Abstract:

【Objective】 The effects of phosphorus placement depth on grain yield and nutrient uptake of summer maize were studied. 【Method】 Pot experiments and a field experiment were carried out to determine the effects of different phosphorus placement depths (T5: 5 cm, T15: 15 cm, and T5/15: 5/15 cm) on grain yield and nutrient uptake absorption and distribution of summer maize. 【Result】The grain yield and total nutrient uptake decreased in the order of T15＞T5/15＞T5＞CK (i.e. the control treatment receiving no phosphorus). Application of phosphorus increased grain yield by 8.5%-20.0% when compared with the no phosphorus control treatment. The grain yield in the treatment of T15 was 5.9%-10.6% higher than that in treatments T5 and T5/15, the N, P and K uptake in treatment T15 was 6.9%-14.7%, 7.5%-17.1%, and 5.0%-13.4% higher than those in treatments T5 and T5/15, respectively, whereas the N, P, and K transferring rate in treatment T15 was 10.4%-17.3%, 8.4%-12.9%, and 12.9%-19.6% lower than the other two phosphorus placement treatments, respectively. The P agronomic efficiency (PAE) and P apparent utilization efficiency (PAUE) in treatment T15 were 55.8%-88.0% and 40.4%-181.4% higher than the other two phosphorus placement treatments, respectively. 【Conclusion】 Consequently, phosphorus application significantly increased the yield of summer maize. Placing all phosphorus at one deep depth resulted in better crop performance compared with splitting phosphorus at two shallow depths. Deeper placement of phosphorus is better than shallower phosphorus placement. The best phosphorus effects can be produced in maize production when all phosphorus is placed at the soil depth of 15 cm.

Key words: phosphorus, maize, nutrient accumulation and distribution, placement depth