Nutrient availability to corn from dairy manures and fertilizer in a calcareous soil

Authors: Leytem, April; Dungan, Robert - Rob; MOORE, AMBER - University Of Idaho

Submitted to: Soil Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/9/2011
Publication Date: 10/1/2011
Citation: Leytem, A.B., Dungan, R.S., Moore, A. 2011. Nutrient availability to corn from dairy manures and fertilizer in a calcareous soil. Soil Science. 170:426-434.

Interpretive Summary: The expansion of the dairy industry in southern Idaho has lead to increased application of manures to meet crop nutrient demands which can alter the uptake pattern of both macro- and micro-nutrients. A greenhouse study was conducted to determine the effects of dairy manure, composted dairy manure, and fertilizer (mono-ammonium phosphate, MAP) application on soil test phosphorus, microbial activity, and nutrient uptake by silage corn. Two Portneuf soils, having either a low or high soil test phosphorus concentration, were amended with the three treatments at four application rates (25, 50, 100, and 200 mg P/kg) with four replications of each treatment in a randomized complete design. Treatments were incubated for two weeks, and then planted with corn grown for approximately three weeks. Soil samples were analyzed prior to planting, whereas plant samples were analyzed at the end of the growing period. Increases in Bicarbonate extractable phosphorus from phosphorus additions were greatest in the MAP and least in the manure treated soils. Plant dry matter production and tissue phosphorus concentration did not differ with treatment. Tissue potassium increased with manure and compost addition while tissue calcium decreased; there was also a decrease in tissue magnesium with compost application. Tissue zinc increased with manure applications, while tissue manganese decreased with manure and compost application on the Low-P soil. Changes in mineral availability were attributed to changes in pH with treatment additions, as well as the influence of added carbon into the soils which affects not only microbial activity but can form complexes with metals either enhancing or decreasing their plant availability. It is important to consider plant nutrient interactions when applying manure and compost to feed-crops as imbalances in potassium, calcium, and magnesium can lead to both grass tetany and milk fever in cattle.

Technical Abstract: The expansion of the dairy industry in southern Idaho has lead to increased application of manures to meet crop nutrient demands which can alter the uptake pattern of both macro- and micro-nutrients. A greenhouse study was conducted to determine the effects of dairy manure, composted dairy manure, and fertilizer (mono-ammonium phosphate, MAP) application on soil test phosphorus (P), microbial activity, and nutrient uptake by silage corn. Two Portneuf soils, having either a low or high soil test P concentration, were amended with the three treatments at four application rates (25, 50, 100, and 200 mg P kg-1) with four replications of each treatment in a randomized complete design. Treatments were incubated for two weeks, then planted with corn grown for approximately three weeks. Soil samples were analyzed prior to planting, whereas plant samples were analyzed at the end of the growing period. Increases in Olsen P from P additions were greatest in the MAP and least in the manure treated soils. Plant dry matter production and tissue P concentration did not differ with treatment. Tissue K increased with manure and compost addition while tissue Ca decreased; there was also a decrease in tissue Mg with compost application. Tissue Zn increased with manure applications, while tissue Mn decreased with manure and compost application on the Low-P soil. It is important to consider plant nutrient interactions when applying manure and compost to feed-crops as imbalances in K, Ca, and Mg can have a negative impact on animal health.