Water and fertilizer were studied together to see how they affect the yield of wheat and maize grown together. The researchers found that the best results came from using 4800m3/hm2 of water, 420kg/hm2 of nitrogen, and 120kg/hm2 of phosphorus. Nitrogen was the most important factor for yield, followed by water. More nitrogen helped wheat grow better, but it didn't make a big difference for maize. After harvesting wheat, the amount of nitrogen affected how much water was in the soil for maize. The study showed a strong link between total yield and water use efficiency.