Biodiversity of the crop structure on farms participating in the Polish FADN in terms of the requirements of the Common Agricultural Policy

Abstract

The crops structure (or cropping pattern) of a farm is a production and economic feature of a farm. In addition, it is an element shaping the biodiversity of rural areas.
The paper presents research on the diversity and uniformity of the structure of crops on farms of various production directions and economic size, participating in the Polish FADN network. We use three biodiversity indicators: the number of plant species cultivated on the farm, the Shannon-Wiener index (H’) and the Pielou equality index (J’).
The research showed the differences of the biodiversity indicator of the crop structure and its uniformity. The greatest diversity (Shannon-Wiener index) (H’ = 1.59) and uniformity (J’ = 0.71) of crops were found on farms with permanent crops, where the share of arable lands did not exceed 25%. Farms with field crops with a high share of industrial plants and potatoes had lower values of the indicators (H’ = 1.42 and J’ = 0.63, respectively), Different results were recorded on farms with granivorous animals, with the lowest diversity (H’ = 0.93) and uniformity (J’ = 0.42). Those farms had also the highest share of cereals in crop structure (75.5%).
In the analysis of farms in terms of economic size, the highest value of the crop structure diversity index (H’ = 1.51) was found on big farms (100≤thous. €<500), with the highest share of industrial plants and vegetables in field cultivation. The lowest diversity, decreasing with the economic size of farms, was characteristic for very small farms (2≤thous. €<8) with the highest (75.3%) share of cereals.
Taking into account the requirements of crop diversification applicable under greening policy, the limit values of the indicators of diversity and uniformity of the crop structure were determined for farms with more than 10 ha of arable land. The comparison of the crop structure indexes obtained in the research with their limit values for farms with different production directions showed that for all compared groups of farms the diversity of the crop structure exceeded the limit value. On the other hand, the uniformity of the sown structure was at the level of the limit value only on farms with field crops, and in other cases it did not exceed the limit value. In the case of all groups of farms, depending on the economic size, the diversity of the crop structure exceeded the limit value, and in the case of its uniformity, this applied to farms with an economic size of more than 50 thousand €.