Breaking Soybean Yield Barriers: Integrating Crop Production Practices & Comprehensive Fertilization Strategies – a Cropping System Approach

This project is studying the effects of different farming systems on soybean yield in major production regions of the Americas. The specific research objectives are to: 1) quantify soybean yields across various production and fertilization practices, and evaluate the interaction among these practices 2) quantify the yield gap between common farmer practice and more intensive systems, 3) measure nutrient uptake and removal across regions and cropping strategies, and 4) examine nutrient partitioning and movement between soybean plant organs.

IPNI-2014-GBL-62

29 Apr 2016

2015 Annual Interpretive Summary


This project is studying the effects of different farming systems on soybean yield in major production regions of the Americas. The specific research objectives are to: 1) quantify soybean yields across various production and fertilization practices, and evaluate the interaction among these practices, 2) quantify the yield gap between common farmer practice and more intensive management systems, 3) measure nutrient uptake and removal across regions and cropping strategies, and 4) examine nutrient partitioning and movement between soybean plant organs. Field experiments were conducted in the 2014/15 season at Ponta Grossa (Parana, Brazil), and Oliveros (Santa Fe, Argentina); and in 2015 near Scandia (Kansas, USA).

The experiment at Ponta Grossa evaluated different combinations of N, P, K, S, and micronutrient fertilization, as well as soil acidity management. Average yield of soybean was 3,600 kg/ha, and for the corn phase of the study it was 10,190 kg/ha. Neither crop at the Ponta Grossa site showed significant response to treatments.

The field experiment at Oliveros evaluated four treatments: common practice (CP); comprehensive fertilization (CF), or CP plus fertilizer input (N, P, K, S, and micronutrients) according to official recommendations; production intensity (PI), which included narrower rows, higher population, but no fertilizer; and ecological intensification (EI), or PI plus fertilizer input. All strategies produced grain yield above 5,200 kg/ha, with no differences among treatments. Increases in seed number (+14%) in response to intensive management were compensated by a 13.5% increase in individual seed weight in response to fertilization.

Scandia included both dryland and irrigated experiments. Treatments for each included the same four indicated for Oliveros, plus an advanced (AD) treatment, which was EI plus further enhanced fertilization. Average grain yields were 4,890 kg/ha and 2,280 kg/ha for irrigated and dryland conditions, respectively. Under irrigation, EI and AD treatments produced significantly more yield than all other treatments, while PI produced more than CF and CP. Under dryland conditions, PI, EI and AD treatment yields were equal, and significantly greater than CP and CF yields. The maximum relative yield gap under dryland conditions was 36% (CP-CF versus PI-EI-AD), while under irrigation it was 24% (CP-CF versus EI-AD). However, the absolute yield gap under irrigation was about double that of dryland—1,470 kg/ha irrigated versus 740 kg/ha dryland growing conditions.

These experiments, along with a new site at Itiquira (Matto Grosso. Brazil), are planned to continue.