TY - JOUR
T1 - Dinitrogen fixation and soil N uptake by soybean as affected by phosphorus availability
AU - Pongsakul, P.
AU - Jensen, E.S.
PY - 1991
Y1 - 1991
N2 - The effects of phosphorus supply (0, 30, and 90 mg P kg-1) on growth, N2fixation, and soil N uptake by soybean (Glycine max (L.) Merr.) were studied in a pot experiment using the 15N isotope technique. Phosphorus supply increased the top dry matter production at flowering and the dry matter production of seeds, straw, pod shells, and roots at late pod filling of inoculated soybeans. Phosphorus supply reduced the N concentration of plant tops at flowering, but increased the amount of N accumulated at both flowering and late pod filling. In inoculated soybeans total N accumulation paralleled the dry matter production. The P concentration in above-ground plant parts of nodulated soybeans was not affected by P application. At flowering only 18 to 34% of total N was derived from N2 fixation, whereas as much as 74% was derived from N2 fixation at late pod filling. Only the addition of 90 mg P kg-1 soil significantly increased the amount of N2 fixed at the late pod filling stage. Phosphorus supply did not influence the uptake of fertilizer or soil N in soybeans, even if the root mass was increased up to 60% by the P supply.
AB - The effects of phosphorus supply (0, 30, and 90 mg P kg-1) on growth, N2fixation, and soil N uptake by soybean (Glycine max (L.) Merr.) were studied in a pot experiment using the 15N isotope technique. Phosphorus supply increased the top dry matter production at flowering and the dry matter production of seeds, straw, pod shells, and roots at late pod filling of inoculated soybeans. Phosphorus supply reduced the N concentration of plant tops at flowering, but increased the amount of N accumulated at both flowering and late pod filling. In inoculated soybeans total N accumulation paralleled the dry matter production. The P concentration in above-ground plant parts of nodulated soybeans was not affected by P application. At flowering only 18 to 34% of total N was derived from N2 fixation, whereas as much as 74% was derived from N2 fixation at late pod filling. Only the addition of 90 mg P kg-1 soil significantly increased the amount of N2 fixed at the late pod filling stage. Phosphorus supply did not influence the uptake of fertilizer or soil N in soybeans, even if the root mass was increased up to 60% by the P supply.
KW - Begrænsning af forurening
U2 - 10.1080/01904169109364244
DO - 10.1080/01904169109364244
M3 - Journal article
SN - 0190-4167
VL - 14
SP - 809
EP - 823
JO - Journal of Plant Nutrition
JF - Journal of Plant Nutrition
IS - 8
ER -