板栗产区有机堆肥产物磷形态特征及其对叶片磷含量的影响

采用Dou的磷形态分级方法和大田试验,研究了板栗产区栗蓬栗叶-菌渣-秸秆-鸡粪混合堆肥(BYZ)、菌渣鸡粪堆肥(ZF)、栗蓬栗叶-菌渣-鸡粪堆肥(BZ1和BZ2)这4种有机物料中的磷形态特征及其对结果枝叶片磷含量的影响.结果表明:1 4种有机堆肥产物全磷含量表现为:BZ1(10.61 g·kg-1)ZF(9.03 g·kg-1)BYZ(8.56 g·kg-1)BZ2(7.68 g·kg-1),并均以无机磷为主,无机磷占全磷的比例在62.88%~73.62%之间;2 4种有机堆肥产物各形态总磷中除ZF以较稳定的HClP含量及其占回收全磷(Prt)比例最高以外,其他3种均以活性的H_2O-P含量及其占回收全磷(Prt)比例最高,Na OH-P含量均较低;3各形态中的无机磷以活性的H_2O-Pi或Na HCO3-Pi占形态总磷的比例最高(89.17%~96.00%),且在回收全磷中BZ2中的无机磷主要分布在H_2O-Pi和HCl-Pi,其他3种的无机磷主要分布在H_2O-Pi、HCl-Pi和Na HCO3-Pi,各形态有机磷主要分布于残留态磷,BZ2中比例最高;4等磷量大田试验结果表明,板栗结果枝叶片单位面积叶片磷含量整体表现为BZ2BZ1BYZZFCK,高峰期(7月)、平均每月叶片磷含量增值与堆肥产物中水溶性无机磷含量及其占回收全磷的比例呈显著或极显著正相关,推测集中深施情况下有机堆肥产物中水溶性无机磷含量及占全磷的比例是当年板栗叶片磷吸收的重要影响因素.整体研究表明,栗蓬栗叶-菌渣-鸡粪堆肥(BZ2)具有高比例的水溶态无机磷和残留态有机磷库,使板栗叶片磷含量最高,且其原料中板栗产业废弃物配比高达80%(栗蓬栗叶60%+菌渣20%),是产区好氧堆肥原料体系的较佳选择.

Characterization of Phosphorus Forms in Organic Composts and Their Effects on Leaf Phosphorus Content of Castanea mollissima in Chinese Chestnut Producing Area

Characterization of the forms of phosphorus (P) in four organic composts including compost of hulls and leaves of Castanea mollissima, edible fungi residues, corn stalks and chicken manure (BYZ), compost of edible fungi residues and chicken manure(ZF), composts of hulls and leaves of C. mollissima, edible fungi residues and chicken manure (BZ1 and BZ2) in Chinese chestnut producing area was conducted by sequential P fractionation developed by Dou et al. Field trial was conducted to study the effects of compost application on leaf phosphorus content of Castanea mollissima. The results showed that total phosphorus content(TP) of organic composts ranked as follows:BZ1(10.61 g·kg^-1) > ZF(9.03 g·kg^-1) > BYZ(8.56 g·kg^-1) > BZ2(7.68 g·kg^-1), and the inorganic phosphorus(P_i) 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_rt) was the highest among P forms in ZF, while that of H₂O-P was the highest in BYZ, BZ1 and BZ2. The content of NaOH-P was very low in all the composts. Active H₂O-Por NaHCO₃-P had the highest inorganic phosphorus proportion(89.17%-96.00%) of all the P forms. The major P_iforms in BZ2 were H₂O- and HCl-extractable P fractions, while H₂O-P_i, HCl-P_i and NaHCO₃-P_i were major P_i 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_rt) among all the composts. Leaf phosphorus contents per unit area of Castanea mollissima 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 H₂O-P_i in the total fractionated phosphorus of composts, which presumably played a key role in leaf phosphorus absorption of C. mollissima measured in the year of deep concentrated fertilization. The results suggested that composts of hulls and leaves of C. mollissima, 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 Castanea mollissima and edible fungi residues accounted for 60% and 20% respectively), which had a high proportion of H₂O-P_i and organic Residual-P pool and led to the highest leaf phosphorus content of C. mollissima.