Effect of Stand Density on Water Use of Mulga (Acacia aneura F.muell.) Woodlands in South-Western Queensland

1976 ◽  
Vol 24 (2) ◽  
pp. 177 ◽  
Author(s):  
AJ Pressland
Keyword(s):  
Soil Moisture ◽  
Water Use ◽  
Stand Density ◽  
Tree Density ◽  
Pan Evaporation ◽  
Permanent Wilting Point ◽  
The Mean ◽  
Acacia Aneura ◽  
Soil Moisture Status ◽  
Wilting Point

The important Australian fodder tree mulga (Acacia aneura F. Muell.) was thinned to densities ranging between 0 and 4000 trees ha-1 near Charleville, Queensland. Water use by the ensuing communities was studied from December 1971 to October 1973. Evapotranspiration over this 22 month period increased with tree density from 814 mm for the totally cleared plots to 852 and 891 mm for those plots supporting 4000 and 640 trees ha-1 respectively. Regression analysis was used to relate soil moisture to time since rain; it was established that the soil had dried to its permanent wilting point within 60 days of rain sufficient to recharge the soil to a depth of 135 cm. The mean apparent maximum evapotranspiration of the mulga communities was 4.7 mm day-1. The ratios of evapotranspiration to pan evaporation (Et/Eo) were influenced by both soil moisture status and tree density. Et/Eo ratios ranged between 0.55 and 0.07 in the summer of 1972, and between 1.05 and 0.05 the following summer. In the winters of 1972 and 1973 Et/Eo ratios ranged between 0.92 and 0.04, and 1.33 and 0.09 respectively. The significance of the results to production and management of mulga lands in south-western Queensland is discussed.

Water use by irrigated Arabica coffee in Kenya

1963 ◽  
Vol 60 (3) ◽  
pp. 381-388 ◽  
Author(s):  
J. A. N. Wallis
Keyword(s):  
Soil Moisture ◽  
Water Use ◽  
Mean Value ◽  
Soil Sampling ◽  
Reliable Measure ◽  
Daily Rate ◽  
Supplementary Irrigation ◽  
The Mean ◽  
Hot Weather ◽  
Soil Moisture Status

The methods proposed by Pereira for unirrigated coffee have been followed in a study of water use by this crop for the 12 years 1950–62. Soil sampling has shown that the procedure provides a reliable measure of evapotranspiration from unirrigated coffee.A modification is proposed which has enabled the rate of water use by irrigated coffee to be followed satisfactorily for the 5 years 1957–62. Occasional soil sampling showed that the modified procedure provided an estimate of the soil moisture status sufficiently reliable and accurate for the regulation of irrigation timing and amount.Irrigation to maintain a favourable soil moisture status has had a marked and beneficial effect on the production of Grade ‘A’ coffee in dry years.The mean daily rate of evapotranspiration from irrigated coffee is estimated to range from 0·15 in. in hot weather to half this rate during the cool and cloudy season.The maximum computed annual totals of supplementary irrigation which were required over a 12-year period ranged from 5·5 in. to 31·5 in. with a mean value of 16·0 in. per year.

SOIL WATER BALANCE AND GRAIN YIELD OF SORGHUM UNDER NO-TILL VERSUS CONVENTIONAL TILLAGE WITH SURFACE MULCH IN THE DERIVED SAVANNA ZONE OF SOUTHEASTERN NIGERIA

2011 ◽  
Vol 47 (1) ◽  
pp. 89-109 ◽  
Author(s):  
S. E. OBALUM ◽  
U. C. AMALU ◽  
M. E. OBI ◽  
T. WAKATSUKI
Keyword(s):  
Soil Moisture ◽  
Grain Yield ◽  
Water Use ◽  
Sandy Loam ◽  
Weighted Average ◽  
Conventional Tillage ◽  
Yield Reduction ◽  
Southeastern Nigeria ◽  
No Till ◽  
Soil Moisture Status

SUMMARYOver a decade after the forest-savanna transition zone of Nigeria was deemed suitable for production of sorghum (Sorghum bicolor), no research has been undertaken on the crop's tillage requirements in the southeastern part of the zone. This study evaluated the effects of tillage-mulch practices on soil moisture, water use (WU), grain yield and water use efficiency (WUE) of the crop in a Typic Paleustult (sandy loam) at Nsukka during 2006 and 2007 growing seasons. In a split-plot design, no-till (NT) and conventional tillage (CT) treatments were left bare (B) or covered with mulch (M) at 5 Mg ha−1. The ensuing treatments (NTB, NTM, CTB, and CTM) represented four tillage methods, which were replicated four times in a randomized complete block. In the monitored root zone, NTB and CTM significantly (p ≤ 0.05) enhanced the soil moisture status over NTM and CTB, but the main effects of the tillage and the mulch factors were not significant. The crop WU was uninfluenced by the treatments throughout the study. Although the grain yield showed higher values with NT than with CT, the differences were significant (p ≤ 0.05) only in 2007 that was marked with erratic rainfall and relatively low mean yield. Mulch significantly (p ≤ 0.05) enhanced the grain yield in 2006, with greater effect in CT than NT. On average, the mulch plots out-yielded their bare counterparts by about 26%. The tillage × mulch interaction was significant (p ≤ 0.01), and showed higher grain yields in NTB, NTM and CTM than in CTB. In the year-weighted average, yield increments in NTB, NTM and CTM over CTB were 53, 53 and 67% respectively, a pointer to the relevance of mulch with the CT but not the NT. Relative WU showed that the crop's water demand was met under all treatments. Hence, the yield reduction in the CTB was not due to water shortage. The WUE varied among the treatments in the same pattern as grain yield. In summary, NTB and CTM proved superior to NTM only in soil moisture status but to CTB in all measured parameters. From a socio-economic viewpoint, however, NTB would be preferable to CTM for growing sorghum in this area.

The Influence of Soil Moisture on the Foliar Activity of Diclofop

Weed Science ◽  
1980 ◽  
Vol 28 (5) ◽  
pp. 534-539 ◽  
Author(s):  
W. A. Dortenzio ◽  
R. F. Norris
Keyword(s):  
Soil Moisture ◽  
Near Field ◽  
Field Capacity ◽  
Herbicide Application ◽  
Wild Oats ◽  
High Soil Moisture ◽  
Herbicide Activity ◽  
Moisture Conditions ◽  
Soil Moisture Status ◽  
Wilting Point

Loss in activity of foliar-applied methyl ester of diclofop {2-[4-(2,4-dichlorophenoxy)phenoxy] propanoic acid} occurred under low soil moisture conditions. A loss in control of yellow foxtail [Setaria lutescens(Weigel) Hubb.], wild oats (Avena fatuaL.), little-seed canarygrass (Phalaris minorRetz.), and barnyardgrass [Echinochloa crus-galli(L.) Beauv.], was observed under greenhouse and growth chamber conditions. When soil was maintained at 2 to 3% above wilting point as compared to near field capacity, herbicide activity was decreased by 15 to 50%. High soil moisture (at or above 67% of field capacity) for at least 2 to 4 days following treatment was needed to achieve maximum effectiveness of the herbicide. Daily furrow irrigations for a period of 10 days following treatment of barnyardgrass in the field resulted in highest activity as compared to that under single irrigation regimes within the 10-day period. The effect of low soil moisture was minimized by increased rates of herbicide application. Hoe-29152 {methyl-2-[4-(4-trifluoromethylphenoxy)phenoxy] propanoate} showed similar losses in activity associated with low soil moisture. No consistent changes in uptake or translocation of14C-labeled diclofop could be detected in association with altered soil moisture status.

scholarly journals The role of the permanent wilting point in controlling the spatial distribution of precipitation

2018 ◽  
Vol 115 (22) ◽  
pp. 5692-5697 ◽  
Author(s):  
Cathy Hohenegger ◽  
Bjorn Stevens
Keyword(s):  
Soil Moisture ◽  
Water Availability ◽  
Precipitation Field ◽  
Resistance Function ◽  
Permanent Wilting Point ◽  
Low Levels ◽  
Dry Out ◽  
Self Aggregation ◽  
Wilting Point

Convection-permitting simulations on an idealized land planet are performed to understand whether soil moisture acts to support or impede the organization of convection. Initially, shallow circulations driven by differential radiative cooling induce a self-aggregation of the convection into a single band, as has become familiar from simulations over idealized sea surfaces. With time, however, the drying of the nonprecipitating region induces a reversal of the shallow circulation, drawing the flow at low levels from the precipitating to the nonprecipitating region. This causes the precipitating convection to move over the dry soils and reverses the polarity of the circulation. The precipitation replenishes these soils with moisture at the expense of the formerly wet soils which dry, until the process repeats itself. On longer timescales, this acts to homogenize the precipitation field. By analyzing the strength of the shallow circulations, the surface budget with its effects on the boundary layer properties, and the shape of the soil moisture resistance function, we demonstrate that the soil has to dry out significantly, for the here-tested resistance formulations below 15% of its water availability, to be able to alter the precipitation distribution. We expect such a process to broaden the distribution of precipitation over tropical land. This expectation is supported by observations which show that in drier years the monsoon rains move farther inland over Africa.

Direct seeding of alfalfa into established Russian wildrye pasture in southwest Saskatchewan

1994 ◽  
Vol 74 (3) ◽  
pp. 539-542 ◽  
Author(s):  
M. P. Schellenberg ◽  
J. Waddington ◽  
J. R. King
Keyword(s):  
Soil Moisture ◽  
Dry Matter ◽  
Near Surface ◽  
Growing Seasons ◽  
Psathyrostachys Juncea ◽  
Matter Production ◽  
Permanent Wilting Point ◽  
Russian Wildrye ◽  
Medicago Sativa L ◽  
Wilting Point

Experiments were started in each of the three years 1989–1991 to examine the effect of severing near-surface roots of established Russian wildrye (Psathyrostachys juncea (Fisch.) Nevskii) on the establishment of two alfalfa cultivars (Medicago sativa L.) in semiarid Saskatchewan. In 2 of 3 yr, up to 75% more seedlings were established of the cultivar Rangelander, a creeping-rooted alfalfa of mixed ssp. sativa (L.) Lesins & Lesins and ssp. falcata (L.) Arcangeli parentage, than of SCMf3713, a tap-rooted ssp. falcata. Severing Russian wildrye roots significantly improved alfalfa establishment and dry matter production in 1990, only 1 of 3 yr. There were no benefits from severing Russian wildrye roots on more than the side adjacent to the alfalfa seedlings. Soil moisture levels in the top 15 cm of soil were at or below the permanent wilting point through much of the growing seasons of 1989 and 1991. Soil moisture was increased only occasionally where Russian wildrye roots were severed. Key words: Sod-seeding, Psathyrostachys juncea, Medicago media

SOIL MOISTURE VARIATIONS UNDER RURAL SURFACE COVERS AT ELLERSLIE, ALBERTA

1980 ◽  
Vol 60 (4) ◽  
pp. 613-623
Author(s):  
STEWART J. COHEN
Keyword(s):  
Soil Moisture ◽  
Water Use ◽  
Soil Moisture Content ◽  
Stand Density ◽  
Growing Season ◽  
Land Uses ◽  
Rural Land ◽  
University Of Alberta ◽  
A Site ◽  
The University

This study examines the effects of rural land uses on soil moisture and soil water use, the latter expressed in terms of vertical latent heat flux (LE). The field program took place during the 1976 growing season, utilizing a site at the University of Alberta Farm at Ellerslic, Alberta. The site contained several different rural surface plots, identically exposed to prevailing weather, thereby permitting direct comparisons of differences in soil moisture and LE between these plots. Thus, the effects of the surface cover were isolated from those of location. It was found that significant differences in soil moisture content had developed, despite the small sizes of the plots. Some generalizations appearing in the literature were evaluated, and several qualifications were found to be necessary, particularly in reference to the influence of stand density and plant activity on water use.

Soil Moisture Redistribution as Affected by Throughfall and Stemflow in an Arid Zone Shrub Community

1976 ◽  
Vol 24 (5) ◽  
pp. 641 ◽  
Author(s):  
AJ Pressland
Keyword(s):  
Soil Moisture ◽  
Arid Zone ◽  
Tree Density ◽  
Ground Flora ◽  
Infiltration Rates ◽  
Close Proximity ◽  
Stem Flow ◽  
Survival And Growth ◽  
Ecological Importance ◽  
Acacia Aneura

Changes in soil moisture under various densities of mulga (Acacia aneura F. Muell.) were followed from December 1971 to October 1973. Stemflow was instrumental in storing water at depth in the soil, being particularly noticeable with medium falls of rain (~ 75 mm); heavy (~ 160 mm) falls tended to mask the effect. Throughfall increased linearly with aggregate rainfall, and percentage throughfall decreased with increasing tree density. Of incoming precipitation, 94% was partitioned as throughfall under a tree density of 40 trees/ha-1 compared with 86% at a density of 4000 trees/ha. No distinct soil moisture patterns due to throughfall were found. Infiltration rates of water into the soil decreased with increasing distance from trees, being 46, 22 and 17 mm/h-1 after 10 min at distances 0.25, 0.5 and 2 m from a tree bole respectively, thus demonstrating that stemflow waters are absorbed at close proximity to the tree bole.The results are discussed in terms of the ecological importance of stem flow and soil moisture patterning to the survival and growth of mulga and associated ground flora.

scholarly journals Development and Evaluation of Pedotransfer Functions to Estimate Soil Moisture Content at Field Capacity and Permanent Wilting Point for South African Soils

Water ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 2639
Author(s):  
Lindumusa Myeni ◽  
Thandile Mdlambuzi ◽  
David Garry Paterson ◽  
Gert De Nysschen ◽  
Mokhele Edmond Moeletsi
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
South African ◽  
Soil Moisture Content ◽  
Field Capacity ◽  
Pedotransfer Functions ◽  
Coefficient Of Determination ◽  
Soil Horizons ◽  
Permanent Wilting Point ◽  
Wilting Point

This study was undertaken to develop new pedotransfer functions (PTFs) for the estimation of soil moisture content at field capacity (FC, at −33 kPa) and permanent wilting point (PWP, at −1500 kPa) for South African soils based on easily measurable soil physico-chemical properties. The new PTFs were developed using stepwise multiple linear regressions with the dependent variable (either FC or PWP) against clay, silt, sand and soil organic carbon (SOC) content from a total of 3171 soil horizons as the explanatory variables. These new PTFs were evaluated and compared with five well-established PTFs using a total of 3136 soil horizons as an independent dataset. The coefficient of determination (r2) values for the existing PTFs ranged from 0.65–0.72 for FC and 0.72–0.81 for PWP, whilst those developed in this study were 0.77 and 0.82 for FC and PWP, respectively. The root mean square error (RMSE) values for the well-established PTFs ranged from 0.052–0.058 kg kg−1 for FC and 0.030–0.036 kg kg−1 for PWP, whilst those developed in this study were 0.047 and 0.029 kg kg−1 for FC and PWP, respectively. These findings suggest that PTFs derived locally using a large number of soil horizons acquired from different agro-climatic locations improved the estimation of soil moisture at FC and PWP. Due to the range of conditions and large soil datasets used in this study, it is concluded that these new PTFs can be applied with caution in other regions facing data scarcity but with similar soil types and climatic conditions.

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