鸭粪和猪粪中易溶性磷含量特征研究

Readily Soluble Phosphorus Characterization in Duck and Swine Manures

有机肥易溶性磷与施入有机肥土壤的水溶性磷流失有很好的相关性,是评价施入有机肥土壤磷素流失潜力的一个重要指标。本文以鸭粪和猪粪为研究对象,根据有机肥磷在H2O和0.5mol·L-1NaHCO3溶液中的相对溶解性来研究有机肥中易溶性磷的形态及其分布特征。采用两种提取方法:(1)独立提取,风干过筛的有机肥分别用H2O和NaHCO3溶液提取。(2)连续提取,有机肥逐级连续用H2O和NaHCO3溶液提取。研究结果表明,16个有机肥全磷含量的变化范围是4.06～35.08g·kg-1。在独立提取步骤中,水提取溶液中,鸭粪溶解性总磷(Pt)(0.64～3.51g·kg-1)占有机肥总磷(TP)的5%～19%,平均为13%,猪粪P(t2.60～5.35g·kg-1)占TP的8%～24%,平均为19%;NaHCO3提取出的溶液中,鸭粪P(t1.14～4.99g·kg-1)占TP的8%～32%,平均为20%,猪粪P(t4.71～14.84g·kg-1)占TP的21%～71%,平均为44%。连续提取中,H2O和NaHCO3分别提取鸭粪总磷的5%～19%和3%～23%;分别提取猪粪总磷的8%～24%和11%～37%。在提取过程中,猪粪中提取出的无机磷和总磷含量均显著高于鸭粪。无论鸭粪还是猪粪,在各提取溶液的磷素均以无机磷为主,占溶解性总磷的77%～99%左右。连续提取条件下测得的易溶性磷含量与独立提取条件下测得结果有很好的相关性(P<0.01)。

There are good correlations between readily soluble phosphorus in applied manure and dissolved P in runoff. Therefore, readily soluble phosphorus can be seen as a key indictor of the potential for applied manure to supply dissolved P to runoff. In this study, the readily soluble phosphorus of duck and swine manure were analyzed according to their relatively dissolvability in distilled water and 0.5 mol·L^-1 NaHCO3. Two extraction procedures were tested： （1）independent, with dried, ground samples being extracted and P measured for each extraction; and （2）sequential, with each sample being repeatedly extracted by H2O, NaHCO3, in that order. Results showed that among the 16 manures, total P varied between 4.06 and 35.08 g·kg^-1. For the independent procedure, in the H2O fraction, dissolved total P（Pt）accounting for 5% to 19% of duck manure total P（0.64-3.51 g·kg^-1）and 8% to 24% of swine manure total P（2.60-5.35 g·kg^-1）. In the NaHCO3 fraction, Pt accounting for 8% to 32% of duck manure total P （ 1.14-4.99 g·kg^-1）and 21% to 71% of swine manure total P （4.71-14.84 g·kg^-1）. Sequentially, H2O, NaHCO3 extracted 5%-19% and 3%-23% of the total P in duck sample, respectively, while 8%-24%and 11%-37% of the total P in swine sample, respectively. For each extractant, Pi and Pt in swine manure were higher than that of duck significantly and Pi was the major form （77%-99% of Pt）in extractant. Duck and swine manure readily soluble P in sequential extraction was significantly related with that in independent extraction（P〈0.01 ）.