不同分子量碳源对砂姜黑土磷素有效性和玉米磷吸收的影响

为探究不同分子量碳源对土壤磷有效性的影响，以安徽省典型砂姜黑土为供试土壤，通过盆栽种植玉米试验，开展了不同碳源(果糖、蔗糖、纤维素)对土壤中磷形态转化和玉米磷吸收影响的研究。结果表明：(1)土壤Olsen-P含量随时间先增加后降低。在玉米间苗7 d后果糖处理Olsen-P含量最高，15 d后纤维素处理Olsen-P含量达最大值，90 d后，相比于对照、果糖和蔗糖处理，纤维素处理土壤Olsen-P含量显著增加了79.74%、54.03%和30.03%(P<0.05)。(2)玉米间苗90 d后，相较于对照处理，纤维素处理显著降低了Fe-P和Ca10-P含量，增加了Ca8-P含量，而对照、果糖和蔗糖处理的Ca2-P含量无显著差异。与对照处理相比较，纤维素处理显著提高了活性有机磷(LOP)和中等活性有机磷(MLOP)含量，减少了中稳定性有机磷(MROP)含量。(3)纤维素处理增加了土壤可溶性有机碳(DOC)含量和磷酸酶活性，降低了土壤p H和交换性钙含量，这是土壤磷有效性增加的重要原因；(4)与对照、果糖和蔗糖处理相比，纤维素处理下玉米磷吸收量显著增加了46.20%、19.05%和19....

Effects of Carbon Sources with Different Molecular Weights on Phosphorus Availability and Phosphorus Uptake in Maize

Phosphorus is easily fixed in soil and has low availability. The release of inherent phosphorus in soil is of great significance for reducing the application of phosphate fertilizer in agricultural production. The study conducted a pot planting experiment to understand the effects of different carbon sources (fructose (GT), sucrose (ZT) and cellulose (XWS)) on the transformation of phosphorus form in soil and phosphorus uptake by maize. The test soil selected the lime concretion black soils of Anhui Province. The results showed as follows: (1) Soil Olsen-P content firstly increased and then decreased with time. On the 7th day, the content of Olsen-P in GT treatment reached the maximum, and on the 15th day, the content of Olsen-P in XWS treatment reached the maximum. After 90 days, compared with CK, GT and ZT, the content of Olsen-P in soil of XWS treatment was significantly increased by 79.74%, 54.03% and 30.03% (P<0.05); (2) After 90 days of planting, compared to CK, GT, ZT and XWS treatments significantly reduced the contents of Fe-P and Ca10-P, and increased the contents of Ca8-P, while there was no significant difference in the contents of Ca2-P among CK, GT and ZT treatments, but all of them were lower than XWS treatments. Compared with CK treatment, XWS treatment significantly increased the contents of active organophosphorus (LOP) and moderately active organophosphorus (MLOP), and decreased the contents of moderately stable organophosphorus (MROP). (3) In XWS treatment, soil DOC content and phosphatase activity were increased, but soil pH and exchangeable calcium content were decreased, which were important factors influencing the increase of soil phosphorus availability. (4) Compared with CK, GT and ZT treatments, phosphorus uptake of maize under XWS treatment was significantly increased by 46.20%, 19.05% and 19.28%. The results showed that compared with low molecular weight carbon sources (fructose and sucrose), high molecular weight carbon sources (cellulose) had better long-term effectiveness in improving soil phosphorus availability and phosphorus absorption in maize. The results of this study provide important information for the regulation and effectiveness of soil phosphorus conversion by using carbon sources in farmland ecosystems.