Validation of fertilizer recommendations for soybean under high yielding crop production systems in Central and South of Russia

Fertilizer recommendations for soybean are developed and adjusted in field experiments conducted in Central and Southern Russia.

IPNI-2013-RUS-SOY56

22 May 2017

2016 Annual Interpretive Summary


Two field experiments were conducted in Belgorod oblast in Central Russia on typical chernozem soils. Soils at both locations had a heavy texture, slightly acid pH, organic matter (OM) content (4 to 5%), high level of Olsen phosphorus (P) (44 to 64 ppm) and a very high level of available potassium extracted with ammonium acetate solution (256 to 338 ppm), the content of available sulfur (S) 3.6 to 5.6 ppm. The following 10 treatments were studied (kg/ha): 1) control, no fertilizers; 2) N18; 3) N9P39; 4) N9P39K60; 5) N18P78; 6)N18P78K60; 7) N9P40K60S10; 8) N18P80K80S20, 9) N9P40K60S10+Foliar fertilizer; 10) N18P80K80S20+Foliar fertilizer. All fertilizers were broadcasted before planting. Foliar fertilizer 18-18-18 containing magnesium (Mg), S, and micronutrients (B, Cu, Fe, Mn, Mo, Zn) was sprayed as a 0.3% solution at 350 litres/ha. Soybean seeds were inoculated and treated with molybdenum (Mo).

There were very favorable weather conditions during the 2016 growing season. The treatments that demonstrated the maximum yield (up to 2.9 t/ha) generally included S additions. The average yield increase due to S was 0.04 to 0.05 and 0.08 to 0.09 t/ha for S rates 10 and 20 kg/ha, respectively. The S removal in the highest yielding soybean was 13 kg S/ha, including 4.6 kg S/ha in the grain. There was not sufficient soil supply of S, and it is one of the yield-limiting factors for growing high-yielding soybeans in this region.

Two field experiments were also conducted in 2016 in Southern Russia on leached and ordinary Chernozem soils. The soils had a heavy texture, slightly acid pH, low OM content, high level of Olsen P and a very high level of available K. The following treatments were studied (kg/ha): 1) Control; 2) Foliar fertilizer; 3) N6P26+Foliar fertilizer; 4) N6P26K18+Foliar fertilizer; 5) N12P52+Foliar fertilizer; 6) N12P52K18+Foliar fertilizer. MAP (monoammonium phosphate) and КСl (potassium chloride) were applied at planting with a 2 х 2 cm placement. Foliar fertilizer 18-18-18 containing Mg, S, and microelements was sprayed as 0.3% solution at 350 liters/ha. Seeds were inoculated and treated with Mo.

A dry and high temperature period occurred in the end of July and the beginning of August, but it did not seriously impact yields in 2016 since the ultra-early soybean variety used finalized pod filling well before this period. Foliar fertilizers increased seed yield by 6% compared to a control. A combination of starter and foliar fertilizers improved seed yield by 14 to 17% and allowed yields of 2.7 to 2.9 t/ha, close to the biological potential. Phosphorus played a major role in starter fertilizers. Soybean slightly responded to potassium (K) fertilizer application. Treatments receiving N6P26K18 and foliar fertilizer were agronomically optimum.