Maize and Soybean Nutrition in Intensive Cropping Systems in Southern Russia.

The Global Maize project of the International Plant Nutrition Institute (IPNI) is an international effort with objectives of creating local Ecological Intensification (EI) practices that increase yields at a faster pace than current grower practices. Such important goals as putting the right fertilizer source, at the right rate, in the right place, and at the right time are all supported by EI management systems. Under the project conducted in Russia local EI solutions are compared to farm fertilization practice (FP).

Field experiments with maize-soybean (chickpea since 2015) rotation were conducted on a common chernozem. The soil had a clay loam texture, high pH, and low OM content. Average initial contents of nitrate­N (N0₃-N) were medium to "increased". Olsen P and exchangeable K (1 M ammonium acetate extractable) tests found P to be "increased", while K was high.

The highest average yield of maize of 6.37 t/ha was obtained through a local EI management including balanced application of NPK fertilizers, splitting the N rate, application of starter PK fertilizer, and Zn seed treatment. Its average improvement over FP was 9%. Maize responded only slightly to added N in both the EI and FP management systems. The average yield increase due to N was 6%. Adequate N0₃-N levels in the soil may explain this low response.

The highest average yield of soybean of 1.96 t/ha was also obtained through EI management including balanced application of NPK fertilizers, Mo seed treatment and inoculation (in the first season). The improvement over FP reached 25%. The yield response to additional N over the low N treatment, for both the EI and FP management, ranged from 6 to 7% and were not significant during all seasons. Improvements in seed protein were obtained with both EI and FP management treatments that provided extra N fertilizer.