Effect of “3414” fertilization and recommended fertilizer quantity for Avena sativa in Qinghai Area

Judicious fertilization is one of the main measures to improve Avena sativa yield. This study aimed to provide a practical, scientific basis for A. sativa fertilization in Qinghai. We used “Qingyin No. 1” as the experimental material in our research. From 2012 to 2014, we applied the “3414” fertilizing scheme to observe A. sativa yield under the influence of different allocations of nitrogen, phosphorus and potassium, as well as the related economic efficiency. The results showed that yield and economic efficiency were always higher with, rather than without, fertilizer treatment. The treatment of N2P2K0 reached the highest output, up to 4 785.22 kg·ha-1, and increased by 1 488.91 kg·ha-1 compared with those without fertilizer treatment; the treatment of N2P2K0 increased by 3 324.71 CNY·ha-1,showing the most significant economic effect. In general, both treatments interact with each other; the effects on A. sativa yield are NP>NK>PK. The results of the quadratic equations between A. sativa fertilizer quantity and its yield were typical, which helps explain the relationship between fertilizer quantity of A. sativa and its yield. However, with a medium fertilizer rate of nitrogen and phosphorus and an increase in potassium, the yield of A. sativa began to decrease. From the above experiment, we conclude that it is possible to omit potassium fertilizer when growing A. sativa in Qinghai Area. Moreover, it can be inferred from the binary quadratic equations of nitrogen and phosphorus that, to obtain the highest yield of A. sativa, the best fertilizer scheme should be nitrogen 118.55 kg·ha-1, phosphorus 176.96 kg·ha-1, up to 4 867.43 kg·ha-1,with net income 12 930.94 CNY·ha-1; the best economic fertilizer scheme should be nitrogen 102.18 kg·ha-2, phosphorus 102.04 kg·ha-1, up to 4 731.25 kg·ha-1,with a net income of 13 111.63 CNY·ha-1.