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适宜的磷素分级方法是研究磷素组分特征与评价其有效性的关键.以磷素的化学与生物活化特点,采用改进的生物有效性的磷素分级方法,应用其研究不同土地利用方式下旱地土与水田土中磷素组分与有效磷(Olsen-P)的关系,并分析环境因子对磷组分的影响.磷素分级方法将磷素分为4个组分:(1)自由扩散或根际截留的磷(CaCl_2-P);(2)有机酸活化和无机弱结合磷(Citrate-P);(3)系列酶矿化的有机磷(Enzyme-P);(4)潜在活化的无机磷库(HCl-P).结果表明,旱地土及水田土4种磷素组分含量均表现为:HCl-P>Citrate-P>Enzyme-P>CaCl_2-P,且旱地土各磷组分均显著高于水田土.Olsen-P与各磷素组分均呈显著正相关,表明各磷素组分对有效磷都有贡献.具体表现为:在旱地土中,Olsen-P与CaCl_2-P和Enzyme-P相关性较高(R~2=0.359;R~2=0.386);在水田土中,Olsen-P与Citrate-P相关性较高(R~2=0.788),说明旱地土中有效磷主要来自土壤自由扩散的无机磷和易矿化的有机磷部分,而水田土中有效磷主要来自弱酸活化的无机磷.冗余分析结果表明,磷素组分主要受土壤pH和黏粒含量的影响,指示在农业生产活动中,可通过调节土壤pH值,提高土壤有效磷含量.
Appropriate phosphorus fractionation method is the key to study the characteristics of phosphorus components and to evaluate the effectiveness of phosphorus components.Based on the chemical and biological activation characteristics of phosphorus, an improved bioavailability phosphorus classification method is applied to study the effects of different land use types The relationship between phosphorus and Olsen-P in lower soil and paddy soils was analyzed, and the effect of environmental factors on phosphorus fractions was analyzed.The phosphorus fractionation method was divided into four components: (1) (2) organic acid activation and inorganic weakly bound phosphorus (Citrate-P); (3) series of enzyme-mineralized organic phosphorus (Enzyme-P); (4) (HCl-P) .The results showed that the content of four kinds of phosphorus in dryland soil and paddy soil were as follows: HCl-P> Citrate-P> Enzyme-P> CaCl 2 -P, All phosphorus fractions were significantly higher than paddy soils.Olsen-P was significantly and positively correlated with each phosphorus fraction, indicating that each phosphorus fraction contributed to available phosphorus.Downly, Olsen- P was highly correlated with CaCl 2 -P and Enzyme-P (R 2 = 0.359; R 2 = 0.386). Olsen-P had a higher correlation with Citrate-P in paddy soils , Indicating that available phosphorus in dry land mainly comes from soil Free-dispersible inorganic phosphorus and easily-mineralized organic phosphorus, while available phosphorus in paddy soil mainly comes from weak acid-activated inorganic phosphorus.The results of redundancy analysis indicated that the phosphorus component was mainly affected by soil pH and clay content, indicating In agricultural production activities, soil pH can be adjusted to increase soil available P content.