旱地小麦深施磷肥对土壤水分及植株氮素吸收、利用的影响

为探明磷肥在旱地小麦生产上的作用,寻求旱地小麦最佳施磷方式,在山西省闻喜县进行了低磷(75kg·hm~(-2))、中磷(112.5 kg·hm~(-2))、高磷(150 kg·hm~(-2))3个施磷量条件下20 cm、40 cm 2个深度施磷的田间试验,研究其对旱地麦田土壤水分及植株氮素吸收、利用的影响。结果表明:增加施磷量,越冬期-孕穗期0~100 cm土层土壤蓄水量提高,且深层施磷效果较好,尤其有利于返青期土壤蓄水量提高。增加施磷量,各生育时期植株含氮率提高,各生育时期植株氮素积累量显著提高,且深层施磷效果较好,尤其开花期含氮率。增加施磷量,花前各器官氮素运转量显著提高,深层施磷叶片氮素运转量对籽粒的贡献率提高,成熟期叶片氮素积累量及其所占比例显著降低。40 cm深度施磷150 kg·hm~(-2)花后氮素积累量最高。此外,越冬-孕穗期0~100 cm土层土壤蓄水量与花前氮素运转量关系密切,尤其与叶片氮素运转量关系密切,开花期土壤水分与花后氮素积累量关系系数最大。总之,增加施磷量,有利于提高花前1 m内土壤水分,有利于促进植株氮素积累、运转,且深层施磷效果显著,尤其可促进叶片氮素转移到籽粒,有利于开花期含氮率提高,有利于花后氮素积累。最终,40 cm深度施磷150 kg·hm~(-2)可显著提高旱地小麦氮肥吸收效率、氮肥生产效率、氮素收获指数。

Effect of Deep Application of Phosphorus Fertilizer on Soil Moisture,Plant Nitrogen Absorption and Utilization in Dryland Wheat

In order to investigate the role of phosphorus (P)in dryland wheat production,trying to find out the best ap-plication way of phosphorus fertilizer of dryland wheat,a field test was carried out in Wenxi,Shanxi province.It includ-ed three phosphorus application levels of low(75 kg·hm-2 ),middle(1 12.5 kg·hm-2 )and high(150 kg·hm-2 ),and the application depth was divided into 2 levels (20 cm、40 cm)to study the effect of phosphorus fertilizer on nitrogen (N) absorption and utilization of dryland wheat and soil water.The results showed that increasing the amount of P from Win-tering Period to Booting stage,0 ~100 cm soil water storage can be increased and the deep P application had a better soil moisture.Deep P application can also increase soil water storage in turning green stage.Increasing the amount of P, N content of plant at different growth stages was increased and the N accumulation amount at different growth stages was significantly improved.Furthermore the deep P application had a higher N content and acumulation especially in the an-thesis stage.Increasing the amount of phosphorus,the translation of N before anthesis was significantly increased.Deep P application promoted leaf nitrogen to be translated into grain.N accumulation amount and N rate of leaf at maturity was significantly decreased.The accumulation of N was the highest at 40 cm depth when applying 150 kg·hm-2 P.In addi-tion,the relationship between 0-100 cm soil water storage from Wintering stage to Booting stage and translation amount of nitrogen before anthesis had a close relationship.0 ~100cm soil water particularly related to the translation amount of leaf nitrogen.The relationship between soil moisture and N accumulation in the flowering stage was the tightest.In short,increasing the amount of P was beneficial for improving the soil moisture at I m depth,It was helpful to promote plant N accumulation,translation.In addition the deep P application helped the translation of N from leaves to grain.It was also helpful to promote the N rate in anthesis stage.Last but not lest,it promoted the nitrogen accumulated after an-thesis.To sum up,40 cm depth applying 150 kg·hm-2 P fertilizer significantly increased N uptake efficiency,N productive efficiency and N harvest index.