JOURNAL OF SOILS AND SEDIMENTS
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2021
·Vol. 21
·期 6
·2287-2300
·
IF 3.308
Kang Longfei,Zhang Guoqiao,Chu Guixin
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 NaHCO 3 -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.
研究领域:
农业
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土壤学
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植物营养
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环境科学
✓ 已验证
DOI
高影响因子
GEODERMA
·
2017
·
IF 4.036
Dasheng Sun,Qingfang Bi,Huaping Xu,Kejie Li,Xipeng Liu,Jun Zhu,Qichun Zhang,Chongwei Jin,Lingli Lu,Xianyong Lin
Soil drying-rewetting can remarkably affect phosphorus (P) transformation, and thus, alter P distribution among P pools; however, little is known about the effect of the degree of drying before rewetting on labile P fractions and the bioavailability of organic P (P o ). In this study, soils with distinct physico-chemical properties were allowed to desiccate to 5%, 10%, 20%, 30%, and 40% water holding capacity (WHC), and soils maintained at 50% WHC were used as controls, and the bicarbonate-extractable P and hydrolyzable P o fractions were analyzed after 5 h of rewetting. Bicarbonate-extractable P o accounted for 33.3–56.4% of extractable total P, and hydrolyzable P o constituted 34.4–79.7% of extractable P o . For extractable P o , 7.7–29.9% was labile monoester P, 6.5–14.9% was diester P, and 17.8–36.5% was phytate-like P. Bicarbonate-extractable inorganic P and P o contents were not affected by 20–40% WHC treatments, but increased by 26.3–48.1% and 5.7–52.9%, respectively, when the soils were dried to 5% WHC. Similarly, labile monoester, diester, and phytate-like P contents increased by 12.5–89.8%, 0–65.2%, and 24.6–65.6%, respectively, in 5% WHC soils. Pearson's correlation analyses showed that the relative increases in bicarbonate-extractable inorganic P and phytate-like P, following extreme drought, were positively correlated with soil organic carbon , oxalate-extractable aluminum (Al), and iron (Fe), suggesting regulatory roles of organic matter and Al/Fe oxides in P transformation during soil drying-rewetting. Taken together, our results suggest that extreme drought events before rainfall or irrigation facilitate an increase in the level of labile P, including considerable proportions of hydrolyzable P o fractions, potentially posing a substantial threat to water bodies in the context of climate change .
研究领域:
生态学
·
环境科学
✓ 已验证
DOI
高影响因子
Materials Science & Engineering C-Materials for Biological Applications
·
2016
·
IF 3.42
Haibin Li,Fei Jiang,Song Ye,Yingying Wu,Kaiping Zhu,Deping Wang
The strontium-substituted hydroxyapatite microspheres (SrHA) incorporated alginate composite microspheres (SrHA/Alginate) were prepared via adding SrHA/alginate suspension dropwise into calcium chloride solution, in which the gel beads were formed by means of crosslinking reaction. The structure, morphology and in vitro bioactivity of the composite microspheres were studied by using XRD, SEM and EDS methods. The biological behaviors were characterized and analyzed through inductively coupled plasma optical emission spectroscopy (ICP-OES), CCK-8, confocal laser microscope and ALP activity evaluations. The experimental results indicated that the synthetic SrHA/Alginate showed similar morphology to the well-known alginate microspheres (Alginate) and both of them possessed a great in vitro bioactivity. Compared with the control Alginate, the SrHA/Alginate enhanced MC3T3-E1 cell proliferation and ALP activity by releasing osteoinductive and osteogenic Sr ions. Furthermore, vancomycin was used as a model drug to investigate the drug release behaviors of the SrHA/Alginate, Alginate and SrHA. The results suggested that the SrHA/Alginate had a highest drug-loading efficiency and best controlled drug release properties. Additionally, the SrHA/Alginate was demonstrated to be pH-sensitive as well. The increase of the pH value in phosphate buffer solution (PBS) accelerated the vancomycin release. Accordingly, the multifunctional SrHA/Alginate can be applied in the field of bioactive drug carriers and bone filling materials.
研究领域:
生物材料学
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骨组织工程
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药物递送系统
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生物医学工程
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再生医学
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生物无机化学
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药剂学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）