猪粪等有机肥料中磷素养分循环再利用的研究

STUDIES ON PHOSPHORUS OF ORGANIC MANURES AND ITS REUTILIZATION

本文研究了有机肥料包括4种猪粪,两种半粪和鸡粪中磷素养分的含量。转化及水稻对它们的吸收利用特点。结果表明这类有机肥料中磷素的55—80%为无机态,它们和无机磷肥一样施入土壤后其磷素迅速被微生物(或化学)固定。盆栽试验表明,水稻能逐步吸收利用其中的磷素,且与对无机磷肥中磷素的吸收利用一样,于7月水稻生育旺期达到高峰,二者趋势甚为一致。有机肥施入土壤在分解过程中,用0.5mol L^(-1)NaHCO_3提取土壤,溶液中的活性有机磷不能用钼兰法直接比色测出,但可被作物迅速利用。有机肥与化学磷肥磷有效性相近,等效值接近1。但前者生产水稻干物效率要高,这与其中所含微生物、有机成分及多种营养元素有关。

To study phosphorus in organic wastes four kinds of ping excrete and two kinds of cattle and chicken excretes were collected for a laboratory study and a greenhouse pot experiment of rice p/ant on a paddy soil derived from Quaternary red clay. The pots without phosphorus fertilizer and with chemical phosphorus fertilizer were taken as controls in the experiment, Results obtained are as follows:1. Total phosphorus contained in these organic excretes ranged from 0.69—5.71%, of: which 55—80% was in an inorganic form which could be extracted by 0.2 moll^(-1) HCl.2. 80%f available phosphorus in organic or chemical phosphorus fertilizers added to. soil were fixed or immobilized temporarilly within a short period.3. Phosphorus added to soil whether as organic or chemical source could be uptaken by rice plant in a similar pattern which indicated a peak of uptake in July, a period of vigrous growth of rice plant.4. There were two forms of phosphorus, i.e., inorganic (P_i) and labile organic (P_0) phosphorus, in the extract (0.5 molL^(-1) NaHCO_3, pH 8.5) of soil in which eight kinds of organic manure with the same total amount of phosphorus were added for decomposition. The P_4+P_0 was found to have a close correlation with the percentage of phosphorus uptaken by. rice plant in total phosphorus content of organic manure added to soil.5. As Nitrogen and potassium nutrients were fully satisfied by application of chemicals.in all treatments with the same amount of phosphorus, more dry matter of rice plant was produced with organic manure than chemical fertilizer. Microorganism, organic material and other nutrients contained in organic manure would be beneficial to rice plant.6. A value of equivalent efficiency of phosphorus in both organic and Chemical P fertilizers was calculated based on the utilization of phosphorus by rice plant. An average of means that the utilization of phosphorus in both fertilizers by rice plant is equivalent roughly,