Estimating Zinc Index Values Based on Litter Constituents and Application Rate Peanut Notes No. 12 2022

— Written By
en Español / em Português

El inglés es el idioma de control de esta página. En la medida en que haya algún conflicto entre la traducción al inglés y la traducción, el inglés prevalece.

Al hacer clic en el enlace de traducción se activa un servicio de traducción gratuito para convertir la página al español. Al igual que con cualquier traducción por Internet, la conversión no es sensible al contexto y puede que no traduzca el texto en su significado original. NC State Extension no garantiza la exactitud del texto traducido. Por favor, tenga en cuenta que algunas aplicaciones y/o servicios pueden no funcionar como se espera cuando se traducen.


Inglês é o idioma de controle desta página. Na medida que haja algum conflito entre o texto original em Inglês e a tradução, o Inglês prevalece.

Ao clicar no link de tradução, um serviço gratuito de tradução será ativado para converter a página para o Português. Como em qualquer tradução pela internet, a conversão não é sensivel ao contexto e pode não ocorrer a tradução para o significado orginal. O serviço de Extensão da Carolina do Norte (NC State Extension) não garante a exatidão do texto traduzido. Por favor, observe que algumas funções ou serviços podem não funcionar como esperado após a tradução.


English is the controlling language of this page. To the extent there is any conflict between the English text and the translation, English controls.

Clicking on the translation link activates a free translation service to convert the page to Spanish. As with any Internet translation, the conversion is not context-sensitive and may not translate the text to its original meaning. NC State Extension does not guarantee the accuracy of the translated text. Please note that some applications and/or services may not function as expected when translated.

Collapse ▲

Question About Litter and Zinc

Attached is a poultry litter analysis report that represents a company that is marketing this material in the east to offset high fertilizer prices. One grower is intending to apply about 500 pound per acre of this material. If he does this, how much of an increase would you expect his zinc index to go up?

Stephanie Kulesza

It’s hard to estimate how an application of zinc will affect the soil Zn-I. The most conservative estimate is to assume all of it will be available. To do this, you would divide the pounds of zinc applied per acre by 0.071 to get the increase in zinc index. I found the conversion factor on the NCDA&CS website (

So, if you’re applying 500 lbs/ac of the first sample (4.5 lbs of Zn/ton), you’d have a maximum soil Zn-I increase of 15. Notice that the three waste analyses are very different in their zinc concentration. It’s really important to have an accurate analysis of the product that you’ll actually be applying to avoid a toxicity issue.


Sample 1 (as Steph indicated) projects a Zn-I increase of 15

Sample 2 projects a Zn-I increase of 2

Sample 3 projects a Zn-I increase of 116

Sample 3 is the one to be concerned about in this group, depending on the Zn-I already in place prior to the application. Uniformity of the litter and the application of litter are really important considerations (as Steph indicated.)  For example, there will be areas of overlap and the increase goes from 116 to 232. This is just under the critical Zn-I of 250. And this assumes the Zn-I is not already at a modest level.

Thanks again Steph!