Soybean performance (<i>Glycine max</i> (L) <i>Merr</i>) on tropical soils with nitrogen and phosphorus fertilization

Abstract

Pot trial was conducted to investigate the effects of soil types, nitrogen and phosphorus application on the yield, and nodulation and nutrient uptake of soybean grown on tropical soils. Results showed that forest soils produced higher dry matter yield, pod number, seed number, nodule number, and nodule weight at 6 and 12 weeks after planting (WAP) than savanna soils. The increment values were averagely 152%, 325%, 275%, 105% and 45% respectively at both periods. The uptake of K, Ca and Sulphur were greater in savanna soils, while forest soils had 19% and 41% increase in the uptake of Nitrogen and Phosphorus, respectively above savanna soils. The interaction between soil type and nitrogen or phosphorus also indicated that forest soil with 25kgNha^-1 or 50kgPha^-1 had significantly higher values for the soybean performance parameters investigated. Soybean grown on forest soil from Odeda I (Typic kandiudalf) had higher seed-weight and number of pods; 2% and 57%, respectively above that from savanna soil (Ayetoro II, Typic kandiudult) both at 25kgNha^-1 fertilization. Forest soil from sedimentary rock/Alluvium (Ikorodu 1(and those from basement complex rock (Odeda I) produced soybean that had higher values in nodule weight and uptake of phosphorus at 50kgPha^-1 compared to savanna soil from sedimentary rock. The incremental values were 59% and 79% respectively. In general, the combined application of 25kgNha^-1 and 50kgPha^-1 appeared optimum for soybean cultivation.

Key words: Tropical soil; soybean performance; nitrogen and phosphorus fertilizers

Moor Journal of Agricultural Research Vol.4(2) 2003: 170-177