scholarly journals Guidelines for irrigation scheduling of banana crop in São Francisco Valley, Brazil. I - Root distribution and activity

2004 ◽  
Vol 26 (3) ◽  
pp. 459-463 ◽  
Author(s):  
Luís Henrique Bassoi ◽  
José Antonio Moura e Silva ◽  
Emanuel Elder Gomes da Silva ◽  
Clovis Manoel Carvalho Ramos ◽  
Gilberto Chohaku Sediyama
Keyword(s):  
Water Management ◽  
Soil Water ◽  
Root Distribution ◽  
Digital Image Analysis ◽  
Water Flux ◽  
Irrigation Scheduling ◽  
Northeastern Brazil ◽  
Rooting Depth ◽  
Irrigation Water Management ◽  
Banana Crop

In order to establish guidelines for irrigation water management of banana cv. Pacovan (AAB group, Prata sub-group) in Petrolina County, northeastern Brazil, the root distribution and activity were measured on an irrigated plantation, in a medium texture soil, with plants spaced in a 3 x 3 m grid. Root distribution was evaluated by the soil profile method aided by digital image analysis, while root activity was indirectly determined by the changing of soil water content and by the direction of soil water flux. Data were collected since planting in January 1999 to the 3rd harvest in September 2001. Effective rooting depth increased from 0.4 m at 91 days after planting (dap), to 0.6 m at 370, 510, and 903 dap, while water absorption by roots was predominantly in the top 0,6 m.

scholarly journals Root distribution of irrigated grapevine rootstocks in a coarse texture soil of the São Francisco Valley, Brazil

2002 ◽  
Vol 24 (1) ◽  
pp. 35-38 ◽  
Author(s):  
LUÍS HENRIQUE BASSOI ◽  
LEILSON COSTA GRANGEIRO ◽  
JOSÉ ANTONIO MOURA E SILVA ◽  
EMANUEL ELDER GOMES DA SILVA
Keyword(s):  
Water Management ◽  
Image Analysis ◽  
Root Distribution ◽  
Digital Image Analysis ◽  
Table Grape ◽  
Rooting Depth ◽  
Coarse Texture ◽  
Salt Creek ◽  
Soil And Water ◽  
Wall Method

An experiment was carried out to determine the root distribution of four grapevine rootstocks (Salt Creek, Dogridge, Courdec 1613, IAC 572) in a coarse texture soil of a commercial growing area in Petrolina County, São Francisco Valley, Brazil. Rootstocks were grafted to a seedless table grape cv. Festival, and irrigated by microsprinkler. Roots were quantified by the trench wall method aided by digital image analysis. Results indicated that roots reached 1 m depth, but few differences among rootstocks were found. All of them presented at least 90 % of the roots distributed until 0.6 m depth, with a greater root presence in the first 0.4 m. The upper 0.6 m can be taken into account as the effective rooting depth for soil and water management.

scholarly journals How to put plant root uptake into a soil water flow model

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 43
Author(s):  
Xuejun Dong
Keyword(s):  
Water Stress ◽  
Soil Water ◽  
Water Uptake ◽  
Root Distribution ◽  
Plant Root ◽  
Root Water Uptake ◽  
Root Uptake ◽  
Water Dynamics ◽  
Rooting Depth ◽  
Plant Root Uptake

The need for improved crop water use efficiency calls for flexible modeling platforms to implement new ideas in plant root uptake and its regulation mechanisms. This paper documents the details of modifying a soil infiltration and redistribution model to include (a) dynamic root growth, (b) non-uniform root distribution and water uptake, (c) the effect of water stress on plant water uptake, and (d) soil evaporation. The paper also demonstrates strategies of using the modified model to simulate soil water dynamics and plant transpiration considering different sensitivity of plants to soil dryness and different mechanisms of root water uptake. In particular, the flexibility of simulating various degrees of compensated uptake (whereby plants tend to maintain potential transpiration under mild water stress) is emphasized. The paper also describes how to estimate unknown root distribution and rooting depth parameters by the use of a simulation-based searching method. The full documentation of the computer code will allow further applications and new development.

scholarly journals Guidelines for irrigation scheduling of banana crop in São Francisco Valley, Brazil. II - Water consumption, crop coefficient, and physiologycal behavior

2004 ◽  
Vol 26 (3) ◽  
pp. 464-467 ◽  
Author(s):  
Luís Henrique Bassoi ◽  
Antonio Heriberto de Castro Teixeira ◽  
José Moacir Pinheiro Lima Filho ◽  
José Antonio Moura e Silva ◽  
Emanuel Elder Gomes da Silva ◽  
...  
Keyword(s):  
Water Consumption ◽  
Water Availability ◽  
Crop Coefficient ◽  
Irrigation Scheduling ◽  
Northeastern Brazil ◽  
Evaporative Demand ◽  
Irrigation Water Management ◽  
Growing Seasons ◽  
Daily Water ◽  
Daily Water Consumption

The water consumption and the crop coefficient of the banana cv. Pacovan were estimated in Petrolina County, northeastern Brazil, in order to establish guidelines to irrigation water management. Evaluations were carried out since planting in January 1999 to the 3rd harvest in September 2001 on a microsprinkler irrigated orchard, with plants spaced in a 3 x 3 m grid. Average daily water consumption was 3.9, 4.0, and 3.3 mm in the 1st, 2nd and 3rd growing seasons, respectively. Crop coefficient values increased from 0.7 (vegetative growth) to 1.1 (flowering). Even with high soil water availability, transpiration was reduced due to high evaporative demand.

Soil Water Measurement as Basis to Optimize Irrigation Scheduling: A Review

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 553f-554
Author(s):  
A.K. Alva ◽  
A. Fares
Keyword(s):  
Soil Moisture ◽  
Water Content ◽  
Soil Water ◽  
Real Time ◽  
Soil Water Content ◽  
Root Zone ◽  
Soil Water Potential ◽  
Irrigation Scheduling ◽  
Rooting Depth ◽  
The Impact

Supplemental irrigation is often necessary for high economic returns for most cropping conditions even in humid areas. As irrigation costs continue to increase more efforts should be exerted to minimize these costs. Real time estimation and/or measurement of available soil water content in the crop root zone is one of the several methods used to help growers in making the right decision regarding timing and quantity of irrigation. The gravimetric method of soil water content determination is laborious and doesn't suite for frequent sampling from the same location because it requires destructive soil sampling. Tensiometers, which measure soil water potential that can be converted into soil water content using soil moisture release curves, have been used for irrigation scheduling. However, in extreme sandy soils the working interval of tensiometer is reduced, hence it may be difficult to detect small changes in soil moisture content. Capacitance probes which operate on the principle of apparent dielectric constant of the soil-water-air mixture are extremely sensitive to small changes in the soil water content at short time intervals. These probes can be placed at various depths within and below the effective rooting depth for a real time monitoring of the water content. Based on this continuous monitoring of the soil water content, irrigation is scheduled to replenish the water deficit within the rooting depth while leaching below the root zone is minimized. These are important management practices aimed to increase irrigation efficiency, and nutrient uptake efficiency for optimal crop production, while minimizing the impact of agricultural non-point source pollutants on the groundwater quality.

scholarly journals 685 PB 227 A SIMPLE COMPUTER PROGRAM FOR UPDATING WATER BUDGETS FOR IRRIGATED VEGETABLES

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 531a-531
Author(s):  
Eric H. Simonne ◽  
Joseph M. Kemble ◽  
Doyle A. Smittle
Keyword(s):  
Water Management ◽  
Computer Program ◽  
Water Use ◽  
Irrigation Scheduling ◽  
Weather Data ◽  
Rooting Depth ◽  
Water Budgets ◽  
Scheduling Irrigation ◽  
Daily Water ◽  
Water Holding

A TurboPascal computer program was developed to calculate daily water budgets and schedule irrigations. Daily water use (di) is calculated as pan evaporation (Ep) times a crop factor (CFi), where i is crop age. The water balance uses a dynamic rooting depth, the soil water holding capacity (SWC) and rainfall data (Ri). di is added to the cumulative water use (Di-1) and Ri is subtracted from Di. An irrigation in the amount of Di is recommended when Di approximates allowable water use. The program cart be adapted to most crop and soil types, and can be used for on-time irrigation scheduling or for simulating water application using past or projected weather data. This program should increase the acceptance of modem scheduling irrigation techniques by farmers and consultants. Additionally, this program may have application in an overall water management programs for farms, watersheds or other areas where water management is required.

Soil water content sensors from laboratory calibration to field monitoring: discrepancies and uncertainties

2021 ◽  
Author(s):  
Angela Gabriela Morales Santos ◽  
Reinhard Nolz
Keyword(s):  
Soil Moisture ◽  
Water Content ◽  
Soil Water ◽  
Root Zone ◽  
Sandy Loam ◽  
Irrigation Scheduling ◽  
Water Monitoring ◽  
Rooting Depth ◽  
Water Fraction ◽  
Laboratory Calibration

<p>Monitoring soil water status is one key option to optimise water use in agriculture. Soil moisture sensors are widely used for investigating available soil water to optimally adapt irrigation scheduling to crop water requirements. Although reliable measurements are subject to proper soil-specific calibration of sensors, meaningful calibration functions are not always available. Another question is the plausibility of soil water monitoring under field conditions. The objective of this study was to calibrate four multi-sensor capacitance probes in the laboratory and  to evaluate the calibrated water content readings under natural conditions in an irrigated field by means of a modelling approach.</p><p>The multi-sensor capacitance probes (SM1 by ADCON Telemetry) were of 90 cm length and contained nine sensors (S1 to S9) at 10 cm spacing. The digital output values were given in scaled frequency units (SFU). The laboratory calibration was carried out on sandy loam and sand. Measurements were undertaken by placing the probes inside a PVC tube backfilled with soil at different water contents. Soil samples were collected using metallic cylinders of 250 cm<sup>3</sup>, from which volumetric water content (θ) was determined gravimetrically. The sensor readings in soil were normalised by using sensor readings in air and water as lower and upper limit, respectively. The pairs of measured θ and normalised SFU were related to each other by curve fitting. For each soil type, eight sensor-specific calibration functions were developed that allowed the calculation of θ in cm<sup>3</sup> cm<sup>−</sup><sup>3</sup> from SM1 readings.</p><p>After calibration, the SM1 probes were installed in a field in Obersiebenbrunn, Lower Austria, where sandy loam is the main soil. Three of the probes monitored irrigated plots and the fourth a rainfed plot. To obtain reference values, one HydraProbe soil moisture sensor (Stevens Water Monitoring Systems) was installed in 20 cm depth, near each SM1. The average daily θ-values from the S2 (20 cm depth) contained in each SM1 probe were compared to the water fraction collected with the corresponding HydraProbe. Moreover, the SM1 θ-values were used to determine the daily soil water depletion in the root zone (Dr) for a rooting depth of 1 m. The obtained Dr datasets were compared to Dr simulated using CROPWAT 8.0 by FAO.</p><p>The field results showed that the SM1 probes were able to reproduce the HydraProbe dynamics of wetting and drying periods during the crop season. Nevertheless, a considerable difference was noted between the sensor measurements. The SM1 overestimated θ in the irrigated plots, whereas it underestimated θ in the rainfed plot. The discrepancies can be attributed mainly to the different physical mechanisms behind the sensors and to the unfeasible reproduction of field bulk density and soil structure in the laboratory. Furthermore, the operational frequency and permittivity response of the SM1 probes should be revised for future versions. The simulation results showed that the observed Dr values were more consistent with CROPWAT Dr results at the end of the simulation period, suggesting that the SM1 required several weeks to consolidate and give representative θ-values for the soil profile.</p>

scholarly journals Soil and Irrigation Water Management: Farmer’s Practice, Insight, and Major Constraints in Upper Blue Nile Basin, Ethiopia

Agriculture ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 383
Author(s):  
Desale Kidane Asmamaw ◽  
Pieter Janssens ◽  
Mekete Dessie ◽  
Seifu A. Tilahun ◽  
Enyew Adgo ◽  
...  
Keyword(s):  
Water Management ◽  
Irrigation Water ◽  
Large Scale ◽  
Soil Acidity ◽  
Management Practices ◽  
Management Strategies ◽  
Field Tests ◽  
Irrigation Scheduling ◽  
Irrigation Scheme ◽  
Irrigation Water Management

This study assessed farmers’ soil and irrigation water management practices, perceptions, and major constraints at Koga, a large-scale irrigation scheme in Ethiopia. Key informant interviews, structured and semi-structured questionnaires, focus group discussions, and field visits were used for data collection. Soil samples were collected for the assessment of soil properties and a comparison with the respondents’ perception of soil-related constraints. A total of 385 respondents were involved in the questionnaire. All of the respondents had a good perception of soil acidity and its management strategies. Respondents’ perception was in line with the mean soil pH, soil texture, infiltration rate, exchangeable acidity, and soil organic carbon obtained from lab analysis and field tests. Soil acidity, unwise use of water, water scarcity, and lack of market linkages hampered the performance of the Koga irrigation scheme. Yet, respondents had a low awareness of irrigation water management. Farmers never used irrigation scheduling, but apply the same amount of water regardless of the crop type. As a result, low yield and water use efficiency were reported. To reduce soil acidity, an adequate lime supply for farmers with hands-on training on how to apply it would be desirable. Farmers should be aware of how to design effective irrigation scheduling and adopt water-saving management strategies.

Agronomic and Physiological Responses of Soybean and Sorghum Crops to Water Deficits II. Crop Evaporation, Soil Water Depletion and Root Distribution

1978 ◽  
Vol 5 (2) ◽  
pp. 169 ◽  
Author(s):  
GJ Burch ◽  
RCG Smith ◽  
WK Mason
Keyword(s):  
Soil Water ◽  
Root Distribution ◽  
Irrigation Scheduling ◽  
Balance Model ◽  
Soil Water Depletion ◽  
Water Depletion ◽  
Irrigated Crops ◽  
Soil Water Extraction ◽  
Moisture Conditions ◽  
Similar Soil

The effects of soil water depletion on crop evaporation and root absorption of water were studied in soybean and sorghum crops. Sorghum did not deplete the maximum soil water store by more than 100 mm, whereas rainfed crops of soybeans, cvv. Ruse and Bragg, depleted the soil water store by 130 and 170 mm, respectively. This was sufficient to reduce soybean yields by 35% and hasten maturity in both cultivars when compared with irrigated crops. The post-flowering efficiency of water use by rainfed crops of soybeans was about one-third that of sorghum. The root distribution of Ruse and its pattern of soil water extraction indicated that during bean- fill it was unable to exploit water from much below 80 cm depth, but this effect was offset by its reaching maturity before yield was severely affected by water stress. As Ruse approached maturity, its root densities decreased in soil layers below 10 cm depth, whereas Bragg, which matured 2 weeks later than Ruse, maintained a deep root system and continued to deplete water down to 120 cm. The contrast in root distribution between soybean cultivars also influenced the level of soil water depletion at which crop evaporation fell below the potential rate. Soil and root resistances to water absorption were used to interpret the effects of root density and soil water depletion on water uptake. The regional implications of the results were examined using a water balance model to analyse historical rainfall records. It was concluded that similar soil moisture conditions could be expected about 1 year in 5, indicating that these results have a ready application for irrigation scheduling in this area.

A model for deficit irrigation analysis of crops

2009 ◽  
Vol 5 (1) ◽  
pp. 31-53
Author(s):  
K. Adekalu ◽  
D. Okunade
Keyword(s):  
Soil Water ◽  
Deficit Irrigation ◽  
Maximum Yield ◽  
Irrigation Scheduling ◽  
Rooting Depth ◽  
Irrigated Agriculture ◽  
Cost Ratio ◽  
Water Reduction ◽  
Benefit Cost Ratio ◽  
Benefit Cost

Scarcity and high cost of water is the most important limiting factor for crop production in irrigated agriculture. Deficit irrigation can be implemented to optimize the use of available water resources and put more land on productive use. A model was developed to determine the savings in water and the economic benefit derived from deficit irrigation. The model was tested using yield-water use data of maize, tomato, okra and cowpea grown under irrigated condition in Nigeria. Cowpea is the main source of plant protein in the local diet and okra one of the major vegetable crops planted in Nigeria. The results indicated that some water reduction is possible without affecting yields. The optimum water reduction is 4, 8, 12 and 18% for maize, tomato, okra and cowpea, respectively. Maximum allowable water reduction increased with increase in the benefit-cost ratio of each tested crop. The maximum allowable water reduction is 9, 13, 21 and 32%, with a corresponding increase in cultivated area by 10, 16, 23 and 50% for maize, tomato, okra and cowpea, respectively, at a benefit-cost ratio of 1.5. The model, in most of the years showed that the optimum moisture reduction level increased with increasing seasonal rainfall. Increasing rooting depth or soil water holding capacity also increased the relative maximum yield for water reduction levels up to 40–50%. The developed model would be useful in determining the effect of soil, water, and crop variables on deficit irrigation of crops in different agro-ecological zones with appropriate crop and soil data input, and proper irrigation scheduling.

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