ADMS

The Institute of Soil Science and Plant Cultivation - State Research Institute in accordance with an Act from the Minister of Agriculture and Rural Development has developed the climatic water balance for all Polish municipalities (3,064 municipalities), and based on the soils categories have identified in those municipalities the current agricultural drought risk for the following crops: winter and spring cereals, oilseed rape and turnip rape, sugar beet, shrubs and fruit trees and strawberries.

In the first reporting period, i.e. from April 1 to May 31, 2013, IUNG-PIB does not state a risk of agricultural drought in Poland. The values of climatic water balance (CWB), which are the basis to assess the risk of drought in most areas, are negative, but these values for above-mentioned crop are much higher than the critical value.

The lowest CWB values were the Mazurskie Lake District and Staropruska Lowland reaching from -70 to -79 mm. Relatively low values were also in the lake district: Lubuskie (the eastern part) and Wielkopolskie (in the western part), from - 60 to -69 mm. However, the highest values of CWB (positive) reported on Południowowielkopolska Lowland were from 60 to 70 mm.

This year, throughout the country the snow cover was until April 5. The largest Polish territory the north-eastern and eastern areas were covered until the middle of the month. The cover in this area was also relatively thick and very thick, from 20 to 50 cm. However, the rest of the country was also reported with a record thick snow covering of up to 10 to 20 cm. Only the coastal areas saw a thin (a few cm) covering of snow for a few days in April.

April this year in terms of thermal conditions was varied. The highest air temperature occurred in southern Poland, reaching more than 9°C (in the Sandomierz Basin and Śląska Uplands), the rest of the country the temperature ranged from 6 to 9°C. In the north of the country (the eastern part), the temperature was lower (4-6°C). In most parts of the Poland, the air temperature was close to the long-term average (of three decades from 1971 to 2000), by 1-1.5°C was higher in the south-eastern part of the country, while in north-east part was lower by 1-1.5°C.

May this year, in terms of temperature was also varied. The highest air temperature occurred in eastern Poland, reaching more than 16°C, and further west it was cooler. On the western edge of the country, the air temperature was 12-13°C. In most parts of the country, the air temperature in May was higher than the long-term average by 1-2°C.

The weather condition in April meant that this year's winter break in the vegetation season lasted much longer in relation to the long-term average. The delay was about three weeks. However, the high temperature in May saw this delay reduced significantly.

In April, a high diversity of precipitation was found. Very low rainfall, less than 20 mm occurred in the Wielkopolska Lake District and Małopolska Uplands, they accounted for less than 50% of normal long-term value. Low rainfall ranging 20-30 mm occurred in the western part of the country and the Śląsko Krakowska Uplands, and was 50-90% of norm for these areas. However, in the east of the country the rainfall was high, at 50-60 mm (about 130-150% of norm).

In May, the lowest precipitation occurred in the north-east of the country (50-60 mm). Slightly larger precipitation occurred in a wide belt of central Poland, west of the Vistula (60-100 mm). The highest rainfall recorded in the Mazowiecka and Śląska Lowlands and the Śląsko-Krakowska Uplands (from 120 to 180 mm).

The forecast conducted by IUNG-PIB for yield on the 31 May, based on weather conditions in autumn 2012 and spring 2013 shows that this year's harvest of cereals, oilseed rape, sugar beet and potato crops will be close to the long-term average.

Heavy rainfall that occurred across the country and occurs at a time of relatively high temperatures could create a major shock of cereals and oilseed rape. There is a high risk for the development of many fungal diseases in cereals such as leaf septoria, brown leaf spot, leaf rust, in the case of rape - stem rot.

In many areas of Poland, after such very heavy precipitations creates a high risk due to large accumulations of water on the fields. The remaining water can cause field crops to rot, and it should be noted that an excess of water for the plants is more dangerous in comparison to its deficiency.