N and P availability and losses as affected by N requirement and P removal based liquid dairy manure and composted separated dairy solids

Quirine Ketterings ¹ , Greg Godwin ¹ , Karl Czymmek ² , and Shawn Bossard ³


Collaborating producers:
Bob Dillan (King Ferry), Tim Fessenden (King Ferry) and Bill Cook (Aurora).

1 Department of Crop and Soil Sciences; 2 Pro-Dairy; 3 Cornell Cooperative Extension, Cayuga County.

Introduction

Phosphorus (P) transport in erosion and runoff from animal feeding operations (poultry, swine, dairy and beef) is a major contributor to surface water eutrophication in the US. High P levels in the main streams and reservoirs have led to local, state and federal attempts to regulate fertilizer and manure application on large confined animal feeding operations (CAFO’s) that tend to have the most unbalanced nutrient budgets.

The P index aims at identifying fields that have high levels of P and are likely to generate runoff. A field with a NY P index <50 is classified as a low risk field for P runoff. Manure applications can be balanced on N requirements of the crop. If the P index is 50-74, it falls in the medium risk class and N based management with the application of best management practices is recommended. Fields with a P index of 75-99 are considered to be high-risk fields that should receive applications of manure and/or fertilizer that do not exceed crop removal. For fields that have a very high vulnerability for P risk through runoff (P index of 100 or higher) should not receive any P application. The P index is not the solution to P imbalances on dairy farms. However, it is a management tool that steers producers towards improved environmental management of the nutrients on their farms while export options are being investigated and evaluated.

One such export mechanism is separation of solids and composting. Unknown is what the nutrient value is of such composted separated solids. Furthermore unknown are the effects of P removal based organic nutrient management on N and P dynamics, soil physical characteristics such as soil bulk density, water holding capacity, aggregation and compaction, availability of micronutrients and general farm economics. In addition, it is unknown what the effects are of organic management on crop quality.

A large-scale field trial was initiated in Aurora, NY, in the spring of 2001 to address several of these questions.

With this experiment, we aim to study:

1. Build-up of P under N requirement and P removal based organic and inorganic fertility management of corn.
   
2. N fertilizer equivalents of composted dairy solids versus liquid dairy manure.
   
3. Timing of the N release peaks as affected by organic N source.
   
4. Effect of time of sampling on soil test results for pH and Morgan extractable P, K, Ca, Mg, Fe, Mn and Zn.
   
5. Effect of N source on organic nitrogen buildup (evaluation of the aminosugar N test)..
   
6. Effect of N source and application method on soil bulk density, water holding capacity, aggregation and compaction.
   
7. The effects of organic based nutrient management on corn silage and grain yield and yield quality.
   

In the spring of 2001, a trial with ten treatments in five replicates was established at the
Musgrave Research Farm at Aurora, NY. The ten treatments are:

1. 20,000 gallons/acre liquid manure (N requirement according to Cornell’s database);
   
2. 7,000 gallons/acre liquid manure (estimated P removal);
   
3. 34 tons/acre composted separated dairy solids (N requirement according to Cornell’s
   database);
   
4. 20 tons/acre composted separated dairy solids (estimated P removal);
   
5. 20 lbs N/acre in the starter band;
   
6. Treatment 5 plus 30 lbs N/acre at sidedressing time;
   
7. Treatment 5 plus 80 lbs N/acre at sidedressing time;
   
8. Treatment 5 plus 130 lbs N/acre at sidedressing time (N requirement according to
   Cornell’s database);
   
9. Treatment 5 plus 180 lbs N/acre at sidedressing time;
   
10. Treatment 5 plus 220 lbs N/acre at sidedressing time.
    

For further information

Information on this project can be obtained from Quirine Ketterings (qmk2@cornell.edu or 607 255 3061). You can also write to: Quirine Ketterings, Nutrient Management Spear Program, Department of Crop and Soil Sciences, Cornell University, 817 Bradfield Hall, Ithaca NY 14853.