论文部分内容阅读
盆栽试验和不同水旱输作的田间试验结果表明,在含有大量非闭蓄态磷酸铁化合物的南方酸性和中性土壤中,在同一条件下,磷肥对旱作的肥效远较对水稻显著。在输作中,磷肥的后效亦有两种情况:在旱—水(早大豆—水稻)输作中,残余在土壤中的磷素供应水平与继续施用过磷酸钙的供应水平比较,在水稻产量上几乎完全相等;但是,在水一旱(早稻—晚大豆)输作中,则继续施用过磷酸钙的,在晚大豆产量上又增加24%。磷肥对水稻和旱作的肥效有所差异的原因,主要是由于在渍水还原条件下土壤磷素向有效的方向转化所致,而其实质就是土壤中非闭蓄态的磷酸铁化合物的有效转化。这种转化过程的方向及其对磷肥后效的影响视条件而异。在旱—水输作时,施在旱作上的残余磷肥由于渍水还原条件的影响而向着有效的方向转化;在水—早输作时,则向着难效的方向转化。因此,在水旱交替的输作过程中,土壤磷素向有效的或难效的两个相反方向的转化过程,即土壤中非闭蓄态的磷酸铁化合物的活化和老化过程,可能是不断地反复地进行着的。根据上述的试验结果,对于南方合有大量非闭蓄态的磷酸铁化合物的酸性和中性水稻土的磷肥合理施用问题提出了一些参考意见。
The results of pot experiment and field experiment of different water and drought transports showed that in the same acidic and neutral soil containing a large amount of non-closed ferric phosphate compounds, the fertilizer efficiency of the phosphate fertilizer on the dry farming was more significant than that on the rice. In the process of transplanting, there are two cases of the aftereffect of phosphate fertilizer. In the dry-water (early-soybean-rice) transpiration, the supply of residual phosphorus in the soil is compared with the supply of continued application of the superphosphate. Rice yields are almost exactly equal; however, the use of superphosphate in the water-dry (early rice-late soybean) translocation continued to increase, adding another 24% to late soybean production. The reason for the difference in fertilizer efficiency between paddy rice and dry-land use is mainly due to the conversion of soil phosphorus to the effective direction under the condition of waterlogging reduction, and its essence is that soil non-closed-state iron phosphate compounds are effective Conversion. The direction of this conversion process and its effect on the afforded phosphate effect varies depending on the conditions. In drought-water transport, the residual phosphate fertilizer applied to dry farming is transformed in an effective direction due to the reduction of waterlogging conditions, and transformed in an inefficient direction during water-early transport. Therefore, in the process of alternation of flood and drought, the conversion process of soil phosphorus to two opposite directions, effective or inefficient, that is, the activation and aging process of non-closed state iron phosphate compounds in the soil may be continuous Repeatedly carried out. Based on the above experimental results, some suggestions are put forward for the rational application of phosphate fertilizer in the acidic and neutral paddy soils with a large number of non-closed-state iron phosphate compounds in the south.