[Characterization of Phosphorus Forms in Organic Composts and Their Effects on Leaf Phosphorus Content of in Chinese Chestnut Producing Area].

Characterization of the forms of phosphorus (P) in four organic composts including compost of hulls and leaves of , edible fungi residues, corn stalks and chicken manure (BYZ), compost of edible fungi residues and chicken manure(ZF), composts of hulls and leaves of , edible fungi residues and chicken manure (BZ1 and BZ2) in Chinese chestnut producing area was conducted by sequential P fractionation developed by Dou . Field trial was conducted to study the effects of compost application on leaf phosphorus content of . The results showed that total phosphorus content(TP) of organic composts ranked as follows:BZ1(10.61 g·kg) > ZF(9.03 g·kg) > BYZ(8.56 g·kg) > BZ2(7.68 g·kg), and the inorganic phosphorus(P) accounted for 62.88%-73.62% of the total phosphorus in the organic composts. The content and proportion of HCl-P in the total fractionated phosphorus(P) was the highest among P forms in ZF, while that of HO-P was the highest in BYZ, BZ1 and BZ2. The content of NaOH-P was very low in all the composts. Active HO-Por NaHCO-P had the highest inorganic phosphorus proportion(89.17%-96.00%) of all the P forms. The major Pforms in BZ2 were HO- and HCl-extractable P fractions, while HO-P, HCl-P and NaHCO-P were major P forms in BYZ, BZ1 and ZF. Residual-P was the predominant organic phosphorus form, and BZ2 showed the highest Residual-P proportion of the total fractionated phosphorus(P) among all the composts. Leaf phosphorus contents per unit area of by field trial on the added phosphorus-equivalent basis were expressed as:BZ2>BZ1>BYZ>ZF>CK. Increment of leaf phosphorus content per unit area in Julyand per month on average showed positive relationship with the content and proportion of HO-P in the total fractionated phosphorus of composts, which presumably played a key role in leaf phosphorus absorption of measured in the year of deep concentrated fertilization. The results suggested that composts of hulls and leaves of , edible fungi residues and chicken manure (BZ2) was a good choice in given area for aerobic composting raw material system in which organic wastes from Chinese chestnut industry accounted for 80% (hulls and leaves of and edible fungi residues accounted for 60% and 20% respectively), which had a high proportion of HO-P and organic Residual-P pool and led to the highest leaf phosphorus content of