Effects of fungicide application and heterogeneous fertilization on the growth and yield of maize and potato

In agriculture, fertilizer and fungicide applications are critical for high yield. For the fertilization, it is known that block and strip fertilizations are common practices. These methods can result in the formation of pockets of soil nutrients. In this case, the orientation of root growth towards soil nutrients is important for absorbing heterogeneous nutrients. Fungicides can permeate into the soil through leaching, which directly or indirectly affects soil environment and root-soil interaction. However, it is not clear if soil micro-organisms change caused by fungicides adding affects crop root growth orientation and yield. A field experiment was conducted in 2015 and 2016, in which maize and potato were planted to explore the effects of fungicides adding and nutrient patches on crop growth and yield. We first generated soil nutrient patch by interlaced fertilization. Then broad-spectrum fungicides were applied through watering. Next, crop yield, shoot biomass, root biomass and root foraging precision were measured. The two-year field experiment demonstrated that watering fungicides and nutrient patches significantly affected plant biomass, yield, root biomass and root growth orientation. Importantly, we observed significant positive interaction between fungicides and nutrient patches. The significant increase in maize plant biomass was due to the application of fungicides under heterogeneous fertilization. Also the significant increase in maize plant biomass was promoted by nutrient patches after fungicide application. Besides, the results suggested that the application of fungicide benefited the adaptation of crops to heterogeneous fertilization. This was because that root foraging precision of maize and potato was promoted by the application of fungicides. Moreover, there was significant increase in root foraging precision of potato. However, the effect of fungicide and nutrient patches on plant growth was significantly affected by the complex interaction between crop type and planting year. Therefore, further studies were necessary to explore the role of fungicides in adaption of crops to nutrient patches and the mechanisms of growth orientation of roots towards soil nutrients. Such study should be based on various crops, ecological environments and cultivation practices, increasing the potential for in-depth understanding of the effects of pesticides on the use of chemical fertilizers.