Manure Application Timing and Tillage Influence on Nutrient Loss from Snowmelt Runoff

Ammar B Bhandari,Ronald Gelderman,Dennis Todey,David German

doi:10.3390/soilsystems5040067

Ammar B Bhandari, Ronald Gelderman + Show 2 more

Open Access

https://doi.org/10.3390/soilsystems5040067

Copy DOI

Abstract

Winter manure application contributes substantial nutrient loss during snowmelt and influences water quality. The goal of this study is to develop best management practices (BMPs) for winter manure management. We compared nutrient concentrations in snowmelt runoff from three dates of feedlot solid beef manure application (November, January, and March) at 18 tons ha−1 on untilled and fall-tilled plots. The manure was applied at a single rate. Sixteen 4 m2 steel frames were installed in the fall to define individual plots. Treatments were randomly assigned so that each tillage area had two control plots, two that received manure during November, two in January, and two in March. Snowmelt runoff from each individual plot was collected in March and analyzed for runoff volume (RO), ammonium-nitrogen (NH4-N), nitrate-nitrogen (NO3-N), total suspended solids (TSS), total Kjeldahl nitrogen (TKN), total phosphorus (TP), and total dissolved phosphorus (TDP). Snowmelt runoff concentrations and loads of NH4-N, TKN, TP, and TDP were significantly higher in runoff from manure application treatments compared to control. The concentration of NH4-N and loads of NH4-N and TDP were significantly (p = 0.05) greater (42%, 51%, and 47%, respectively) from untilled compared to fall-tilled plots. The November application significantly increased RO, NH4-N, and TDP concentrations and loads in the snowmelt runoff compared to January and March applications. Results showed that nutrient losses in snowmelt runoff were reduced from manure applications on snow compared to non-snow applications. The fall tillage before winter manure application decreased nutrient losses compared to untilled fields.

Highlights

Manure is an important source of plant nutrients for crop production [1] that improves soil quality by increasing organic matter, water infiltration, and soil productivity and reducing surface runoff [2,3]
Winter manure applications significantly increased nutrient loads and potential loss in snowmelt runoff compared to no manure application
The snowmelt runoff was greater with high soil volumetric water content in the sub-surface (51 cm depth), indicating site hydrology is vital and needs to be considered in any winter manure nutrient loss study to understand the risk of water quality impairment by the runoff from frozen soils

Summary

Introduction

Manure is an important source of plant nutrients for crop production [1] that improves soil quality by increasing organic matter, water infiltration, and soil productivity and reducing surface runoff [2,3]. Over-applications of manure [4], winter applications [5], and applications based on crop nitrogen (N) needs [6,7] can result in nutrient loss from land to water. Land-applied manure contributes a significant amount of N and phosphorus (P) to the Gulf of Mexico. A computer model predicted that approximately 14% of the total nitrogen and 48% of the total phosphorus that reached the Gulf was from manure sources, contributing to hypoxia (lack of oxygen) [8]. The current national standard on winter manure management guidelines in the US restrict winter manure application when a risk of runoff exists and if the land is saturated or frozen. Winter manure application is still common in many Northern US states and Canadian provinces because of limited storage capacities in traditional concentrated animal feeding operations (CAFOs), lack of storage facilities in small farms, and more time available for manure application and spreading and to avoid soil compaction [4,13,14]

Objectives

Methods

Results

Conclusion