8/11/2019 Session 37. Crop Water Budgeting-Dr. Govardhan Das

1/14

Date : 7 August 2007

Time : 09.00 to 10.30 hrs.Venue : BIRDS Training Center, Muthyalapadu

Topic :Crop Water Budgeting

Faculty :Dr. S. V. Gov ardh an Das

International Learning Workshop on

Demand-side Managementof Groundwater

30 July - 10 August 2007

8/11/2019 Session 37. Crop Water Budgeting-Dr. Govardhan Das

2/14

Scheme of Presentation

What is CWB

What are the pre-conditions

Pre-CWB Exercises

CWB Workshop

Post-CWB Exercises

Expected outputs

What changes are observed

8/11/2019 Session 37. Crop Water Budgeting-Dr. Govardhan Das

3/14

What is CWB?

A set of activities carried out to match groundwater

balance with Rabi crop plans, in a Hydrological Unit

Estimations are based on farmer collected data

8/11/2019 Session 37. Crop Water Budgeting-Dr. Govardhan Das

4/14

What are the pre-conditions?

Hydrological Monitoring Network should have beenestablished

Rain Gauge Stations

Observation Wells Farmers trained in data collection, recording and

display

A minimum data of one Hydrological Year should

have been recorded

8/11/2019 Session 37. Crop Water Budgeting-Dr. Govardhan Das

5/14

Set of Activities!

Crop Water Budgeting Workshop (CWBW)

Pre-CWBW Activities

Post-CWBW Activities

8/11/2019 Session 37. Crop Water Budgeting-Dr. Govardhan Das

6/14

Pre-CWBW Activities

Data collection and updating

Groundwater Balance Estimation, using CWB

package

Projection of Groundwater Balance at the end of

Rabi, based on farmer crop plan

Material preparation

Training GMC in conduct of CWB

FFS methodology tried out successfully

8/11/2019 Session 37. Crop Water Budgeting-Dr. Govardhan Das

7/14

CWB Workshop

Estimation of groundwater recharge Rainfall data collected by farmers

Extent of each geological formation estimated by farmers andstaff

Standard recharge rates, per GEC 97 norms

Estimation of groundwater draft Well Census by farmers per September

Average well discharge data collected by farmers

Average pumping hours

Computation of groundwater balance beginning of Rabi

Automated in Excel spreadsheet

8/11/2019 Session 37. Crop Water Budgeting-Dr. Govardhan Das

8/14

CWB Workshop

Farmer Crop Plan Well-wise, farmer-wise record kept

Data updated through group exercises

Crop-Water Requirement

Arial extent of each crop computed

Standards of the ANGRAU

Projection of water requirement for Rabi

Projection of groundwater requirement for Rabi

8/11/2019 Session 37. Crop Water Budgeting-Dr. Govardhan Das

9/14

Post-CWBW Activities

Habitation level sharing of CWBW results Creating platform for decision making

Encouraging women participation

Crop Adoption Survey

Analysis of changes in cropping, irrigation, etc.

Computation of groundwater balance, based on

CAS

Comparison of CAS data of the present year with

that of previous year

8/11/2019 Session 37. Crop Water Budgeting-Dr. Govardhan Das

10/14

Expected Outputs

Base line resource inventory information updated

Groundwater use in Kharif quantified

Groundwater need for Rabi crops quantified

Groundwater Balance for Rabi projected based on

PHM data, resource inventory and crop plan Triggering discussion around crop plans and

groundwater need

Facilitating changes in crop choices

Knowing the difference between crop plan and

actual cropping

Calculation of water saved through CWB

8/11/2019 Session 37. Crop Water Budgeting-Dr. Govardhan Das

11/14

What changes are observed?

CAS data for Rabi 2005 and 2006 is now availablefor the entire APFAMGS project area

A comparative analysis of CAS data of two years is

done in the Newsletter (Telugu).

Main crops in APFAMGS area, grown in Rabi 2005

were:

sun-flower, rice, groundnut, citrus, sajja, red-

gram, jowar, chilly, tomato, ragi, sugar-cane,

mango and vegetables

8/11/2019 Session 37. Crop Water Budgeting-Dr. Govardhan Das

12/14

What changes are observed?

In Rabi 2006, in APFAMGS area;

Sun-flower retains its first place

Area under rice and red-gram reduced by almost

half

There is a drastic reduction of area under red-gram

and sajja

The area under chilly dramatically increased from

2,000 to 11,000 acres Other crops are grown in more or less the same

extent

8/11/2019 Session 37. Crop Water Budgeting-Dr. Govardhan Das

13/14

SN

Rock type

Recharge Rate as % of RF

1 Hard rock, without fractures 1%

2 Phyllites and Shales 4%

3 Granulites 5%

4 Hard Sandstone/Limestone 6%

5

Soft Basalt

7%

6 Laterite 7%

7 Soft Sandstone 8%

8

Granitic rock, with clay 8%

9 Western Coast 10%

10

Granitic rock, without clay

11%11 Fractured Basalt/Limestone 13%

12 East Cost 16%

13

Indo Gangetic Alluvium

22%

Recharge rate (Source: GEC 97)

Factors controlling groundwater quantity

8/11/2019 Session 37. Crop Water Budgeting-Dr. Govardhan Das

14/14

Thank U