Effects of Different Topdressing Conditions on Photosynthetic Characteristics and Yield for Peanuts under Mulched Drip Irrigation

摘要

The cropping patterns as drip irrigation under mulch were assumed in the experiment with peanut variety "Fu Hua 17" to study the effects of different topdressing on photosynthetic characteristics and yield for peanuts. Five different treatments were carried out to determine the photosynthetic characteristics, and a comprehensive evaluation was made in combination with the yields. The results showed that the diurnal changes for T1 (PK+Ca) and T2 (N+Ca) in the photosynthetic rate were lower than those in T3 (N+PK) and T4 (N+PK+Ca), a fact illustrating that N, P and K elements have a direct impact on peanut photosynthetic rate, chlorophyll SPAD value of the three treatments continued to decline at the beginning of flowering, which means that leaf chlorosis and fertilizer shortage appeared earlier for peanuts in the middle and late period. The sequence of yield was: T4 (N+PK+Ca) > T3 (N+PK) > T2 (N+Ca) > T1 (PK+Ca) > T5 (CK without topdressing). T4 yield was slightly higher than T3, a result showing with sufficient NPK, increasing Ca fertilizer could increase yield and efficiency. The studied results could offer theoretical basis for revealing the yield increasing mechanism of integrated management of water and fertilizer under mulched drip irrigation.