Purpose

Phosphorus (P) fertilization methods significantly affect soil P availability, transformation, and crops yield. However, contradictory or paradoxical results are often available, and debates about this issue have never ceased so far. Therefore, the aims of this study are to explore influences of different P application methods on availability and transformation of added P in drip-irrigated system, and the responses of maize P uptake and its agronomic performances to P fertigation are also investigated.

Materials and methods

Here, we conducted a pot and filed experiments in drip-irrigated calcareous soil. Treatments included different P sources (phosphoric acid; polyphosphoric acid) with basal and split repeated application manners.

Results and discussion

Compared to the basal application, the average values of C_DGT-P (P concentrations tested via diffusive gradient in thin films technique), Olsen-P, water-soluble P, and in situ P in the split repeated P application increased by 23.7%, 10.2%, 16.5%, and 34.4%, respectively (pot experiment). Furthermore, the average values of labile P (resin P and NaHCO₃-P) and moderately labile P (NaOH-P) with the repeated P addition increased by 19.7% and 12.6%, whereas the concentrations of non-labile P lowered by 19.3%, respectively, relative to basal application treatment (pot experiment). The same trend was obtained in field experiment, implying that complete repeated P addition significantly increased P availability, reduced soil P transformation, and decreased P fixation. Therefore, a better agronomic performance of maize (P uptake, grain yield, and phosphorus use efficiency) was achieved in the complete repeated P application rather than basal application. Besides, diffusive gradient in thin film technique (DGT) was proved to be an accurate and powerful approach in testing soil available P.

Conclusions

Our findings elucidate that repeated delivering P through fertigation method can be recommended as an effective P application strategy in drip-irrigated field, especially in semi-arid and arid regions. The feasibility of DGT method was certified and C_DGT-P could well characterize plant-accessible P.

中文翻译：

---

通过施肥将石灰分流到石灰性土壤上，通过减少磷的固定来增加磷的利用率和玉米产量（玉米）

目的

磷施肥方法显着影响土壤磷的有效性，转化和农作物的产量。但是，经常有矛盾或矛盾的结果，关于这一问题的辩论迄今从未停止过。因此，本研究的目的是探讨滴灌系统中不同磷肥施用方式对磷素有效性和添加磷转化的影响，并研究了玉米磷素吸收及其对磷肥的农艺性状。

材料和方法

在这里，我们进行了盆栽并在滴灌钙质土壤中进行了实验。处理方法包括不同的磷源（磷酸，多磷酸），采用基础和分次重复施用的方式。

结果与讨论

与基础施用相比，C _DGT -P（通过薄膜技术中的扩散梯度测试的P浓度），Olsen-P，水溶性P和原位P在重复多次施用P中的平均值增加了23.7％。 ，分别为10.2％，16.5％和34.4％（盆栽实验）。此外，不稳定的P（树脂P和NaHCO ₃的平均值-P）和中等不稳定的P（NaOH-P），重复添加P分别比基础施用处理（盆栽试验）增加了19.7％和12.6％，而非不稳定P的浓度分别降低了19.3％。在田间试验中获得了相同的趋势，这表明完全重复添加磷显着增加了磷的利用率，减少了土壤磷的转化，并减少了磷的固着。因此，在完全重复施用磷肥而不是基础施用中，可以获得更好的玉米农艺性能（磷的吸收，籽粒产量和磷的利用效率）。此外，薄膜扩散技术（DGT）中的扩散梯度被证明是测试土壤有效磷的一种准确而有效的方法。

结论

我们的发现表明，在滴灌领域，特别是在半干旱和干旱地区，通过施肥方法重复施用磷可作为一种有效的磷施用策略。DGT方法的可行性得到了认证，并且C _DGT -P可以很好地表征工厂可访问的P。