Improving N and S Fertilizer Management System under Crop Rotation

Crop response to S-containing fertilizers and various N sources is studied under winter barley – sugar beet – winter wheat – maize rotation.

IPNI-2016-RUS-9

02 Jun 2018

2017 Annual Interpretive Summary


Field experiments with winter barley during the 2016-2017 season were conducted at four agricultural enterprises of AgroGard agroholding, Kuban Branch, located in different districts of Krasnodar Krai. Soils at these locations are Typical and Common Chernozems (Voronic Chernozems Pachic) with moderate organic matter (3.3 to 4.3%) and low concentrations of available sulfur (S) (2 to 4 ppm) routinely extracted with 1M potassium chloride (KCl) solution. A cool spring delayed winter barley growth and development, but the rest of the season was quite favorable. Grower practice for phosphorus (P) and potassium (K) fertilizers was considered to be optimum based on soil fertility and attainable yields of winter barley. Fertilizer treatments (kg/ha) for this crop were: 1) Grower practice for nitrogen (N): 80 to 88 N, 68 P and 26 K, including 10-26-26 prior to planting, monoammonium phosphate (MAP) at planting, ammonium nitrate (AN) spring topdressing; 2) Recommended N: 80 to 85 N, 68 P, 26 K, including 10-26-26 prior to planting, MAP at planting, AN spring topdressing; 3) Recommended N: 80 to 85 N, 68 P, 26 K, including 10-26-26 prior to planting, MAP at planting, urea spring topdressing; 4) Recommended N+S1: 83 to 88 N, 68 P, 26 K, 8 S, including 13-19-19-6 prior to planting, MAP at planting, Ammonium Nitrate spring topdressing; 5) Recommended N+S2: 83 to 91 N, 68 P, 26 K, 16 S, including 16-20-0-12 + KCl prior to planting, MAP at planting, AN spring topdressing.
    Grower fertilizer practice produced yields of 6.6 to 7.1 t/ha (Moisture content = 14%) for winter barley grain. The right source, rate, and time for both N and S in treatment #5 increased grain yield by 0.3 to 0.4 t/ha, or 5 to 6% in three field experiments compared to grower practice. Protein concentration in barley grain was increased by 0.2 to 0.8% in these three locations. A grower nutrient management practice was considered to be optimal in one location. Spring topdressing with AN had the same effect as urea on grain yield and quality of winter barley in two locations. Ammonium nitrate was, however, the much preferable source of N at the other two locations. From the study, it seems that cool spring temperatures could negatively affect the rate of urea hydrolysis in heavy textured Chernozem soils. High soil pH could also have led to ammonia volatilization resulting from surface application of urea.