scholarly journals Soil water storage, yield, water productivity and transpiration efficiency of soybeans ( Glyxine max L.Merr ) as affected by soil surface management in Ile-Ife, Nigeria

2017 ◽  
Vol 5 (2) ◽  
pp. 141-150 ◽  
Author(s):  
Omotayo B. Adeboye ◽  
Bart Schultz ◽  
Kenneth O. Adekalu ◽  
Krishna Prasad
Bragantia ◽  
2010 ◽  
Vol 69 (suppl) ◽  
pp. 153-162 ◽  
Author(s):  
Antonio Carlos Andrade Gonçalves ◽  
Marcos Antonio Trintinalha ◽  
Marcos Vinicius Folegatti ◽  
Roberto Rezende ◽  
Cássio Antonio Tormena

Irrigated agricultural fields usually show variable crop water demand. If water application is done to match this spatially variable demand, the water use efficiency can be substantially improved. Soil water management by irrigation has been one of the most important factors to increase crop yield. To look for the economic viability of the process, the use of several inputs, particularly water, should be done with high efficiency levels. Historically, irrigation uniformity has been evaluated above the soil surface, in which applied water was the only factor to be taken into account. However, the crop will respond to soil water content uniformity, which can differ from the uniformity of water application. To evaluate temporal stability of spatial pattern of soil water storage (SWS), this work was done on a Brazilian clayed soil. Volumetric water content from soil surface to 0,30m depth, was measured by TDR in 80 points regularly spaced (3 x 3 m) on an experimental area cultivated with bean crop, irrigated by conventional sprinkling. The evaluations were done immediately before and after a water application by irrigation. Experimental semivariograms made from values obtained in the field showed that SWS distribution was spatially structured and strongly stable in time, being regulated mainly by intrinsic factors of the soil. In addition, obtained results showed that water application uniformity did not influence the spatial distribution pattern of SWS in these soil conditions.


2002 ◽  
Vol 138 (2) ◽  
pp. 135-152 ◽  
Author(s):  
S. R. GAZE ◽  
M. A. STALHAM ◽  
E. J. ALLEN

The neutron probe (NP) is used widely to measure changes in soil water storage in research and more recently to aid irrigation scheduling. Its accuracy is rarely questioned and most of the relationships between soil water changes and productivity are based on its use. A field experiment was conducted at Cambridge University Farm in 1999 to address whether the NP could accurately measure changes in soil water content (SWC) under irrigation or substantial rain (>10 mm). The experiment was a replicated split-plot design with four irrigation treatments allocated to the main plots, and surface profile (ridge, flat) and crop (potato cv. Saturna, bare soil) treatments allocated to the subplots. The mean results from four NP access tubes per plot installed to measure soil moisture deficit (SMD) across the row-width were analysed. The NP was inconsistent in measuring known irrigation or rainfall input. In relatively dry soil (SMD>40 mm), the NP generally measured 93 to 110% of 18 mm of irrigation within 4 h of irrigation. The NP recorded much less water applied as irrigation in wetter soil, and often only 40 to 70% of the applied irrigation (18 or 36 mm) was measured. There were occasions when the NP did not measure all the water input even when the SMDs before irrigation were greater than the water subsequently applied. Some of the ‘missing’ water might be attributed to drainage, however, results from an additional experiment using an open-topped tank of soil showed that the NP was unable to detect all the water added to the soil, particularly where the water was largely confined close to the soil surface. Replicated measurements of the change in SMD in the field experiment were precise for a given event and treatment (mean S.E. = 1·3 mm) but were not accurate when compared against the input measured in rain gauges. It was concluded, that the NP could not be used reliably to measure changes in soil water storage after irrigation or substantial rain. For periods when there were minimal inputs of water, there was a closer correlation between changes in SMD measured by the NP and those predicted by a modified Penman–Monteith equation than after substantial inputs of water. However, for predicted changes in SMD of c. 20 mm, there was a range of c. ±5 mm in the changes in SMD measured by the neutron probe.The value of the NP for monitoring SMDs where there is irrigation, or substantial rain, must be seriously doubted. Consequently, its limitations for scheduling irrigation, testing models or quantifying the effects of treatments on crop water use in potatoes must be appreciated, especially where the areal sampling limitations of single access tubes positioned only in the ridge centre have not been addressed.


2012 ◽  
Vol 9 (11) ◽  
pp. 13117-13154 ◽  
Author(s):  
B. te Brake ◽  
M. J. van der Ploeg ◽  
G. H. de Rooij

Abstract. Water storage in the unsaturated zone is a major determinant of the hydrological behaviour of the soil, but methods to quantify soil water storage are limited. The objective of this study is to assess the applicability of clay soil surface elevation change measurements to estimate soil water storage changes. We measured moisture contents in soil aggregates by EC-5 sensors, and in volumes comprising multiple aggregates and intra-aggregates spaces by CS616 sensors. In a prolonged drying period, aggregate-scale storage change measurements revealed normal shrinkage for layers ≥ 30 cm depth, indicating volume loss equalled water loss. Shrinkage in a soil volume including multiple aggregates and voids was slightly less than normal, due to soil moisture variations in the profile and delayed drying of deeper soil layers upon lowering of the groundwater level. This resulted in shrinkage curve slopes of 0.89, 0.90 and 0.79 for the layers 0–60, 0–100 and 0–150 cm. Under a dynamic drying and wetting regime, shrinkage curve slopes ranged from 0.29 to 0.69 (EC-5) and 0.27 to 0.51 (CS616). Alternation of shrinkage and incomplete swelling resulted in an underestimation of volume change relatively to water storage change, due to hysteresis between swelling and shrinkage. Since the slope of the shrinkage relation depends on the drying regime, measurement scale and combined effect of different soil layers, shrinkage curves from laboratory tests on clay aggregates require suitable modifications for application to soil profiles. Then, the linear portion of the curve can help soil water storage estimation from soil surface elevation changes. These elevation changes might be measurable over larger extents by remote sensing.


1984 ◽  
Vol 6 (2) ◽  
pp. 75 ◽  
Author(s):  
GG Johns

Soil water was monitored over a six year period in an intact shrub invaded semi-arid Elrcalyptlts popztlrlea woodland (control) and on areas which had been treated by either shrub-clearing, or by ringbarking of trees and shrub-clearing. Measurements were made under both the shrubby thicket areas near the eucalypt, and the sparsely shrubbed interthicket areas more distant from the trees. Average soil water storage over the six years for all treatments was only 26 nun. Much of this water was stored in the upper 500 Inm of the profile and hence was susceptible to direct evaporation from the usually bare soil surface. In the intact n.oodland and following wet weather, significantly more soil water was stored under thickets than under the interthicket areas. With the return of dry weather this cxtra soil water was rapidly depleted, and thicket soils would often become drier than interthicket soils. After pro- longed dry weather, soil matric potentials of - 10 to -1 2 MPa were recorded at a depth of 500 mm. Matric potentials by this time were least negative under thickets. Shrub clearing without rinpbarking increased thicket and interthicket soil water storage by 17% and 2396 respectively. The ring- barking and shrub clearing treatment increased thicket profile storage more than that of the interthicket (81% and 64% respectively). The effect of ringbarkinp lvas often pronounced at a distance of 25 rn from the tree. The contrasting soil water response to the two treatments indicated that in this semi-arid environment only a relatively srnaU change in soil water balance may accrue from incomplete clearing. The ren~oval of both shrubs and trees is probably necessary to make a large difference to soil water storage.


Water ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 37
Author(s):  
Tomás de Figueiredo ◽  
Ana Caroline Royer ◽  
Felícia Fonseca ◽  
Fabiana Costa de Araújo Schütz ◽  
Zulimar Hernández

The European Space Agency Climate Change Initiative Soil Moisture (ESA CCI SM) product provides soil moisture estimates from radar satellite data with a daily temporal resolution. Despite validation exercises with ground data that have been performed since the product’s launch, SM has not yet been consistently related to soil water storage, which is a key step for its application for prediction purposes. This study aimed to analyse the relationship between soil water storage (S), which was obtained from soil water balance computations with ground meteorological data, and soil moisture, which was obtained from radar data, as affected by soil water storage capacity (Smax). As a case study, a 14-year monthly series of soil water storage, produced via soil water balance computations using ground meteorological data from northeast Portugal and Smax from 25 mm to 150 mm, were matched with the corresponding monthly averaged SM product. Linear (I) and logistic (II) regression models relating S with SM were compared. Model performance (r2 in the 0.8–0.9 range) varied non-monotonically with Smax, with it being the highest at an Smax of 50 mm. The logistic model (II) performed better than the linear model (I) in the lower range of Smax. Improvements in model performance obtained with segregation of the data series in two subsets, representing soil water recharge and depletion phases throughout the year, outlined the hysteresis in the relationship between S and SM.


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