Soil Water Changes in Creosotebush and Bur-Sage during a Dry Period in Southern Arizona

Soil water was recorded in paddocks with artificial windbreaks and in unsheltered paddocks at each of two stocking rates over a dry period of 29 days after soil had drained to field capacity following heavy rain. Significantly less water (12.3 mm) was lost from the two sheltered paddocks compared with the two unsheltered paddocks, a large saving of water over a single drying period. Since the metabolizable energy intake by grazing animals was higher by an average of 18% in the sheltered paddocks at both stocking rates it is inferred that some of this water was used for plant production, resulting in a higher herbage availability over the dry period in the sheltered paddocks than in those without shelter. Windbreaks should be considered in environments where there are periods during which water stress is the only factor limiting plant growth and the occurrence of rainfall is uncertain. Windbreaks may be of particular use in paddocks with lambing or lactating ewes or paddocks used for fattening lambs.

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Effect of Drought and Topographic Position on Depth of Soil Water Extraction of Pinus sylvestris L. var. mongolica Litv. Trees in a Semiarid Sandy Region, Northeast China

Forests ◽

10.3390/f10050370 ◽

2019 ◽

Vol 10 (5) ◽

pp. 370 ◽

Cited By ~ 2

Author(s):

Lining Song ◽

Jiaojun Zhu ◽

Jinxin Zhang ◽

Ting Zhang ◽

Kai Wang ◽

...

Keyword(s):

Soil Moisture ◽

Soil Water ◽

Northeast China ◽

Water Sources ◽

Dry Period ◽

Growth And Survival ◽

Topographic Position ◽

Pine Trees ◽

Use Efficiency ◽

Soil Water Extraction

Drought and topographic position are the most important factors influencing tree growth and survival in semiarid sandy regions of Northeast China. However, little is known about how trees respond to drought in combination with topographic position by modifying the depth of soil water extraction. Therefore, we identified water sources for 33-year-old Mongolian pine (Pinus sylvestris L. var. mongolica Litv.) trees growing at the top and bottom of sand dunes by comparing stable isotopes δ2H and δ18O in twig xylem water, soil water at various depths and groundwater during dry and wet periods. Needle carbon isotope composition (δ13C) was simultaneously measured to assess water use efficiency. Results showed that when soil moisture was low during the dry period, trees at the top used 40–300 cm soil water while trees at the bottom utilized both 40–300 cm soil water and possibly groundwater. Nevertheless, when soil moisture at 0–100 cm depth was higher during the wet period, it was the dominant water sources for trees at both the top and bottom. Moreover, needle δ13C in the dry period were significantly higher than those in the wet period. These findings suggested that trees at both the top and bottom adjust water uptake towards deeper water sources and improve their water use efficiency under drought condition. Additionally, during the dry period, trees at the top used shallower water sources compared with trees at the bottom, in combination with significantly higher needle δ13C, indicating that trees at the bottom applied a relatively more prodigal use of water by taking up deeper water (possibly groundwater) during drought conditions. Therefore, Mongolian pine trees at the top were more susceptible to suffer dieback under extreme dry years because of shallower soil water uptake and increased water restrictions. Nevertheless, a sharp decline in the groundwater level under extreme dry years had a strong negative impact on the growth and survival of Mongolian pine trees at the bottom due to their utilization of deeper water sources (possibly groundwater).

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CONTEÚDO DE ÁGUA NO SOLO EM CULTIVO DE MILHO SEM E COM COBERTURA MORTA NA ENTRELINHA NA REGIÃO DE ARAPIRACA-AL

Irriga ◽

10.15809/irriga.2010v15n2p173 ◽

2010 ◽

Vol 15 (2) ◽

pp. 173-183 ◽

Cited By ~ 4

Author(s):

Gustavo Bastos Lyra ◽

José Leonaldo de Souza ◽

Iedo Teodoro ◽

Guilherme Bastos Lyra ◽

Gilson Moura Filho ◽

...

Keyword(s):

Zea Mays ◽

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Grain Filling ◽

Dry Period ◽

Traditional System ◽

Straw Mulching ◽

Crop Development ◽

Grain Filling Period

Avaliou-se a variação do conteúdo de água no solo em diferentes fases de desenvolvimento do milho cultivado sem (Tradicional) e com cobertura morta (Capim) na entrelinha. Observações agrometeorológicas e da cultura foram realizadas na região de Arapiraca, AL (09º38'35" S; 36º40'15" W; 260 m) entre julho e outubro de 2005, na transição do período úmido e seco. Consideraram-se nas análises as seguintes fases de desenvolvimento do milho: inicial (20 d), crescimento (35 d), intermediária (40 d) e final (30 d). A umidade volumétrica do solo foi estimada pelo modelo de van Genutchen em função de medidas do potencial matricial de água no solo. Medidas do potencial foram obtidas por tensiômetros automáticos instalados a 0,15 m de profundidade. O sistema com cobertura morta manteve conteúdo de água no solo superior ao sistema Tradicional em 65,8 % dos dias (75 dias) do ciclo. Contudo, o conteúdo de água no sistema Tradicional sobressaiu-se ao com cobertura morta na maior parte do período de enchimento de grãos (80 %), o que resultou numa maior produtividade de grãos no Tradicional. Na transição entre o período chuvoso e seco da região não é recomendado o uso da cobertura morta na entrelinha durante todo o ciclo do milho, principalmente se o período de enchimento de grãos coincidir com o período seco. Para eventos de chuva de moderado a forte (> 7 mm d-1) a cobertura morta aumenta a capacidade de infiltração da água no solo. Porém, para eventos fracos, a água fica armazenada na cobertura, sendo perdida diretamente para a atmosfera. UNITERMOS: cobertura morta, movimento de água no solo, semi-árido, Zea mays. LYRA, G.B.; SOUZA, J.L.; TEODORO, I.; LYRA, G.B.; MOURA FILHO, G.; FERREIRA JÚNIOR, R. A. SOIL WATER CONTENT IN MAIZE CROP WITH AND WITHOUT STRAW MULCHING IN ARAPIRACA REGION, ALAGOAS, BRAZIL 2 ABSTRACT The soil water content in different crop development stages of maize cultivated with straw mulching and in traditional system, i.e., bare soil rows, was evaluated. Agro meteorology and crop fields observations were carried out in the Arapiraca region (09º38'35" S; 36º40'15" W; 260 m), state of Alagoas, Brazil, from July through October, 2005, in the transition between humid and dry periods. The following stages of maize development and their lengths (days) were considered: initial (20), crop development (35), mid-season (40) and late (30). The soil moisture was estimated from van Genutchen`s model in function of soil water potential. Potential measurements were obtained from automatic tensiometers, installed at the depth of 0.15 m The soil water content in the mulching system was higher than in the traditional one in 65.8 % of the cycle (75 days). However, the soil water was higher in the traditional system in the grain filling period (80 % of days); this resulted in higher grain yield in the traditional system. The use of mulching is not advisable during all maize development cycle in the transition between humid to dry period in that region, mainly if the grain filling period is in the dry period. For moderate to heavy rainfall events (> 7 mm d-1), the infiltration capacity is incremented by mulching. However, for weak events, the rainfall water is stored in mulching and is directly lost to the atmosphere. KEYWORDS: straw mulching, soil water movement, semi-arid, Zea mays

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Water storage change estimation from in situ shrinkage measurements of clay soils

Hydrology and Earth System Sciences ◽

10.5194/hess-17-1933-2013 ◽

2013 ◽

Vol 17 (5) ◽

pp. 1933-1949 ◽

Cited By ~ 20

Author(s):

B. te Brake ◽

M. J. van der Ploeg ◽

G. H. de Rooij

Keyword(s):

Soil Water ◽

Volume Change ◽

Water Loss ◽

Water Storage ◽

Bulk Soil ◽

Soil Water Storage ◽

Dry Period ◽

Soil Layers ◽

Storage Change

Abstract. The objective of this study is to assess the applicability of clay soil elevation change measurements to estimate soil water storage changes, using a simplified approach. We measured moisture contents in aggregates by EC-5 sensors, and in multiple aggregate and inter-aggregate spaces (bulk soil) by CS616 sensors. In a long dry period, the assumption of constant isotropic shrinkage proved invalid and a soil moisture dependant geometry factor was applied. The relative overestimation made by assuming constant isotropic shrinkage in the linear (basic) shrinkage phase was 26.4% (17.5 mm) for the actively shrinking layer between 0 and 60 cm. Aggregate-scale water storage and volume change revealed a linear relation for layers ≥ 30 cm depth. The range of basic shrinkage in the bulk soil was limited by delayed drying of deep soil layers, and maximum water loss in the structural shrinkage phase was 40% of total water loss in the 0–60 cm layer, and over 60% in deeper layers. In the dry period, fitted slopes of the ΔV–ΔW relationship ranged from 0.41 to 0.56 (EC-5) and 0.42 to 0.55 (CS616). Under a dynamic drying and wetting regime, slopes ranged from 0.21 to 0.38 (EC-5) and 0.22 to 0.36 (CS616). Alternating shrinkage and incomplete swelling resulted in limited volume change relative to water storage change. The slope of the ΔV–ΔW relationship depended on the drying regime, measurement scale and combined effect of different soil layers. Therefore, solely relying on surface level elevation changes to infer soil water storage changes will lead to large underestimations. Recent and future developments might provide a basis for application of shrinkage relations to field situations, but in situ observations will be required to do so.

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Soil water storage in an upland forest after selective logging in Central Amazonia

Revista Brasileira de Ciência do Solo ◽

10.1590/s0100-06832004000100006 ◽

2004 ◽

Vol 28 (1) ◽

pp. 59-66 ◽

Cited By ~ 6

Author(s):

S. J. F. Ferreira ◽

F. J. Luizão ◽

S. M. Ross ◽

Y. Biot ◽

W. M. P. Mello-Ivo

Keyword(s):

Soil Water ◽

Water Storage ◽

Selective Logging ◽

Soil Water Storage ◽

Forest Plot ◽

Dry Period ◽

Upland Forest ◽

Central Amazonia ◽

Undisturbed Forest ◽

Two Phases

Soil water storage of Central Amazonian soil profiles in upland forest plots subjected to selective logging (in average, 8 trees or 34, 3 m³ of timber per hectare were removed) was measured in four layers, down to a depth of 70 cm. The study lasted 27-months and was divided in two phases: measurements were carried out nearly every week during the first 15 months; in the following year, five intensive periods of measurements were performed. Five damage levels were compared: (a) control (undisturbed forest plot); (b) centre of the clearing/gap; (c) edge of the gap; (d) edge of the remaining forest; and (e) remaining forest. The lowest values for water storage were found in the control (296 ± 19.1 mm), while the highest were observed (333 ± 25.8 mm) in the centre of the gap, during the dry period. In the older gaps (7.5-8.5 year old), soil water storage was similar to the remaining and the control forest, indicating a recovery of hydric soil properties to nearly the levels prior to selective logging.

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Use of water by six grass species. 2. Root distribution and use of soil water

The Journal of Agricultural Science ◽

10.1017/s0021859600086081 ◽

1979 ◽

Vol 93 (1) ◽

pp. 25-35 ◽

Cited By ~ 65

Author(s):

E. A. Garwood ◽

J. Sinclair

Keyword(s):

Soil Water ◽

Perennial Ryegrass ◽

Tall Fescue ◽

Italian Ryegrass ◽

Grass Species ◽

Total Water ◽

Dry Period ◽

Temporary Reduction ◽

Dry Conditions ◽

Harvest Year

SUMMARYThe use of soil water by six grasses (perennial ryegrass, cocksfoot, timothy, rough stalked meadow grass (RSMG), tall fescue and Italian ryegrass) was measured over 2 years. The swards were cut either at 3-week (C3) or 6-week (C6) intervals. In both years the maximum soil water deficit attained under C6 was greater than under C3. Following several of the cuts from C6 there was a marked, although temporary, reduction in the rate of water uptake.An extended dry period in the second harvest year revealed substantial differences in the total water used and in the patterns of uptake from the soil profile by the grasses. Effective depths of utilization of water under treatment C6 were: RSMG, 40 cm; timothy, 70 cm; cocksfoot, 70 cm; perennial ryegrass, 80 cm; tall fescue > 100 cm. This order of depth of utilization corresponded with the order of yields obtained during drought conditions. An examination of the root systems of four grasses also showed that, particularly under treatment C6, roots of tall fescue were more numerous at depth than those of timothy, cocksfoot or perennial ryegrass, and under this treatment it showed its greatest tolerance to dry conditions. Drought tolerance in these grasses appears largely determined by the volume of soil exploited by the roots for water.

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