Agricultural Research Management Information System

Home
Research Summary
Search
About Us
- ARMIS
- Brochure
Contact Us
Report
User Request
Data Input
Help
- Operation Manual
  - PDF
  - Video
- Program Area & Commodity
We have reached 37600 number of research entries at this moment.

- Logout

Research Detail

Home
Research
Detail

Study on Determination of Water Balance Components and Crop Coefficient of Wheat

NAZMUN NAHAR KARIM
MASTER OF SCIENCE (M.S.) IN IRRIGATION AND WATER MANAGEMENT, Department of Irrigation and Water Management, Bangladesh Agricultural University, Mymensingh Exam, Roll No. 6, Reg. No. 12333, Session : 1983-84, Semester : January - June, 1999

Abstract/ Executive Summary:

A research work was conducted both in the field and lysimeter at the Bangladesh Institute of Nuclear Agriculture farm, Mymensingh during November 1998 to March 1999 to study the water balance components and crop coefficients of wheat in silty loam soil. The bulk density of the experimental soil was found to be 1.42 and 1.00 gm/cc in field and lysimeter, respectively. The volumetric field capacity and hydraulic conductivity of the field and lysimeter soil were 44%, 0.12 cm/day and 49.040%, 0.24 cm/day, respectively. There were five treatments, each replicated four times in a randomized block design in the field and had no replication in the lysimeter. The various components of water balance viz. irrigation, effective rainfall, change in soil moisture storage, deep percolation, flux density, actual evapotranspiration were determined. Besides those, crop coefficients al different growth stages, total water requirement, water use efficiency and harvest index were also determined. Total change in soil moisture storage (depletion) under different treatments were 10.755, 10.575, 10.785, 12.300 and 14.904 cm in the field; and 19.145, 15.400, 13.860, 17.039 and 19.140 cm in the lysimeter, respectively. Total change in soil moisture was more in the lysimeter than in the field. Zero flux plane was found to very near to the soil surface in the early stage of the crop growth. With the span of time, zero flux plane gradually moved downward and upward soil water flux increased from the deeper layer of the soil profile. Total deep percolation for different treatments were 3.91, 3.95, 4.09, 1.11 and 1.31 cm, respectively. There was no deep percolation in the lysimeter. Total water requirement of wheat under different treatments were 14.405, 13.675,22.515, 22.147 and 20.356 cm in the field and 19.145, 17.269, 16.590, 20.809 and 21.350 cm in the lysimeter, respectively. Actual evapotranspiration was maximum during yield formation stage (16.597 em) in the field and during vegetative stage (10.360 crn) in the lysimeter, respectively. Crop coefficient values varied under irrigated and non-irrigated conditions. Under the irrigated condition, crop coefficient values were 0.40, 0.65, 1.79, 0.35 and 0.68, 0.89, 0.89, 0.30 at the early, vegetative, yield formation, ripening stages in the field and lysimeter, respectively. Highest water use efficiency was observed at early stage, both in the field and lysimeter, respectively.

Keywords: Study, Determination, Water balance component, Crop co-efficient, Wheat

Location: The field and lysimeter at the Bangladesh Institute of Nuclear Agriculture farm, Mymensingh

Start Date: 00-11-1998

End Date: 00-03-1999

Program Area: Crop-Soil-Water Management

Commodity: Irrigation scheduling

Objectives:

1.To determine the various components of water balance equation viz. changes in soil water storage, deep percolation, actual evapotranspiration of wheat in Old Bramhaputra flood plain soil, 2. To determine the crop coefficient (Kc) of wheat at different growth stages, 3. To determine water requirement and water use efficiency, and 4. To compare the water balance components and crop coellicients in the lysimeter and the field.

Methodology:

Field - The experimental field was laidout in randomized block design having Sm X 4m individual plots with four replications [Fig 3. 1 (a)j. Each plots were separated from each other maintaining 0.5 III wide buffer zone to prevent seepage between nearby plots and replicates, respectively. Five sets of tensiometer at different soil depths (15,30,45,60,75,90, 105, 120 ern) were installed in five plots of one replication. Fifteen access tubes were installed in three replications. Lysimeter - The experiment was carried oul in non-weighing gravity type lysimeter . There are ten boxes in the lysimetric system. Five boxes were taken for this experiment. Each lysimeter boxes has a surface area of 2 sq. meter (2 m X 1 m) with effective soil depth of 1.S m and separate arrangement in each boxes tor irrigation, drainage and run-off Tensiometers were not installed in lysimeter boxes because of nonavailability of the same. Replications in lysimeter experiment were not possible due to limited number of boxes. There were five irrigation treatments for both field and lysimeter experiments as follows: To = Control (no irrigation) T 1 = Irrigation at early stage [0-25 Days after sowing(DAS)] T2 = Irrigation at vegetative stage [30-60 Days after sowing (DAS)] T3 - Irrigation at yield [ormation stage [65-85 Days afler sowing (DAS)] T4 = Irrigation at ripening stage [90-120 Days after sowing (DAS)] During the experimental period, meteorological data, soil, crop growth and development data were recorded. Water table fluctuations were also recorded during the experimental period. Fortnightly, mean of daily temperature (max. and min.), pan evaporation, wind speed, relative humidity, sunshine hour, rainfall and water table fluctuations were recorded. Crop coefficient or Kc value is the empirical ratio of actual evapotranspiration (ETcr) of a crop to reference crop evapotranspiration (ETcr). The ratio was calculated as follows: Kc = ETcr. / ETa The water use of the crop is generally described in terms of water use efficiency (WUE) which is the ratio of crop yield to the total amount of water used during the entire crop growing period. It was calculated as follows: WUE = Y /ETcr where WUE = water use efficiency, kg/ha/cm Y = grain yield, kg/ha ETcr = actual crop evapotranspiration, cm Harvest index is the ratio of grain yield to the biological yield i.e. ground over biomass. It was calculated as follows : Harvest Index = Grain yield/ (Grain yield+Straw yield)

Source of Information: MASTER OF SCIENCE (M.S.) IN IRRIGATION AND WATER MANAGEMENT, Department of Irrigation and Water Management, Bangladesh Agricultural University, Mymensingh Exam, Roll No. 6, Reg. No. 12333, Session : 1983-84, Semester : January - June, 1999

Article Link (Online Journal):

Funding Source:

Total Budget (Tk.) :

Achievement/Findings:

Total change in soil moisture was more in the lysimeter than in the field. Zero flux plane was found to very near to the soil surface in the early stage of the crop growth. With the span of time, zero flux plane gradually moved downward and upward soil water flux increased from the deeper layer of the soil profile. Total deep percolation for different treatments were 3.91, 3.95, 4.09, 1.11 and 1.31 cm, respectively. There was no deep percolation in the lysimeter. Total water requirement of wheat under different treatments were 14.405, 13.675,22.515, 22.147 and 20.356 cm in the field and 19.145, 17.269, 16.590, 20.809 and 21.350 cm in the lysimeter, respectively. Actual evapotranspiration was maximum during yield formation stage (16.597 cm) in the field and during vegetative stage (10.360 cm) in the lysimeter, respectively. Crop coefficient values varied under irrigated and non-irrigated conditions. Under the irrigated condition, crop coefficient values were 0.40, 0.65, 1.79, 0.35 and 0.68, 0.89, 0.89, 0.30 at the early, vegetative, yield formation, ripening stages in the field and lysimeter, respectively. Highest water use efficiency was observed at early stage, both in the field and lysimeter, respectively.

Knowledge Management: Thesis