoff from the soil profile 0.0–0.60 m (water supply to the groundwater level) was found to be negligible in the growing season, a substantial groundwater recharge occurs in an off-season period and/or at the beginning of growing season. Mulching was not proved to reduce evaporation. The best type of management providing for the economical water regime appears to be a one-cut variant. Relationships between botanical composition and GR water regime are also described.

scholarly journals Difference in Canopy and Air Temperature as an Indicator of Grassland Water Stress

2013 ◽  
Vol 1 (No. 4) ◽  
pp. 127-138 ◽  
Author(s):  
Duffková Renata
Keyword(s):  
Soil Moisture ◽  
Water Stress ◽  
Moisture Content ◽  
Air Temperature ◽  
Temperature Difference ◽  
Soil Moisture Content ◽  
Growing Season ◽  
Plant Residues ◽  
Dead Plant ◽  
Linear Correlations

In 2003–2005 in conditions of the moderately warm region of the Třeboň Basin (Czech Republic) the difference between canopy temperature (Tc) and air temperature at 2 m (Ta) was tested as an indicator of grass­land water stress. To evaluate water stress ten-minute averages of temperature difference Tc–Ta were chosen recorded on days without rainfall with intensive solar radiation from 11.00 to 14.00 CET. Water stress in the zone of the major portion of root biomass (0–0.2 m) in the peak growing season (minimum presence of dead plant residues) documented by a sudden increase in temperature difference, its value 5–12°C and unfavourable canopy temperatures due to overheating (> 30°C) was indicated after high values of suction pressure approach­ing the wilting point (1300 kPa) were reached. High variability of temperature difference in the conditions of sufficient supply of water to plants was explained by the amount of dead plant residues in canopy, value of va­pour pressure deficit (VPD), actual evapotranspiration rate (ETA) and soil moisture content. At the beginning of the growing season (presence of dead plant residues and voids) we proved moderately strong negative linear correlations of Tc–Ta with VPD and Tc–Ta with ETA rate and moderately strong positive linear correlations of ETA rate with VPD. In the period of intensive growth (the coverage of dead plant residues and voids lower than 10%) moderately strong linear correlations of Tc–Ta with VPD and multiple linear correlations of Tc–Ta with VPD and soil moisture content at a depth of 0.10–0.40 m were demonstrated.

scholarly journals Spatial-Temporal Simulations of Soil Moisture Content in a Large Basin of the Loess Plateau, China

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Zhiqi Wang ◽  
Xiaobo Feng ◽  
Zhihong Yao ◽  
Zhaolong Ma ◽  
Guodong Ji
Keyword(s):  
Land Use ◽  
Soil Moisture ◽  
Seasonal Variation ◽  
Moisture Content ◽  
Loess Plateau ◽  
Soil Moisture Content ◽  
Spatial And Temporal Variation ◽  
Slope Aspect ◽  
The Loess Plateau ◽  
Basin Scale

Soil moisture is a crucial factor limiting the growth and survival of plants on the Loess Plateau. Its level has a severe impact on plants’ growth and development and the type and distribution characteristics of communities. This study area is the Jihe Basin in the Loess Plateau, China. Multiple linear regression models with different environmental variables (land use, topographic and meteorological factors, etc.) were developed to simulate soil moisture’s spatial and temporal changes by integrating field experiments, indoor analysis, and GIS spatial analysis. The model performances were evaluated in the Jihe Basin, with soil moisture content measurements. The result shows that soil moisture content is positively correlated with soil bulk density, monthly rainfall, topographic wetness index, land use coefficient, and slope aspect coefficient but negatively correlated with the monthly-averaged temperature and the relative elevation coefficient. The selected variables are all related to the soil moisture content and can account for 75% of the variations of soil moisture content, and the remaining 25% of the variations are related to other factors. Comparing the simulated and measured values at all sampling points shows that the average error of all the simulated values is 0.09, indicating that the simulation has high accuracy. The spatial distribution of soil moisture content is significantly affected by land use and topographic factors, and seasonal variation is remarkable in the year. Seasonal variation of soil moisture content is determined by the seasonal variation of rainfall and the air temperature (determining evaporation) and vegetation growth cycle. Therefore, the proposed model can simulate the spatial and temporal variation of soil moisture content and support developing the soil and water loss model on a basin scale.

scholarly journals Influence of Organic and Inorganic Soil Amendments on Soil Moisture Content and Micronutrients

2019 ◽  
pp. 1-12
Author(s):  
E. K. Kago ◽  
Z. M. Kinyua ◽  
J. M. Maingi ◽  
P. O. Okemo
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Amendment ◽  
Soil Moisture Content ◽  
Soil Amendments ◽  
Orange Peel ◽  
Petri Dish ◽  
Significant Difference ◽  
Dry Soil ◽  
Metham Sodium

Aims: This study was carried out to evaluate the influence of organic and inorganic soil amendments on soil moisture content and micronutrients in semi and arid areas.   Methodology: The study was laid out as randomized complete block design (RCBD) in split plot arrangement for two seasons. The treatments were ChalimTM, Super-hydro-grow polymer and Metham sodium, Metham sodium, Metham sodium + Orange peel, Super-hydro-grow polymer, Control, Brassica tissue, ChalimTM + Super-hydro-grow polymer, Brassica tissue + Orange peel and Metham sodium + Super-hydro-grow polymer. Soils were sampled from each experimental site, dried and taken to laboratories for determination of Zinc, Iron, Manganese and copper both at initial and at the end of the experiment using a SpectrAA- 40 atomic absorption spectrometer, PSC-56 programmable sample changer. Moisture content was calculated by subtracting total dry soil plus Petri dish weight from total wet soil plus Petri dish weight. Calculated moisture content was recorded in all samples across the two seasons for analysis. Results: There was a significant difference (p≤0.05) in the treatment effect on soil moisture content in except for MS and CM+OP in both season one and season two in the green house. A combination of both organic and inorganic soil amendments like BT+OP, BT+ SHG had the highest moisture content. There was significant difference (p≤0.05) in the soil amendments effect on the amount of Micronutrients in the beginning and end of the experiement. Conclusion: Through this study, it was realized significant difference (p≤0.05) in the soil amendments effect on soil moisture content in all the treatment in both seasons. BT +SHG soil amendment was superior in maintaining soil moisture content in both season 1 and 2. It is therefore recommended that Metham sodium should not be applied in very dry soil to avoid reduction of the moisture content. There was micronutrient increment in all the treatments. BT+ SHG was superior soil amendment in increment of micronutrients.

scholarly journals Inter-annual variation of carbon uptake by a plantation oak woodland in south-eastern England

2012 ◽  
Vol 9 (12) ◽  
pp. 5373-5389 ◽  
Author(s):  
M. Wilkinson ◽  
E. L. Eaton ◽  
M. S. J. Broadmeadow ◽  
J. I. L. Morison
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Eddy Covariance ◽  
Carbon Balance ◽  
Annual Variation ◽  
Soil Moisture Content ◽  
Growing Season ◽  
Co2 Uptake ◽  
Growing Season Length ◽  
Net Co2 Uptake

Abstract. The carbon balance of an 80-yr-old deciduous oak plantation in the temperate oceanic climate of the south-east of Great Britain was measured by eddy covariance over 12 yr (1999–2010). The mean annual net ecosystem productivity (NEP) was 486 g C m−2 yr−1 (95% CI of ±73 g C m−2 yr−1), and this was partitioned into a gross primary productivity (GPP) of 2034 ± 145 g C m−2 yr−1, over a 165 (±6) day growing season, and an annual loss of carbon through respiration and decomposition (ecosystem respiration, Reco) of 1548 ± 122 g C m−2 yr−1. Although the maximum variation of NEP between years was large (333 g C m−2 yr−1), the ratio of Reco/GPP remained relatively constant (0.76 ± 0.02 CI). Some anomalies in the annual patterns of the carbon balance could be linked to particular weather events, such as low summer solar radiation and low soil moisture content (values below 30% by volume). The European-wide heat wave and drought of 2003 did not reduce the NEP of this woodland because of good water supply from the surface-water gley soil. The inter-annual variation in estimated intercepted radiation only accounted for ~ 47% of the variation in GPP, although a significant relationship (p < 0.001) was found between peak leaf area index and annual GPP, which modified the efficiency with which incident radiation was used in net CO2 uptake. Whilst the spring start and late autumn end of the net CO2 uptake period varied substantially (range of 24 and 27 days respectively), annual GPP was not related to growing season length. Severe outbreaks of defoliating moth caterpillars, mostly Tortrix viridana L. and Operophtera brumata L., caused considerable damage to the forest canopy in 2009 and 2010, resulting in reduced GPP in these two years. Inter-annual variation in the sensitivity of Reco to temperature was found to be strongly related to summer soil moisture content. The eddy covariance estimates of NEP closely matched mensuration-based estimates, demonstrating that this forest was a substantial sink of carbon over the 12-yr measurement period.

REGRESSIONS FOR ESTIMATING STRAW YIELDS AND N AND P CONTENTS OF SPRING WHEAT AND N MINERALIZATION IN A BROWN LOAM SOIL

1988 ◽  
Vol 68 (2) ◽  
pp. 337-344 ◽  
Author(s):  
C. A. CAMPBELL ◽  
R. P. ZENTNER ◽  
F. SELLES
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Spring Wheat ◽  
N Mineralization ◽  
Soil Moisture Content ◽  
N Uptake ◽  
Growing Season ◽  
Net N Mineralization ◽  
Loam Soil ◽  
Growing Season Precipitation

Data from an 18-yr crop rotation study carried out on a Brown loam soil at Swift Current, Saskatchewan, were used to estimate equations that relate spring wheat straw yields, and N and P content of grain and straw to moisture use (MU). Moisture use was defined as soil moisture content in 0- to 120-cm depth at seeding, less soil moisture content at harvest, plus growing season precipitation. Grain yields were also related to straw yields and to N content of the straw. Potential net N mineralization (Nmin) in summerfallow (periods during the growing season with negative Nmin omitted) was related (r = 0.74**) to precipitation received during the spring to fall period. An attempt to relate apparent net Nmin (determined by N balance) in cropped systems to growing season precipitation or to MU was not successful. Highly significant linear regressions were obtained for straw yields, grain N and P contents vs. MU, and for grain yield vs. straw yield (r = 0.66** – 0.83**), but the other relationships were less reliable (r = 0.41** – 0.55**) though still significant. We discussed how these relationships might be used to estimate fertilizer N requirements, for examining N immobilization-mineralization, and for estimating residue sufficiency for erosion control on summerfallowed land. Key words: Straw:grain ratio, N uptake, P uptake, crop residues, N mineralization

scholarly journals WATER TABLE BEHAVIOR AND SOIL MOISTURE CONTENT DURING THE WINTER

1970 ◽  
Vol 50 (3) ◽  
pp. 361-366 ◽  
Author(s):  
J. C. van SCHAIK ◽  
E. RAPP
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Water Table ◽  
Soil Moisture Content ◽  
Growing Season ◽  
Grass Cover ◽  
Irrigation Project ◽  
Southern Alberta

Water table recession in an irrigation project in southern Alberta was compared with moisture translocation in covered lysimeters during two winters. Upward translocation to the surface 60 cm during one winter amounted to 1 to 2 cm of water in dry soils having a grass cover, and 2 to 2.3 cm in moist soils with no vegetation. Observations between growing season and freeze-up indicated that a considerable amount of water may drain downward. The upper 30 cm of soil generally is not influenced by upward translocation if the soil is dry before freeze-up.

scholarly journals The Regulatory Mechanism of 2-Acetyl-1-Pyrroline Biosynthesis in Fragrant Rice (Oryza sativa L.) Under Different Soil Moisture Contents

2021 ◽  
Vol 12 ◽  
Author(s):  
Haowen Luo ◽  
Meiyang Duan ◽  
Leilei Kong ◽  
Longxin He ◽  
Yulin Chen ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Growth Parameters ◽  
Oryza Sativa L ◽  
Dry Weight ◽  
Transcript Level ◽  
Fragrant Rice ◽  
Moisture Contents ◽  
Significant Difference

2-acetyl-1-pyrroline (2-AP) is the key compound of rice aroma. However, the responses of 2-AP biosynthesis in fragrant rice under different soil moisture and the corresponding mechanism are little known. The present study evaluated the effects of different soil moisture on 2-AP biosynthesis through a pot experiment. Four soil moisture contents, that is, 50% (SM50), 40% (SM40), 30% (SM30), and 20% (SM20), were adopted, and SM50 treatment was taken as control. The pots were weighed and watered to maintain the corresponding soil moisture content. The results showed no significant difference in growth parameters (plant height, stem diameter, and plant dry weight) among all treatments. Compared with SM50, SM40, SM30, and SM20 treatments significantly (p&lt;0.05) increased 2-AP content by 32.81, 23.18, and 53.12%, respectively. Between 20 to 90% higher proline content was observed in SM40, SM30, and SM20 treatments than in SM50. Enzymes including proline dehydrogenase, ornithine transaminase, and 1-pyrroline-5-carboxylate synthetase exhibited lower activities with soil moisture declined. Higher diamine oxidase activity was observed in SM40, SM30, and SM20 treatments compared with SM50, and real-time PCR analyses showed that transcript level of DAO1 was greatly increased under low soil moisture treatments, especially in SM20 treatment. Transcript levels of PRODH, DAO2, DAO4, DAO5, OAT, P5CS1, and P5CS2 decreased or maintained in SM40, SM30, and SM20 treatments compared with SM50. We deduced that low soil moisture content enhanced 2-AP biosynthesis mainly by upregulating the expression of DAO1 to promote the conversion from putrescine to 2-AP.

EFFECTS OF SEEDING TREATMENT AND SOIL MOISTURE CONTENT ON THE EMERGENCE OF LETTUCE

1985 ◽  
Vol 65 (1) ◽  
pp. 193-199 ◽  
Author(s):  
G. E. CHEVRIER ◽  
K. A. STEWART
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Field Capacity ◽  
Lettuce Seeds ◽  
Lactuca Sativa L ◽  
Seeding Method ◽  
Significant Difference ◽  
Dark Green ◽  
Fluid Drilling

Lettuce seeds (Lactuca sativa L. ’Boston Dark Green’) were sown by fluid drill and as dry seed into soils at 25%, 50%, 75% and 100% field capacity (FC). Fluid drilling reduced the time to initial emergence and 50% emergence at soil moisture levels between 50% and 100% FC. At 25% FC, neither seeding method performed well with fluid drilled seed being entrapped inside the carrier gel after it had dehydrated. After 2 wk, no significant difference in final percent emergence was noted between seeding treatments at any soil moisture level. In a second experiment, fluid drilled lettuce seeds emerged earlier and reached 50% emergence sooner than dry seed, germinated seed sown without gel and dry-seed in gel at 40%, 50% and 75% FC. Gel-seeded treatments were not significantly affected by soil moisture whereas the emergence of seeding treatments without gel application was markedly improved as soil moisture content increased. After 2 wk, the percent emergence of dry seeded lettuce at 40% FC was significantly lower than the other seeding treatments. No differences were noted among treatments at 50% FC whereas at 75% FC, the emergence of dry seed in gel was significantly reduced.Key words: Lettuce, fluid drilling

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