Water productivity is just a simple rate of the mass of crops (Tons per hectarea) over the volume of water added (irrigation + precipitation). In case there is no irrigation, simply use precipitation in the growing season of the crop.

Use efficiency is a simple term that consist on measuring the volume of water used by crops exclusively for transpiration. For example of the total volume of precipitation what is the volume transpired by the crop. Note that different crops have different water use efficiencies because of their adaptations to drought.

Hoe these comments clarifies yor concerns

Kind Regards

Sincerely

Jose Navar, Ph.D OSU

Dear Jose

Thanks for the information but still I am understanding the concept and way to calculate it. Can you please help me by providing some example if is it possible for you or else send me the literature. 

WUE = economic yield of crop/ applied water (kg/ha-mm) this term is used generally for irrigated crops where during the crop season there is meagre rain. 

Dear Jayesh

Thanks for the information and would like to know the reference for using the above equation. 

Water Use Efficiency is discussed in many chapters of Tow, P.; Cooper, I.; Partridge, I.; Birch, C. (Eds.)(2011) Rainfed Farming Systems, Springer, Dordrecht, The Netherlands, In particular its aspects are discussed in Chapter 1 'Principles of a Systems Approach to Agriculture: Some Definitions and Concepts (Tow, Cooper Partridge, Birch & Harington.  Also Chapter 4 //water availability & Use in Rainfed Farming Systems: Their relationship to system structure, operation and Management (O'Leary, Walker, Joshi & White).

Please study  the following papers which can be obtained from Researchgate.net:

1-Potato cultivar Marfuna yield and water use efficiency responses to early-season water stress.

2- Response of dryland wheat production and precipitation water productivity to planting date.

3-Water use efficiency and yield of garlic responses to the irrigation system, intra-row spacing and nitrogen fertilization.

4-Water use efficiency of winter wheat under deficit irrigation

Hi Vikram,

There is extensive literature referring to water use efficiency. As mentioned above by José, some terms need to be clarified.

Water Use Efficiency-- Yield= Water Use x Water Use Efficiency x Harvest Index (Passioura et al., 1996)

Crop Water Productivity-- CWP (kg m-3) = Marketable crop Yield/ Actual Evapotranspiration

I suggest you read the following reviews to help you with your research. Feel free to ask more questions if I can be of assistance.

https://www.researchgate.net/profile/Abraham_Blum/publication/257213831_Effective_use_of_water_EUW_and_not_water-use_efficiency_WUE_is_the_target_of_crop_yield_improvement_under_drought_stress/links/0deec52b3f5c3773ae000000.pdf

https://www.researchgate.net/profile/Sander_Zwart/publication/223256563_Review_of_Measured_Crop_Water_Productivity_Values_for_Irrigated_Wheat_Rice_Cotton_and_Maize/links/0f3175313875fbe343000000.pdf

Article Effective use of water (EUW) and not water-use efficiency (W...

Article Review of Measured Crop Water Productivity Values for Irriga...

Total water input = the amount of irrigated water applied + rainfall.

Water productivity = grain yield / total amount of water supplied.

You should have a measured amount of irrigation water and rainfall (if there is) and that would be the total water input. Then, use this data to calculate of the water productivity. This is just a straight forward computation. A more precise but complex way can be found on the articles that other researchers have suggested above.

Dear All, what about water productivity in fisheries and/or in the environment?

water productivity (kg/m3) in simplest term can be calculated as=Water use efficiency (kg/ ha-mm)/10

Thank you Ram.

Water productivity (WP) and Water use efficiency (WUE) are mostly used interchangeably. However, this is a significant difference between the two. This book and journal (https://books.google.de/books?hl=en&lr=&id=L-hw0eRvpD4C&oi=fnd&pg=PA27&dq=water+use+efficiency&ots=1GmT8JsaNl&sig=5wGWfP7Kz3V1cLisgcbJjSmMGTo&redir_esc=y#v=onepage&q=water%20use%20efficiency&f=false and https://ageconsearch.umn.edu/record/208411/files/H046807.pdf) provide more clarity on WP and WUE.

I would say that WP is a subset of WUE. WUE is a concept that is mostly use to quantify water use - economics, energy, agriculture etc. WP is mostly an irrigated agriculture concept which is defined as the mass marketable value of crop (dry yield most times) per unit of water use to produce the crop (Transpiration, but Actual evapotranspiration is mostly use).

WP = Y/ETa

The journal below should help as well to provide more clarity.

Article Review of Measured Crop Water Productivity Values for Irriga...

Thanks lot for the insight and reading materials Olawale Ogunsola.

I have calculated water use efficiency and water productivity by underlining the difference between them. Water use efficiency is determined as the amount of irrigation water delivered to the field divided by the amount of water applied to the filed. water use efficiency is dimensionless and expressed in ratio or percent. The water productivity is the ratio of the amount of yield produced and the volume of water exactly applied to the field. Water productivity is expressed in different units such as kg/m3, and economic terms etc.

Water Productivity is calculated by the amount of water supplied and the grain yield. Water Use Efficiency: (WUE) refers to the ratio of water used in plant metabolism to water lost by the plant through transpiration. It can be calculated using the following formulas:

• Water Use Efficiency (Eu): Eu = Wu / Wd, where Wu is the water beneficially used and Wd is the water delivered.
• Water Productivity: It is the crop yield per cubic meter of water consumption.

Significance of Calculating Water Productivity and Water Use Efficiency: These calculations are crucial for sustainable agriculture and water management. They help in decoupling a country’s economic growth from its water use, meaning the economy can continue to grow without needing more water. They are also key indicators in the set of Sustainable Development Goals (SDGs).

Improving Water Use Efficiency: There are several ways to improve water use efficiency:

Remember, improving water use efficiency requires an integral system approach and an interdisciplinary focus on possibilities for root system management. It’s most effectively achieved by applying various water-saving and water-optimizing approaches simultaneously.