Water in Polish agriculture
The effects of climate change will be significant for agricultural production in Poland. The sector is facing two important challenges - the need to reduce greenhouse gas emissions, and the necessity to conduct adaptation measures to the climate change taking place. One of the elements of adaptation measures, especially from the agricultural point of view, is the problem of water.
Water is a resource necessary for agricultural production. The amount of rainfall in Poland has not changed significantly for 150 years, however the distribution has become unfavorable in recent decades. It rains less in summer (in the growing season), and rainfall is torrential, causing rapid outflow of water from the catchment area. In winter, rain is more frequent than snow. In such a situation, it is crucial to care for the renewal of water resources, their quality and accessibility (not only for the agricultural sector), retention and deceleration water outflow from the catchment area.
Agriculture uses about 70% of renewable water resources. Industry comes second (20%), and only in the third place is the use of water for municipal purposes (10%). The report "Analysis of the shaping and use of water resources for agriculture and rural areas" prepared at the request of the European Fund for the Development of Polish Villages, shows that in recent years Poles have been gradually learning how to save water - for the needs of the national economy and the population we collect it by 9% less than in 2000.
The latest report by the European Environment Agency (EEA) on water stress shows that more and more Europeans suffer from scarcity of water resources. “Water stress” is a situation in which the amount of water of adequate quality is not sufficient to meet the needs of humanity and the environment. According to the report, every year, water-related disasters affect 20% of Europe's territory and seriously affect up to 30% of Europeans. The situation in southern and south-western Europe is particularly worrying. In these regions, river flows can drop by as much as 40 percent during the summer months if average temperatures increase by 3°C. The main pressure on water availability in these areas is exerted by factors such as agriculture, municipal needs and tourism. European action on the situation focuses on many aspects. Modern technology, such as drones or remote sensing systems, is increasingly used to monitor the condition of the our planet, its climate and water use. The agricultural and industrial sectors are under increasing control.
Poland is one of the poorest countries in Europe in terms of water
Fresh water resources constitute only about 3% of all water resources on Earth. Their volume is estimated at approx. 35 million km3, of which over 67% are glaciers and snow cover. The second significant parts of freshwater resources are stored underground - in its deeper layers - it accounts for almost 30% of the total volume of freshwater. Waters used by man - rivers, lakes and shallow groundwater - it is only 0.4% of freshwater resources.
Poland is one of the poorest countries in Europe in terms of water. In the years 1946-2016, the annual average of water resources per capita in Europe amounted to 5 000 m3 of water, while in Poland the water resources amounted to only 1 800 m3. In years with lower rainfall, Poland has a little over 1 100 m3 per person, and in wet years 2 600 m3 per person. Experts are concerned about the trend of the declining amount of water resources in Poland. The threshold of 1 700 m3 / person is the limit from when there is "water stress", i.e. threats of water shortage.
In Poland, the average value of total annual rainfall is about 196 km3. Of this volume, approx. 28% run off by river systems, mainly by 2 rivers - the Vistula basin (55%) and the Odra basin (25%). Inflow from outside of the country's borders accounts for 12.6% of the total flowing water resources. The rest of the rainwater it evaporates, currently, for about 3/4 of the year in the amount of about 60%. The rest of the rainwater (about 20%) infiltrates, supplying groundwater resources. Renewal of the first layer of water underground, which is used by people, lasts an average of 3 years.
Additionally, more than 60% of precipitation falls in the period of greater water evaporation (60%), and in the period of lower evaporation value (50%) we have about 40% of annual rainfall. This arrangement causes along with climate change, the risk of droughts in Poland increases more than floods.
Currently in Poland are about 100 large water reservoirs and over 32 000 small retention facilities, including small water reservoirs with a capacity of less than 5 million m3 (which are possible to stop a total of about 7% of the average annual water runoff from Poland).
The water footprint is the sum of the consumer's direct and indirect water consumption. The indirect use of water is the amount of water that has been used to produce a given product (e.g. vegetable or meat).
Some examples: to produce 1 kg of beef we need 14 500 liters of water, 5 990 l for 1 kg of pork and 4 330 l for 1 kg of poultry. However, it is not only animal production that consume huge amounts of water. Contrary to appearances, products of plant origin or grains also absorb a lot of water. You need 140 l of water to produce 1 cup of coffee, and 30 l to produce 1 cup of tea. The production of 1 kg of potatoes requires 290 l of water, and the production of one kilogram of crisps as much as 1 040 liters of water. The cost of water for cabbage is 280 l, lettuce 240 l, a large tomato is 50 l, one almond equals 4 liters of water and this does not include transport. However, the production of a kilogram of ketchup and tomato puree is over 700 l of water. To prepare a loaf of bread, we need 462 l, a kg of wheat grain takes 1000 liters, and a kilogram of rice - almost 3000.
A problem from the past
In the second half of the 20th century, the melioration system was implemented in Poland in accordance with the concept of the so-called agriculture dehydration. There was a drainage of wetlands and drainage of excess water from the fields as a quick way to increase the acreage of crops. The system of ditches and channels should be built to drain water during the period of its excess or to keep it in during the shortage by closing gates and weirs. In practice, however, melioration system works only by accelerating the outflow of water from the catchment area, which contributes to the occurrence of drought in periods with less rainfall, and even short-term but torrential situations rains lead to floods, freshets and flooding. This system is costing Poland unnecessary water losses.
An important role in securing rural areas against water shortage is the improvement of the technical condition and investments in water drainage, which, in addition to supporting agricultural production and protection against flooding are an important element of environmental protection. However, most of the existing drainage systems require modernization and expansion. In the fight against drought in agriculture, it is important to provide plants with water by means of irrigation devices, e.g. based on groundwater, which are at a good level. In the EU countries, the share of the area equipped with irrigation systems in relation to the agricultural land area is on average 9%, while in Poland it is only less than 2%.
Soil and water management
The soil itself has enormous water retention potential. How much water it can hold, depend on the organic matter content, aeration level and soil management. For example, diversified crop rotation may play an important role as well as limited plowing and management based on good quality fertilizers and a high proportion of natural fertilizers. Soil rich in organic matter also has a structure that allows water to infiltrate deep into the soil profile and restore water resources underground. The soil, covered with vegetation or the remains of catch crops, stores water better and does not erode.
Water control problem
So far, no institution, has been established in Poland specialized in detecting and prosecuting offenses and crimes against the environment, incl. water resources. Its operation should apply to offenses related to both illegal abstraction of water, as well as its pollution. The problem is also excessive water consumption by some users, which, in the absence of flow monitoring, can dry the watercourse completely. The protection of water resources in the context of agriculture also requires taking into account the issue of water quality.
Water is not just essential for food security. The lack of water is a threat health, life and sustainability of public order. Poland is a European country with low resources water per capita. This overlaps with the water management strategy of the last 100 years: allow rainfall to flow into the sea as quickly as possible. This has however led to agricultural drought lasting already for many years, practically on all over the country.
1. Woda w rolnictwie. 2020, Koalicja Żywa Ziemia.
2. Gospodarowanie wodą w rolnictwie w obliczu susz. 2020, Ministerstwo Rolnictwa i Rozwoju Wsi.
Report by Olaf Horbanczuk