-
[show abstract]
[hide abstract]
ABSTRACT: Identification of drainage water allows assessing the effectiveness of water management. Passive capillary wick-type lysimeters
(PCAPs) were used to monitor water flux leached below the root zone under an irrigated cropping system. Wireless lysimeters
were developed for web-based real-time online monitoring of drainage water using a distributed wireless sensor network (WSN).
Twelve PCAP sensing stations were installed across the field at 90cm below the soil surface, and each station measured the
amount of drainage water using two tipping buckets mounted in the lysimeter and continually monitored soil water contents
using two soil moisture sensors installed above the lysimeter. A weather station was included in the WSN to measure micrometeorological
field conditions. All in-field sensory data were periodically sampled and wirelessly transmitted to a base station that was
bridged to a web server for broadcasting the data on the internet. Communication signals from the in-field sensing stations
to the base station were successfully interfaced using low-cost Bluetooth wireless radio communication. Field experiments
resulted in high correlation between estimated and actual drainage with r
2=0.95 and confirmed a reliable wireless communication throughout the growing season. A web-linked WSN system provided convenient
remote online access to monitor drainage water flux and field conditions without the need for costly time-consuming supportive
operations.
Irrigation Science 04/2012; 29(5):423-430. · 1.63 Impact Factor
-
O Tresca,
D C Carroll,
X H Yuan,
B Aurand,
V Bagnoud,
C M Brenner,
M Coury,
J Fils,
R J Gray,
T Kuhl,
C Li,
Y T Li,
X X Lin,
M N Quinn, R G Evans,
B Zielbauer,
M Roth,
D Neely,
P McKenna
Plasma Physics and Controlled Fusion. 53(10).
-
[show abstract]
[hide abstract]
ABSTRACT: The application of crop residues (mulches) to irrigation furrows can have a large impact on improving surface water quality from surface irrigated lands in central Washington state. This study showed that soil erosion in furrows can be effectively controlled by the use of crop residues at rates of about 0.66 Mg ha−1 in the furrow area. The runoff leaving the residue applied treatments was often clear. There was a large decrease in nutrients leaving the field due to reduced sediment losses. The use of surge flow was superior to continuous flow furrow irrigation for maintaining acceptable application uniformities because of increased wetted perimeters and slow advance rates when crop residues were present. Surge flow with residues resulted in a more uniform water application when compared to constant flow furrow irrigation at the same residue loadings and inflow rates, and also reduced soil-attached fertilizer losses.
Agricultural Water Management.
-
[show abstract]
[hide abstract]
ABSTRACT: Among greenhouse gases, carbon dioxide (CO2) is one of the most significant contributors to regional and global warming as well as climatic change. A field study was conducted to (i) determine the effect of soil characteristics resulting from changes in soil management practices on CO2 flux from the soil surface to the atmosphere in transitional land from perennial forages to annual crops, and (ii) develop empirical relationships that predict CO2 flux from soil temperature and soil water content. The CO2 flux, soil temperature (Ts), volumetric soil water content (θv) were measured every 1–2 weeks in no-till (NT) and conventional till (CT) malt barley and undisturbed soil grass-alfalfa (UGA) systems in a Lihen sandy loam soil (sandy, mixed, frigid Entic Haplustoll) under irrigated and non-irrigated conditions in western North Dakota. Soil air-filled porosity (ε) was calculated from total soil porosity and θv measurements. Significant differences in CO2 fluxes between land management practices (irrigation and tillage) were observed on some measurement dates. Higher CO2 fluxes were detected in CT plots than in NT and UGA treatments immediately after rainfall or irrigation. Soil CO2 fluxes increased with increasing soil moisture (R2=0.15, P<0.01) while an exponential relationship was found between CO2 emission and Ts (R2=0.59). Using a stepwise regression analysis procedure, a significant multiple regression equation was developed between CO2 flux and θv, Ts (CO2flux=e-3.477+0.123Ts+6.381θv; R2=0.68, P⩽0.01). Not surprisingly, soil temperature was a driving factor in the equation, which accounted for approximately 59% in variation of CO2 flux. It was concluded that less intensive tillage, such as no-till or strip tillage, along with careful irrigation management will reduce soil CO2 evolution from land being converted from perennial forages to annual crops.
Journal of Environmental Management.
-
[show abstract]
[hide abstract]
ABSTRACT: A long-term research project was initiated in 1983 on a 1.2 ha trickle-irrigated Vitis vinifera vineyard to address water management of White Riesling (WR), Chenin blanc (CB), and Cabernet Sauvignon (CS) grapes in central Washington. Six large drainage lysimeters, two per cultivar, were installed to monitor crop water use. Each lysimeter contained two vines. Vines were balance pruned and shoot-thinned to achieve an equivalent crop level of about 15 Mg/ha of grapes. Analyses showed that published crop coefficients (ETo) for mature grapes greatly overestimate water use early and late in the season for Washington conditions although peak crop coefficients of about 0.8-0.9 were similar. Annual crop water use for all three cultivars ranged from 130 mm for one-year-old vines in 1985 to as much as 540 mm for mature vines in 1990. The average crop water use for small, young vines (1985–1986) was about 146 mm/yr, and from 1987–1990 for mature plants it was about 417 mm/yr for all three cultivars.
Agricultural Water Management.
-
[show abstract]
[hide abstract]
ABSTRACT: In-field sensor-based site-specific irrigation management is of benefit to producers for efficient water management. Integration of the decision making process with the controls is a viable option for determining when and where to irrigate, and how much water to apply. This research presents the design of decision support software and its integration with an in-field wireless sensor network (WSN) to implement site-specific sprinkler irrigation control via Bluetooth wireless communication. Wireless in-field sensing and control (WISC) software was designed by four major design factors that provide real-time monitoring and control of both inputs (field data) and outputs (sprinkler controls) by simple click-and-play menu using graphical user interface (GUI), and optimized to adapt changes of crop design, irrigation pattern, and field location. The WISC software provides remote access to in-field micrometeorological information from the distributed WSN and variable-rate irrigation control. An algorithm for nozzle sequencing was developed to stagger nozzle-on operations so as evenly distributed over the 60-s cycle. Sensor-based closed-loop irrigation was highly correlated to catch can water with r2 = 0.98.
Computers and Electronics in Agriculture.
