scholarly journals The effects of three techniques that change the wetting patterns over subsurface drip-irrigated potatoes

2015 ◽  
Vol 13 (3) ◽  
pp. e1204 ◽  
Author(s):  
Mohammad N. Elnesr ◽  
Abdurrahman A. Alazba

<p> </p><p>Wetting pattern enhancement is one of the goals of irrigation designers and researchers. In this study, we addressed three techniques (dual-lateral drip, intermittent flow and physical barrier methods) that change the wetting pattern of subsurface drip irrigation. To study their effect on the yield and water-use efficiency (WUE) of potatoes, field experiments were conducted for four seasons, during which the soil-water balance was continuously monitored using a set of capacitance probes. The results of the soil water patterns showed that both the dual-lateral and intermittent techniques increased lateral water movement and eliminated deep percolation, whereas the physical barrier had a limited effect on the top soil layer. The crop results indicated that the yield and WUE increased significantly in response to the application of the dual-lateral drip (up to 30%); the intermittent application also positively affected the yield (~10%) and the WUE (~14%), but these effects were not statistically significant according to the statistical model. The physical barrier showed a non-significant negative effect on the yield and WUE. These findings suggest the following recommended practices: the use of dual-lateral drip technique due to its beneficial results and its potential for increasing yields and reducing water consumption; the application of intermittent flow with more than three surges; and restricting the use of physical barriers to soils with high permeability.</p><p><span style="font-size: 12pt; font-family: 'Times New Roman',serif; line-height: 115%; mso-ansi-language: EN-US; mso-bidi-font-family: 'Simplified Arabic'; mso-fareast-language: EN-US; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-bidi-language: AR-SA;" lang="EN-US"><br style="font-size: 12pt; font-family: 'Times New Roman',serif; line-height: 115%; mso-ansi-language: EN-US; mso-bidi-font-family: 'Simplified Arabic'; mso-fareast-language: EN-US; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-bidi-language: AR-SA;" /></span></p>

2020 ◽  
Vol 20 (3) ◽  
pp. 860-870 ◽  
Author(s):  
Tao Li ◽  
Jian-feng Zhang ◽  
Si-yuan Xiong ◽  
Rui-xi Zhang

Abstract Assessing the spatial variability of soil water content is important for precision agriculture. To measure the spatial variability of the soil water content and to determine the optimal number of sampling sites for predicting the mean soil water content at different stages of the irrigation cycle, field experiments were carried out in a potato field in northwestern China. The soil water content was measured in 2016 and 2017 at depths of 0–20 and 20–40 cm at 116 georeferenced locations. The average coefficient of variation of the soil water content was 20.79% before irrigation and was 16.44% after irrigation at a depth of 0–20 cm. The spatial structure of the soil water content at a depth of 20–40 cm was similar throughout the irrigation cycle, but at a depth of 0–20 cm a relatively greater portion of the variation in the soil water content was spatially structured before irrigation than after irrigation. The autocorrelation of soil water contents was influenced by irrigation only in the surface soil layer. To accurately predict mean soil moisture content, 40 and 20 random sampling sites should be chosen with errors of 5% and 10%, respectively.


Biologia ◽  
2007 ◽  
Vol 62 (5) ◽  
Author(s):  
František Doležal ◽  
David Zumr ◽  
Josef Vacek ◽  
Josef Zavadil ◽  
Adriano Battilani ◽  
...  

AbstractWater movement and uptake by roots in a drip-irrigated potato field was studied by combining field experiments, outputs of numerical simulations and summary results of an EU project (www.fertorganic.org). Detailed measurements of soil suction and weather conditions in the Bohemo-Moravian highland made it possible to derive improved estimates of some parameters for the dual permeability model S1D_DUAL. A reasonably good agreement between the measured and the estimated soil hydraulic properties was obtained. The measured root zone depths were near to those obtained by inverse simulation with S1D _DUAL and to a boundary curve approximation. The measured and S1D _DUAL-simulated soil water pressure heads were comparable with those achieved by simulations with the Daisy model. During dry spells, the measured pressure heads tended to be higher than the simulated ones. In general, the former oscillated between the simulated values for soil matrix and those for the preferential flow (PF) domain. Irrigation facilitated deep seepage after rain events. We conclude that several parallel soil moisture sensors are needed for adequate irrigation control. The sensors cannot detect the time when the irrigation should be stopped.


Author(s):  
Chengfu Yuan

Abstract In order to explore the regional water-salt balance mechanism in Hetao Irrigation District. Field experiments were conducted in 2018 and 2019 in Heji canal study area. The SWAP model was calibrated and validated based on field experiments observed data. The SWAP model was used to simulate soil water-salt dynamic in saline wasteland after calibration and validation. The results showed that model simulation results of soil water content and soil salt concentration agreed well with the measured values. Soil water content and soil salt concentration changed obviously under the effect of farmland irrigation in crop growing period. Soil salt was accumulated in saline wasteland. The soil salt accumulation of each soil layer in saline wasteland was 0.164, 0.092, −0.890 and −1.261 mg/cm3, respectively. Soil water content gradually increased and soil salt concentration gradually decreased in autumn irrigation period. Soil salt was leached in saline wasteland. The soil salt accumulation of each soil layer in saline wasteland was −1.011, −1.242, −1.218 and −1.335 mg/cm3, respectively. The saline wasteland became in drainage and salt drainage region for cultivated land. The saline wastelands had an obvious role in adjusting salt balance and maintain salt dynamic balance in Hetao Irrigation District.


2011 ◽  
Vol 57 (No. 3) ◽  
pp. 115-121 ◽  
Author(s):  
X.B. Zhou ◽  
Y.H. Chen ◽  
Z. Ouyang

The results of two seasons' work on soil water content (SWC), evapotranspiration (ET), total dry matter (TDM), and harvest index (HI) of crops under different row spacing (RS), as well as possible ways to improve water utilization, have been reported. Field experiments were carried out at the Experimental Farm of Shandong Agricultural University (36&deg;09'N, 117&deg;09'E) in 2006&ndash;2007 and 2007&ndash;2008. Four types of RS were treated under two different water conditions (rainfed and irrigated) and set up in a randomized plot design. RS did not exhibit any obvious effects on SWC during the study period. SWC was enhanced evidently by irrigation, especially in the 10&ndash;60 cm soil layer. Irrigation increased the ET of crop. At the seeding-jointing stage, the ET of RS14 was significantly higher than those during other treatments (P &lt; 0.05). Irrigation increased yields, ET, and TDM, while it decreased water use efficiency and HI. There were significantly negative correlations between TDM and RS (P &lt; 0.05). The HI of the rainfed crop was higher than that of the irrigated crop. Results showed that high yields of wheat could be achieved in northern China by reducing RS under uniform planting density conditions.


Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2241
Author(s):  
Niannian Yuan ◽  
Yujiang Xiong ◽  
Yalong Li ◽  
Baokun Xu ◽  
Fengli Liu

Field experiments and micro test pit experiments are conducted at the Four Lake Watershed with a shallow groundwater table in the Hubei province of China in order to study the effect of controlled pipe drainage on soil moisture and nitrogen under different experiment scales. Soil moisture and nitrogen contents are continuously observed at the effective soil depth; water and nitrogen balance are calculated after several heavy rainfalls. The results showed that controlled pipe drainage significantly reduced the fluctuation of soil water content in the entire growth stage. There is a positive correlation between the soil moisture and the control water level in the test pits but no obvious correlation between them in the field experiments, which is related to the vertical and lateral recharge of groundwater in the field. After rainfall, soil organic matter mineralization was enhanced, and the control pipe drainage measures increased the relative content of soil mineralized ammonia nitrogen, which enhanced the stability of soil nitrogen and helped to reduce the loss of nitrogen. The calculation of soil water and nitrogen balance in the field and micro-area after rainfall showed that the soil water storage increased in the effective soil layer under the control water level of 30 cm and 50 cm after rainfall, and the amount of nitrogen mineralization was larger than that under the free drainage treatment.


2019 ◽  
Vol 136 ◽  
pp. 07025
Author(s):  
Guangying Zhang

This paper first studies the vertical structure and soil physical properties of Songlin Plot and Huangshan Plot in Chongling Small Watershed. Then, based on a series of field experiments, this paper obtains the basic parameters and infiltration characteristics of soil water movement in two runoff Plots with different land use types. After that, this paper analyzes the seasonal variation, vertical spatial change and the response to precipitation of land with different use types based on the data monitored in the runoff Plots under natural rainfall conditions. The result shows that the changes of soil water at different depths of Songlin Plot and Huangshan Plot are basically the same and that the soil water supply is completely controlled by precipitation. The water storage capacity of Songlin Plot is stronger, while the soil moisture variation of Huangpo Plot is higher, which indicates that Songlin Plot is more stable in terms of soil moisture content and stronger in self-adjustment.


Author(s):  
qi Chen ◽  
Yuanqiu Liu ◽  
Jiahui Huang ◽  
Yunhong Xie ◽  
Tianjun Bai ◽  
...  

The conversion of natural forests to planted forests has become a global trend, and the practice has wide-ranging effects on soil. This study aimed to explore the differences in soil water movement after the conversion of evergreen and deciduous broad-leaved mixed forests (natural forest, NF) to Chinese fir (Cunninghamia lanceolate (Lamb.) Hook.) plantations (CFP, 20–21 years old). Soil samples from five layers (0–5, 5–10, 10–20, 20–30, and 30–50 cm) were collected from NF and CFP before and after rainfall event in the Peng Chongjian watershed, Jiangxi Province. The physical properties of the soils, including the mean and coefficient of variation (CV) of soil moisture content and the soil particle composition, were determined in both forest types. The δD of soil water and the litter water-holding capacity were also measured. The results showed that the variation ranges of moisture content in each soil layer after the rainfall was 21.13%–49.40% in CFP and 21.33%–43.87% in NF. There were no significant differences in soil bulk density or porosity; the clay and silt contents were significantly increased in topsoil, while the sand was significantly decreased (P < 0.05). After the rainfall, soil water in CFP responded more promptly than NF. In the process of infiltration, the contribution of rainfall to soil moisture gradually decreased with increasing soil depth. Topsoil (0–5 cm) in NF responded promptly to rainfall, but the response showed a lag effect with the increase of soil depth. With the extension of infiltration time, the contribution of precipitation to deep soil gradually increased. The results showed that the soil did not degrade after the conversion of NF to CFP, a significant guiding result for plantation cultivation.


2009 ◽  
Vol 36 (8) ◽  
pp. 752 ◽  
Author(s):  
Heidi-J. Hawkins ◽  
Hans Hettasch ◽  
Adam G. West ◽  
Michael D. Cramer

Proteaceae of the Cape Floristic Region, South Africa, transpire throughout the summer drought, implying access to deep water. Hydraulic redistribution by Protea ‘Sylvia’ [P. susannae E. Phillips × P. exima (Salisb. Ex Knight) Fource; Proteaceae] was investigated in overnight pot and field experiments, where it was hypothesised that (1) Proteaceae replenish water in upper soil layers, (2) hydraulic redistribution facilitates nutrient uptake and (3) shallow-rooted understorey plants ‘parasitise’ water from proteas. Potted Sylvias redistributed ~17% of the tritiated water supplied, equating to 34 ± 1.2 mL plant−1. Shallow-rooted Cyanodon dactylon (L.) Pers. (Poaceae), plants growing in the same pots as Sylvia contained amounts of labelled water similar to those found in Sylvia, indicting water parasitism. In the field, Sylvia plants growing in aeolian sands took up the deuterated water applied at 1.2 m depth as indicated by increased δ2H of plant xylem water from –38 ± 0.8 to 334 ± 157‰. This deuterated water was then redistributed to the upper soil layer (0.2 and 0.4 m), as indicated by increased δ2H of soil water from –24.5 ± 0.7 to –8.0 ± 3.0‰ and soil moisture from 0.48 to 0.89%. Lithium, as a K-analogue, was taken up equally by plants watered with deep water and those not watered, probably since both had access to naturally-occurring deep water. Water in stems of the shallow-rooted understorey shrub, Leysera gnaphalodes (L.) L. (Asteraceae) had similar δ2H values to stems of Sylvia (P = 0.939), again indicating water parasitism was tightly coupled to the protea. We conclude that hydraulic redistribution by Proteaceae plays an important role in soil water replenishment, water supply to shallow-rooted plants, and, thus, ecosystem structure and function during the summer drought of the Cape Floristic Region.


Agriculture ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1099
Author(s):  
Ruofan Li ◽  
Juanjuan Ma ◽  
Xihuan Sun ◽  
Xianghong Guo ◽  
Lijian Zheng

The ridge–furrow mulching system with plastic film (RFMS) has been widely used in semi-arid areas in order to improve soil water and heat conditions, crop yields and water use efficiency. It is of practical significance to study the effect of mulching and ridge types on soil water and heat in order to optimize mulching measures and improve the effectiveness of the ridge and furrow system. To clarify the combined effect of soil water and heat beneath the system and the influence of ridge morphology on it, field experiments were conducted with three treatments, including conventional planting in bare land (CK), a ridge–furrow (wide ridge with 70 cm width and 10 cm height, narrow ridge with 40 cm width and 15 cm height) mulching system with complete plastic film (RFWN) and a ridge–furrow (equal ridge with 55 cm width and 15 cm height) mulching system with complete plastic film (RFE). An insufficient irrigation system was adopted and the two-dimensional numerical software HYDRUS-2D was used to simulate the soil water and heat flow under the experimental conditions. The model was calibrated and verified according to test data for the period of 2018 to 2019, which showed good agreement between the simulated and measured values. The simulation results revealed that the ground temperatures of RFWN and RFE were much higher than that of CK, and the average value of 0–25 cm during the growth period could increase by 2.29–4.61%. Compared with CK, RFWN and RFE reduced soil evaporation (84.71–93.73%) and field evapotranspiration (12.02–21.75%), while they increased root water uptake (25.87–40.98%) and T/ET (48.85–80.15%). Plastic film mulching and ridge morphologies affected the infiltration range and the direction of soil water movement, increased soil moisture when there was no rainfall or irrigation and reduced soil water and heat fluctuations, which was more conducive to crop growth, especially under the RFWN system. The simulation method proposed in this paper is an effective technique for calculating the soil water and heat dynamics under different ridge and furrow sections under the condition of film mulching, and it can be used for the optimal management of soil water and heat in this area.


Biologia ◽  
2006 ◽  
Vol 61 (19) ◽  
Author(s):  
Vlasta Štekauerová ◽  
Viliam Nagy ◽  
Dana Kotorová

AbstractThe unsaturated zone of soil is one of the most important and complicated parts considering the water movement in the hydrologic cycle. Water transfer through its upper and lower boundary directly influences the amount of water in this zone. The depth of groundwater table usually delimits the lower boundary. The soil surface with or without plant canopy is the upper boundary. The soil surface reacts directly on meteorological conditions primary through evapotranspiration. It is determining the inflow of precipitation into deeper layers of a soil profile. Both physical and hydrophysical properties of the upper soil layer are changed under the extreme meteorological conditions. In case of such conditions the water can flow along preferential pathways down to the groundwater without filling up the soil matrix. Changes of physical and hydrophysical characteristics of the soil surface layer or of the root zone depend on the vegetation type, too. The water storage of 0–30 cm and 30–60 cm soil layers was calculated from monitored data of soil water contents in two different ecosystems, and the calculated water storages were compared with the integral water contents that are related to hydrolimits (field capacity, point of decreased availability and wilting point) in 1999 and 2000. It should be noted that it was considerably dryer in 2000 than in 1999, and during the vegetation period, it was also warmer in 2000 than in 1999. The higher air temperatures during the vegetation season and the lower cumulative rainfall in 2000 comparing to 1999 resulted in a decrease in the integral water contents in the root zone.


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