Seasonal variation and implications of soil water content in the cultivation of olive trees

2018 ◽  
pp. 339-344
Author(s):  
G. Arampatzis ◽  
E. Hatzigiannakis ◽  
N. Kourgialas ◽  
G. Psarras ◽  
V. Kinigopoulou ◽  
...  
1988 ◽  
Vol 68 (2) ◽  
pp. 405-416 ◽  
Author(s):  
D. R. COOTE ◽  
C. A. MALCOLM-McGOVERN ◽  
G. J. WALL ◽  
W. T. DICKINSON ◽  
R. P. RUDRA

Soil-erodibility indices were investigated in two regions of Ontario to evaluate their seasonal variation and differences between soil types. Shear strength and water-stable aggregates >0.5 mm were strongly negatively correlated with gravimetric soil water content for a Guelph sandy loam soil in southwestern Ontario. Similar variation of shear strength was estimated in three other southwestern Ontario surface soils as a result of seasonal changes in moisture content. Shear strength and aggregate stability increased as four eastern Ontario soils, ranging in texture from loamy sand to clay, dried and warmed following spring thaw. Laboratory incubation at constant temperature and water content showed that shear strength increased in two fine-textured soils with increasing degree days but changed very little in two coarse-textured soils. At the point-of-thaw in the field, all of the eastern Ontario soils exhibited very high values of the indices 1/shear strength and 1/aggregate stability, averaging approximately 15 times those of early July. During spring fallow and seed-bed to 10% canopy periods, the mean values of these indices were 3.7 and 1.4 times, respectively, those in early July. For winter-thaw conditions in the three southwestern Ontario soils, the index 1/shear strength averaged 17 times greater than in the summer. Spring values of this index averaged approximately twice those of summer. Results suggest that Ontario soils are much more susceptible to erosion under thaw and spring conditions than later during the growing season. Soil water content and soil warming may affect the re-establishment of resistance to erosion in soils rendered erodible by freezing, thawing, and saturation. Key words: Erodibility, shear strength, aggregate stability


2000 ◽  
pp. 329-336 ◽  
Author(s):  
A.M. Palese ◽  
V. Nuzzo ◽  
B. Dichio ◽  
G. Celano ◽  
M. Romano ◽  
...  

2020 ◽  
Vol 10 ◽  
Author(s):  
Elena Nikolaevna Ikkonen ◽  
Norma Eugenia García-Calderón ◽  
Ervin Stephan-Otto ◽  
Elizabeth Fuentes-Romero ◽  
Abel Ibáñez-Huerta ◽  
...  

Since soil CO<sub>2</sub> flux is a key component of ecosystem carbon balance, quantifying its contribution to the ecosystem carbon flux and understanding the factors that underlie its temporal variation is crucial for a better comprehension of ecosystem carbon dynamics under climate change and for optimal ecosystem use and management. Our objectives were to quantify the contributions of total soil CO<sub>2</sub> efflux (<em>F</em><sub>S</sub>) to ecosystem respiration (<em>R</em><sub>E</sub>) and heterotrophic soil CO<sub>2</sub> efflux (<em>F</em><sub>H</sub>) to <em>F</em><sub>S</sub> in two <em>chinampa</em> ecosystems with different natural grass covers. We also aimed to identify the main environmental drivers of seasonal variability of these contributions. The CO<sub>2</sub> fluxes were measured on each site about every 14 days from September 2008 to August 2009 in the Xochimilco Ecological Park in Mexico City using dark chamber techniques. For two studied sites, <em>R</em><sub>E</sub>,<em> F</em><sub>S</sub> and <em>F</em><sub>H</sub> were estimated on average as 94.1 ± 8.5, 34.7 ± 3.5 and 16.5 ± 1.7 (± S.E.) mg C-CO<sub>2</sub> m<sup>-2</sup> h<sup>-1</sup>, respectively. &nbsp;On average over the study period and sites, the annual cumulative <em>R</em><sub>E</sub>, <em>F</em><sub>S</sub> and <em>F</em><sub>H</sub> fluxes were 824 ± 74, 304 ± 31 and 145 ± 15 g C m<sup>-2</sup> year, respectively. The <em>R</em><sub>E</sub>, <em>F</em><sub>S</sub> and <em>F</em><sub>H</sub> varied between the winter and summer seasons; this variation was explained mostly by seasonal variations of soil temperature, soil water content and shoot plant biomass. Temperature sensitivity of CO<sub>2</sub> fluxes depended on vegetation type and plant growth differences among the sites and decreased in the following order: <em>R</em><sub>E</sub> &gt; <em>R</em><sub>s</sub> &gt; <em>R</em><sub>H</sub>. The contribution of <em>F</em><sub>S</sub> to <em>R</em><sub>E</sub> and <em>F</em><sub>H</sub> to <em>F</em><sub>S</sub> for the two studied sites and period averaged about 38% and 50%, respectively regardless of the site vegetation type, but the degree of <em>F</em><sub>S</sub>/<em>R</em><sub>E</sub> and <em>F</em><sub>H</sub>/<em>F</em><sub>S</sub> variability depended on the differences in seasonal dynamics of plant cover. The contribution of <em>F</em><sub>H </sub>to <em>F</em><sub>S</sub> varied from 37% in summer to 73% in winter at the site without a seasonal shift in dominant plant species, but <em>F</em><sub>H</sub>/<em>F</em><sub>S</sub> was close to constant during the year at the site with a seasonal change in dominant plant species. During the cold period, the contribution of <em>F</em><sub>H </sub>to <em>F</em><sub>S</sub> increased following plant growth decrease. The linear regression analysis showed that plant biomass was the dominant factor controlling the seasonal variation of <em>F</em><sub>H</sub>/<em>F</em><sub>S</sub> ratios, whereas the plant biomass dynamic followed the dynamics of soil water content, water table depth, and soil temperature. Our results suggest that seasonal variation of soil contribution to total fluxes from the <em>chinampa</em> ecosystem is locally differentiated. These differences were related to differences in seasonal dynamics of cover productivity which has been associated with localization of soil water content. This finding has important implications for assessing the contribution of the chinampa ecosystem to the global carbon budget.


2018 ◽  
Vol 9 (4) ◽  
pp. 672-678 ◽  
Author(s):  
G. Arampatzis ◽  
E. Hatzigiannakis ◽  
V. Pisinaras ◽  
N. Kourgialas ◽  
G. Psarras ◽  
...  

Abstract Olive trees constitute one of the most dynamic cultivations for Mediterranean countries, while their economic importance is high. As water constitutes a fundamental factor affecting olive tree production, soil water content is a most critical parameter that must be monitored to improve olive trees’ cultivation management. Effects of precipitation, irrigation, and soil management on water content in four soil depths (10, 20, 30, 40 cm), four periods of the year (February–March, April–May, June–July, August–September) and three successive years were determined in 12 Mediterranean olive groves (Trifilia, southern Greece) as well as their respective fruit and olive oil yields. Significantly higher soil water content was recorded in the first (+16.8%) and third (+27.4%) year compared to the second year. Higher (+6.8%) water content was observed in irrigated olive groves compared to rainfed fields. Higher (+5.6%) water content was observed in sustainable olive groves compared to intensively managed fields. Significantly, higher soil moisture was recorded at 40 and 30 cm depth compared to 10 cm depth while intermediate values were observed at 20 cm. Marked increase in fruit yield was achieved through sustainable management (+39%) compared to intensive olive groves. The potential to improve irrigation practices in the area was also indicated by results of the present study.


2011 ◽  
pp. 323-330 ◽  
Author(s):  
J.E. Fernández ◽  
J.M. Torres-Ruiz ◽  
J.L. Muriel ◽  
R. Romero ◽  
M.J. Martín-Palomo ◽  
...  

2013 ◽  
Vol 10 (8) ◽  
pp. 13015-13047 ◽  
Author(s):  
G. Fu ◽  
Y.-J. Zhang ◽  
X.-Z. Zhang ◽  
P.-L. Shi ◽  
Y.-T. Zhou ◽  
...  

Abstract. This study aims to understand the response of ecosystem respiration (Reco) to warming and clipping in the alpine meadow of Tibet. A field warming experiment using open top chambers was conducted in three alpine meadow sites at elevation 4313 m, 4513 m and 4693 m on the Tibetan Plateau since July 2008. Clipping was conducted three times a year since 2009. Reco was measured from June to September in 2010–2012. For most cases, the seasonal variation of Reco was mainly affected by soil water content rather than soil and air temperature, especially under warmer environment. Experimental warming tended to decrease seasonal average Reco by 21.6% and 10.9% at elevation 4313 m and 4513 m, respectively, but significantly increased seasonal average Reco by 11.3% at elevation 4693 m. The different responses of Reco to experimental warming could be mainly dependent on temperature and water availability condition. Clipping decreased seasonal average Reco by 6.9%, 36.9% and 31.6% at elevation 4313 m, 4513 m and 4693 m. The consistent declines caused by clipping may be mainly attributed to clipping-induced decline in aboveground biomass. Our findings suggested that the response of Reco to warming differed among the alpine meadow and was regulated by soil water content on the Tibetan Plateau.


Author(s):  
M.C.H.Mouat Pieter Nes

Reduction in water content of a soil increased the concentration of ammonium and nitrate in solution, but had no effect on the concentration of phosphate. The corresponding reduction in the quantity of phosphate in solution caused an equivalent reduction in the response of ryegrass to applied phosphate. Keywords: soil solution, soil water content, phosphate, ryegrass, nutrition.


2010 ◽  
Vol 59 (1) ◽  
pp. 157-164 ◽  
Author(s):  
E. Tóth ◽  
Cs. Farkas

Soil biological properties and CO2emission were compared in undisturbed grass and regularly disked rows of a peach plantation. Higher nutrient content and biological activity were found in the undisturbed, grass-covered rows. Significantly higher CO2fluxes were measured in this treatment at almost all the measurement times, in all the soil water content ranges, except the one in which the volumetric soil water content was higher than 45%. The obtained results indicated that in addition to the favourable effect of soil tillage on soil aeration, regular soil disturbance reduces soil microbial activity and soil CO2emission.


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