Effects of suboptimal fertilization on arable crops

The production of high yields and adequate product quality requires a sufficient and balanced supply of the soil with nutrients. The field trial, conducted since 1989 for purpose of demonstration, shows the impact of different fertilizer forms (organic and mineral fertilizer) on the one hand and the effects of an unbalanced fertilization on the other hand. No differences in yield and product quality have been observed between the treatments «cattle slurry» and «mineral fertilizer», both well adapted to the nutrient demand of the crops. But the annual application of 250 decitonnes of farmyard manure per hectare resulted in reduction of crop yield and product quality due to the low availability of nitrogen in manure to the crops and the low content of potash of the manure. The lack of a single nutrient element (N, P or K) in the mineral treatments affected crop yield, nutrient contents of crops and soil negatively already after few years. All crops have revealed deficiency symptoms of N, P or K in these treatments.