ADMS

The Institute of Soil Science and Plant Cultivation - State Research Institute Puławy, in accordance with the requirements of the Polish law, has developed the climatic water balance for the whole of Poland (3,064 local districts) based on the soil categories identified in those local districts; the current state of agricultural drought risk has been accessed for the following crops: rape and turnip rape, and sugar beet.

In the twelve reporting period from 21 July to 20 September 2012, we have not stated an agricultural drought occurrence in Poland. The value of climatic water balance (CWB), on the basis of which the drought risk assessment is calculated was negative but significantly higher than the critical values.

In the period between 21 VII - 20 IX 2012, CWB values relative to the previous ten-day period, have increased across the country by an average of 10 mm, it means that the observed water deficit is smaller than in previous sixty-day period. The greatest increase of CWB from 20 to 50 mm occurred south west part of country. However, in the north of Poland a decrease (10-50 mm) of CWB was recorded. Ten days ago, these values were only slightly negative or even positive, so it does not cause any significant deterioration of water for the plants.

The lowest CWB values from -100 to -119 mm were recorded in Chelmnsko-Dobrzynski and Wielkopolski Lake district. However, positive CWB values were not recorded in Poland.

In July, Poland was very diverse in terms of precipitation.

The lowest rainfall occurred in the south-eastern part of Poland, in the Krakowsko-Częstochowska Uplands, Śląska and Południowowielkopolskiej Lowlands (from 40 to 75 mm) which is 60-100% of the long-term norm (average of 1971-2000). Whilst the highest rainfall in July was recorded in south-western part of Poland in Warmia and Mazury, on the coast and in the Bieszczady Mountains (120-250 mm) which is 160-240% of the long-time norm.

In August, we saw a higher precipitation in southern, western and northern-eastern parts of Poland (from 80-140 mm). The lowest precipitation was recorded in central Poland, in a belt from the north towards the south from 30 to 50 mm.

In the first ten days of September across the country very low rainfall occurred, from 2 to 12 mm or in general they were not recorded (Chelminsko-Dobrzynski Lake District, the western part of the Wielkopolski Lake District, Szczecin coast and Western Bieszczady).

In the second ten days of September, the rainfall was highly variable. In many parts of Poland was in high or very high amounts (in south-western Poland were between 35 and 90 mm) and in other areas it was minimal from 1 to 25 mm (Szczecin Seashore, Plain Północnopodlaska, and in the Lublin Uplands, Basin Przedborska and Nidziańska, or did not even occur.

Within the whole sixty day period the lowest values of rainfall were recorded from  the eastern parts of Pobrzeża Gdanskiego thru to the Wisła valley, Chełmińsko-Dobrzyński Lake District, Lowlands of Środkowomazowiecka, Południowomazowieckie Ascension, Południowowielkopolska Lowlands, Śląsko-Krakow Uplands, to the Malopolska Uplands (from 40 to 110 mm). The highest precipitation was recorded in the south-western part of Poland and the Koszalin Coastland (1115-180 mm).

In July, there were very large variations in air temperatures and sunshine duration in Poland. The lowest temperatures were recorded in the north (17-18°C) and highest in south-east of Poland (20.5-21.5°C). The air temperature in July was higher than the norm of 1971-2000. The largest deviation of the mean monthly temperatures (more than 3°C) was recorded in Lublin and Sandomierz Basin, while the lowest deviation (up to 1°C) was recorded in the north-western part of Poland. For the rest of the country in July, the air temperature was higher than the norm from 1 to 3°C.

Throughout August, the warmest area was in the Śląska Lowlands and Uplands, Malopolska Uplands and the Sandomierz Basin (from 19 to 19.5°C). However, the coldest was in the northern and north-eastern parts of Polish regions from 15 to 17°C.

In the first twenty days of September, there was a very wide variation in air temperature in Poland. The lowest temperature was recorded in the north-western edge of the country (13.5-14.5°C) and the highest in Małopolska (16.5-17°C). In the second ten days of this month, the lowest temperature were recorded in the south-western part of the country, from 12 to 14°C, and the highest in the north and in the southern part of Mazosze and Lublin (15-16.5°C).

The highest sunshine duration in August was recorded in the south-western part of Poland, it was 240-290 hours. Poland’s least sunny region this month was the northern part of the country (175-210 hrs.).

Throughout the sixty-day period, evapotranspiration was highest in the south of Mazowsze, Wielkopolska and the Lublin Uplands (240-260 mm) and the lowest on the Szczecin Coastland and in a broad belt of the northern Poland (175-200 mm). However, in the first ten days of September the most hours of sunshine were in the north of the country (an average of 6.5-7.5 hours per day), and at least the southern area of Poland (an average of 4-5 hours per day).

In the second ten days of this month, the sunshine duration was very different, from the highest number of hours (5-6.5 hours. per day) in the west of the country, with the lowest value in the east of the country to 3.5-4.5 hours.

Throughout the sixty day period, the highest evapotranspiration took place in Wielkopolska, Mazowsze and in the south in the Lublin Uplands (185-210 mm) and lowest in the north of the country (160-180 mm).

Another relevant periods should be considered as favourable for crops in terms of moisture, because there were no areas with water excess, and a small deficit does not cause adverse effects in the course of the growing season.