Agronomic practice and performance of organic farms in different environmental conditions in Lithuania

ABSTRACT The aim of this study was to determine the impact of plant diversity and agricultural practices on crop productivity on organically managed mixed and arable farms under different natural conditions. Organic farms in three regions of Lithuania, differing in landscape homogeneity, soil quality and farming intensity, were evaluated. The results showed that there were arable farms in all regions, regardless of the soil fertility and the largest number of mixed farms was in Western Lithuania. On the mixed farms, perennial forage grass prevailed in the cropping structure, whilst cereals were the main crops on the arable farms with grain legumes grown to restore soil fertility. Short crop rotations and a low diversity of crops predominated. The average grain yields of the winter and spring cereals and the grain legumes were 3283, 2539 and 2917 kg ha−1, respectively. The productivity of the cereals and grain legumes depended on the region, and for spring cereals also on the interaction between region and farm type. Significantly lower yields of winter and spring cereals were recorded on the arable farms in East Lithuania, compared with the arable farms in the other regions. For organic farming systems, especially for arable farms, it was recommended to explore and implement the use of mixed or strip relay intercrops and multicultural cropping systems or blocks, thereby increasing spatial and temporal crop diversity and using plants that provide ecological services (e.g. legume swards). Reduced tillage practice to increase humification of plant residues in the soil was also recommended.