LW-R-6: Agricultural irrigation

The picture shows an open field in the middle of which there is a sprinkler system that sprinkles water onto the field in a circular pattern.Click to enlarge
With decreasing summer precipitation and increased heavy rainfall, irrigation can become interesting
Source: Photograph: © Martina Nolte | Wikimedia Commons/CC BY-SA 3.0

2019 Monitoring Report on the German Strategy for Adaptation to Climate Change

Table of Contents

 

LW-R-6: Agricultural irrigation

Under climate change conditions, the need for irrigation is likely to increase and extend to additional crops To date there have been no regularly collected data available on agricultural irrigation. Any information obtained from the Bundesfachverband Feldberegnung (Federal professional association for matters of field irrigation) in the past has not been updated.

The column chart shows the area under irrigation in thousands of hectares in the years 1976, 1983, 1987, 1994, 2001 and most recently 2008. The values were highest in 1983 and 1987. A trend analysis cannot yet be carried out.
LW-R-6: Agricultural irrigation

The column chart shows the area under irrigation in thousands of hectares in the years 1976, 1983, 1987, 1994, 2001 and most recently 2008. The values were highest in 1983 and 1987. A trend analysis cannot yet be carried out.

Source: Bundesfachverband Feldberegnung (irregular surveys among the German federal states on the state of irrigation)
 

Irrigation becomes more lucrative

A basic requirement for high and stable agricultural yields is an adequate supply of water. Especially in the production of potatoes and vegetables or special crops, rainwater alone will usually not suffice. In such cases, superior quality and high production yields can only be achieved with additional irrigation of the fields in question.

Two adverse effects of two distinct climate trends can already be observed today in respect of adequate water supply for agricultural crops during the main growth period, which is of crucial importance for ensuring good yields: On one hand, (early) summer precipitation declines, while on the other, summer precipition can, with greater frequency, occur as heavy-rain events, thus impairing the availability of rainwater for plants. Farmers have the option to respond to this situation by growing more varieties with tolerance of drought stress, or by adapting their tillage operations in a way to increase soil moisture or by means of increased and more efficient watering or irrigation of agricultural crops.

This is why an expansion of irrigation, especially of sensitive agricultural crops or crop rotations, is to be expected as one of the possible responses by farmers. In other words, climate change shifts the focus more strongly to irrigation; at the same time as increases in the efficiency of water use in agriculture become more relevant.

In Germany, a total of 451,800 hectares of agricultural land was irrigated in 2015. More than half of this took place in north-eastern Lower Saxony. In other Länder of Germany, there are also regions where intensive irrigation is practised; however, the irrigated areas are less extensive (Statistisches Bundesamt, data collected in 2015). Irrigation water is used in particular in fruit growing, partly as frost protection, as early onset of flowering entails the risk of damage from late frosts.

To date there have been no annual surveys of cultivation areas equipped with irrigation technology and enjoying water abstraction rights; trend statements are therefore not available at present. Data collated by the Statistische Bundesamt on farm businesses and irrigated cultivation areas, nevertheless show a distinct increase from 2009 until 2015. During this period, the actually irrigated area increased from 372,750 hectares by 21 % to 451,800 hectares. In 79 % of businesses sprinklers are used for irrigation, 32 % of farmers use (also) drip irrigation. Nationwide 77 % of water for irrigation purposes is abstracted from groundwater and spring water whereas approximately 11 % is derived from surface water and from public or private supply networks respectively (Statistisches Bundesamt, data collected in 201529).

The interest in irrigation has been mounting nationwide since 2002. Funding for industry-wide institutions in respect of irrigation issues has been continued by the European Agricultural Fund for Rural Development (EAFRD), i.e. the EU, as well as by the Federal Government and the German Länder since 2014 which is being continued for the current IASCP funding period which began in 2018. Funding is granted on condition that the equipment installed be water-saving.

From an ecological point of view, irrigation cannot be judged to be of equal value in all regions or situations. Adverse effects of irrigation can manifest in terms of lowering the groundwater level and changing the soil’s mineral balance. For the time being the proportion of agricultural abstraction of water for irrigation which amounts to 1.25 % of the sum total of water abstraction is very low in Germany (Statistisches Bundesamt, data collected in 2016)30. Nevertheless, sustained impacts on the water regime in regional irrigation ‘hotspots’ or conflicts of use cannot be ruled out. In north-eastern Lower Saxony, the limitations placed on businesses by means of water allocations – in accordance with permission required under water law – might be a limiting factor for any further expansion of irrigation. During the 2018 drought, it is estimated that some of these water allocations were indeed exceeded. This shows why it is essential to take measures for increasing the efficiency of water use. Opportunities include the improvement of humus content, furthering deep root penetration, optimal tillage, creative crop rotation, choice of suitable species and varieties, adapting planting densities, irrigation control and adapting irrigation technology.

29 Destatis –Statistisches Bundesamt 2017: Land- und Forstwirtschaft, Fischerei – Bewässerung in landwirtschaftlichen Betrieben / Agrarstrukturerhebung 2016.
https://www.destatis.de/DE/Themen/Branchen-Unternehmen/Landwirtschaft-Forstwirtschaft-Fischerei/Landwirtschaftliche-Betriebe/Publikationen/Downloads-Landwirtschaftliche-Betriebe/betriebe-bewaesserung-5411205169004.pdf?__blob=publicationFile
30 Destatis 2018: Umwelt –Nichtöffentliche Wasserversorgung und nichtöffentliche Abwasserentsorgung – Fachserie 19 Reihe 2.2 – 2016. 113 pp.
www.destatis.de/DE/Themen/Gesellschaft-Umwelt/Umwelt/Wasserwirtschaft/Publikationen/Downloads-Wasserwirtschaft/wasser-abwasser-nichtoeffentlich-2190220169004.pdf

 

 

Interfaces

BO-I-1: Soil moisture levels in farmland soil

LW-I-1: Agrophenological phase shifts

 

Objectives

Furthering the infrastructure for agricultural irrigation via IASCP by more efficient use of water, e.g. reducing water loss in the irrigation of agricultural land (DAS, ch. 3.2.3)

Further development of water-saving tillage systems and irrigation technology, extending irrigation opportunities (BMELV’s sustainability concept, p. 10)

Giving proper consideration to qualitative aspects of irrigation water (based on DIN 19650, DIN 19684-10) and assessment of water management aspects in respect of the abstraction of water for irrigation purposes (DWA-M 590)