Long Term Manure & Crop Management Field Laboratory

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The long term manure management and cropping system trial is a field laboratory that is being used to optimize nutrient and energy cycling within integrated, environmentally and economically sustainable livestock and crop production systems. The 14 hectare (43-acre) field laboratory situated at Glenlea Research Station started with 96 plots (20m x 20m). In 2015, select plots were split in order to accommodate additional fertility treatments, increasing to 144 plots.

General Approach:

  • Long-term replicated field trial at NCLE is being used to compare impacts of alternative types of manure and manure management on annual and mixed annual/perennial cropping systems.
  • A multi-disciplinary approach is being used with participation of Plant Science, Animal Science, Soil Science, Food Science, and Microbiology.
  • Soil conditions at the beginning of the trial will be the base reference to help in comparing treatment effects
  • Parameters of all facets of the production system and those from research findings to be stored in a data base for modeling efforts


In order to optimize crop growth while minimizing loss of nutrients to the environment, additional nutrients must be supplied in appropriate amounts and forms. Livestock manure can be used to provide many essential nutrients for crop growth, however it does not provide key nutrients such as nitrogen and phosphorus in the same proportions that crops require. Availability of nutrients in manure is difficult to predict, and thus its usage can also pose the risk of polluting surface and ground waters. Long-term study sites are important for developing sound manure management practices using knowledge that accounts for changes over time with different soil types and cropping systems.

Two phases have been completed since its establishment in 2007:

Phase 1: 2007-2015
This phase focused on availability and uptake of nitrogen and phosphorus from annual applications of commercial fertilizer, in comparison to annual and intermittent applications of liquid pig, solid pig, and solid dairy cattle manure in two long-term crop rotations (annual crops and perennial grass forage).

Phase 2: 2015-2017
Building on findings from Phase 1, this phase focused on determination of: 

  • Effects of long term applications of manure nitrogen on release of nitrogen from soil to crops
  • Effect of suspending manure application for several years on the drawdown of soil test phosphorus
  • The availability of nitrogen and phosphorus from liquid and solid manures applied intermittently to cropland

Current Study: 2017-present

  • Greenhouse gas measurements under select treatments began in 2017
  • Focus continues to be around capacity of manured soil to continue to release plant-available nitrogen, phosphorus and other essential nutrients and how this affects
    crop yield
  • Measurement of nitrous oxide emissions from select treatments to gain a better
    understanding of soil nitrogen transformations in generating greenhouse gases

For more information, contact Dr. Mario Tenuta, 474-7827