Does Intensive Management Shift Macro- and Micro-Nutrient Uptake and Partitioning in Winter Wheat?.

There is limited information on the impacts of management practices on macro- and micro-nutrient uptake dynamics in winter wheat (Triticum aestivum L.) in Kansas. Our objectives were to determine the effects of multiple management strategies on accumulation and partitioning of twelve nutrients throughout the wheat growing season. One field trial was established during 2015-16 in Belleville, Kansas. The wheat variety ‘Everest’ was used to compare fourteen treatments including two controls using a randomized complete block design. Treatment combinations included plant density, application of N, Cl, S, fungicide, and growth regulator. The controls represented standard management (SM) or “farmer’s practice” with yield goal of 5 Mg ha^-1 and intensive management (IM) or “kitchen-sink” with yield goal of 8 Mg ha^-1. Other treatments consisted of either individual additions to the SM control or removals from the IM control. Total aboveground plant biomass was collected at five developmental stages (tillering, flag leaf, anthesis, soft dough, and maturity) and plants were partitioned into leaf, stem, head and grain. Mean grain yield for treatments under SM and IM was 3.5 and 5.4 Mg ha^-1, respectively. On average of treatments, about 70-85% of total nutrient uptake at maturity occurred by anthesis for all nutrients, except for K (100%), Cl (100%), and B (50%). The IM increased total nutrient uptake at maturity relative to the SM, but generally had no effect on nutrient partitioning to plant components. Fungicide application was the major treatment factor affecting plant nutrient uptake and yield. Removal of fungicide application from the IM control reduced yield by 1.9 Mg ha^-1 and the accumulation of Cl, Cu, Mg, N, P, and S at maturity. Understanding plant nutrient uptake and partitioning is crucial for the development of well-balanced nutrient management program. Adoption of adequate management strategies will improve nutrient use efficiency while sustainably increasing profitability.