The WBC is a free, online interactive tool designed to give farmers and decision-makers the ability to quantify how certain agricultural practices increase water retention and decrease soil erosion.
A screenshot of the Water Balance Calculator online tool.
Measuring how better management of coffee farms improve water resources in the Coffeelands
Blue Harvest started as an idea of how to restore and improve the management of water resources in coffee producing areas in El Salvador, Honduras and Nicaragua, while increasing the productivity of coffee farms located in our target watersheds. As we have pointed out in the blog previously (here; here, here and here) coffee production and processing can have severely negative impacts on drinking water sources in the Coffeelands, through overuse, poor recharge and contamination by wastewater. Yet, managed correctly, coffee farms can provide ample amounts of quality drinking water for rural communities. The Blue Harvest project does this through a combination of approaches:
- on the farm, by decreasing runoff and increasing soil infiltration;
- at the wet mill, by promoting the efficient use of water to mill coffee and the proper treatment of wastewater;
- in the watershed, by identifying key farms that served as recharge sites for community water sources;
- in the community, through improving local water governance.
Through this combination of different approaches, we have improved the quality and quantity of water and increased the productivity of farmers whose farms lie in our target watersheds. Yet while we understand in general terms that the practices we promote not only help improve productivity, but also increase the provision of drinking water, we were left with a question.
What agricultural practices provide the biggest positive benefits for the environment? What is the 3 key practices we want to see every coffee farmer doing?
These are questions we are working on answering. As part of the project monitoring, we are measuring water and soil characteristics. The key variables that we want to see positive changes in are:
- Soil moisture – Soil moisture is the amount of water stored in the soil
- Water recharge – water recharge is the amount of water that moves downward from surface water to groundwater
- Soil erosion – soil erosion is the loss of the top layer of soil due to water and wind
These factors are key for plant productivity as well as for water security for communities downstream. In collaboration with Limnotech, an environmental engineering and science firm, we have developed a tool that allows us to model hydrological impacts that result from different types of farm management.
The WBC is a free, online interactive tool designed to give farmers and decision makers the ability to quantify how certain agricultural practices increase water retention and decrease soil erosion. The goal of the WBC is to help farmers prioritize the most effective practices to improve soil and water resource management while at the same time contributing the farm’s productivity. The improvements in these natural resources result in an increased water availability downstream for water users. The tool models the impact of 28 different agricultural practices, incorporating microtopographic and local climate variables to provide a best estimate of the impact on water and soil resources. The WBC is designed for coffee agroforestry systems and will provide a comparison between other types of land uses – basic grains, cacao and coffee systems. The practices included are key soil and water practices such as terracettes, live barriers, ground cover, and shade management.
The tool can look at farm level interventions on farms of any size. It can compare impacts on pre- and post intervention scenarios. The tool can be applied to several farms in a landscape or watershed to model the results at a larger scale.
So, what are the best practices? Yeah… If only it was that easy. Ultimately, the best practices depend several factors: climate; proximity/location to water sources and the topography of the farm. Currently, Blue Harvest is analyzing various scenarios using the tool to in order to provide some more general principles on to what are the best practices that provide the best ROI for increasing water resources. Stay tuned.
See the tool here: www.waterbenefitscalculator.com
You will need to register and create a user account to use the tool.