Factors which affect the growth of grain legumes on a solonized brown soil. II. Genotypic responses to soil chemical factors

摘要

Lupins (Lupinus angustifolius cvv. Yandee, 75A-258 and P22872, and L. pilosus cv. P20957) nand field peas ( cv. Dundale) were grown in the glasshouse in a sieved solonized brown nsoil. The soil was taken from sequentially deeper zones in the B horizon of the natural nprofile (8-83 cm below the surface). The pH (in CaC12) increased from c. 6.3 to c. 8.2 with ndepth while sodium and chloride concentrations reached 83 and 62 mol m-3 (soil solution) nrespectively in the deepest unfertilized subsoil. Sodium concentrations reached 159 mol m-3 nwhen the subsoil was fertilized. When plants were grown in the deepest subsoil, the growth nof shoots and roots was inhibited by up to 75% in L. angustifolius but less severely in L. pilosus nand pea. Roots of pea were iffected least by the deep subsoil. Shoots of L. angustifolius, nbut not L. pilosus or pea, had 5-vere chlorosis in the expanding tissue and necrosis of the noldest leaflets when grown on the deepest soil. Expanded leaflets of L. angustifolius had nsodium and chloride concentrations up to 200 mol m-3 while iron concentrations were less nthan 20pg g-I dry weight in expanding tissues. Concentrations of manganese and zinc nexceeded requirements for maximum growth but copper concentrations were sufficiently low nto suggest deficiency in growing tissue of Yandee and 75A-258. No symptoms of deficiency nwere apparent. It is concluded that adverse chemical factors in the subsoil restrict root ngrowth of L. angustifolius in the field. L. pilosus and field peas, on the other hand, appear nto be significantly better adapted to these sodic, alkaline subsoils.