Comparison on nutrient requirement characteristics of seed-producing corn and yield-producing corn in the Hexi Corridor

Hexi Corridor, Gansu Province, is the largest corn seed production base in China. Over use of chemical fertilizers in corn seed production is common in this area. The amount of nutrients for forming 100 kg economic yield and the nutrient absorption characteristics were compared between inbred line seedproducing corn and yieldproducing corn from the same breeding line. The results show that the yield of seedproducing corn is lower than that of yieldproducing corn, about 61.14 percent of the yieldproducing corn. The average uptake amounts of nitrogen, phosphorous and potassium for forming 100-kg grain in seedproducing corn are 2.653 kg, 1.115 kg and 3.447 kg with the N∶P2O5∶K2O ratio of 1∶0.42∶1.30, less than those in yieldproducing corn, and about 73.8%, 62.4% and 73.3% of the yieldproducing corn, respectively. There are differences in the nutrient accumulation between seedproducing corn and yieldproducing corn. More nutrients are absorbed in seedproducing corn at the seedling stage; similar amounts to yieldproducing corn are absorbed at the jointing stage, and less required after the jointing stage. The total nutrient requirement in seedproducing corn is 63.0%-85.3% of that in yieldproducing corn. Therefore, less fertilizer should be applied and more nutrients should be provided in the early growing stage in seedproducing corn.