A Precision Manure Management Approach to Minimize Impacts.

For centuries, animal wastes such as poultry litter, swine manure and
cattle manure have been land applied to agronomic crops as a plant
nutrient source. Unfortunately, the typical distribution of N, P, and K in
manures does not match the relative proportions of each nutrient needed
by the receiving plant. Often, P is applied in excess of plant
needs, leading to the accumulation of both organic and inorganic forms
of P in the soil. If transported off-site, this soil-P has the potential
of creating serious water quality problems, such as eutrophication,
algal blooms, and eventually fish kills. Technologies developed and
refined over the last twenty years have made site-specific
management of commercially available fertilizers both economical and
practical. Those same technologies - georeferenced soil sampling,
spatial analysis of soil-based plant nutrients, and targeted
applications rates - show promise for management of manure-nutrient
sources. Although the logistics are more difficult and the economics less
favorable, variable rate application of manure can be and should be
an option available to farmers trying to manage the imbalance of manure
nutrients, crop needs and water resource protection. This paper will
explore the use of precision agriculture technologies for manure
management and address how these modern technologies can improve our
management of manures, working towards a solution of the centuries old
problem.