滴灌分次施肥下夏玉米养分积累及土壤无机氮残留的特性

在滴灌条件下,以玉米郑单958为试材,设4个施肥处理:CK(对照)、T1、T2、T3,探究氮、磷、钾肥分次施肥处理对夏玉米养分吸收和土壤无机氮残留的影响。结果表明,各处理夏玉米对氮素和磷素吸收速率最大的时期均为大喇叭口期至吐丝期,钾素为拔节期至大喇叭口期;吐丝期至成熟期氮、磷吸收积累量分别占全生育期43.05%~54.07%、41.76%~52.27%,钾几乎不再吸收(T3处理除外)。处理间比较,玉米V12期T3处理植株磷含量显著低于T2处理29.18%(2019年)和CK处理17.61%(2020年);吐丝期T1处理钾含量显著高于T3处理30.73%(2019年)和20.51%(2020年)。与CK和T2处理相比,T1和T3处理均能显著降低成熟期深层土壤无机氮残留。各分次追肥处理百公斤玉米子粒产量养分吸收量氮、磷、钾均值分别为2.31、0.90、2.09 kg。综合分析,在T1处理基础上推荐黄淮海夏玉米滴灌条件下播种期、大喇叭口期、抽雄吐丝期氮、磷、钾分次施肥比例为40%:20%:40%、35%:25%:40%、75%:25%:0,可更好满足玉米各生育期对养分的需求,降低深层土壤硝态氮残留。

Characteristics of Nutrient Accumulation and Soil Inorganic Nitrogen Residue in Summer Maize under Split Fertilization with Drip Irrigation

Under drip irrigation, using Zhendan 958 as the test material, four treatments for NPK fertilizer supply were designed to explore the effect of split application of NPK fertilizer on nutrient uptake of summer maize and soil inorganic nitrogen residue. The result showed that the maximum absorption rate of nitrogen and phosphorus was from the V12 to the R1 stage, respectively, while for potassium, it was from the V6 to the V12 stage. The accumulation of nitrogen and phosphorus from R1 to R6 accounted for 43.05%-54.07% and 41.76%-52.27% of the total growth stage, respectively, while potassium was less absorbed. Among all treatments, at the V12 stage, the phosphorus content of plant in the T3 treatment was significantly lower than that in the T2 treatment(-29.18%, 2019) and CK(-17.61%, 2020). At silking stage, the potassium content of the T1 treatment was significantly higher than that of the T3 treatment by 30.73%(2019) and 20.51%(2020). Compared with CK and T2, nitrate nitrogen and ammonium nitrogen in T1 and T3 decreased in different degrees. For all treatments, the average values of N, P2O5, K2O absorbed per 100 kg kernel yield were 2.31 kg, 0.90 kg and 2.09 kg, respectively. Under drip irrigation in summer maize, the proportion of fertilizer application at sowing, V12 and R1 stage was suggested as T1 treatment, i.e. nitrogen fertilizer 40%∶20%∶40%; phosphorus fertilizer: 35%∶25%∶40%; potassium fertilizer: 75%∶25%∶0, which could meet the nutrient demand of maize at different growth stages, and reduce the inorganic nitrogen residue in soil.