Potato resistance to water and nitrogen stress: beneficial effects of rye and soybean pre-crops

Problem: Both water and nitrogen stress in crops is a problem for agriculture across Europe and beyond. If irrigation cannot be scheduled, dry seasons lead to water stress in potato crops, resulting in yield losses and lower tuber quality. Furthermore, nitrogen stress can also cause similar problems on yields and lower tuber quality for potato crops. Nitrogen stress and deficiency in crops can be caused by excessive irrigation and heavy rains, because of nutrient leaching. The latter can also potentially contaminate local and ground water. 

Solution: Pre-crops are used to improve soil structure and fertilization for the subsequent crops planted in the same field area. Using adequate pre-crops require less water and nitrogen fertilizer input. In west Switzerland, rye and soybean pre-crops for following potato crops have been tested, in very sandy, well-draining soils, where water use efficiency can be low. It was observed that yield losses were minimized with the pre-crops planted before. With rye as a pre-crop, water stress lessened the yield loss from 25% in comparison with 36% after soybean. However, yield loss after nitrogen stress amounted to 4.8% after soybean and 12% after rye. These results, together with weather and soil conditions, guide the choice of a suitable pre-crop for enhanced yield performance of potato.