Investigations of agricultural water use

Water scarcity is one of the biggest challenges in South Africa, alongside the effects of climate change, human vulnerability and the loss of biodiversity and ecosystem functions. Agriculture in particular is threatened by pronounced dry seasons and water scarcity. As the centre of wheat, wine and fruit cultivation, the Western Cape has great national importance for the food security of the country. In addition, South Africa has been a major exporter of agricultural and forestry products to Europe for years.

The German-South African joint project FarmImpact is developing innovative and integrative solutions for improved water and energy management for South African agriculture. The project is using the Climate Smart Agriculture approach, which includes both environmental (land management) and technological (irrigation) measures to reduce water use. Field measurements and modelling of the water consumption of wine and fruit crops will be linked in the interdisciplinary project.

Windbreak hedges and digital irrigation

One of the main goals of the windbreak strip is to reduce the water requirements of agricultural crops. These protective strips produce different field areas which have different evapotranspiration properties and a correspondingly lower need for irrigation. In order to adapt irrigation to the reduced water needs, FarmImpact will provide an application-based foundation that will provide the farm with information about actual water use and future demand.

The novelty of the research approach lies in the intelligent combination of networked microclimatic measurements, drone-based remote sensing, wind field modelling and ecophysiological modelling (Expert-N). The aim is to achieve a solid scientific basis for agro-economic assessment and optimised water management. The FarmImpact concept is aiming to grow water-efficient agricultural, wine and fruit products through the use of windbreak strips based on new scientific methods. Against this backdrop, the development of a web-based software tool for predicting the actual need for irrigation in the operational areas restructured by the water efficiency concept is an innovation. Between two windbreak strips, there are typically zones with different wind speed and evapotranspiration reduction. By integrating current weather forecasts, measurement data from the soil moisture sensors installed in the zones and the results of microclimatic-ecophysiological modelling, the prediction tool can accurately dictate the actual irrigation needs for the particular farm or directly link them to controllable irrigation systems.

Sustainable water and land use

Based on many years of field measurements, FarmImpact is developing practical recommendations for regional agriculture. On the one hand, this includes the design of a water-efficient agricultural practice to improve crop water use through windbreak hedges, including improved tree selection and a technological part for predicting irrigation needs. In addition, the objective of increasing soil fertility, reducing soil erosion and providing additional ecological services is being pursued through integrated landscape measures (windbreak strips, ecological support zones, land management). Furthermore, an increase in economic resilience at the company level is to be achieved through an integrative agro-technical concept.

In FarmImpact, the integration of digital technologies in a combination of online measurement with data warehousing, drone remote sensing, modelling and a software-based decision support system will drive the second stage of digitisation in agriculture, which is a realisation of Agricultural Production 4.0. With the help of the water demand analysis and the optimised concept of wind protection hedges, agriculture can use water resources more efficiently and adapt production to the future challenges of climate change.