Evapotranspiration Measurement and Irrigation Scheduling for Several Tropical Fruit Crops Using the EnviroScan System

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 549f-550
Author(s):  
Mongi Zekri ◽  
Bruce Schaffer ◽  
Stephen K. O'Hair ◽  
Roberto Nunez-Elisea ◽  
Jonathan H. Crane
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Use ◽  
National Parks ◽  
Quantitative Information ◽  
Irrigation Scheduling ◽  
Management Tool ◽  
Fruit Crops ◽  
Tropical Fruit

In southern Florida, most tropical fruit crops between Biscayne and Everglades National Parks are irrigated at rates and frequencies based on experience and observations of tree growth and fruit yield rather than on reliable quantitative information of actual water use. This approach suggests that irrigation rates may be excessive and could lead to leaching of agricultural chemicals into the groundwater in this environmentally sensitive area. Therefore, a study is being conducted to increase water use efficiency and optimize irrigation by accurately scheduling irrigation using a very effective management tool (EnviroScan, Sentek Environmental Innovations, Pty., Kent, Australia) that continuously monitors soil water content with highly accurate capacitance multi-sensor probes installed at several depths within the soil profile. The system measures crop water use by monitoring soil water depletion rates and allows the maintenance of soil water content within the optimum range (below field capacity and well above the onset of plant water stress). The study is being conducted in growers' orchards with three tropical fruit crops (avocado, carambola, and `Tahiti' lime) to facilitate rapid adoption and utilization of research results.

scholarly journals Environmentally Friendly Soil Water Conservation Techniques

2019 ◽  
Vol 9 (1) ◽  
pp. 5513-5520
Keyword(s):  
Plant Growth ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Use ◽  
Water Scarcity ◽  
Water Retention ◽  
Direct Method ◽  
Environmentally Friendly ◽  
Cultivated Plants

The conservation of water resources through their optimal use is a compulsory for countries with water shortages in the arid and semi-arid regions, and it should be in an environmentally friendly manner to avoid the serious consequences of the use of environmentally harmful substances, the implications of which are currently evident from climate change, pollution of water bodies, soils, etc. Since Egypt is one of those countries suffering from water scarcity and uses about 82.5 percent of its water consumption in agriculture, according to data of the Ministry of Irrigation in 2010, so this research is focusing on the use of new methods to increase the efficiency of irrigation water, to achieve high productivity of agricultural crops with less water use that will certainly help to alleviate or solve the water scarcity issue. The study used a physical based model, to simulate the methods used to increase sand soil properties to ensure larger water retention index. Within this work, soil have been sampled from different areas, to simulate the behavior of arid lands, under different water retention techniques. Soil was exposed to different techniques, as it was mixed with soil additives in different quantities and different types. Physical barriers of cohesive soil and polyethylene sheets were used in addition to studying the effect of mulch on water storage capacity in noncohesive soil. Water retention have been measured using the direct method of determination soil water content by oven drying and the volumetric water content (𝞱v ) with time graphs have been plotted in groups, as well as the cultivated plants have been monitored as to measure the influence on plants growing and irrigation efficiency. And the experiment showed that the use of rice straw (RS) and wheat straw (WS) in the powder condition have a significant effect in increasing in the soil water content and even to the plant growth, the WS obtained 𝞱v values approaching the loam soil at times and slightly less in the case of RS, when the percentage of RC and WS was 30% to the sandy soil volume/volume (v/v). Also the use of mulch of RS showed a noticeable increase in 𝞱v and significant improvement of plant growth to that without mulch. These proven technologies can be used in sandy land targeted for reclamation to reduce water use in agriculture.

Effects of burning on soil-water content and water use in a Paspalum quadrifarium grassland

2001 ◽  
Vol 50 (2) ◽  
pp. 97-108 ◽  
Author(s):  
Karina M Sakalauskas ◽  
José L Costa ◽  
Pedro Laterra ◽  
Liliana Hidalgo ◽  
Luis A.N Aguirrezabal
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Use

On-farm measurement of the water use and productivity of maize

2008 ◽  
Vol 48 (3) ◽  
pp. 274 ◽  
Author(s):  
K. L. Greenwood ◽  
G. N. Mundy ◽  
K. B. Kelly
Keyword(s):  
Dairy Cows ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Use ◽  
Water Productivity ◽  
Weather Data ◽  
Local Conditions ◽  
High Yields ◽  
Crop Coefficients

Maize, as a C4 species, is likely to use water more productively than the perennial ryegrass and white clover pastures typically grown for dairy cows in northern Victoria. However, only estimates of water use by irrigated maize crops are available for this region. We measured the growth and water use of three commercial maize crops used for silage in northern Victoria. Crops under centre pivot irrigation were monitored in 2003–04 (Spray 1) and 2004–05 (Spray 2). A border-check irrigated crop (Border-check) was monitored in 2004–05. The Spray 1 crop was irrigated 30 times and received 782 mm of rainfall and irrigation. The crop yielded 22 t DM/ha, giving a water productivity of 28 kg DM/ha.mm (including irrigation, rainfall and change in soil water content). In the cooler, wetter summer of 2004–05, the water productivity was 34 kg DM/ha.mm for the Spray 2 crop and 30 kg DM/ha.mm for the Border-check crop. Crop evapotranspiration was estimated from weather data and a daily soil water balance was computed according to FAO 56. The estimated and measured changes in soil water content were in good agreement and indicated that the basal crop coefficients in the model (Kcb = 1.15 during the mid-season, before correction for non-standard humidity and wind speed) were appropriate to local conditions. Maize grown for silage in northern Victoria has higher water productivity than pastures. However, high yields are required to make it economically viable compared with alternative forages for dairy cows. These data will assist dairy farmers to select the optimum forage mix for their enterprises.

scholarly journals Water Use, Growth, and Fruit Yield of `Hosui' Asian Pears under Deficit Irrigation

1994 ◽  
Vol 119 (3) ◽  
pp. 383-388 ◽  
Author(s):  
Horst W. Caspari ◽  
M. Hossein Behboudian ◽  
David J. Chalmers
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Use ◽  
Deficit Irrigation ◽  
Fruit Size ◽  
Fruit Growth ◽  
Volume Measurements ◽  
Pyrus Serotina ◽  
Return Bloom

Five-year old `Hosui' Asian pear (Pyrus serotina Rehder) trees growing in drainage lysimeters and trained onto a Tatura trellis were subjected to three different irrigation regimes. Weekly water use (WU) was calculated using the mass-balance approach. Soil-water content of control lysimeters was kept at pot capacity, while deficit irrigation was applied before [regulated deficit irrigation (RDI)] and during the period of rapid fruit growth [late deficit irrigation (LDI)]. Soil-water content was maintained at ≈50% and 75% of pot capacity for RDI and LDI, respectively. Deficit irrigation reduced mean WU during RDI and LDI by 20%. The reduced WU was caused by lower stomatal conductance (gs) on deficit-irrigated trees. RDI trees had more-negative diurnal leaf water potentials (ψl). The ψl, gs, and WU remained lower for 2 weeks after RDI was discontinued. RDI reduced shoot extension and summer pruning weights, whereas winter pruning weights were not different between treatments. Except for the final week of RDI, fruit growth was not reduced, and fruit from RDI grew faster than the control during the first week after RDI. In contrast, fruit volume measurements showed that fruit growth was clearly inhibited by LDI. Final fruit size and yield, however, were not different between treatments. Return bloom was reduced by RDI but was not affected by LDI.

scholarly journals Application of a Dielectric Measurement Technique for Calculating Water Loss from Two Texture-contrasting Soils Grown with Upland Rice

2018 ◽  
Vol 1 (1) ◽  
pp. 8-14
Author(s):  
Bandi Hermawan ◽  
Pajrina Pajrina ◽  
Sumardi Sumardi ◽  
Indra Agustian
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Use ◽  
Water Loss ◽  
Electrical Impedance ◽  
Upland Rice ◽  
Sandy Loam ◽  
Dielectric Measurement ◽  
Loamy Sand

Most of the water loss from the soil profile occurred through the evapotranspiration process especially when the plant covers were under maximum growth periods.  This study aimed to apply a technique of measuring a dielectric variable for calculating soil water content and crop water use in the coarse and medium textured soils grown with upland rice.  A couple of wires were inserted into the soil repacked in a 10-kg polybag grown with upland rice, the electrical impedance representing the dielectric value was measured using an instrument called the impedance meter.  The impedance values were converted into the soil water content using a nonlinear regression model of ? = a.ebZ where a and b were constants.  Results showed that the proposed technique of measuring the electrical impedance has successfully been applied to calculate the soil water content and the water use by upland rice grown in loamy sand and sandy loam soils.  Cumulative water loss from loamy sand was about 4 L plant-1 higher for the coarse loamy sand in the first 30 days of a measurement period, but about 10 L plant-1 higher for finer sandy loam on the 90th day of the rice growth period.  Higher biomass of upland rice in the sandy loam soil could increase the evapotranspiration rates and be the main reason for higher water use in this soil.

scholarly journals 533 Monitoring Soil Water Content in Tropical Fruit Orchards in Southern Florida with Multi-sensor Capacitance Probes and Tensiometers

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 487C-487 ◽  
Author(s):  
R. Nuñez-Elisea ◽  
B. Schaffer ◽  
M. Zekri ◽  
S.K. O'Hair ◽  
J.H. Crane
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Volumetric Soil Water Content ◽  
Tropical Fruit ◽  
Soil Water Tension ◽  
Scheduling Irrigation ◽  
Southern Florida ◽  
Fruit Orchards ◽  
Water Tension

Tropical fruit trees in southern Florida are grown in porous, oolitic limestone soil that has very low organic matter content and water-holding capacity. Thus, trees require frequent irrigation during dry periods. In these soils, a quantitative basis for monitoring soil water content to determine when and how much to irrigate has been lacking. Multi-sensor capacitance probes (EnviroSCAN™, Sentek, Australia) were installed in commercial carambola, lime, and avocado orchards to continuously monitor changes in soil water content at depths of 10, 20, 30, and 50 cm. Eight probes were installed per orchard. Volumetric soil water content was recorded at 15-min intervals with a solar-powered datalogger. Results were downloaded to a laptop computer twice a week. Monitoring the rate of soil water depletion (evapotranspiration) allowed irrigation before the onset of water stress. The time at which soil reached field capacity could be determined after each irrigation (or rain) event. Soil water tension was recorded periodically using low-tension (0–40 cbars) tensiometers placed adjacent to selected capacitance probes at 10- and 30-cm depths. Soil water tension was better correlated with volumetric soil water content at a 10-cm depth than at 30-cm depth. Using multi-sensor capacitance probes is a highly accurate, although relatively expensive, method of monitoring soil water content for scheduling irrigation in tropical fruit orchards. Whereas tensiometers require periodic maintenance, the multi-sensor capacitance probe system has been virtually maintenance free. The correlation between soil water content and soil water tension obtained in situ indicates that tensiometers are a less precise, but considerably cheaper, alternative for scheduling irrigation in tropical fruit orchards in southern Florida.

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