Effect of combined fertilization with rock phosphate and elemental sulphur on yield and nutrient uptake of soybean

Greenhouse pot experiments were carried out in 2013 and 2014 at the University of Bonn, Germany, to study the effect of combined fertilization of rock phosphate (RP) with elemental sulphur (ES) on growth, grain yield and nutrient uptake of soybean. Treatments included RP, ES, combined application (RPES), triple superphosphate (SP), magnesium sulphate (MgS), SP and magnesium sulphate (SPMgS) and an unfertilized control. Combined fertilization (RPES) resulted in a significant increase of soil-plant analysis development (SPAD) values, grain yield, yield components and nitrogen and in part phosphorus uptake of the shoot. Single application of RP or ES only tended to affect crop growth and nutrient uptake. Application of MgS and/or SP significantly increased grain yield in both years suggesting an effect of sulphate.