Location: Soil and Water Management Research
Project Number: 5062-12000-010-23-T
Project Type: Trust Fund Cooperative Agreement
Start Date: Mar 1, 2018
End Date: Jun 30, 2020
The objective is to evaluate the effects of a nitrification inhibitor, 3,4-dimethylpyrazol succinic acid (DMPSA) and a soil microbial additive on yields, nutrient use efficiency and grain and tuber quality in potato and corn production and environmental losses of nitrogen in the form of nitrous oxide and nitrate leaching.
Field experiments will be conducted over two potato (Solanum tuberosum L. cv. Russet Burbank) and corn (Zea mays L.) growing seasons. The potato crop experiment will be conducted in Sand Plain Research Farm in Becker, MN on a Hubbard loamy sand (sandy, mixed, frigid Entic Hapludoll). The corn crop experiment will be evaluated on two locations with different soil textures, i.e., at the University of Minnesota Research Station in St. Paul: Waukegan silt loam (fine-silty over sandy or sandy-skeletal, mixed, superactive, mesic Typic Hapludolls), and at the Sand Plain Research Farm in Becker: Hubbard loamy sand (sandy, mixed, frigid Entic Hapludoll). Each site year, 8 treatments will be evaluated each replicated 4 times, including (1) no N fertilizer or additives, (2) urea with no additives, (3) urea plus the urease inhibitor NBPT, (4) urea plus the nitrification inhibitor DMPSA, (5) urea plus NBPT plus DMPSA, (6) urea plus a commercially available microbial product , and (7) urea plus DMPSA + microbial. In these field experiments, the following parameters will be measured: Temperature, rainfall/irrigation, soil nitrate and ammonium, N2O emissions using static chambers, potato plant N nutrition by petiole NO3- content; corn plant N Nutrition by medium leaves at BBCH 33-36 and BBCH 51-59 developmental stages and Cob-leaves at BBCH 61-69, aboveground biomass and N uptake (corn and potato), corn grain yield; potato yield and grade; crop nitrogen use efficiency, and tuber quality including specific gravity, dry matter content, internal defects and N content of tuber and starch, corn quality including protein, grains/cob, grain rows/cob, and NO3--N leaching effect of treatments in corn and potato. Parallel laboratory experiments will also be conducted to determine the effects of DMPSA and the microbial product on nitrogen transformations with specific emphasis on nitrification and nitrous oxide emissions as affected by soil texture. Lab incubation studies will be conducted over a 64-day period, with treatments similar in design to the field experiment. The exact design of the lab treatments may change after results from the first year of field experiments, but the number of treatments will be held to seven. In the lab experiment, the following parameters will be measured: Soil NH4, NO2 and NO3 concentrations and nitrous oxide production.