Effects Of Long Term Fertilization On Phosphorus Pools And Its Forms In Yellow Paddy Fields Of Southern China

Based on data collected in a long term fertilization experiment in the yellow paddy inFujian, the effect of different long-term fertilization on the available phosphorous,total phosphorus and phosphorus component were studied. The results show that, thecontent of A-P and TP increase with the age of experiment in the treatments offertilization in double-rice term and decrease in single-rice term. While, with thetreatment of fertilizer was not applied (CK), they decrease both double and single riceterms, especially the content of A-P which reduce by64.9%. In the26thyear offertilization experiment, compared with CK, the content of TIP, TOP and TP increasedmarkedly (p<0.01) by46.2%～114.2%,16.0%～41.8%and29.2%～73.8%in NPK,NPKM and NPKS, respectively. And the highest growth race was found in thetreatment of NPKM. Compared with the soil before the experiment, the content of TIPin soil with CK treatment was decrease which the Al-P component was depletionfastest, while the content of TOP was increase and the increasing rate of Moderatestability component was highest in TOP. The ratio of Al-P and Ca-P to TP infertilization treatments were higher than that of CK treatment, while the ratio oforganic phosphorus to TP was lower. There have a decline trend in the ratio of TIP toTOP with all experiment treatments, while the fertilization treatments was higher thanCK, especially the treatment of NPKM. Addition, there have a positive correlationbetween the ratio of TIP to TOP and the content of organic matter(p<0.01). Thecontent of organic phosphorus in yellow paddy soil have a increasing trend withexperiment age, whether it was fertilized or not. The effect of NPKM treatment onincreasing the content of available phosphorus, inorganic phosphorus and organicphosphorus was most significant among different treatments, but the differencesamongst the content of inorganic phosphorus and organic phosphorus component ofthe treatment of NPKS and NPK was not significant.Under the cultivation patterns of double and single cropping rice of yellow paddy, thehighest crop yields were achieved when the contents of available phosphorus were 17.56mg/kg and16.94mg/kg, respectively. Additional, the content of availablephosphorus increased5.08mg/kg when the content of total phosphorus increased0.1g,suggesting that the rate of total phosphorus convert to available phosphorus was5%approximate.