甜菜对不同施用部位磷种肥的吸收与利用

用P~(32)示踪法研究结果表明,甜菜在1～2片真叶期已开始吸收磷肥。至叶丛繁茂期,单株绝对吸磷量和对磷肥利用率均明显增高,但单株相对含磷量却明显降低;磷肥施到距种子2、4cm以下可显著提高甜菜对磷肥的利用率。至7月中旬利用率分别达4％和7.9％,比种、肥混施分别提高60％和2倍;磷酸二铵做种肥,其分解产生的NH_4对甜菜有毒害作用,可降低出苗率、保苗率,也影响对磷肥的吸收利用。采用种、肥分层施可缓解和避免NH_4~ 对甜菜的伤害。

Study on Effect of Phosphorus Seed Manure Uptaked and Applied in Different Position of Sugarbeet

The research results with P32 trace technique has indicated that sugarbeet began to uptake phosphorus fertilizer in 1-2 true leaf stage. Both absolute uptake amount and utilization ratio of phosphorus fertilizer per plant were increased significantly till the leaves lush growing stage, but the relative amount of phosphorus per plant decreased notably. The utilization ratio of P fertilizer on sugarbeet will improve markedly if it is spread under the seeds of 2~4 cm.By mid of July,its utilization ratio reached 4% and 7.9% respectively, which has increased 60% and 200% over mixed spreading both of them.If ammonium phosphate (NH4)2HPC4 is used as seed manure, NH 4 decomposed into soil-will produce toxic action to the sugarbeet which could reduce the percentage of seedling emerged, and keep a full stand of seedlings, P fertilizer uptake and utilization influence also,seed manure spread layer by layer which could reduce or avoid the injury of NH 4 in soil to sugarbeet.